lesterp

I am interested in a cyclocross bike and I would need a 56cm frame. I want the most upright geometry possible. What determines upright geometry and design? Are there particular models that are the most upright? Thanks.

Loose Chain

I just purchased a Surly Cross Check and simply love the thing, I knew I would. IMO it has a bit more aggressive geometry than a few other similar bikes. By this I mean the head tube is relatively low along with a slightly higher bottom bracket definitely keeps you in a more traditional "racing" tuck. However, I must be fair and say, this Surly is way more relaxed than my two Italian racers. I too wanted a more relaxed geometry and a more upright sitting potion and the Surly gets me that, more upright but not as upright as a "hybrid" or townie bike and is not a overly large fit like the Rivandale fit.

What makes for a more upright fitting is a higher, longer steering tube, more extension spacers on the stem and buying a "larger" frame. That meaning buying a frame to the large end of what fits you. I am a believer in the Lemond saddle height formula (.883 X PBH = SH) and I like having clearance on the top tube for uneven terrain. I also feel the effective top tube length is more important to bike fit than seat tube length.

I ride a 56cm c/t Pinarello Italian racer, I purchased a Surly Cross Check in 54cm c/t but IMO the 54 Surly, if measured the same as the Pinarello is a 56. They both have the same tt length. The result the Surly gives me a more relaxed sitting position without being too upright. If I had wanted a more upright fitting I would have gotten the 56 or purchased the Surly LHT instead in a 54 because it has a longer, higher steering tube

knobster

I normally ride a 54cm road bike (5'10", 32" inseam) but when I started looking for a do-it-all bike, the cross bike I have didn't feel right at 54cm as it was too upright for me. I ended up going with a 56cm. It's a Specialized Tricross. This may work well for you if you normally ride a 56cm.

Loose Chain

Usually going bigger make you more upright.

knobster

huh? That makes no sense. Bigger means longer top tube which means more stretched out, not more upright.

flargle

Bigger also means a longer headtube, which moves the handlebars up and back toward the saddle. Put differently, a smaller frame means more seatpost showing, which moves the saddle up and away from the bars.

Loose Chain

Actually the longer head tube and the fact that the seat will be lower in relationship to the top of the head tube because your legs don't grow longer just because you bought a larger frame means the fit will be more upright. The bars will be higher, the position will be more upright.

I will stay with what I said, normally, a larger frame results in a more upright position for the same bike model.

knobster

Interesting. Learn something new every day. Makes sense if you look at the seat tube and how it pushes you back the smaller the frame. It just doesn't make sense when you think about larger frame means more upright. Gotta take it all in consideration though.

seat_boy

It depends if you're buying a frame or a bike. If you're building up from the frame, you can control where (and if) you cut the steerer tube. You can then make the bars about as high as you want to. If you're buying a bike, the steerer tube almost always comes pre-cut from the factory (I think Surly ships the LHT with the steerer tube uncut).

Loose Chain

True, my Surly CC came with the steering tube uncut. This allowed me to leave it extra long. I don't have the bars set high but I have the ability to both raise and lower my bars from their current position considerably which I feel only adds long term versatility to the bike.