I’m looking for a new roadie frame and am getting seriously confused about sizing.
My curent roadie is ~57cm top tube centre to centre, and I’m not sure if it’s a bit big or not. I don’t want to introduce bias, but it does ‘feel’ a bit long and on longer rides i get sore shoulders and neck.
I’m 177cm, inseam ~82cm so pretty standard proportions.
Looking at a frame that is 55cm top tube c-c, 57cm seat tube c-t; will this be too small?
what sizes are you guys riding, and how tall are you?
Im about 179cm.
Roady 54 sq 90 stem 175 cranks.
Track frames both 53 st x 55tt.
If your buying from a shop then ask for a bike set up.
If not tell them your situation and see if you can pay for a pro bike set up.
I can ride a 53sq up to a 57sq frames and be ‘alright’. If your not comfortable or confident in choosing frame size, go see somebody who does bike fits.
I’m 181cm. 88cm inseam (long legs). Right now I’m riding 59st 57tt track with a 120mm stem. Feels good though I could probably do with a shorter stem. I’ve also ridden a 57st 55tt and it felt fine, but maybe a little small.
183 cm.
2 x 55 trad = 54.5 tt, with 100mm stems
1 x 52s = 55 tt, 100 mm stem.
1 x 56 eff with 100mm stem. (a little long)
fitting by height is a stupid idea. same with inseam. it depends a lot on your torso and arm length. seat tube measurements are irrelevant. head tube is very important. a really short headtube won’t really make you faster.
FWIW i cant ride specialized or argon or cervelo (or anything else with long tt really). their bikes with the correct top tube either don’t exist or feel crap on the road.
173cm
Roadie… Right now a compact 56 that’s a little big
Ideal 54 compact
Or in classic 54 TT 52 ST
I got short legs…
Go to a shop and try some bikes on they’ll tell you what size you need…
I’m 178cm, and the bike that fits me best is 55cm ctc square.
I’ve had bikes with seat tubes anywhere from 51cm to 56cm, and top tubes from 53 to 58cm. I’ve got most of these to work one way or another.
Seat Tube
Inseam clearance when standing over the bike is obvious factor, but BB height and the angle of the seat tube will affect this too. A track bike with steep angles and high BB might mean you need a cm or two less if you want to protect your soft bits.
Seat tube length will often relate directly to head tube length, if you’re interested in the saddle-to-bar drop.
Top Tube
A short top tube with a long stem puts more of your weight over the front wheel, increasing steering responsiveness, but then the long stem adds a different kind of stability to balance this out (classic old Colnago geo). My track bike is like this, and I don’t like the feel of it personally (53 tt and a 130mm stem). Feels weird compared to my other bikes (normally 55tt with a 100mm stem)
A long top tube with a short stem leaves your weight more over the rear wheel (assuming standard saddle position) which can feel more stable down hills, but the short stem adds its own twitchiness, so it’s a fine balance.
You’ll see long top tubes on time trial/triathlon bikes made for more aero positioning. Not so comfortable for commuting.
That’s my opinion anyway - I’ve been interested in this since trying to figure out why my old 51 x 58 bike felt so different from my 53 square track bike. (The 58cm long frame had risers, so the reach was actually similar.)
this is what i used when i looked at buying my first decent bike, its not perfect but it will definitely give you a better idea than just guessing about
188cm, longish arms & legs and I’m pretty flexible (especially for an OFB). A long ETT relative to ST seems to suit me best.
Paconi Roadie 59ETT 58 ST 120mm stem
Dean Roadie (crit bike) 60ETT 59ST 110mm stem
Llewellyn Track 60 ETT 59 ST 110mm stem
anything less than about a 59ETT feels cramped to me, I start having to dick about with setback & crazy long stems to fit on, then handling gets all weird.
My mate DC like his bikes the exact opposite, with extra setback, short ETT and 130mm stems. Everybody’s different, I tell everyone who asks to go get a fitting, it’ll save you $ in the long run.
With TT + stem length, is it mainly about what feels comfortable? The shorter the length the more upright your are going to be and vice versa so what are the guidelines for figuring out the right length?
I got fit at queensland sports medical centre by Leon Vogels. He was a road rider on european teams then was on the Davitamon-Lotto Professional Team fitting their riders. Money well spent. Only trouble was the crazy waiting lists to see him!