Thinking about a TT bike...
 

This has been on my mind more lately. I do a lot of long rides on a smooth trail unbothered by traffic and am considering a TT bike for supplemental training. I am 6'1" or so with 35" cycling inseam...so medium long legs...only 77 cm seat height though...but longish arms as well. Have been reading about long-low and narrow-high TT bike geometry and likely would fit best on a narrow-high geometry with tallish head tube to match my legs...but more importantly to match my lack of flexibility. I am old and not uber flexible. So I want to start at least on a bike with a higher and less aggressive position which I can bring down a bit over time but will likely never be super aero. I want a bit more aero than my road bike but hold my torso up with my elbows. I don't want to add aero bars to my road bike either...prefer a TT specific bike with upright seat tube angle and sized best for this position.
I am considering either a Cannondale Slice or Cervelo P2C...both with taller head tube.
Any advice from those that have taken the plunge? Do you think a size 58cm would be too big?...again thinking about head tube length.
Thanks

Pay the $ for a professional bike fit by someone who fits TT bikes. It's really hard to figure out on your own, and completely different from road bike sizing.

I needed narrow/high in a very small frame with 700c wheels (a lot of qualifications there) and ended up on a Scott Plasma.

I think you are right. I need to find a fitter to determine a bike with suitable stack and reach including best sta.
Do you suggest any particular fit method for a TT bike? I have seen a picture of an adjustable TT bike ...more like a stationary bike fixture which can be adjusted to dial in fit.
Thanks

I didn't really do that research - the fitter I used is a local with a great reputation who was recommended to me by team mates. He is trained in the BG and F.I.S.T. systems. We did the initial fit on a TT bike that his shop had for sale, which was a candidate bike for me (Specialized Transition) then after we determined my rough reach/stack for the frame, I picked a different frame, bought it at a different shop, and had a final fit session on my purchased bike.

I had another fit (for my road bike) by a different person using BG fit, and that was pretty good too.

I think it comes down to the individual as much as the fit system though - they have to both know a lot and be good at listening and interpreting your body and your goals and how those things can come together on a variety of frame offerings. For what you are looking for, you might look for someone who does a lot of Triathlon fittings since you are looking for a training fit and probably value comfort over pure speed.

If you happen to be anywhere near Boulder - Jason at University Bikes was my fitter, and he was great.

I would think a 58 on a P2c would work for you. I am right about 6ft tall and the 56 works for me.

Does the shop selling either the Cervelo or the C'dale do proper fitting? because if they do then they can dial you into which size will work right for you.

as for getting a TT bike....well, when riding solo they are great. There is an adjustment for sure to be made physically. Your neck and shoulders may be very sore after your first few long rides until you get used to the position and develop those little muscles. You may also fatigue a bit more quickly on those early rides as well as you use slightly different leg muscles and such when riding in the TT position. after you build up those muscles a bit you will feel very comfortable on the bike and in the Aero position.

Draw back is that you really shouldn't use the TT bike when riding with other people. perhaps with one or two people where you aren't in an echelon is ok but they are much safer for solo riding. I find when riding with others in my TT rig you don't get into the aero position enough to make it worthwhile/comfortable because of brake location.

I was midway b/t a 54 and 56 P2C. I went w/ the 54 and ended up happy I did.

how tall are you and whats your inseam?

I also considered the 54 but I have used one a few times for short rides (my wife has one) and I am glad I went with the 56, although I could make a 54 work with a longer stem and set back seat.

Thanks...excellent advice. Yes, I will be valuing comfort a bit over nth degree speed so am looking for more of a training fit. I have no desire to compete...at least initially. I am intrigued by the position and think it may work out. If I place my elbows on my road bike handlebar top and scoot to the front of the seat I could see myself riding for miles comfortably in this position provided the handlebar wasn't too low.
Thanks again.
PS: sadly a long way from your beautiful community of Boulder.

Thanks manutd. Do you think I will be too stretched out on a 58 P2C? Is there much fore/aft adjustability of seat post and or elbow pads and hand supports? I see you own a Roubaix SL3. I too have one...a size 58. What size Roubaix do you ride?

There's a ton of fore/aft adjustability of the seatpost. It comes with a 2 position seat post that allows for an effective seat tube angle of 75 or 78 degrees.

The adjustability of the pads depends on what bars you spec.

FWIW, I'm close to your size and ride 56cm P2C.

General rule of thumb in sizing a TT bike is to go for the smaller size if your between sizes. Lots of people ride one frame size down from their road bike to the their TT bike.

The caveot to that advise is that if you're not looking for a low racing position it could be less applicable.

I had heard that...one size down for TT bike. A question about your fit on the P2C. Are you running a flat or riser stem to get the bar height where you want it? Would you say your fit is aggressive or average? I was thinking that a 58 maybe best for a bit higher position my aging body may appreciate...especially if like you say, there is tons of fore/aft adjustability with two seat tube angle positions and able to vary stem length.
Which seat tube position do you ride in?
Many thanks.

Nice timing, Campag, as I have been having similar thoughts of building a TT bike with no experience in the subject.

Have you, or anyone here, looked at the differences between a tri bike and TT bike setup, because my understanding is that the tri has steeper seat tube angles and a much more pushed forward location. I have an idle Nashbar alum frame with a 74 deg STA, and was thinking a zero setback post might let me sneak up on the TT style. Do most folks go for the tri, or is there really no difference.

Also, C4L, I get a kick out of the similarity we have in bikes. We have both weighed in on flat bar road bikes, I have become a Campy convert, and am now thinking a TT for long solo. Please stop stealing my thoughts. :lol:

Hey Roll,
Deal...no more thought stealing. :) Figured it maybe time to take a stroll over to the Tri zone. I would even consider Tri's on a very low level but I hate to run...but grew up swimming competitively. Couldn't really tell you anything on the subject really...Tri versus TT...maybe there is a difference. :) I am not even interested in the rule about limiting forward sta...I am mostly looking for a TT position and comfort to train out on the road...and will see what comes from it. Thought it maybe good to add another bike and since I haven't gone here yet I am probably overdue. Hope it works out for you as well.
PS: Can anybody explain to Roll and I what the comfort difference is in seat tube angle between 78 and 75 degrees? I understand the tradeoff in hip angle and ability to get more aero with a more upright seat tube...but how about comfort? Is a shallower sta more comfortable as a rule but less aero...not unlike a road bike with more laid back sta taking more weight off the hands?

Luckily, I have never had the Tri bug. An irrational fear of sharks precludes me swimming. No, need to explain the fresh water difference, because it is irrational.

I have been thinking a TT set up because all of my hard efforts are solo against a personal clock, and I have a box of spare bike guts less shifters that could go to a budget build. I just know nothing about fit for that.

My advice, stay far away from time trial bikes. They are mean, they constantly try to hurt you, for some reason they always want to go fast. Stay AWAY!!!!

I am just shy of 6'1 and I think the 56 is perfect for me. I am not too cramped but not stretched out either. As mentioned there is a lot of play in the seat position some positioning adjustment is available for pads but also stems can be swapped out if needed. I got a thorough fitting done at the store I bought from and at first we weren't sure if 54 or 56 but once the sizing started he believed the 56 was ideal.

You should probably go to the Cervelo dealer and speak to their fitter and see what he thinks.

I ride a 56 sized Roubaix SL3 and it fits like a glove. I feel like I am too stretched out on a 58 sized bike and the 56 just feels right for me.

I had a tri coach a few years back and he said that I looked to be in a very good position on my bike.....I wouldn't say it is very aggressive (have some spacers in there) but still a decent drop to get into that aero position.

are you getting a tt bike to actually use in time trials or to ride on the bike trail?

A shallow angle would more closely replicate your road position so you wouldn't need to adapt or change your pedal style or posture. That in addition to high aerobars would be the most comfortable.

I'd pick a frame about the right size that has a tall headtube, and figure on getting a riser stem, or better yet an adjustable stem.

Don't do it....everyone will try and pass you and then brag about it here. TT bikes require full speed at all times...You don't want that!

General solo training fly...no plans initially for TT's but will see what the future holds. The position appeals to me. I know its purposeful riding but I ride long distances on open road...some cycle specific road...and would like to give it a go.

I hear ya. Last night I was out riding and saw a bike well up in the distance and it took me a while to reel him in. Guy was a monster...say about 6'5" and on a mountain bike with nobbies. :) I paced him for while and he was averaging 18-19 mph. The guy did not look like an accomplished rider at all...in fact quite the contrary. So after pacing him for a half a mile or so, I dialed up to 300 watts and accelerated to 22mph or so and figured the guy would soon become a distance memory and I forgot about him. About 2 miles up the road as I rode into town and stopped for traffic, the guy had been glued to my back wheel the whole time....lol. Light turned, I hadn't clipped in and he took off. I caught him again but this time, I put him away. :)...but what a freak the guy was...lol. I see the same dynamic with road bikes and TT bikes all the time...of course I would never do this. ;)

Makes sense rruff...thanks. I thought perhaps a more upright sta would be more comfortable because the elbows basically support the upper body and no need for weight to be more rearward as on a roadbike to reduce upper body loading.
Thanks again.

Thanks...sounds like I maybe best served on the 58 P2. Perhaps not the best to extrapolate from road bikes, but I think I would appreciate the taller head tube of the 58 and could endure being fractionally more stretched out...or adjust out the small difference in reach between the 56 and 58 P2 framesets. You will laugh as we are close to the same size...I couldn't ride a 56 Roubaix. I ride a 58 Roubaix with 140mm stem and very little drop.
I believe I would like the more upright position of a 58 P2 as well but yes I will heed your good advice and get a fitting prior to purchase.
Thanks again.

http://i72.photobucket.com/albums/i1...rt/garage3.jpg

That was the original build. I've got it about 2 cm lower.

I'm using the rearward seat position, mostly because that makes it UCI legal, but i'd likely be faster in the forward position.

honestly, if it just the position that you are looking to replicate, you can probably get pretty darn close with your road bike plus clipons and a forward post. more importantly, it will give you some time to figure out what kind of aero position you can tolerate before committing to a bike that may not be the right size if your flexibility does or does not improve.

if you are doing the time trial racing thing, a different bike can certainly help, particularly if it allows you to achieve an optimal position that the road bike is incapable of matching or if you are racing in a category where every second counts. furthermore, intentions to race might entice you to opt for a more aggressive position.

friendly warning: i know at least three riders who got time trial bikes as a different flavor to quench their upgraditis with no intentions of racing. none of them have touched their tt bikes since 6 months after purchase. tt training/position is an acquired taste, and it may behoove you to try a sample prior to dropping coin on an all out race rig.

p.s. slice/p2 are both solid platforms assuming the geometry matches up, and can be obtained relatively modestly. good luck with the decision making process, and remember to enjoy it! agonizing over which bike to get is one of the best aspects of getting a new bike.