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Road bike VS TT bike - how fast will you be?
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 2009-08-25 8:51 PM |
Member  29  New-Brunswick |  Subject: Road bike VS TT bike - how fast will you be?So your probably asking yourself "How much time will I save switching from a road bike to a TT bike?" Everyone's answer will be different but I thought I would share my experience, not just "I think.." but back it with actual data. I own a Giant OCR 2 road bike with some add on aero bars, they are a little high and I'm not in an optimal aero position when riding on it.. This is an entry level road bike around $1100 CDN. I got a 2008 Specialized Transition TT bike with Mavic Cosmic wheel with Tubulars. I've done a 17KM Time Trial 3 times (2 with TT bike and once with Road bike) and here is what I got. With TT bike 25:06 min 25:02 min With Road Bike 26:20 min Roughly 1:15 min difference over 17K. So if that had been 20K TT then I would guess about 1:30 min difference. Road bike cost $1100 TT Bike cost $4000 (Would have cost about $2000 more but got a sponsor deal) So the retail being about $6000 this means $2000 for every 30 sec I'm saving. Or $1000 per 15 sec shaved. Yep a lot of money! But according to some studies, you run out of the bike faster from a TT bike vs road bike, I'm not sure how true this is, very hard to test and prove.. Well I just thought I would share this, maybe it can help you decide if its worth spending the money on a TT bike. You wouldn't need to spend that much of course and still be able to take advantage of the more earo position the TT bike offers. |
| 2009-08-26 12:40 AM in reply to: #2370705 |
Veteran 812  | Subject: RE: Road bike VS TT bike - how fast will you be? Well a 5% difference is pretty significant. And it's very important to note for everyone that wind resistance is an exponential factor. If you were doing 26 mph instead of 24 mph, the difference would have been much greater. If you were doing only 18 mph, the difference would have been even less. What might have been more interesting though is if you tried a comparison between an $1100 road bike and an $1100 tri bike. How much of that 1:15 gain would have you gotten with a Quintana Roo kilo? Edited by mrcurtain 2009-08-26 12:41 AM |
| 2009-08-26 12:45 AM in reply to: #2370705 |
Master 1547 | Subject: RE: Road bike VS TT bike - how fast will you be? keep track of these, I would be interested to see the numbers once you get up to say n=10 for each. Right now it's not enough data to really tell if it's making a statistical difference. |
| 2009-08-26 5:05 AM in reply to: #2370922 |
Elite 7783  PEI, Canada | Subject: RE: Road bike VS TT bike - how fast will you be? sax - 2009-08-26 2:45 AM keep track of these, I would be interested to see the numbers once you get up to say n=10 for each. Right now it's not enough data to really tell if it's making a statistical difference. I agree, it would be interesting to see the results after a few more runs. I assume the 1st place in Sackville was on the TT bike.  Great race! |
| 2009-08-26 9:38 AM in reply to: #2370705 |
Expert 2555 Colorado Springs, Colorado | Subject: RE: Road bike VS TT bike - how fast will you be? Nice data, but just about useless. A slight change in wind speed or direction could easily account for the difference. |
| 2009-08-26 10:13 AM in reply to: #2371426 |
Not a Coach 11473 Media, PA | Subject: RE: Road bike VS TT bike - how fast will you be? Donskiman - 2009-08-26 10:38 AM Nice data, but just about useless. A slight change in wind speed or direction could easily account for the difference. x2. Also impossible to extrapolate to any other rider. |
| 2009-08-26 12:06 PM in reply to: #2371541 |
Veteran 378 The Cold North | Subject: RE: Road bike VS TT bike - how fast will you be? Donskiman - 2009-08-26 10:38 AM Nice data, but just about useless. A slight change in wind speed or direction could easily account for the difference. I have to agree. While it seems really great now, you may have had different conditions. I have the following results for my 2 most recent 15K time trials (road bike one week, new tri bike the next): Road bike - 28:26 New Cervelo - 28:37 Do I think my Cervelo is slower than my Opus road bike with tri bars? No, but we had an awesome headwind last night when I rode my tri bike, so I can't compare the 2. |
| 2009-08-26 12:23 PM in reply to: #2370705 |
Master 2426 Central Indiana | Subject: RE: Road bike VS TT bike - how fast will you be? Interesting testing info here- http://www.cyclingnews.com/features/how-aero-is-aero FWIW- Assuming same helmet was being used in a 3 TTs, reparent's experience (~5% improvement TT bike vs road bike w/aerobars) is reasonably close to this test's results. |
| 2009-08-26 12:59 PM in reply to: #2370705 |
| 70 | Subject: RE: Road bike VS TT bike - how fast will you be? I only blew about $2k on both of mine and I can tell the difference from one to the other. Its all aerodynamics until you get off the bike and then I can tell the difference in my legs. To each his own, but I think you can save the same amount of time for a hell of a lot cheaper than $1-2k per :30. I notice the difference from roadie to TT. Not pushing yourself thru the wind as much and the geometry is supposed to save your big run muscles a bit more by putting more in front of the cranking. That said, even if you buy a 'cheap' TT at $1500 or $2k, save the time you would on a roadie, and then have more energy for the run that you have worked harder to increase speed, then you are just as far ahead. |
| 2009-08-26 1:53 PM in reply to: #2370705 |
Member 29 New-Brunswick | Subject: RE: Road bike VS TT bike - how fast will you be? Yeah I agree its not enough data to go with for now. But I've ridden that same route more then once and my results thus far has always been very consistent. But true there is a lot of factors that can influence those numbers. Like someone pointed out, if I was a stronger rider then the difference might have been more (in %) and same holds true if I was a slower rider.. How much time was saved because of better wheels? (I have not yet tested this but plan on doing this on my next TT to give me an idea).. What would the difference be with a $1500 TT bike? If I converted my road bike into a more aero positition with a proper bike fit, how much time could I save? This type of testing could go forever! To the person who compared her road bike to a newly purchased cervelo TT bike I'd like to add that you will get faster on your new bike the more you ride it, my first race on my TT bike was not as fast as I am now because I weren't use to the different position, working different muscles ect.. So yeah I do realize my data is not very scientific and 100% accurate. And I am certainly not trying to say a $6000 bike is what you need to shave that amount of time. I know more testing needs to be done and I would be happy to test other bike in different price range for comparision as well. Anyone else who has similar data to share please post them for us to look at  |
| 2009-08-26 2:06 PM in reply to: #2372235 |
Not a Coach 11473 Media, PA | Subject: RE: Road bike VS TT bike - how fast will you be? reparent - 2009-08-26 2:53 PM Anyone else who has similar data to share please post them for us to look at Really, no offense, but any other data like this would be equally useless in coming to any conclusions. There are ways to test some of these things, but they require more work to control for the multitude of variables. Absent a wind tunnel, a power meter would be a first step. |
| 2009-08-26 2:44 PM in reply to: #2372235 |
Veteran 378 The Cold North | Subject: RE: Road bike VS TT bike - how fast will you be? reparent - 2009-08-26 1:53 PM To the person who compared her road bike to a newly purchased cervelo TT bike I'd like to add that you will get faster on your new bike the more you ride it, my first race on my TT bike was not as fast as I am now because I weren't use to the different position, working different muscles ect.. Thanks for the reassurance!! I've only had it for 2 weeks, so I'm looking forward to the changes. I agree my legs feel fantastic when I get off my TT bike compared to my road bike. |
| 2009-08-26 3:28 PM in reply to: #2372363 |
Expert 1484 | Subject: RE: Road bike VS TT bike - how fast will you be? I have a stretch of road that I ride a lot. Bit over a mile, it's fairly wind protected, straight, flat, I ride it at the same time of day.... Between my road bike and Tri bike at the same HR and perceived effort, I am about 5% faster on my Tri bike. With aero helmet, disc rear and deep front, I am little more than 5% faster on the Tri bike. The funny thing is I feel slower on the Tri bike. But time after time, over the same routes about the same time of day and conditions I end up being about 5% faster. Yesterday I rode a 30 mile mostly uphill route home. Have done it several times on my road and several times on my Tri bike, yep still about 5% faster on the Tri bike. I really expected my road bike to be faster on the mostly up hill route, but the Tri bike is just faster on the flat sections and downhill parts. |
| 2009-08-26 3:45 PM in reply to: #2370705 |
| Master 2460 | Subject: RE: Road bike VS TT bike - how fast will you be? |
| 2009-08-26 3:50 PM in reply to: #2370705 |
Cycling Guru 15134 Fulton, MD | Subject: RE: Road bike VS TT bike - how fast will you be? reparent - 2009-08-25 9:51 PM But according to some studies, you run out of the bike faster from a TT bike vs road bike, I'm not sure how true this is, very hard to test and prove.. It is really only one study people cite, and it is bunk. There are "tri/tt" bikes that have 73 degree seat tubes and longer top tubes. Not all tri bikes are uber-steep angles. Your position on the bike and the overall aerodynamics have more of an affect on the speed you can go while your fitness and ability to regulate your bike effort are what make it easier to run off of the bike. |
| 2009-08-26 4:59 PM in reply to: #2372515 |
Extreme Veteran 580 | Subject: RE: Road bike VS TT bike - how fast will you be? Daremo - 2009-08-26 3:50 PM reparent - 2009-08-25 9:51 PM But according to some studies, you run out of the bike faster from a TT bike vs road bike, I'm not sure how true this is, very hard to test and prove.. It is really only one study people cite, and it is bunk. There are "tri/tt" bikes that have 73 degree seat tubes and longer top tubes. Not all tri bikes are uber-steep angles. Your position on the bike and the overall aerodynamics have more of an affect on the speed you can go while your fitness and ability to regulate your bike effort are what make it easier to run off of the bike. I hate to hijack, but I am debating this very issue right now, so I am curious to get your thoughts. I have a Giant TCRaw (alum/carbon) with aero bars and fast forward seat post. I have been fitted and am pretty aero (I know, technical term, right?). My husband wants to get me on a lighter bike because he thinks that will give me a speed advantage, but I thought for tris, it was more about aero than weight (not that weight is not a factor). So, if I upgraded to a lighter tri bike, can I still expect a 5% savings or because I am already aero, this savings would be less? Fwiw, I feel great running off the bike on my road bike with aerobars. |
| 2009-08-26 5:11 PM in reply to: #2372264 |
Member 29 New-Brunswick | Subject: RE: Road bike VS TT bike - how fast will you be? JohnnyKay - 2009-08-26 4:06 PM Really, no offense, but any other data like this would be equally useless in coming to any conclusions. There are ways to test some of these things, but they require more work to control for the multitude of variables. Absent a wind tunnel, a power meter would be a first step. Well I'm not really trying to come to a conclusion, just curious to know what other people's experience is riding a road bike vs a TT bike at race pace. And I don't think the personal testing I've done is "useless" as you put it as it does have "some" merit to a certain point. I know that I am faster on my TT bike and no one could tell me differently. Of course I will continue to test some more but it takes time, I can't do an all out TT everyday. True, if I had a power meter it would be even better, might start looking around for one (more for training but could still be used for testing..) |
| 2009-08-26 5:16 PM in reply to: #2372694 |
Member 29 New-Brunswick | Subject: RE: Road bike VS TT bike - how fast will you be? So, if I upgraded to a lighter tri bike, can I still expect a 5% savings or because I am already aero, this savings would be less? Fwiw, I feel great running off the bike on my road bike with aerobars. This is not coming from an expert but I'm pretty sure you would not save much time by going with a lighter bike if you already have an aero position on your bike. If the bike you bought were "more areo" then your current setup then you'd most likely get your advantage from that more then from the weight you'd save. Having said that, if you ride in places where there are a lot of hills then the lighter bike could help you more. |
| 2009-08-26 7:50 PM in reply to: #2372504 |
Master 2426 Central Indiana | Subject: RE: Road bike VS TT bike - how fast will you be? agarose2000 - 2009-08-26 4:45 PM http://www.bikeradar.com/news/article/how-aero-is-aero-19273 Good article from last year. To save people the trouble, this is the same article I referenced earlier. It's been widely re-quoted by other mags/websites besides bikeradar. Basically it tests a single pro cyclist on closed outdoor racetrack using powermeter in different bike configurations inc. stock road bike, road bike + aerobars +/- TT helmet, TTbike +/- TT helmet. Total aero benefit was roughly equal to going from 40kph to 44kph at same power. It did not involve running following biking. |
| 2009-08-27 9:44 AM in reply to: #2371426 |
Expert 1123 Columbus | Subject: RE: Road bike VS TT bike - how fast will you be? Donskiman - 2009-08-26 10:38 AMNice data, but just about useless. A slight change in wind speed or direction could easily account for the difference. Yeah I'd agree you need to do at least 10 on each ride in comparable conditions and the type of road bike and components versus the type of TT bike and components will make a big difference. I have a bottom of the line TT bike (2008 Schwinn Prologue 20lbs Al frame w/ carbon fork, shimano 105s <$1000) if you compare it to the 2009 Cervelo R3 <$6000 and there are more expensive bikes and upgrades out there. Though I would like to see scientific data in this area. The differences we want to test are frame shape and aero bars. Otherwise bikes should be equal in weight and components and more. The rider should be the same, the weather and road conditions the same. |
| 2009-08-27 10:59 AM in reply to: #2370705 |
Master 2404 Redlands, CA | Subject: RE: Road bike VS TT bike - how fast will you be? I have a 16 lb Road bike, and no Tri bike. Right now I can only afford an entry level Tri bike. Since my bike, a PF RS2, is a size smaller which I flipped the stem at about 77 and tossed on some aero bars. I don't think I can get any faster with an entry level bike, and I doubt I can with even a 4k bike. |
| 2009-08-27 11:06 AM in reply to: #2370705 |
Cycling Guru 15134 Fulton, MD | Subject: RE: Road bike VS TT bike - how fast will you be? I have a 14.1 lb road bike (no joking, actually weighed each individual piece of the bike) and a 19 lb tri bike. My tri bike is signficantly faster in races and even in training rides. On the same route under similar conditions earlier in the year (back to back days) I rode them to compare for sh-ts and grins. The tri bike was 1 mph average faster and that was with normal non-aero rims and my usual helmet. Same effort level. Weight means very little in the big scheme. Your position on the bike, your overall aerodynamics (Coefficient of Drag) and efficiency in the position are what make you faster, not the weight. In other words, tell your husband he's full of sh-t.  |
| 2009-08-27 11:22 AM in reply to: #2374002 |
Not a Coach 11473 Media, PA | Subject: RE: Road bike VS TT bike - how fast will you be? furiousferret - 2009-08-27 11:59 AM I have a 16 lb Road bike, and no Tri bike. Right now I can only afford an entry level Tri bike. Since my bike, a PF RS2, is a size smaller which I flipped the stem at about 77 and tossed on some aero bars. I don't think I can get any faster with an entry level bike, and I doubt I can with even a 4k bike. You can if that entry level tri bike puts you in a more aerodynamic position. It's got nothing to do with bike weight. |
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