xfimpg

I thought i'd ask in here because I'm not convinced of what I heard.

A local bike fitter (Specialized dealer) informed me that a mountain bike geometry promotes leaning forward more than a road bike, which is one of the reasons why mountain biking is harder on the lower back.

?? Well, this is the first I've heard of this.

Regardless of the back pain comment, has anyone heard this leaning geometry comment before? Or something to that effect?

Wake

You mean you can tuck better than this
https://www.flickr.com/photos/cmphoto/2670010069/
on a mountain bike?

xfimpg

Nah, I think he meant more of a neutral riding position, like on the hoods.

badamsjr

Not sure about leaning geometry, but MTB frames usually have longer top tubes, because of straight vs drop bars. I guess if you put drop bars on a MTB with the same length stem, it would stretch you out more.

I put a shorter adjustable stem on my MTB tourer with drop bars, for this, and to raise the bars some.

apclassic9

don't you lean forward on a MTB to go uphill (for traction) and lean forward on both for downhill (for speed)?

joe_mn

my older mtn bike has a 22" frame. i only use it for riding on pavement. i was riding my old schwinn collegiate w/upright bars for a few weeks and when i got back on the mtn bike i almost crashed in the first block. whoa, my balance was really messed up. i did not feel comfortable for at least 1 hr of the ride. strange sensation.

Velo Dog

I don't MB much anymore (I'm 65; the hills are steeper now), but I was sort of a pioneer around here in the early '80s. That was before suspension, before downhill became the headliner at every event, even before fat tires, and you had to work hard on technique. Climbing was particularly tricky, because the tires didn't grip very well--it was a constant balancing act between keeping enough weight on the front wheel so you didn't pick it up and enough weight on the back that you didn't break traction. In those circumstances, even moving your head forward and back would make a difference. The bikes in those days were designed to be ridden everywhere, not just to blast downhill, and so you'd often be stretched out to keep the front wheel down.
Having said that, though, the FRAME geometry--head and seat tube angles etc.--doesn't vary much from one bike to another. Most of the change in seating position comes from the stem length and height, with some probably from the saddle fore-and-aft. If you're having back problems, try a stem change.

pablosnazzy

i think it's how you set the bike up. i lean forward pretty aggressively on my road bike, because that is how it was set up, and also on one of my mountain bikes, but on my two other mountain bikes i'm more upright.

xfimpg

Yes, definitely as you get around the +/-16% gradients and up.


Downhill is more of a neutral position, but definitely leaning back if it's too steep, so you don't endo (over the handlebars you go!).