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2013-07-18 1:17 AM


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Subject: Ironman Bike Sizing Question?
Looking at a new aero bike strictly for training and racing triathlon, specifically IM and HIM length.

Went to my LBS today and had a chance to test fit and ride Shiv's and P2's. Guys were very helpful, knowledgeable, and efficient at answering my questions, and getting me comfortable into the bikes.

My question I'd like help on: Is there a downside to the bike size they fit me to? Is there any downside to riding a bike on the smaller side? Any reason to question the size they came up with? Is there any reason I might be fitting on smaller bikes than I should, and would that ever turn into a problem?

I'm 5'10", muscular 185-190lbs, wear a 34" inseam pant (36" in jeans), very flexible. We started out on a Medium Shiv (54cm) and a 54cm P2. Top tube reach was too long on both, so they swapped me to a Small Shiv (51.5cm), and we hit the marks for position. Set my seat height, seat position, reach on the aero bars, drop on the bars. They didn't have a 51cm P2, but they tried to mate up the geometry on the 54cm P2 to the fit on the Shiv.

What I felt on the trainer and then on the road:

P2 54cm: Felt a little sketchy because I felt a bit too long of reach. I felt like my back was collapsing down (belly button sagging) because I was reaching too far, which felt less stable steering, and was awkward on the bullhorns. BUT, if I slid my forearms 'back' on the pads so my upper arm was at a right angle with my body I felt a lot more stable, so I could get a shorter stem to gain a better fit. The P2 did feel a bit less 'twitchy' than the Shiv, but when I was outstretched, I didn't have nearly as much control either.

Shiv Small (51.5cm): Fast, responsive, felt lighter handling and faster accelerating, likely stemming from my feeling of compact and stable, rather than overstretched. It felt twitchy at times, but in general I felt like I was very close to the bike, and very close to the front end for handling. When I transitioned from bars to horns and back around the block, I could tell I was more twitchy, feeling like the shorter base was letting my body movements effect the bike more, maybe the longer P2 dampened some of my shifting better? I felt decidedly as if my weight was sitting over the crank, and definitely forward onto the bars when I got out of the saddle.

Ultimately, both were fantastic bikes, felt very good, but I preferred the Shiv. I'm going to hunt down a P2 51cm to try out another fitting to see if it was just a matter of over-sized frame.

I also did a less extensive fit on a Speed Concept at a different shop, fit better on a small than I did on a medium in the speed concept as well, but the shop (rather the gerbils running it) SUCKED BUTT, so as big of Trek fan as I am, I won't be going back. I did not get the Speed Concept off of the trainer and take it outside, however.

So if I'm feeling great on a 51.5cm bike on my first day, is there any reason NOT to buy one in that size? (Rather favoring a 54cm instead?) Is there any reason to think that if a 52cm bike feels great today will stop fitting well after some amount of training, or will I notice a difference in handling, control, speed, power, etc etc?

Should someone my size really fit into a 51cm bike? Or better question: will I really feel comfortable, stable, and not exhausted steering a 51cm bike 112mi?


2013-07-18 3:58 AM
in reply to: Chokebait

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Subject: RE: Ironman Bike Sizing Question?
Sounds to me like you need a bike with more stack and less reach.  My wife has similar numbers to you (5'11" and 34" inseam) and ended up on a size 58 Cannondale Slice.  Her fitter told her that to get on a Cervelo they would have to make some abnormal alterations to get it to fit which is what it sounds like you would have to do on the P2.  Another suggestion for her was a Blue Triad but she didn't try that one at all (no dealer nearby).
2013-07-18 5:10 AM
in reply to: Chokebait

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Subject: RE: Ironman Bike Sizing Question?
I'm not a fitter, just someone who has been fit, has two bikes that fit perfectly, and asked a lot of questions. But I'm surprised at how small the bikes you were put on are. Was the seat post raised up to meet you on both? Did it feel like you were leaning too far down? Did you have to strain your neck more than what was comfortable to look forward?

From what you've said so far, it would be a shame if you didn't have an opportunity to sit aboard a Slice before making your final choice.
2013-07-18 5:51 AM
in reply to: Chokebait

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Subject: RE: Ironman Bike Sizing Question?
You're looking at a fair investment (or at least that's a fair bit of money for most of us)... I would highly suggest that you do it right and get a bike fit FIRST and then go back looking for bikes that fits YOU. By your description, it sounds like they made some rough adjustments to the bike to get you on it, but you never did a bike fit.

It's entirely possible that the 51cm Shiv fits you well. Height and inseam doesn't tell you much about how a rider will fit a bike, but you also mentioned that you are very flexible and muscular (which I will translate as strong core for this argument), and a smaller frame might give you the stack you need. The big question is really, how will the shorter reach work for you?
2013-07-18 7:00 AM
in reply to: audiojan

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Subject: RE: Ironman Bike Sizing Question?
FWIW, I'm 5'9" with a 30 inseam (i.e., all body) and I ride a 52 cm felt. bike was properly fit to me and I love it.

Echo the sentiment of the bike fit before the purchase.
2013-07-18 9:06 AM
in reply to: audiojan

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Subject: RE: Ironman Bike Sizing Question?

Originally posted by audiojan You're looking at a fair investment (or at least that's a fair bit of money for most of us)... I would highly suggest that you do it right and get a bike fit FIRST and then go back looking for bikes that fits YOU. By your description, it sounds like they made some rough adjustments to the bike to get you on it, but you never did a bike fit. It's entirely possible that the 51cm Shiv fits you well. Height and inseam doesn't tell you much about how a rider will fit a bike, but you also mentioned that you are very flexible and muscular (which I will translate as strong core for this argument), and a smaller frame might give you the stack you need. The big question is really, how will the shorter reach work for you?

Yes, definitely go get the fit first. What they're doing is taking semi educated guesses at how to get you onto a bike. A good fit session will first find the relation of the various contact points to each other. Meaning the saddle position (and possibly type), the elbow pads, the bar position, etc. Basically any point you are making contact with the bike. From there you'll have information to select a bike & size that will work best with those points established.

And don't worry about what size someone seemingly "should" fit on based on height. It can be very individual and varies by manufacturer, and even between models within that. There are a couple 6'3" professionals who do quite well on Med Shivs, for example.



2013-07-18 10:52 AM
in reply to: brigby1


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Subject: RE: Ironman Bike Sizing Question?
Ok, so at the risk of exposing my own ignorance here, I'll just try to elaborate on what we did....

Whole process took about 2.5 - 3hrs (I forget what time I got there exactly, little after 4 p, left at 7p, an hour after they had closed!). I have NO idea if these angles are proper, but as an engineer, I pay attention to numbers/geometry. The end result felt quick and stable on the Shiv Small.

I'm 5'10", but visibly mostly leg.

1) No, I didn't sit on a fitting machine. The tech said their process for new triathletes = initial fitting to determine which frame/bike you should be on, buy the bike, initial fitting/build to get you in the right geometry, ride for 6wks - 6mos, do a full ~3-4hr fitting and adjust the bike after getting used to it, adjust as needed thereafter long term.

2) They assumed I would fit on a M Shiv or 54cm P2, so they pulled them out of the rack.

3) We started with the Shiv. We adjusted my seat height to put my foot at BDC at ~20deg with my leg at approx. 150deg. We adjusted the seat backwards to put the point of my toe ~5cm in front of the pedal shaft. When I reached out for the bars, setting my elbows on the pads properly was REALLY long, instantly felt awkward/unstable. I slid my elbows back to be approx. 90degrees to my torso, which put me behind the steering tube for the Medium...

4) They brought out a Small Shiv. Measured out the approx. position for seat height and position, adjusted, sat on it, measured angle leg, knee position, adjusted slightly again to meet the leg geometry I mentioned above. Reached out for the bars, stack height was way too tall. We removed one of the stack spacers and flipped the stem down, moved the aero bars out (longer) about an inch. Starting back at the foot, I was ~20deg incline at heel at lowest part of the stroke, ~150deg in the leg, back wasn't slammed totally flat, but felt good proportion (40% weight) on my arms when just sitting, not pedaling, hit about 110degrees between leg and torso. My upper arm and torso were ~90degrees. At top end, my thigh only came up to 115deg, didn't crowd my 'gut' at all. Knees don't contact the bars or elbows (except on the bullhorns obviously).

5) We rough adjusted the P2 54cm to match that geometry, but the reach was ultimately too long. To set back the bars to make the reach comfortable, the stem needed to be so short that the wings would have to basically be touching the steering tube (other words: at least 2" shorter stem, which they didn't have in stock). We adjusted everything else out to get me in the right geometry, but obviously I wasn't as stable reaching out.

6) Roll them outside and rode around for 20-30min, switching between the two back and forth. Much more stable on the Shiv Small, really felt great, but could really tell I was close to the front end of the bike (twitchy handling), even though it didn't 'endo' at all when I hammered the front break from the seat.

BUT, I'm not sure that a former mountain biker feeling like he's close to the front end of a Tri bike is a bad thing?

So where does that fall in terms of how much trust I should put into the fitting?
2013-07-18 11:01 AM
in reply to: 0

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Subject: RE: Ironman Bike Sizing Question?

The Shiv is a very adjustable bike.  I know nothing about the P2 other than that I tried one, and didn't like it as much as the Shiv.

My experience:

Everyone told me to get a fit first.  When I called our 3 bike shops and asked them to do a fit so I could by a bike, they said, "Uh, you need to get a bike first, then we do the fit." Well, WTF do I do now?

I ended up going in and talking to the guys who sold Specialized stuff (they are all roadies), and they convinced me that I would be fine on the Shiv because of its options. 

I am 5'6" with a 30" inseam, so long torso--S Shiv.

I then got a 3 hour fit, and it's had a few tweaks, but I'm happy with it now.

At some point I'd like to have a Retul fit, just to compare numbers. 



Edited by switch 2013-07-18 11:07 AM
2013-07-18 11:21 AM
in reply to: Chokebait


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Subject: RE: Ironman Bike Sizing Question?
I'd love to get a look at the Slice, the shop says they aren't stocking the Slice anymore because they can't sell them. Similar components, the Slice was the older frame and more expensive, so they just don't move.

I'm trying to find one within a few hours drive to go try out, but after getting fit to 51cm frames, now I'm a little nervous about driving somewhere if they only have EITHER a 51 or 54cm Slice. Maybe I can get lucky and find both somewhere.

But then I gotta ask two questions:

1) Why does the Slice come up over the P2 or the Shiv? Is it notably a better bike, and/or better bike for the money? (Contrary to what my shop is saying?)

2) Which Slice? The Slice 3 frame or the RS? Big price gap there, big geometry gap there.
2013-07-18 11:48 AM
in reply to: switch

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Subject: RE: Ironman Bike Sizing Question?
Originally posted by switch

The Shiv is a very adjustable bike.  I know nothing about the P2 other than that I tried one, and didn't like it as much as the Shiv.

My experience:

Everyone told me to get a fit first.  When I called our 3 bike shops and asked them to do a fit so I could by a bike, they said, "Uh, you need to get a bike first, then we do the fit." Well, WTF do I do now?

I ended up going in and talking to the guys who sold Specialized stuff (they are all roadies), and they convinced me that I would be fine on the Shiv because of its options. 

I am 5'6" with a 30" inseam, so long torso--S Shiv.

I then got a 3 hour fit, and it's had a few tweaks, but I'm happy with it now.

At some point I'd like to have a Retul fit, just to compare numbers. 

If you ever get to Okoboji, talk to Cenna Vaelli at Okoboji Expedition Company.  I took the "figure out what bike I want and what size I should get then get fitted approach". He worked miracles with my bike fit.  Spent three hours with me for a $120.  Totally worth it and I will see him again soon.

 

2013-07-18 11:53 AM
in reply to: Daffodil

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Subject: RE: Ironman Bike Sizing Question?
Originally posted by Daffodil

FWIW, I'm 5'9" with a 30 inseam (i.e., all body) and I ride a 52 cm felt. bike was properly fit to me and I love it.

Echo the sentiment of the bike fit before the purchase.


I'm about 2 inches shorter and ride a 52cm Felt. And it's worked wonderfully.

Frankly you need to go with what feels comfortable. If you feel more comfortable on a smaller bike, go with the smaller bike, don't try to fit yourself onto a bike that doesn't fit you. You're butt's going to be on that sucker for 1000s and 1000s of hours so you best be comfortable on it!


2013-07-18 12:52 PM
in reply to: Chokebait

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Subject: RE: Ironman Bike Sizing Question?
Originally posted by Chokebait

I'd love to get a look at the Slice, the shop says they aren't stocking the Slice anymore because they can't sell them. Similar components, the Slice was the older frame and more expensive, so they just don't move.

I'm trying to find one within a few hours drive to go try out, but after getting fit to 51cm frames, now I'm a little nervous about driving somewhere if they only have EITHER a 51 or 54cm Slice. Maybe I can get lucky and find both somewhere.

But then I gotta ask two questions:

1) Why does the Slice come up over the P2 or the Shiv? Is it notably a better bike, and/or better bike for the money? (Contrary to what my shop is saying?)

2) Which Slice? The Slice 3 frame or the RS? Big price gap there, big geometry gap there.


You'd be best served by actually getting a fit, maybe from one of these guys:
http://www.slowtwitch.com/fitters/statelist.php?state=kansas
Barring that possibility, you've described yourself as long legged\short torsoed, which is what the Slice 3/4/5 (not the Slice RS) was built for. So was the Trek Speed Concept, but you said you won't be going that route. As to whether it's a better bike, if it fits you properly, it's the best bike you could buy. The Slice is NOT more expensive than the Shiv, don't know where that comes from (unless you're talking about the alloy Shiv, which you shouldn't be!). Price enters the conversation when there is more than one bike that is built to your geometry. You're looking for the bike that puts you in the most aerodynamic position with the greatest comfort. There are still a lot of bike shops that don't understand this. They see the bigger price tag on tri bikes and do their best to sell them, without understanding how fundamentally different they are from road bikes and mountain bikes. You're not getting fit so things stop hurting and you're not getting fit so it feels 'better', which is how a lot (most?) shops "fit" people on road bikes. This concept of tri bike geometry is pretty new as things go, and your average bike salesman\wrench probably isn't up on it. If you don't see a fit bike in the shop, they probably aren't in much of a position to discuss stack and reach coordinates.

The difference between the Shiv and Slice *frames* aren't nearly as significant as your ability to ride it powerfully. Provided the bike isn't too BIG, you could technically "get fit" on ANY bike. We could raise the seat post, slide the saddle around, put spacers under the headset, slide the arm pads around...fine. But we've done a lot of things to YOU in the process, like maybe arched your back, made your knees knock your chest, made it feel like you're falling off the front, made it so you can't steer, made it so you can't see without craning your neck, etc. You'll swear it's all helping because you paid for it, but 10 miles down the road you'll be in agony. That's pointless. I WISH I could ride a Slice, personally. They're very well made, very well supported, and the price is among the lowest out there. Unfortunately, I don't fit on one. If you're one of the lucky ones, pat yourself on the back!
2013-07-18 1:40 PM
in reply to: fisherman76

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Subject: RE: Ironman Bike Sizing Question?

I ride a 54cm P2 and am 5' 11'', 170 pounds. 32 waist, 32 inseam. 

I feel great on it. My road bike is a 56cm and it feels awesome so I was surprised to find that I needed a smaller tri bike. 

2013-07-18 2:01 PM
in reply to: fisherman76


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Subject: RE: Ironman Bike Sizing Question?
Originally posted by fisherman76
You're not getting fit so things stop hurting and you're not getting fit so it feels 'better', which is how a lot (most?) shops "fit" people on road bikes.


Without trying to come off as arguing here, a few comments to pose a question based on your point here:

What I told the wrench at the shop was to "I'm new, so nothing is going to feel normal, so fit me into a tri geometry/body position, and I'll see if it makes me cry or not." My goal here was to see which bike I would 1) fit best in once I learned how to ride in the proper position, and 2) would let me get into that position more comfortably with the most power, NOT to find a bike I would be comfortable on right now. Luckily for me, I'm flexible enough that getting into aero mode didn't turn out to be difficult for me.

I want to find the bike, or bikes, that I could take a crane, hold myself in the air, bend my body into proper aero position, and sit me down on top of the bike, and FIT. Meaning the bike must be sized such that when I get superimposed onto it, I'm in a powerful position to motor it. The Shiv Small did that better than the Shiv Medium or P2 54cm, BUT, in general, I'm hearing people tell me that a 51.5cm bike is too small for me. What I'm NOT hearing is the reason why?

So he built up the adjustments on the Shiv from foot to arse to elbow, fitting me into what they use as their standard to Tri Geometry. End result wasn't very far off of the FIST fit method on here from what I can tell. If I started humping my back, flaring my knees, etc as I pedaled on the trainer after each adjustment, he'd correct me. (See my other response post with the list of the geometry that he put me into). I felt very comfortable, and very responsive steering. The only 'complaint' I have is that I felt very close to the front of the bike, but I'm assuming that I SHOULD EXPECT to feel that way, considering I've never ridden aero before, and contrarily spent most of my cycling time trying to keep weight on my back wheel so I didn't somersault down a mountain.

When we got to where the 'wrench' said my form and the bike should be pretty close for where I'd want to ride long term, I felt 100% comfortable just relaxing on the drops, on a Small Shiv. Unfortunately, they didn't have in stock 1) a shorter stem to test out on the P2 54cm, or 2) a 51cm P2 for me to try.

Ultimately, those comments were meant to give more information so I can ask these questions:

Is there something wrong with the body position/geometry that he used? Specifically something different isn't just the difference of two effective systems (ford vs. chevy)?

Your post seems to favor the Slice heavily over the Shiv, seemingly because it's a more powerful bike? That seems like a 'ford vs chevy' subjective statement, which I appreciate and welcome because it's more encouragement to take the time to drive a few hours and find a Slice to test fit and ride before I commit to buying a Shiv. My initial question however is more about is there any objective reason to NOT believe in the fit job that put me on a 51.5cm Shiv instead of a 54cm Shiv?

Short version of the question: the Exception vs. the Rule. If my fitting is correct, am I going to be the ONLY 5'10" guy in history that was able to be comfortable, powerful, and aerodynamic on a 51cm bike? I'm not prone to believe I'm the Exception at anything, so when I don't fit into the Rule, I have doubts.
2013-07-18 2:40 PM
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Subject: RE: Ironman Bike Sizing Question?
If the shop didn't fit you on a fit bike, and wasn't certified by FIST or Retul, you can't get behind what they're doing, because it's not standardized. Did they give you your stack and reach coordinates? If not, yes, there is something wrong with what they used. Maybe you got 90% there. Maybe 100%, Can't tell. You can't equate it to cars. We're not talking different engines, colors, chassis weights, transmissions, or weight. We're talking about fitting you on a bike that has a very specific purpose in life. I understand that looking at two tri bikes in the same 'size' and comparing their stack and reach measurements and seeing they only differ by 1.5 cm in either coordinate doesn't seem like a lot. But triathlon is about a million little things being perfect over LONG periods of time under extreme stress. You can't possibly have a feel for what is more powerful while trying out different bikes in that shop, unless they hooked up a power meter and showed you, and even then, have you ever trained with a power meter before? I *feel* like I'm working less hard on my tri bike than on my road bike to generate the same wattage, and in fact I can generate slightly more on my tri bike. That wattage plus the aerodynamic savings of the tri bike position equate to very real and measurable speed. The difference is after 5 hours of riding my tri bike, I'm still generating that power.


Your post seems to favor the Slice heavily over the Shiv, seemingly because it's a more powerful bike? That seems like a 'ford vs chevy' subjective statement, which I appreciate and welcome because it's more encouragement to take the time to drive a few hours and find a Slice to test fit and ride before I commit to buying a Shiv. My initial question however is more about is there any objective reason to NOT believe in the fit job that put me on a 51.5cm Shiv instead of a 54cm Shiv?


Wrong. I don't favor sh*t, I just want everyone to be on the right bike for them!

I made a HUGE leap that you were a long legged\short torsoed person and suggested that COMMONLY the Slice is a very good fit for people like that and that it would be a shame if you didn't get a chance to try one. You don't have access to a certified fitter and you aren't working with the coordinates that would help you make a more educated decision on what to TRY (not even talking BUY yet), so I, like anyone else trying to be helpful, am trying to work with the limited information you've given us to give you *options*. If you won't buy Treks because you dislike someone's vibe or refuse to seek out a shop with a Slice in your size, or for some reason feel like you need to defend this shop that put you on a Shiv and a P2, I don't really care. You might be fine, you might not. I'm trying to help eliminate the 'might not' as much as possible. Given what you've told us you're somewhere between a Shiv at a stack\reach of 512/418 and a P2 at 515/385. I still think your stack sounds a *little* low for your height, but I can't argue because I'm completely in the dark. However, the "size 54" Slice has a stack\reach of 509/398 which is pretty much the same stack as the two bikes you tried but with a reach that's perfectly in between the two. The Trek SC has almost the exact same measurements. The bike is not the thing that's more powerful, it's the rider that's ABLE to be as powerful as they are capable of because the bike isn't in the way. The bike enables you to get into the best aerodynamic position. Every centimeter makes a difference in taking you out of your optimal position. Go ahead and take the Shiv. When you're creeping up on hour 3 on the bike at 80% FTP and your neck starts to hurt, or your shoulders get sore, or your fingers get numb, remember that you argued that it wouldn't happen because this is the Ford, and everything else was just a Chevy.

Let's assume your stack and reach are 510\400. Your Ford, Chevy, and Toyota are the Slice, Speed Concept and Kestrel 4000. There's no Cervelo or Felt on the lot. The Shiv might be on the lot.

You aren't trying to argue, but you are, and there's a difference between asking for help about a topic you are entirely new to and learning, and defending your own limited experience against that advice. The latter is arguing. There is a LOT of information available to you if you carefully absorb it, but you have to approach this as something NEW. Being stubborn will get you across the finish line, but it won't be the fun way, and you will have missed out on a lot of cool conversations and the opportunity to learn a lot about a lot of topics. If the sport is going to grow, I hope it's because there are more open minded people in it, not stubborn ones.

Edited by fisherman76 2013-07-18 2:40 PM
2013-07-18 2:51 PM
in reply to: Chokebait

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Subject: RE: Ironman Bike Sizing Question?
You're putting the cart before the horse. You need a fitting from a professional fitter FIRST to determine what bikes fit you best and what size to buy. Once you know that, go shopping for the bike. You can then go and compare bikes that fit you and get them adjusted to be more comfortable and then go for a ride and decide. Shops carry only certain brands and they are going to try to sell them to you whether they fit or not.

Then after you buy the bike go back to the fitter so he/she can adjust it so you are in the most optimal position. If you are buying a bike for IMs and HIMs you are going to be on the bike for many hours. You want the most optimal fit, not a bike that may or may not fit that is adjusted to sort of be comfortable. Remember you not only want to get through the bike, but you also want to have some legs to run on.

I have a friend who was going to buy a pretty expensive bike and the shop pople were telling her to buy a 52 cm bike. After going for her fitting, the fitter told her she should be in a 54 cm. bike and that's what she got. Then she went to have the right sized bike fit to her. She loves her new bike.


2013-07-18 4:07 PM
in reply to: onetwotri

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Subject: RE: Ironman Bike Sizing Question?

This is basically what you want to do. ST has some other articles on fitting worth reading, detailing various aspects of fit coordinates more. It's possible to do that without a fit bike, but it takes longer and is quite a bit more cumbersome. You want to find a position that will work well for you. That's what the fit coordinates being discussed will give. Usually things are based in some way from the bottom bracket. From there one should be able to get a list of bikes that should work reasonably well without having to go more extreme on things like the stem angle or length.

The bike shop seems to be skipping the coordinate part and just putting parts together hoping that it will fit, or rather, that you'll think it feels nice and get it. Are they taking measurements for the contact points at all? Leg angles were mentioned, but that's not it. They're kind of doing more like process of elimination in each frame type. What you want is the spacial relation between the various points written out (or printed out). This is possible to do with levels & tape measure, but is a bit more cumbersome. I have my bike tweaked how I liked, but am not able to measure as precisely as I'd like. So I had the Trek store do that for me. They found these coordinates and compared that to what their bikes could do. We could see it wouldn't work, their bikes were too tall for the reach I need even in the lowest position. I didn't have to try on a bike at all to see this.

2013-07-18 4:28 PM
in reply to: onetwotri


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Subject: RE: Ironman Bike Sizing Question?
Not trying to 'defend my shop' in the least.

Been there twice, and I've gotten conflicting information about pricing, so I really don't have any reason to be loyal to them. In fairness, knowing in advance what similarly kitted Slices vs P2's, P3's, and Shiv's would cost (the cheaper of the lot), I immediately suspected that when they said "the slice is too high priced for it's componentry and we can't get them to sell", I knew they MEANT "the price is too low on the Slice so the profit margin is too low for us to make money on selling it", or "Specialized and Cervelo give us the best breaks on selling their lines, but we CAN ORDER Cannondale at a custom order price". The Trek shop was 100% blatantly obvious not a tri shop, and the guys there were fairly obviously not familiar with Tri bike fitting, nor tri bike components (other than prices of course). If it weren't 3hrs to the nearest Trek Shop, I'd keep the Speed Concept on my list, or maybe someone can calm my fears that I won't need to worry about having close access to an authorized dealer for service, fitting, etc?

I was rather trying to better illustrate the process we used to size out bikes and why said process made sense to me.

What I'm finding out based on responses here that nullifies my process (yay for starting over):

1) Only a select few dozen people in the US (two in Kansas, not surprisingly, they are both in Kansas City/Topeka metro area) know how to properly size aero bikes or position a tri rider on a bike. If that's the case, then it surprises me, considering how many triathletes there are in the country, but I obviously must go get fitted by one of these two people.

2) A 'Shoe fitting' paradigm doesn't apply to bikes. i.e. the fitting machine is ALWAYS right. If I go into any store, they will have a shoe size gauge (fitting machine). For the last 15yrs, my foot, as gauged, is a 9.5 D. I've only once in that time ever felt a good fit in a pair of 9.5D shoes (under armour cross training shoe), Adidas I was in 9's, Brooks and Inov8 I'm in 10.5's (except for the Talon 265, which I'm a 10) , Asics and Salomon's 10's. I wear a 32x36 jean too, but I don't try jeans without trying them on either, as there are many styles of jeans that a 32x36 just doesn't fit me properly, even though the numbers say they should. So I was wrong in the assumption that the bike fitting, like a shoe gauge or a jean size, saved time in determining a starting point, but actually getting on the bike would ultimately determine your proper fit. It doesn't make sense to me, but what I'm garnering here is that nobody needs to sit on a bike before they buy it, just get on a fitter, find a frame geometry that suits, and order the bike?

Both items honestly surprise me. But if that's the case, I learned something about bike fitting/buying and tri fitters, and I guess I'll be making a trip to KC or OKC soon.
2013-07-18 4:34 PM
in reply to: 0


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Subject: RE: Ironman Bike Sizing Question?
Out of the two fitters in KS listed on Slowtwitch's database, one is Retul, the other FIST, which should I use?

EDIT: And I stopped by that local shop today to pick up some gu, apparently the reason he didn't give me dims for my stack/reach is they're Body Geometry Fitters and he gave me basically the first half of a fitting for free.

Now as to whether BG, Retul, FIST, whatever else is out there (isn't Retul by the same guy that developed BG for Specialized?), I'm assuming there is a favorite, or more current version of triathlon fitting theory to use? Who is the front runner I should be looking for?

Edited by Chokebait 2013-07-18 4:55 PM
2013-07-18 8:18 PM
in reply to: Chokebait


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Subject: RE: Ironman Bike Sizing Question?
I also spent a little time researching geometry today. It looks like "Small" on the Shiv is a bit of a misnomer. It's a lot more similarly sized to a 54cm or a Medium in other brands than to a small (and doesn't appear to be a "S/M", it's really a Medium sized bike). The Dims of a S Shiv are almost spot on with a Slice 54cm, really similar except shorter reach to a M SC7.
2013-07-18 8:36 PM
in reply to: Chokebait

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Subject: RE: Ironman Bike Sizing Question?
Originally posted by Chokebait

Looking at a new aero bike strictly for training and racing triathlon, specifically IM and HIM length.

Went to my LBS today and had a chance to test fit and ride Shiv's and P2's. Guys were very helpful, knowledgeable, and efficient at answering my questions, and getting me comfortable into the bikes.

My question I'd like help on: Is there a downside to the bike size they fit me to? Is there any downside to riding a bike on the smaller side? Any reason to question the size they came up with? Is there any reason I might be fitting on smaller bikes than I should, and would that ever turn into a problem?

I'm 5'10", muscular 185-190lbs, wear a 34" inseam pant (36" in jeans), very flexible. We started out on a Medium Shiv (54cm) and a 54cm P2. Top tube reach was too long on both, so they swapped me to a Small Shiv (51.5cm), and we hit the marks for position. Set my seat height, seat position, reach on the aero bars, drop on the bars. They didn't have a 51cm P2, but they tried to mate up the geometry on the 54cm P2 to the fit on the Shiv.

What I felt on the trainer and then on the road:

P2 54cm: Felt a little sketchy because I felt a bit too long of reach. I felt like my back was collapsing down (belly button sagging) because I was reaching too far, which felt less stable steering, and was awkward on the bullhorns. BUT, if I slid my forearms 'back' on the pads so my upper arm was at a right angle with my body I felt a lot more stable, so I could get a shorter stem to gain a better fit. The P2 did feel a bit less 'twitchy' than the Shiv, but when I was outstretched, I didn't have nearly as much control either.

Shiv Small (51.5cm): Fast, responsive, felt lighter handling and faster accelerating, likely stemming from my feeling of compact and stable, rather than overstretched. It felt twitchy at times, but in general I felt like I was very close to the bike, and very close to the front end for handling. When I transitioned from bars to horns and back around the block, I could tell I was more twitchy, feeling like the shorter base was letting my body movements effect the bike more, maybe the longer P2 dampened some of my shifting better? I felt decidedly as if my weight was sitting over the crank, and definitely forward onto the bars when I got out of the saddle.

Ultimately, both were fantastic bikes, felt very good, but I preferred the Shiv. I'm going to hunt down a P2 51cm to try out another fitting to see if it was just a matter of over-sized frame.

I also did a less extensive fit on a Speed Concept at a different shop, fit better on a small than I did on a medium in the speed concept as well, but the shop (rather the gerbils running it) SUCKED BUTT, so as big of Trek fan as I am, I won't be going back. I did not get the Speed Concept off of the trainer and take it outside, however.

So if I'm feeling great on a 51.5cm bike on my first day, is there any reason NOT to buy one in that size? (Rather favoring a 54cm instead?) Is there any reason to think that if a 52cm bike feels great today will stop fitting well after some amount of training, or will I notice a difference in handling, control, speed, power, etc etc?

Should someone my size really fit into a 51cm bike? Or better question: will I really feel comfortable, stable, and not exhausted steering a 51cm bike 112mi?


Dont buy anything yet get in touch with the pro bike fitter the one that does pre-bike fitting(they fit you before you buy a bike). Most multi IM finishers told me choose the pro bike fitter that is not connected to any store to eliminate bias. Its your back and knees.


2013-07-18 9:46 PM
in reply to: Chokebait

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Subject: RE: Ironman Bike Sizing Question?
I must be one of the luckiest guys out there. See bike, like bike, REALLY like bike price, get on bike, fit not bad, buy bike and love it. 1400 road miles, lots of trainer hours and not an issue to put in 4-5 hours comfortably. Not at all against a proper bike fitting by a QUALIFIED fitter, if you are not comfortable aero, forget about it! BUT, I also think lots of folks are way over thinking it, and lets face it, fitters get paid a nice fee for a fitting session, great gig to have! Yes, different bikes have different geometries, but most of today's builders are making bikes now for the (tri) masses that are fairly adjustable. I bought a Giant Trinity Composite, new (last years model), Ultegra, 105, heavy wheels with decent Shimano hubs. Giant makes this as a S, M, L, XL. Medium fit well on initial setup (5-10, 163) $1500 out the door! A few minor tweeks along the way ( 2mm seat ht, extended and raised the aero bars a bit) and off we go! I also think that lots of what cyclists think is bad fit is bad body. Lack of flexibility (especially as we age, I am 53), lack of core body strength and upper body strength (think traps!) turns an aero position ride into a literal pain in the neck, back and a$$.
2013-07-19 6:28 AM
in reply to: Chokebait

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Subject: RE: Ironman Bike Sizing Question?
I have not read every reply, so I might have missed something.

The reach on the small shiv is 385. You would have to go all the way to the 48cm P2 (reach 389) to be in the ball park of the Shiv reach.

Someone correct me if I am wrong. The Shiv is considered a short tall bike and the P2 is long low. You can make adjustments to make a short tall bike into a long low bike and vice versa, but why not just look at stack and reach numbers that suit you. Problem with your original experience is that they are trying to fit you on 2 totally different bikes. Without actual numbers sounds like you might be better on a short tall bike. Look at stack and reach numbers and narrow you search to short tall bikes and then compare how they feel.

As far as fit goes (as you put it retul FIST etc etc) FIST is a system and retul is a tool. a good fitter who has access to Retul would still need to use that data in a system. Now if You can find a Retul fitter who is a certified FIST fitter you are golden. You can also find Guru fitters who are FIST certified. Get properly measured so you can find out where to start looking (short tall or long low) and then go from there.
2013-07-19 7:47 AM
in reply to: qrkid

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Subject: RE: Ironman Bike Sizing Question?

Originally posted by qrkid I have not read every reply, so I might have missed something. The reach on the small shiv is 385. You would have to go all the way to the 48cm P2 (reach 389) to be in the ball park of the Shiv reach. Someone correct me if I am wrong. The Shiv is considered a short tall bike and the P2 is long low. You can make adjustments to make a short tall bike into a long low bike and vice versa, but why not just look at stack and reach numbers that suit you. Problem with your original experience is that they are trying to fit you on 2 totally different bikes. Without actual numbers sounds like you might be better on a short tall bike. Look at stack and reach numbers and narrow you search to short tall bikes and then compare how they feel. As far as fit goes (as you put it retul FIST etc etc) FIST is a system and retul is a tool. a good fitter who has access to Retul would still need to use that data in a system. Now if You can find a Retul fitter who is a certified FIST fitter you are golden. You can also find Guru fitters who are FIST certified. Get properly measured so you can find out where to start looking (short tall or long low) and then go from there.

Yes, you're on the mark. Get the fit so you have an idea of what to look at. A more average person may have a lot bikes to choose from, but one doesn't know that until until they get the fit. Note in the article I linked before, a bike that "fits" was considered to be one that would work well with the saddle &bars selected with no head tube spacers and a flat stem of ~90-100mm in length. From there they found the frames that fit this well. The farther away from those one goes, the less the bike really "fits" the rider even though adjustments could be made so that one might be able to get on it. Like the Storck the guy was using prior.

Look at the reach of the bikes for the most appropriate length first as the only other adjustment for length is the stem, and that affects handling. From there look at the stack to see how well that matches up. While you want as little as you can here, there are generally more options and a bigger available range of adjustment towards the stack than reach. In this, the Shiv is a tall bike, one of the tallest if I'm remembering correctly. Cervelo bikes run long and low. The P2 is taller than a P3, but it's still a fairly low bike. Do know that "narrow" may be used in place of "short in length".

2013-07-19 8:17 AM
in reply to: qrkid

Connecticut
Subject: RE: Ironman Bike Sizing Question?
not trying to hijack this thread, but can a person's stack and reach measurements change (as they get older, stronger, more flexible, etc....)?

thanks
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