JAJ0404

I ride a 2004 Roubaix that I purchased new. Still rides great, but looking to buy new in 2024 to get technical upgrades. I had a fit done when I bought, but I'm wondering if I need some adjustments. I'm 5'10", so very average, but my inseam is 28.5", very short. Should I be looking at a different crank size than standard? Anything else? My fit seems OK, but wondering if it could be better?

oldbobcat

Without knowing the size of the Roubaix or seeing how you sit on it, who knows?

Polaris OBark

Inseam should be measured with a book shoved up in between your legs to the point it would be uncomfortable. If it really is 28.5", it is even shorter than mine. I'm using 165mm cranksets, but the correlation between inseam and optimal crank-length is not straightforward.

Fit can always be better.

A shorter crank-length allows you to run the saddle a bit higher, which can mean the difference between a well-fitting frame (if you can tolerate unsanctioned stand-over height) and a more poorly fitted frame. I had a custom bike built, but the dimensions are very similar to a Trek Domane. The sloping top tube for me was key. (I never fit classic horizontal top tube road bikes well.)

Iride01 

Fit probably could be better, but when you don't have any specific complaint then how will we even begin to speculate? Do you like the position the Roubaix gives you? Get another Roubaix. Take your current bike with you and put them side by side to see if the same size frame today gives you about the same position of the bars, saddle and pedals as does your old bike.

If you are looking for another bike altogether, then stay focused on the position you want to be in. Again compare side by side with your old bike or at least be aware of the stack height.

Don't be tempted by the sexier looking Tarmac or other race frames that will put you in a more aero position, unless you know that you want to be in that position. It's really gross to see a race geometry bike messed up with steerer tube extenders and weirdly angled stems just to get back to the geometry a relaxed fit road bike provides.

You don't get to pick the size crank when you buy your new bike. It is what the mfr thinks a person riding that size bike should have. If you think you need smaller cranks then consider the smaller size bike if you are in the margins between two sizes of bike and they have different size cranks spec'd for them. If size crank means ring size, you don't get to pick that either. But possibly a different tier level of the same bike frame might have a different brand crank with different ring sizes.

Polaris OBark

Or just get a new crankset. GRX 11-speed 46/30T was $150. I've seen them on sale.

roadcrankr

Dang. I thought my 29" inseam at 5-8 height put me in weird territory. lol
A sloping top tube makes my exposed seatpost look more normal on my Cannondale Supersix.
But my traditional geometry '94 Merlin Extralight looks goofy.
Thank goodness for longer stems. I run 120mm ones on both 52cm bikes.
And use 170mm crankarms. I experimented a spell with 167.5 and 172.5, but those never felt right.
Watch your handlebar width, too. My 44cm's on each feels fine. Somebody at 5-10 might need wider.

Iride01 

44 cm is wide for any road bike with drop bars, IMO. I'm 71" tall and use 38cm wide drops. I did have to change the 42 cm bars out that my bike came with. Wide tends to brace me too much and my shoulders and arms were bearing too much of the swaying motion that happens naturally while you pedal along the road. Narrower bars also seem to let me be more responsive to maneuvering around pot holes and road hazards that suddenly appear.

However I'm okay with to each their own.

JAJ0404

Thanks for the comments, my current frame is 54CM with 172.5 cranks. The size feels good, but maybe, if anything, slightly too big, so for years I thought maybe my next bike would be a 52CM. But lately I've been thinking that the bigger frame keeps the top of the head tube higher, giving me a LESS aero position, which is what I want. I definitely want the endurance positioning. My fit isn't giving me any pain, but I'm wondering if there's something else it's costing me, like less power? Or something. Just noodling for some ideas to check


I agree on the narrower bars, wide makes me feel like I'm leaning too far forward and all my weight is on the bars.

Polaris OBark

I've always suspected short legs are a performance handicap.

If it is just a side-product of fit, 165mm crank-arms might help mitigate that, because you wind up raising the saddle.

Like you, I am on a 54cm, and 52cm is definitely too small and sub-optimal. I now put 165mm cranks on most of my bikes.

Iride01 

You can't go by the height of the top tube. You need to learn to look at the stack height in the specs. Otherwise you might find you have too much reach from saddle to bar and are still in that more aero position than you might want.

Todays Roubaix has one of the highest stack heights of bikes out there today. I didn't search hard for the geometry of a 2004 Roubaix you have currently so I don't know how it compares. If you go to a shop then just tell them you want a road bike with a relaxed fit. Sizing varies between one model of bike to the next, so don't just assume that a 54 in one model is the same as a 54 in another model bike. And from my experience with different sizes, you can usually ride a bike a size up or down from ideal. Just might have to change up more stuff like stem length.

JAJ0404

Thanks for the tips, I have a good bike shop, I'm sure they'll give me a good fit, I just don't remember them taking inseam into the equation and didn't know if it made much of a difference. I will definitely bring my current bike in, and also will tell them how I ride. I love the hoods, the tops and the part in-between those two sections, I rarely go into the drops. My current geometry did feel a little cramped and I had to go to a longer stem to feel comfortable. I don't ride sitting up, but I'm not so aero that my head is near my knees I think I've learned enough to just let them know of my shorter inseam and let them factor it in, if necessary at all. THANKS!

oldbobcat

Inseam rarely plays into a bike fit these days unless yours is at one end of the spectrum or another.

JAJ0404

It is, 28.5" and I'm 5'10"

oldbobcat

Obviously.

Iride01 

I don't know if there is anything to it, but a lot of the cyclists on the World Tour teams that are sprinters seem to have short legs for their size. Cavendish, Ewing are a few. But perhaps it's just the muscle mass in their thighs that makes for that perception. I certainly haven't measured or compared pictures side by side.

Curious though what feels cramped about the size of your old bike that had you putting a longer stem on it? I think I have somewhat long legs for my size. 34.5" inseam, 71" tall. I got the smaller of the two sizes according to Specialized that they recommended in their sizing charts. And still the distance from my knees to the bars seems like a lot.

And... is your old bike a Specialized Roubaix or a Fuji Roubaix? If a Fuji, that might explain some of the things that are confusing me about what you say you want compared to what a Specialized Roubaix should already be giving you.

Velo Mule

Check out this website by framebuilder Matt Appleman: Guide to crank length

JAJ0404 I am also 5'-10" with a long torso and short legs and I am going down the same path for reducing knee pain from riding. I tried a pair of 165mm cranks instead of the standard 170's I had, and so far the shorter crank feels much better.

It is my understanding that a lot of bike fitters are measuring inseam and tibia lengths but, not changing the crank length recommendations. It is perplexing to me how a range of bodies with different leg lengths should all be riding on 170mm cranks.

JAJ0404

It's the Specialized, first year they made the Roubaix. I didn't feel cramped all the time, but anytime I tried to get a little aero for stretchs, I didn't feel like I could, so I was a little too upright. I couldn't lower the bar any more, so I compensated with the longer stem.

JAJ0404

See, this is why I ask. I know I can't be the only one. But these last two posts have me thinking. If I shorten the crank, if I'm thinking this through correctly, I need to raise the seat slightly to keep a proper fit. I like the more upright geometry of an endurance bike over a racer, but maybe I compensate with a shorter stem? I think the conclusion I've come to is I have to go to my bike shop and say look, you need to spend an extra 30 minutes with me making sure this is the right fit given x, y and z.

Iride01 

Being fit to a bike won't necessarily guaranty you a position you are comfortable in. Certain bike geometry sort of demands a certain position. If that's the position you want, can tolerate and won't just say it feels strange the first ride and then muck up everything that was set to give you that position, then you'll get use to it.

So above all, be sure to get the bike that gives you the position you want. Don't buy a bike that you have to make give you a certain position.

I had to work some at staying aero. It takes time to get use to staying in the drops for some of us. It also helps me greatly to not have my belly I get during the winter.

oldbobcat

Look at your arm length. At a relaxed stance, if your fingerips drop to a point half-way between your hips and your knees, a shorter stem will only force you to sit more upright and throw all your weight in the back seat. If they barely reach past your hips, that might work. But for this build (the gorilla) you need a bike that's long in the top tube and short in the head tube.