So far I'm liking my new Transition Sentinel, but it definitely seems to have a tendency to pitch forward under braking. Based on what I've seen, this behavior stems from the low amount of anti-rise present in the suspension design. My REEB SST (also Horst link) also does that minorly, but I think it's less noticeable with the shorter travel and flex stay. I'm curious if there is anything to be done with suspension setup and balance to counteract or minimize that behavior.
Suspension setup/balance for a bike with low anti-rise?
snow snakes
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So far I'm liking my new Transition Sentinel, but it definitely seems to have a tendency to pitch forward under braking. Based on what I've seen, this behavior stems from the low amount of anti-rise present in the suspension design. My REEB SST (also Horst link) also does that minorly, but I think it's less noticeable with the shorter travel and flex stay. I'm curious if there is anything to be done with suspension setup and balance to counteract or minimize that behavior.
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It'll be some combination of slowing rear rebound, increasing fork compression damping, and increasing fork spring rate.
The biggest thing in preserving geometry is increasing the fork spring rate. Damping will slow the rate of the bike pitching forward but braking over long enough distances will result in a similar fork dive amount unless the spring rate is increased. So it depends a bit on if the issue is during quick stabs of the brakes (damping), scrubbing off a lot of speed (spring rate), etc.
The biggest thing in preserving geometry is increasing the fork spring rate. Damping will slow the rate of the bike pitching forward but braking over long enough distances will result in a similar fork dive amount unless the spring rate is increased. So it depends a bit on if the issue is during quick stabs of the brakes (damping), scrubbing off a lot of speed (spring rate), etc.
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That's extremely helpful, thank you. I was having a hard time figuring out whether I needed to increase spring rate or add damping. In this case, it sounds like I may need to reduce the rear rebound and add some (low speed?) damping in the front to keep it propped up a bit.
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If you don't mind spending some money, I'd give Avalanche a call and have them tune your shock.
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Slowing the rear rebound and adding some LSC on the fork isn't a bad place to start. If it ends up feeling dead/wooden or the rear starts packing down then open the dampers back up and try increasing fork pressure.
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I'm dead in the middle on LSC before changing anything (Lyrik Ultimate 3.1) and it does feel pretty supple with the Radial tires on there. I'm probably more inclined to add LSC before more pressure, since I've yet to be able to use the last 15mm of travel (no volume spacers).
I run my LSC completely open, one click of high speed on the zeb on my spire. PSI is right around what they recommend for my weight possibly +2-3 psi
I switched to an 11-6 in the rear immediately after 2 rides on the SDU so not much info there other than a quality rear shock + tune makes that bike feel incredibly planted and predictable.
Not a huge fan of the zeb but the bike doesn't get out of sorts at all under hard braking.
Smuggler is the same way but that has a Dougal tuned mezzer pro + a coil in the rear, overall I find transition's bikes really work well with coils after riding the smuggler with the float-x for almost 1k miles. Swapping the coil really calmed that bike down and increased traction significantly.
this probably isn't very helpful but sharing experience with transitions suspension
I switched to an 11-6 in the rear immediately after 2 rides on the SDU so not much info there other than a quality rear shock + tune makes that bike feel incredibly planted and predictable.
Not a huge fan of the zeb but the bike doesn't get out of sorts at all under hard braking.
Smuggler is the same way but that has a Dougal tuned mezzer pro + a coil in the rear, overall I find transition's bikes really work well with coils after riding the smuggler with the float-x for almost 1k miles. Swapping the coil really calmed that bike down and increased traction significantly.
this probably isn't very helpful but sharing experience with transitions suspension
I don't think slowing down shock rebound is a good solution. Increase your fork compression damping, maybe your fork spring pressure but mostly make sure your weight is in the appropriate place before getting on the brakes.
You need to exaggerate the dropped heels and hip hinge stance when braking on bikes that don't squat much.
You need to exaggerate the dropped heels and hip hinge stance when braking on bikes that don't squat much.
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All good suggestions, but I wouldn't go too crazy with the suspension tuning just to try to mitigate brake dive. These changes come with compromises, and if the bike feels good elsewhere, I personally wouldn't want to sacrifice that.
The reality is all bikes require some amount of rearward weight shift under heavy braking. Bikes with lower anti-rise just require a bit more, similar to how longer chainstays require more effort to get the front end off the ground, but it is something you can adjust to. I actually prefer bikes with lower anti-rise, since it helps the suspension feel more supple and active under breaking.
That said, if the bike is diving too much on sustained steep terrain, then that's probably something that should be addressed with some suspension, geo, or cockpit changes. I would start with raising the bars or adding air to the fork.
The one change that I would recommend that has almost no compromise in my experience is installing a Luftkappe in the fork to get a more coil-like spring curve. This adds actual position-sensitive midstroke support without affecting the small bump sensitivity and generally feels better everywhere (pumping rollers, pushing through berms, keeping the front end higher in the steeps, smashing rock gardens, etc.) in addition to reducing brake dive. You could accomplish something similar with a 3 chamber air spring (e.g., DSD Runt), although I haven't personally tried one. A coil fork is even better, but that does add quite a bit of weight.
The reality is all bikes require some amount of rearward weight shift under heavy braking. Bikes with lower anti-rise just require a bit more, similar to how longer chainstays require more effort to get the front end off the ground, but it is something you can adjust to. I actually prefer bikes with lower anti-rise, since it helps the suspension feel more supple and active under breaking.
That said, if the bike is diving too much on sustained steep terrain, then that's probably something that should be addressed with some suspension, geo, or cockpit changes. I would start with raising the bars or adding air to the fork.
The one change that I would recommend that has almost no compromise in my experience is installing a Luftkappe in the fork to get a more coil-like spring curve. This adds actual position-sensitive midstroke support without affecting the small bump sensitivity and generally feels better everywhere (pumping rollers, pushing through berms, keeping the front end higher in the steeps, smashing rock gardens, etc.) in addition to reducing brake dive. You could accomplish something similar with a 3 chamber air spring (e.g., DSD Runt), although I haven't personally tried one. A coil fork is even better, but that does add quite a bit of weight.
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Good stuff all around.
My first thought was making sure that the fork and shock were balanced.
Also, I’m a fan of lots of low speed compression damping in the fork, precisely because I HATE fork dive under hard braking in the steeps.
In my case, I finally got enough lsc damping with the Lift damper. And the times I notice it working, is the sections of trail like the end of Reverence when we rode it together. Steeper tighter turns where the fork is loaded up.
Also, I feel like the more travel you have, the more important it is to set things up correctly. I remember times at Galbraith on oriental express, where I almost bottomed my 170mm yari on my old Kona, braking hard in the chunk coming into a tighter corner. That amount of fork dice is way more noticeable with 170mm of travel than it is with 120mm of travel.
My first thought was making sure that the fork and shock were balanced.
Also, I’m a fan of lots of low speed compression damping in the fork, precisely because I HATE fork dive under hard braking in the steeps.
In my case, I finally got enough lsc damping with the Lift damper. And the times I notice it working, is the sections of trail like the end of Reverence when we rode it together. Steeper tighter turns where the fork is loaded up.
Also, I feel like the more travel you have, the more important it is to set things up correctly. I remember times at Galbraith on oriental express, where I almost bottomed my 170mm yari on my old Kona, braking hard in the chunk coming into a tighter corner. That amount of fork dice is way more noticeable with 170mm of travel than it is with 120mm of travel.
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When I first got my Privateer 141 I noticed the same thing. I was already familiar with the fork as it was used on my previous frame (ht). My first reaction was to increase air pressure on the fork. Rear shock was on the lower end of the recommended sag range, which made the pitching behaviour more prominent. After experimenting a bit I settled on my "normal" fork air pressure but I added a little bit of LSC (I may add an extra click if riding super steep tech). I have also increased rear shock sag (still within the recommended range) so that the bike sits a bit lower. I tend to run minimal LSC on the rear shock on extended downhills to free up the rear too. Last change I did was position the bars 10mm higher. The above changes have certainly helped with the pitching forward thing, but I suspect I have adapted to the bike's behaviour over time as well. My riding technique has probably changed in that time too.
I've come to learn that suspension set up can be a compromise, and one's "local trail" settings may not be optimal on shuttle days for example. Don't be afraid to experiment and even go to the extremes in order to find what works for you.
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46 Posts
I’ve been working on tuning my new sentinel as well. After lots of bracketing I found that the recommended settings are close to spot on but I needed to run a little less pressure in the fork, a little more in the shock and thebslow lsr one additional click on both the fork and the shock.
I’m 175lbs running -
Fork:
70psi
Hsc 3 clicks from closed
Lsc 9 clicks
Rebound 10 clicks
Shock:
190psi
Lsc 3 clicks
Rebound 8 clicks
It pedals well and is a solid downhill platform setup like this.
I’m 175lbs running -
Fork:
70psi
Hsc 3 clicks from closed
Lsc 9 clicks
Rebound 10 clicks
Shock:
190psi
Lsc 3 clicks
Rebound 8 clicks
It pedals well and is a solid downhill platform setup like this.
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2,836 Posts
Would it indicate that I need more or less air spring pressure then? I generally assume unused travel -> too much pressure or volume spacer delete, and dive -> needs more compression damping or pressure. What would you do in this instance?
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Good to know! I‘m 10 pounds heavier and at 75 PSI in the fork and 200 PSI in the shock, so seems like I’m moving towards a good setup.
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50,076 Posts
Right now im having this problem, it started when I put the mezzer back on. Despite the claims that the 2-chamber spring is better, it beats the hell out of my hands when I have it stiff enough not to dive. Any other way, like more IRT pressure, makes progressive, which means more dive and hitting a “wall” late in the travel. AND it has HBO on top of that. The rear end might be a little over-sprung, but if I increase rebound again im just beating my hands/body to death. The Zeb has a secus and is by far the best air spring I’ve used…but i want to kick manitou in the face for using an air spring on an enduro fork. STOP DOING THIS INDUSTRY! The ultimate solution is probably a lighter spring…but this all worked a lot better with the zeb. This matches my experience with other two chamber springs as well, you want more linear in a fork IME and these lean way towards progressive and the initial travel in the mezzer is too harsh because the negative spring is too small, so you try to set it up more progressive.
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5,850 Posts
Due to my obscenely high centre of gravity I have a similar issue of front diving and rear lifting due to brake dive.
I run a ton of LSC on the fork to control the dive. It's a dynamic event, that's more solve via damper to me.
My solution on the rear depends on which shock I run.
For my CCDB and Fox van rc I used to run a softer spring (400 vs recommend 475), on the EXT I run the rebound closed and a 500lb spring.
It's a bit of trial/error depending on what kit you have and what it's capable of.
I run a ton of LSC on the fork to control the dive. It's a dynamic event, that's more solve via damper to me.
My solution on the rear depends on which shock I run.
For my CCDB and Fox van rc I used to run a softer spring (400 vs recommend 475), on the EXT I run the rebound closed and a 500lb spring.
It's a bit of trial/error depending on what kit you have and what it's capable of.
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46 Posts
I should have mentioned that I am running the xt build with lyrik / super deluxe combo.
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