[westin]

This is a x-post from the All Mountain and obviously posting in the Pivot section may be helpful.


Looking for input about my stem length and height on my first "All Mountain". It's only been 3 good rides. The specs....

Medium Pivot 5.7 carbon
5'10" with 32" inseam
Stem: Thomson X4 70mm 0 rise
Post: 125mm Reverb (obviously not a setback post)
Bar: Whisky 740mm with 15mm rise
Fork: Revelation World Cup 150mm

I chose the above based largely on reading about short stem/wide bar & checking local riders' positions with similar longer travel bikes in my size and comparing to Pivot's geometry. Fork and rear shock sag are dialed in perfectly and I've tweaked things such as bar rotation and saddle positioning.

Everyone local said I'd be crazy for putting anything longer than 70mm with a wide bar. Doing a search on mtbr shows the same theory. So far the wide bars and short stem are perfect when the Reverb is dropped and the trail goes down or gets twisty. Unfortunately I feel cramped while climbing when the Reverb is extended.

Each ride I take a spacer out and the lower bar position feels good while climbing; the best feel thus far is not having any spacers under the stem. This gives me more of a stretched out climbing position with the post fully extended, but while cruising on the flats it feels like the TT is too short and the position too low. Without a dropper post the bike would feel totally unrideable going downhill. So far it's not very comfy and reclined as I thought an all-mountain bike should be. When I put a few spacers back on the climbing suffers dramatically with front end wandering and not a lot of power from the quads, but it's more comfy.

Just put a 90mm 7degree stem on to test fit, and played with spacers, and although I can't ride it (late night) the comfort feels much better sitting on the bike like my large-sized Mojo carbon from years back, but I'm wondering if I'd lose the great flickable traits when the trail pointed down and got twisty.

Is this a matter of getting used to a very slack trail bike and completely different setup, or do you all-mountain riders see something I don't in terms of setup? Will I have to decide whether it's set up as a trail/cornering/jumping bike or more of a general all-around bike that climbs a bit better?

 

[Sablotny]

I also had the medium recommended for me

I'm 5'-11", also with a 32" inseam, and I ride a Large Mach 4 with 120mm stem. I'm an XC rider, and need to stretch out and get power for climbing. The upright position that seems to be so hep right now is great for descending, but I just couldn't do it.

 

[westin]

Whew, got it figured. Cross post from All Mountain....

Everyone has made sense with their objective replies. Thank you.

The past hour or so was spent at a short section of trail that has a little bit of everything: quick bursts of climbing, not so steep downhill, turns, a ditch with a square edge rock and some twisting trees. A friend brought out 4 stems, a bunch of spacers and a whole lotta patience. Even he asked "what do you want this bike to do....if you want this 6 inch slack angle bike to climb and feel like your short travel steep angle bike all the time then you may as well sell one because there's no use owning two bikes with a lot of overlap." Nope, I bought this 5.7 with the intent of going fast and being comfortable pointed down and in the fast turns.

First up was the 100mm stem. It felt comfortable climbing like my xc 29er carbon ht, but it doesn't take a rocket scientist to predict what it'd feel like in the turns and trees with the dropper post slammed. Felt like I was holding an xbox remote control at full arm's length.

The 90mm felt the same, almost, no matter the spacer setup. In fact it was almost as useless in the tight and turns but worse in the climbing.

Flipped, spacers here, spacers there. Nothing even close to a 90% bike (great in 90% of situations). After double checking shock sag, tire pressure and fork pressure we went back to the 70mm 0 rise. Moved a spacer, raised my saddle about 2mm and lowered the nose just a hair; the fore/aft plumb line through spindle was there and so was power without sit bone discomfort. Then he rotated the bar forward a few millimeters.

Jackpot! When dropped I could rail the tight turns descent quickly, but when fully extended I had a bit more seat to bar room that gave me plenty of power for sprinting and climbing. Entirely new bike, uh, it is an entirely new bike. Now I'm sitting "in" vs atop and with the bar below and back. What a relief!

 

[mikedirt]

Do you think part of the issue was because of the 650b front? I've also got the 5.7c and have a 650b wheel being made. This info should help. Thanks!

 

[danK]

He posted in the AM forum it was not being used to a short stem, wide bar and slack angled front.

Do you think part of the issue was because of the 650b front? I've also got the 5.7c and have a 650b wheel being made. This info should help. Thanks!

 

[JMW503]

Whew, got it figured. Cross post from All Mountain....

Everyone has made sense with their objective replies. Thank you.

The past hour or so was spent at a short section of trail that has a little bit of everything: quick bursts of climbing, not so steep downhill, turns, a ditch with a square edge rock and some twisting trees. A friend brought out 4 stems, a bunch of spacers and a whole lotta patience. Even he asked "what do you want this bike to do....if you want this 6 inch slack angle bike to climb and feel like your short travel steep angle bike all the time then you may as well sell one because there's no use owning two bikes with a lot of overlap." Nope, I bought this 5.7 with the intent of going fast and being comfortable pointed down and in the fast turns.

First up was the 100mm stem. It felt comfortable climbing like my xc 29er carbon ht, but it doesn't take a rocket scientist to predict what it'd feel like in the turns and trees with the dropper post slammed. Felt like I was holding an xbox remote control at full arm's length.

The 90mm felt the same, almost, no matter the spacer setup. In fact it was almost as useless in the tight and turns but worse in the climbing.

Flipped, spacers here, spacers there. Nothing even close to a 90% bike (great in 90% of situations). After double checking shock sag, tire pressure and fork pressure we went back to the 70mm 0 rise. Moved a spacer, raised my saddle about 2mm and lowered the nose just a hair; the fore/aft plumb line through spindle was there and so was power without sit bone discomfort. Then he rotated the bar forward a few millimeters.

Jackpot! When dropped I could rail the tight turns descent quickly, but when fully extended I had a bit more seat to bar room that gave me plenty of power for sprinting and climbing. Entirely new bike, uh, it is an entirely new bike. Now I'm sitting "in" vs atop and with the bar below and back. What a relief!

Glad to hear you got it dialed in Westin. I actually cheated a bit and was professionally fitted during the build process. I'm 5'8.5 I tried out stems between 45mm to 70mm on an 800mm bar (since cut down to 780mm). I ended up with 55mm, which has turned out to be perfect for descending and climbs for AM rides and Enduro/Super D races. Which is to say I had to spend a few hours playing around with different stems, spacer combo's, and saddle position as well to get the dialed cockpit.

Stoked you're enjoying the bike.

 

[gticlay]

This is a weird thread that I don't understand. :?: I can't imagine setup being that touchy where you go from cramped 50% of the time to completely dialed with just a stem. Yes it makes a difference but THAT much?

 

[gticlay]

Seat moved back a few mm, bars rotated forward a few mm, Reverb height adjusted a few mm, fork and shock sag dialed in, stem spacer taken out.

Yeah, basic feel stuff. Maybe I've been riding too long :thumbsup:

 

[westin]

Seat moved back a few mm, bars rotated forward a few mm, Reverb height adjusted a few mm, fork and shock sag dialed in, stem spacer taken out.

This is a weird thread that I don't understand. :?: I can't imagine setup being that touchy where you go from cramped 50% of the time to completely dialed with just a stem. Yes it makes a difference but THAT much?

 

[JMW503]

This is a weird thread that I don't understand. :?: I can't imagine setup being that touchy where you go from cramped 50% of the time to completely dialed with just a stem. Yes it makes a difference but THAT much?

Depends. For some folks, maybe not. Won't speak for Westin, but for me, moving from 680-720mm bars to an 800mm bar was a pretty big jump and needed to be worked through. Additionally, I was starting to develop knee and back pain, so I wanted to get my positioning corrected. Spending the up front time resulted in no more knee and back pain, along with fun and comfortable riding.

Not just the stem, but the stem, with bar width and saddle positioning to get the dialed ride.

 

[westin]

All my riding has been on steep angled xc hardtails or short travel bikes. Well, had an Ibis Mojo carbon in 2008 or so but it was set up very xc-ish race. Never had a stem shorter than 90 or 100 and never had a bar wider than 685.
Along comes 70mm stem and 740 bar and 150mm fork with 5.7" rear and slack angles. I was a fish out of water, ha. Oh, and no bar ends.

Yeah, basic feel stuff. Maybe I've been riding too long :thumbsup: