I did do some searching through old threads and didn’t find what I was looking for, my apologies if this has been asked before.
What sort of time gains - in terms of k/ph - do you actually get from a carbon fibre aero bike? Is there a standard time gain or would it vary based on the rider?
(My bf estimated I would gain about 2k/ph if I was on a light tri bike. And of course he’s always right (and if he’s reading this, Hi Sweetie!) but I was curious about Slowtwitch opinions. No such bike in my future any time soon (broke!) but I am curious.)
carbon fiber has nothing to do with it
weight has nothing to do with it
The biggest difference comes from getting your body in an aerodynamic and powerful position that you can maintain comfortably. Tri bikes have features that facillitate this, but you can often achieve the position on a road bike as well.
The 2nd biggest difference comes from the aerodynamic features of the bike, which come in varying degrees of excellence, and not always in carbon fiber.
If you compare the speed difference between an average round tube road bike and average road bike position, to a very aerodynamic tri bike with good aerodynamic wheels and an excellent position, the speed difference can be huge, around 4kph or so.
If your position on the road bike is already excellent with the use of clip on aearo bars then the difference may be a lot smaller, maybe just 1 or 2 kph
so there is no standard time gain, but without a doubt you can gain a lot with careful choice of equipment and careful work on your position. I regularly out bike friends at time trials and triathlons who are stronger than me by a lot when we are on road bikes together.
I do this by paying attention to details. Each one alone seems silly but the 100 of them add up to a lot.
IF you can stay aero, IF you ride in the proper position and IF you do not drop wattage as compared to your roadie…3mph +/- would be a fair number. Fact is that many folks get a Tri bike and ride in the bull horns, cant shift as readily, cant slow as readily, are not as comfortable and drop their wattage due to the position change as compared to a road bike.
As an example - Tracy has a very nice Giant Trinity Carbon Tri bike (Dura-Ace w/carbon crank - bar ends) and a Specialized Dolce Expert roadie (Ultegra CT crank - STI). Last sat last week she was VERY happy that she was on her road bike for a 68 mile club ride just for the ease of use and brakes being as easy as the shifters to operate. She had spend most of her time on the Tri bike cause her friends all ride their tri bikes and they are convinced that their tri bikes are faster (while they sit up and chat on rides, one has a new Orbea Ordu and is afraid to ride in her aero bars…).
Going forward I am certain that she will be spending far more time on the road bike.
So, will a tri bike make you faster? Maybe, and only if you ride it in the proper position.
R10C, though full of negativity, makes a good point. You need to do a lot of work (experimentation) to figure out how you can get in the aero position comfortably enough to stay there.
Otherwise you won’t stay there, and wasted wattages will cry out in despair =)
Sometimes a slight more of the seat or angle of the bars and EUREKA!
I can see that positioning would be a big deal. So some people lose power in an aero set up compared to a road bike because of how they ride? I didn’t know that.
There’s definitely no point in me getting a tri bike yet - I’m riding a cyclocross bike (Kona Jake the Snake) that I got used (I could afford it), I don’t have aero bars on it and frankly, because I’m a pretty new rider, I’d probably kill myself and crash the bike in about 2 minutes if I did have aero bars on it.
I know I have a lot of improvement to do on my riding before I start to worry about a new bike (Saturday was the 5th time I’ve ridden 60k or over - did 92k @ 30.2k/ph, but I’m also just figuring out how to pace and go up and down hills most efficiently). Plus I’m overweight and I can gain speed by losing weight - which is why I would’ve thought a lighter bike would be an advantage over a heavier bike (aluminum vs. carbon fibre).
It depends on a lot of variables- such as will the tri bike improve your position or will you simply replicate the position you use on the current bike. Also the bike you choose can have a big difference.
These 2010 superbikes have really thrown down the gauntlet when it comes to speed
Your current speed is also a factor. The faster you go the less total time you will save even though you save a greater percentafe oftime.
Finally realize everything on the bike matters and there are alot of places to gain time without buying a frame. Use fast tires with latex tubes, get an aero helmet, tinker with your position.
as a rule of thumb 9 grams of drag saved = 1 watt=3 seconds faster over 40k.
a lighter bike will be a teeny bit faster, even on a flat road, but unless it is a time trial straight up a hill, usually a small aerodynamic improvement is more important than a small weight improvement on the bike
now, losing weight off your body reduces weight AND drag, so go for it =)
It really is just academic curiousity on my part
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Ahh…you have not seen enough yet - give it a few years. It is shameful that so many go out and spend so much on a bike to make them faster, and they go slower (than on their roadie). Or they are not comfortable, or they are afraid to ride aero and on and on. All the while that same money spent on a coach would have made all the diffrence in the world (and possibly add some podium time).
Way off topic but…if folks want to spend money on a cool bike - awesome. If folks want to spend money to “buy time” - that is where folks get a bit mis-guided. I am certain that well over 50% of MOP AG+ would probably be better served with a roadie specific bike over a Tri specific bike (at IM disntace and 70.3) as comfort is king.
Definitely at this point my gains will come from learning to ride more effectively, gaining strength, and weight loss. I actually really like my bike (it’s green!) and figure I should stick with it for as long as I can. When I’m a bit more stable on the bike we might look at getting clip-on aero bars, but I don’t see that happening this year.
(Actually this really all came about because I had wanted to be a bit closer to my bf in terms of speed on Saturday’s ride, and then I realized he was riding his P2C in aero and I was like ‘cheater’… )
That´s a pretty good average, particularly on a cyclocross bike!
One option would be just to keep the Snake, get an ´aero´ road wheelset (if you haven´t already), a Fast Forward seatpost and some aerobars. You are rightly wary of the full on ´aero´postition, but try it out in quiet conditions on a route you know well and you´ll be fine, I promise.
Plenty of stuff available second hand if you´re on a budget.
make him ride on continental gatorskin tires
and get yourself some continental GP 4000S or Vittoria EVO CX 320 tpi tires and latex tubes!
=)
Definitely at this point my gains will come from learning to ride more effectively, gaining strength, and weight loss. I actually really like my bike (it’s green!) and figure I should stick with it for as long as I can. When I’m a bit more stable on the bike we might look at getting clip-on aero bars, but I don’t see that happening this year.
(Actually this really all came about because I had wanted to be a bit closer to my bf in terms of speed on Saturday’s ride, and then I realized he was riding his P2C in aero and I was like ‘cheater’… )
Heh heh heh…some how I don’t think he’ll go for that!
Barchettaman, I actually do have race wheels (404s) though I’ve never ridden on them. I was looking on Craigslist for wheels so I could have a separate set for road tires vs. cyclocross tires (not that I ever use the cyclocross ones) and saw them for either $700/750 cdn (the girl selling them was getting sponsored by HED) and it seemed like too good a deal to pass up. I feel a little silly having them (the only tri I’ve ever done was a try-a-tri) but the price was just too good. I also have an aero helmet - my bf got a Rudy something or other and it didn’t fit him right so I have it now.
Aero tri bike (carbon or not) will do nothing if you are in the wrong position, wrong fit bike, wrong clothes etc.
I was using a slightly wrong sized bike and was not wearing tight clothes, I changed the clothes and got some adjustments done to that bike and I think I got around 2kph faster as I could put more power down in comfort and my clothes were flapping in the wind like a parachute. that was all nice, I then got a better fit bike with deep wheels, even tighter clothes and got another 2 kph in my estimations. biggest gains I made was due to riding harder in my training and doing more training and also learning to stay in the profile position and getting power down.
I think the gains are less what is mentioned. I changed from road bike to tri bike lately, and I did not went from a good age grouper level to good pro level with it. If it really is 2k/h or more, then I should have noticed I can ride with the real dudes in this sports now. Not the case. I think most athletes have a very bad position on the road bike then.
Most important thing I noticed is that I do ride my tt training rides faster with the new bike. Although it is a hillier course then most tris I have seen so far, and i think some of the gains could be explained by 2-3 kgs lighter tri bike too. The tri bike is more comfortable though. That surprised me most.
Don’t be disappointed if you don’t notice big gains at first. I had been riding steel road bike when I got a TT bike. Expected huge improvements. Took it to my first race, after riding the new bike for less than 100km. Was SLOWER than my steel road bike!
Why? I think my position wasn’t established, and, I just plain wasn’t used to the difference, especially in terms of muscle groups. After spending a lot more time on it, I am now markedly faster on the TT bike than my road bike.
I’m pretty surprised at the gain in speed people are saying you can get assuming an optimal set-up and usage of the set-up. One of the reasons why I posted this was b/c I thought my bf’s estimate of a 2k/ph gain was huge! It’s pretty amazing.
Actually, I am getting a professional bike fit done on Wednesday, I don’t know if I’ll get any more power out of it (though that’d be cool), just as long as we solve the stabby pain I get next to my IT band in my right knee I’ll be happy.
Here’s an example of what is possible, based off of position:
I regularly ride a light road bike (just to show weight doesn’t really matter) on a very technical loop course that has six hills of varying heights and steepness. Normally it takes me 50 minutes to ride this course, most of it sitting up on the bar tops or the levers.
This past week I bolted some bars on my road bike and tried it again and it was even a fairly windy day. I rode all flats and directions that I could feel the wind, including some uphills, in the aerobars and finished in 45 minutes. I did it directly afterwards on my tri bike with a fairly radical (think Graeme Obree egg) position and did it in 41 minutes. As I mentioned, the course is fairly technical with about 30 turns and six significant hills.
I suspect that were I to make a comparison on a flatter, more typical course used for most tris, the difference would be even greater than four minutes. This is a function of body position, not the actual aero properties of the bike, which is six years old and has one aero tube. Body position is what matters. The very last 1-3 secs per kilometer can be acheived by a high-zoot tri frame like a Cervelo, Trek or other properly designed frame, but you can get 98 percent there with a well designed frame of any matterial at long as it has reasonably narrow tubes.
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