UKC

Having tried out a Trek Domane 2.0 in 56 and 58cm frames, I'm now a bit confused as to which is best. This is my first road bike, I'm used to riding a mountain bike. The 56 is a better fit with the seat most of the way back, but the 58 fits with the seat pushed forward.

So is it best to have a bike slightly smaller, or slightly bigger? FYI I'm 6' tall with 90cm inner leg.

In reply to adsheff:

I'm just a cm shorter than you and ride a 56 cm trek road bike which I think is plenty large enough. In who's opinion do these bikes "fit" when I first started riding road bikes after years of riding mtb my ideas about bike fitting were totally different to what they are now a few years later.

90 cm /34 inch inside leg seems rather long to me which would surely give you a shorter torso and hint towards the smaller frame.

Personally I'd go with what a reputable shop or bike fitter says as at least you have some comeback if there is a problem.

In reply to gethin_allen:

Yeah I did that Gethin, he told me I should go 58, put a smaller stem on it and move the seat forward. But the 56 felt fine without any stem swapping, so now I'm confused.

In reply to adsheff:

If you are happy with more seatpost showing and therefore a slightly more racey position then I'd go for slightly smaller. I'm 6'1" with 33.5" inside leg and ride a 56cm with seat right back and 130mm stem, I prefer that to a 58cm with shorter stem and more central saddle. I find having the seat back a more powerful position than seat forward (although this can depend on the frame and geometry). Also, if it matters to you, a slightly smaller bike for your height with longer stem and larger seat to handlebar drop looks nicer too! Short stems and tall headtubes look less cool IMO.

In reply to gethin_allen: 90cm is actually 35.5 inches, which might mean that the 2cm larger frame would be a better fit for feet on pedals, but as you say less so for reach to the bars.

In reply to adsheff: I'm 6ft with 34" inside leg. I ride a Specialized Tricross with a 56cm frame. I find the bike ridiculously comfortable now that I've tweaked the saddle height & position, and the tilt on the bars, to fit me.

With a longer inseam like you have the larger frame might be better, provided the reach to the bars can be adjusted to fit. However, I wouldn't be too keen on moving the saddle a long way forward to accommodate this, since that could muck up the pedalling geometry.

I'd suggest that ideally you should try to arrange a reasonably long test ride on the 56cm, or another bike of the same size & frame geometry, to check that the pedalling fit is good for you. I'd see a real risk of knee problems over time if there's a mismatch in the powertrain.

In reply to Martin W:

"> 90cm is actually 35.5 inches"
Indeed it is, brain not working to well that late in the evening.

Although as you say this does support the long leg high saddle short reach theory. ble now that I've tweaked the saddle height & position, and the tilt on the bars, to fit me.

In reply to adsheff:

The two frames on the Domane are actually pretty much the same height, the larger one just has a longer top tube.

In reply to adsheff:

I was recently told by a reliable friend that slightly small is better than slightly too big.

In reply to adsheff:

smaller lookers better if that helps

In reply to adsheff:

I consider top tube length over seat tube when sizing a frame, one thing to bear in mind is that as you adjust to riding a road bike you generally achieve a longer lower position on the bike. Would the shorter top tube on the smaller frame be ok for this without a silly length stem which affects the way the bike handles.

In reply to Mooncat:

id say if you really are bang in between and neither is exactly ride, go an find a frame that really does fit exactly. Compromising on too small will mean a bigger drop seat to bars which might make it less comfy and too big is a nightmare (been there!) and then youre into small stems which can be twitchy... there are so many nice bikes around that i would avoid buying anything that isnt 100% right.

In reply to IMA:

I agree smaller looks better, I'd also add I ride a 58 and have an 89 inseam but have long arms and body. I am equally happy on a 60 but opted for my ideal and slightly smaller frame as I did a bit if tri so to easily fit tri bars without a massive setup change the 58 would do whereas the 60 would have been too long.

It sounds like you have legs as long as mine and a shorter upper body (I'm six three with a positive ape index) so personally I would go for the 56.

Happy riding.

Toby

In reply to VS4b:

Agree with this to, don't rush the shopping and choosing is almost as much fun as riding.

Toby