Riding AM on FTM - adjusting cockpit
Since building my alum FTM approx. year and half ago I'm leaning more and more into AM, last half year almost exclusively ride aggressive XC or AM. No jumps or large drops yet but lots of rock gardens, hard rocky, steep uphills, rocky and unstable/gravel descends, etc...
At the beginning of my FTM affair I did mostly XC with moderate tech. stuff and used to have 90mm 6 degrees rised stem with wide 680mm bar with 30mm rise. Then, when I realized I'm getting swayed to more aggressive riding I swapped the stem for shorter one (70mm).
Lately, I notice more and more when climbing doing steep, rocky uphills the front sometimes has hard time keeping the line and sometimes tend to stall, I'd say more then I used to tolerate in the past. I'm aware about keeping proper riding position, adjusting rider's weight positions according to the terrain, etc...so I think this is not the reason.
Additional detail - having 140mm TALAS at front, lately I tend to keep it fixed at 140mm not utilizing the TALAS feature (while before that used to drop the fork to 100mm (seldom to 120mm) when long and steep/tech uphill is expected.
Also, when descending rock gardens, sometimes I wish the front to be heavier to help keeping the line or perhaps having longer stem...
I ride small frame, my weight is approx. 150 lbs., the bike has TALAS 140mm fork.
I'd like to hear people's experience with FTM riding tech/ AM terrain regarding preferred stem length, how often do you find shortening the fork travel for tech. uphill aids, etc...
Last week I swapped the bar for 20mm rise (instead of 30 that I used to have) or the same length with the same 70mm stem. Can't figure yet it this helps to stabilize the front on uphills though. Need to gain more riding hours with one.
I'd consider getting back to longer stem (back to 90mm). Is the majority of FTM riders (at least reading this forum) who rides similar terrain prefer longer stems indeed (perhaps frame geometry suggest for that ?)
My ML has a 90mm stem. I usually just leave the Talas at 140mm as well. I think ML/FTM models are simply light on the front end...mine has always wandered a bit. It's usually easily overcome with body positions. On the steep and techy climbs I move up to the horn of saddle and weight the bars slightly more. I notice the wandering most when I'm tired or too lazy to make the adjustments in body position.
I'm not sure what can be done with geo to lessen the wandering that wouldn't have more detrimental impacts on other areas of riding, particularly the descents.
Maybe take a look at your spacers? I've wondered if lowering the bars a bit might help.
Of course, I move my body over the cockpit to figure a proper position depending on the terrain, mostly trying to keep the front loaded when climbing but then sometimes need to distribute the weight to the rear as well to increase traction on loose/gravel terrain.
Spacers ? That might also be an idea..I have 2-3 spaces under the stem. I think will first try to get back to 90mm stem, them will remove 1-2 spacers to see how that helps (and how impacts rocky garden descends...)
I use a 70 mm stem on my FTM. When I went from 90, I went down one or two spacers and wandering is not an issue for me. For long climbs I set the fork to 120 and it's good to go.
Me likey the 70 stem!
Shorter stem but same bar moves your shoulder a tad back and less weight to press down the front. Then the same length but slightly lower rise drops the weight back to the front a little to compensate from before.. had experienced similar as noted from my endless bar/stem changes. Not on an FTM but the same applies to me for different bikes.
Finetune the measurements of my setup where the reach and weight loading is optimal in terms of how I like it and noted the numbers down
Whenever I change bar/stems these days (sometimes for diff kind of rides) I try to get back the same reach from should to grips..see if the below pic helps ( was reading a couple of threads and adapted this from the original ideas there after some modifications on my own.. cant find those threads now)
A good first measurement is with the extended saddle position for climbs.
Slide that thing forward to where you get a good pedal stride on steep ups. It's good to slide the saddle to far forward just to experience the sensation so yu know what will feel good.
Comfortable knee position and correct leg extension will put your saddle in a good starting position to calculate the rest of the numbers from.
Don't forget to adjust your sag after you make changes
Quick ques.. do you guys measure the fork sag just sitting on it or standing up...
Mine is measured done standing up @ ~25-30%... and it works out well on the trails. Its almost impossible to get that kind of sag when sitting down esp with 6" or more travel... unless the air spring is 1/2 of what's recommended and that's too spongy when actually riding.
Standing, couple good pumps w/ the feet an dcheck. Usually ride around first for a bit. Best way to make sure is after a good ride.
If the ground isn't level you can do it twice. Just check sag, put bike in opposite direction, check % again.
OP, I don't ride an FTM but a Motolite. However, the geo on the bikes is the same when runnoing the ML with a 130mm fork, which I have.
You mentioned that you went from a 90mm stem to a 70mm stem but you didn't mention anything about changing out your bars. Making a jump like that, I would also move to a 710mm bar. It will give you a lot more control over those rocky descents. Also, are you running QR lowers or TA lowers on the Talas? I'm running a Pike with a 20mm coil on one bike and a Revelation w/ QR lowers on the ML. I can definitely feel a difference in stiffness between the two forks... added burl of the Pike probably helps a bit too.
For climbing, I noticed a big difference with the ML going from 20mm to 30mm to 50mm bars. I was just screwing around with it to try and find a good fit. Taking stack height out of the equation, I found the jump to the 50mm bars made the front end wander way too much on the climbs so moving to the 20mm helped a lot. My stack height was low to begin with so a compromise at 30mm rise bars was perfect. It doesn't necessarily translate perfectly for your bike fit but definitely play with the stack height on that stem and see how dropping it affects the climbs.
Regardless, get rid of that narrow bar and pick up some 710mm or wider. HUGE difference going downhill. That'll be the only way to tell if the 70mm stem is right for you.
I also have a Small FTM with a 140 Talas. Most of the time I set the Talas according to the type of trail I am in, rather than per climb or descend. If i head to a flat trail I set it to 100 or 120 and can ride much much faster. In the mountains it is set at 140 and I leave it on both climbs and descends.
My Joplin usually takes care of the quick adjustments, also propedal at times, but I never mess with the Talas after the initial setup of the day.
As far as the front end wandering, I am pretty light at 135lb, but after setting the sag late last season I decided to up the rear shock pressure 5 or 10lb (i forgot) but it was able to help me plant the front end much much better in both climbs and descends.
as a note, I have the DT swiss 240/ 4.2d wheelset, and 100mm 0deg Thompson stem and I ride pretty stretched out with my seat nearer the rear of the Joplin.
mnigro-- try a long flat bar. I had a 760mm flat for awhile... ridiculous amount of leverage for the climbs...
but swapped back to something with a little rise as the feeling is too weird to get used when the bike gets air.