General Discussion Triathlon Talk » Bike Sizing Question Rss Feed  
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2008-11-22 12:10 PM

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Expert
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Boise, ID
Subject: Bike Sizing Question

I am looking to buy a 2008 Cervelo P2C Dura Ace before they are all sold out. My LBS has one that is a 58cm that I am pretty sure I could get a really good deal on. My question is...how important is getting the correct frame size? My road bike is a 58, but the guys at the bike shop tell me I probably need to be on a 56. I have never had a professional fit done so I am just going off what they say at the shop. I installed a shorter stem on my road bike and it is much more comfortable now. I am 6'0" which would seem to dictate a 58. So are there ways to work around a slightly larger frame size or do I need to just keep saving and get a 2009 in the 56 size? Also I was thinking I read somewhere that tri bikes seem to run a little smaller anyway...is that true?

 Thanks in advance for your help!



2008-11-22 2:01 PM
in reply to: #1821169

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Master
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Cumming, Georgia
Subject: RE: Bike Sizing Question

I'm not sure how valuable my input is but I am 6' and my frame size is 60.  If I were you I would shop around and get the input from other shops.  If they want to sell you the bike they should do a free generic fit as part of the purchase.  If more than one shop put you on the same frame then chances are good that it is the right size.  Either way I would have a professional fit done.  When I bought my bike I was able to get them to include the fit in the purchase.  In the end you will be happier and healthier with the proper size frame and fit.



Edited by csharp1171 2008-11-22 2:02 PM
2008-11-22 2:14 PM
in reply to: #1821169

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Champion
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Subject: RE: Bike Sizing Question

What really matters is your torso and leg length so all folks your height will not ride same size bike.

You could do a search on line for fit guides...you can put in your measurements and they will generate ideal frame dimensions you can compare to the geometry for the bike you are looking at.

2008-11-22 2:59 PM
in reply to: #1821245

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Subject: RE: Bike Sizing Question
KathyG - 2008-11-22 1:14 PM

What really matters is your torso and leg length so all folks your height will not ride same size bike.

 This is very true.  Also, different bikes have different geometry. I'm 6', but since I'm female I have a shorter upper body.  I ride a 56 cm road bike (Trek Madone). I did a test ride on a 57 cm Orbea Orca and the difference in the top tube length was amazing. There was no way that bike would have been comfortable. And I didn't want to just put a shorter stem on it since that makes the bike's handling a little squirrelly.

2008-11-22 3:24 PM
in reply to: #1821169

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Expert
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Boise, ID
Subject: RE: Bike Sizing Question

Thanks for the help so far.

I definitely want to get a professional fit on whatever bike I end up buying. But unfortunately the only professional fitter around here isn't actually located in a bike shop. So I don't know how to get a decent fit before I actually buy the bike. Is my best bet to just measure myself, buy whatever frame size the measurments indicate and then take the bike to the fitter? I'm just worried about blowing over 2k on a bike, taking it to the fitter and having him tell me I bought the wrong bike.

2008-11-22 3:39 PM
in reply to: #1821293

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Subject: RE: Bike Sizing Question
You could ask if they will let you take it on a "test" ride for a few hours and jump over to the bike fitter.  I would rather risk losing the fitting fee versus buying a bike that doesn't fit and will only cause injury or take away the enjoyment. 


2008-11-22 4:16 PM
in reply to: #1821169

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Muncie, IN
Subject: RE: Bike Sizing Question
Fit is more important that frame size. I have short legs and a long torso. I just bought a QRoo Caliente size medium. My inseam really had me on a small but my torso fit better to a medium. I was able to get the seat low enough for my legs but still had enough drop and the bike really feels good with my torso. I wouldn't have known this without having a fit done with the bike.

Bottom line is ask the lbs if you can put the bike on a trainer and adjust it to see if it will fit. If they want a customer and want to unload the inventory I would think that they would at the very least do that for you.

Edited by jmickle11 2008-11-22 4:42 PM
2008-11-22 4:47 PM
in reply to: #1821169

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Subject: RE: Bike Sizing Question
Aarondb4 - 2008-11-22 1:10 PM

My question is...how important is getting the correct frame size?

Pretty much THE critical thing in a bike purchase.  Other than that, the rest is just gravy ......

Yes, most people will go smaller on a tri bike because it "allows" them to get a more aggressive position.  But most tri bikes also use different geometry and shorter top tubes proportionate to a road bike.  So hypothetically you would ride the same frame size from the same manufacturer in both road and TT bike.  But different people choose different reasoning to go smaller.

I'm 6'-1" and used to ride 60's for all my bikes back in my road racing days.  As I got older and got back into cycling a lot more I bumped down to 58's.  When I ordered my Felt I actually decided to go for a 56 ...... but they mis-shipped a 58.  I sat in the shop for about 15 minutes really looking at the numbers for the geometry compared to my old TT bike (a Specialized Transition 58) and even had the shop get me some wheels so I could at least get the frame vertical to the proper height and really check it out.  I ended up getting the 58 ........



Edited by Daremo 2008-11-22 4:48 PM
2008-11-23 11:21 AM
in reply to: #1821169

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Boise, ID
Subject: RE: Bike Sizing Question

Thanks for the help everybody.

I found a fit studio here that says they have an adjustable frame to fit me on to figure out a frame size and then will fit me to the bike once I buy it all for $200. So I will be checking that out this next week. I just hope I can find a 2008 P2C in my size, I am not a fan of the paint scheme on the 09.

2008-11-23 1:56 PM
in reply to: #1822005

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Subject: RE: Bike Sizing Question

Sound like you are on the right path.  I have been looking for a bike fitter in Canada for years.  The states have had great bike fitting certifications for quite a while.  In Canada we are quite behind in this manner.  I did find a professionally certified guy here in town, the only one that I know of and he definitely knows his stuff (website triway.ca).  He seems like a very nice young guy, and I would definitely see him again before my next bike purchase. 

I am interested to hear about your experience with the other fit studio!  I have heard good things about those adjustable frames.

Until then,

Bill

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