I am getting ready to buy my first tri bike. I plan to go have my measurements done first , then try to find the bike(s) with the best geometry for me, at which point I will select based on the usual remaining considerations (price, is it pretty, etc.). A few questions:
I take it a F.I.S.T. fitting is the way to go?
Once I get the the measurements done, is the best approach to go to a few bike shops that distribute different models and see what brands they recommend for me?
If i take the F.I.S.T. numbers to a non-F.I.S.T. fitting shop, will they be able to understand it (enough to make an approrpriate bike recommendation)?
I am being meticulous about this because I took my current beloved road bike into a local shop that I trust highly, hoping to have them help make some changes to get me into a better position on the bike; only to have them do some quick measurements and reveal that due to my ususually long femur (who knew?) they could not make adjustments to get the bike fit correct to get max power, etc. etc.
Sheracer - I’m a FIST fitter and when I do prefits and I can say that process goes somein’ like this: Interview (what race distances you doing, injury history, strengths and limiters w/in the bike arena, past bikes and how they felt, etc. etc.) then I’d guess at some settings on the fit bike get you up on there in your shoes and pedals with bike shorts and a tight fitting top (so body angels can be seen and measured) then we’d let the tweaking begin! The goal would be to find some place supremely comfortable and yet powerful. The comfort would come from your feedback of each change as we progress toward some body angle that speak to both power and safety (joint safety). Then when finished you’d hop off and I’d measure the bike.
While we could measure dozens of things - the hard reality is that we’d wind up with really only three numbers that mattered for a stock bike purchase*: “bike size” - this is what the industry uses so you gotta have a starting place and if that we’re, for example, a 54cm bike then so be it. Then - and this is the part that matters - “seat angle” (example for argument 77 degrees) and “top tube length” (example for this story 53cm).
Then we’d go to internet and take some serious time researching each bike. We’d go to a brand (Felt, Cervelo, Scott, Specialized, KHS, etc. etc) and we’d find the model we were curious about (B22, P2c, CR1, Transition, etc. etc) we’d find the geometry button for that model and compare across the chart: Felt’s B22 comes in a 54cm and that bike is 78degrees in the seat tube angle and the top tube for that bike is 52.5cm (not saying this is true for Felt, I’m just giving an example). So we’d conclude that this bike would work and we could get it perfect by sliding the seat on the rails a touch to get the angle perfect and we could go with a slightly longer stem to make cockpit length perfect. Then we’d get to KHS and they make a 54cm bike that is 72 degrees with a 55.5cm top tube (again this is all made up people so relax) So we’d conclude that this bike would be a nightmare for you because it’s too shallow and the cockpit is way too long.
So, in the end - you don’t HAVE to be measure by a FIST fitter but it’s sure gonna help because a FIST fitter will be more willing to look towards a position on the bike that should work better for triathlon. A Serottta fitter, a FIT KIT fitter, other fitters could still spit out a bike size for you and a seat tube angle and a top tube length but it might be a seat angle and top tube length that they think is right for triathlon. That’s were the hiccup cold occur. There is a chance that you body, your flexibility, your build would allow for a tri bike set at 72degrees and with a really long top tube so a road bike fit from a Serotta minded fitter might work. FIST is a philosophy one that I could argue for and one that others can argue against.
When you are all said and done - do some research on the web first then see if your favorite local bike shop (LBS) carries one of the bikes that works for you. You’re wise to take time in the prefit, it’ll be worth it in the long run.
"While we could measure dozens of things - the hard reality is that we’d wind up with really only three numbers that mattered for a stock bike purchase*: “bike size” - this is what the industry uses so you gotta have a starting place and if that we’re, for example, a 54cm bike then so be it. Then - and this is the part that matters - “seat angle” (example for argument 77 degrees) and “top tube length” (example for this story 53cm). "
I would settle for stack, reach and STA. Then I’d try to find the bike with the longest front center that met the first three criteria. Finally, I would order the P2C in a 56.
Give me the fist measurements and I will tell you which bikes you can achieve your position on regardless of who stocks them. That way you are forearmed going into the other, possibly less fit educated, stores.
I am learning here, so be patient, but I don’t understand why you select bike size first. Isn’t that a function of seat angle and “reach” i.e. top tube length?
Jacknine, I picked bike size first because that’s what 99% of every shop worker and industry every-man uses. When most folks want to buy a bike they walk into the shop, sales says “how tall are you”, customer answers “5feet 9inches tall” and the sales persons says “great, I’ve got a 56 over here that’ll be perfect”.
The sales guy is basing the bike selection of 56cm on the height of the customer. It’s a guess and, frankly, not a horrendous one (better than judging by hair color) - 7 out of 10 times that 56cm is probably gonna work. But we’re here on ST and we want more out of life. We’re not going to live by the distance from the center of the bottom bracket to the top of the steat tube or center of seat tube or whereever that bike maker is measure their 56s. We also want to know other factors - like seat tube angle, top tube length, stack, reach, drop, etc.
This gets difficult because most sales people are not trained well enough to have you say to them “hey, I want a bike that’s 78 degrees, with a stack around 53, a reach around 43… and, oh by the way, I’m 5’6” tall" They’ll star at you blankly and then say “do you like blue?”.
So… it’s nice to see a fitter who can tell you the numbers that are best for you then do research on the web to see what bikes fit that bill - then go to mr. shop man and say “hey, I’m looking for this brand, this model in this size…go one?”
Thanks, very helpful. I have dropped my well known LBS in part because they do not use a “scientific approach” e.g. FIST. Instead, they start with the bike model, pick a size and then fit by eyeballing.
I am in the process of deciding on my next tribike, but the actual make and model is secondary to determining which bike will give me the optimal fit.
OK keeping the story alive…I had a great F.I.S.T. fit done yesterday, any recommendations on bikes/manufacturers is welcome, numbers are below. Granted I’m trying to keep costs down as its my first tri bike, (and who doesn’t need to keep costs down?) and I’m told once I adapt, I may want to switch bikes…so I’ve heard. Anyhow - thank you in advance!
(saddle used: Arione Tri)
seat angle: 76 degrees
saddle height: 72.6 cm
saddle to middle of pad: - 0.7 cm
tip of saddle to handlebar: 40.4 cm
crank length: 172.5
saddle to aero pad: 36.7 cm
180, 613
stack: 565
reach: 475
(w/90 mm at 20 degrees)
handlebar width: 38 cm
aerobar width pad: 30 cm outer-outer
aeropad (back) to aerobar tip: 31.0 cm