Pro XC Stem Angles

[nickf]

What's up with these crazy stems lately on the pro XC circuit? Yes, most pro bike setups are questionable to us mere mortals. But many of them have the bars sitting halfway down the head tube. My hunch is that new MTB frames are getting far too slack, dadbod geometry? Your thoughts?

[Hexsense]

XC MTB have been too tall for racers under 5'7" for a long long while.
The move to 29" raise the head tube. Then 120mm fork travel raise it even more.

I'll put myself as an example. I'm not a pro. Far from it. But I don't pedal well at all unless I lean over a bit.
Now what?
I have to lean over regardless of bar height and stem length to pedal well. But if I keep stock bar setup I feel cramped. The bar is simply too close to my shoulder socket that I have to bend my elbow a lot to absorb the bar too close to me. So something have to change.

A) I can push the bar forward by using longer stem. But that rotate my shoulder up -> less comfortable.
B) Or I can drop bar height. This ease my bent elbow and it doesn't rotate my shoulder upward. This is the most comfortable setup by far. Any taller and I have to bend my elbow more and that's less comfy.

So there it goes. Weird looking setup to solve too tall headtube problem.

[JaeOne3345]

For the smaller men and many of the women, the drop stems really do not put the bars crazy low in comparison to the saddle.

I'm 5'3" (160cm) on a 29" and without the FSA drop stem the bars were higher than the saddle. My saddle to bar drop is actually extremely conservative.

[rothwem]

Enh, its not just the short people that have issues. I'm 6'2" riding an XL Epic and I've got a drop stem on mine too.

I think there's an aero component for the pros, and attempting to achieve parity between their road position and their mtb position.

I also think its a reflection of modern mtb geometry. The HTA is slacked out for a confident descending position, which puts the front wheel way out front, and the center of gravity of the rider is pushed way back. The trail/enduro bikes like the Ibis Ripmo's, SC Hightowers and similar make up for that by making the seat tube angle really steep (76-77*), so that riders can winch themselves up steel hills without the front end lifting up, but that makes the pedaling position on relatively flat, non-technical surfaces terrible. Most of the riders of those bikes don't really care though, they're designed to be slow pedaled up climbs, then have the seat dropped for shredding down steep descents.

A modern XC racer, or anyone who likes going fast everywhere (including the climbs), doesn't have that luxury. So in order to have your slack HTA for good descending AND your roadie-ish/power producing STA, you've got to lower the bars to transfer the weight forward, otherwise you'll have the front end come up on any low speed, steep climbs.

One possible solution is to lengthen the chainstays--Specialized has started doing this on the larger sizes, but they're keeping the steep STAs, my guess is that they're offsetting crazy slack (63*) HTAs with the chainstay length. Too long and the bike starts to be hard to turn though, and for an XC race bike I think that's probably not ideal. Who knows though? Maybe all of the pros will soon be on 450mm chainstays with normal bar heights and a 60* HTAs in a few years.

[JaeOne3345]

Agreed.

I couldn't stand my positioning when it came time to put power down while I was using a typical -6 degree stem.