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Anyone have experience with the DSD Runt? I've been thinking of getting one for either my stock GRIP 38, or for my Pike. I've read some great things about them and the improvements in both comfort and posture.
No experience with the runt specifically, but I've been running my version of the runt for years.
It's makes standard airsprings better, does take some fair tinkering for air pressures to find the sweet spot.
Yes, I have a runt in a Fox 36 (with a Secus). I would say it's better than the MRP option. I don't think the Runt offers true game changing performance but think the adjustability is great and can definitely improve setup. However, I also have a 38 with a Smashpot V1 and I would recommend this instead. It's amazing, just drool worthy amazing. I would choose Smashpot everytime over the Runt and/or Secus unless weight is a true concern.
Running a Runt on a 36. It's similar to a Manitou IRT, so you can search a lot of feedback there.
It does the thing it claims - ups midstroke, and endstroke is not a stiff ramp like tokens. Set initial travel air spring, and set midstroke to endstroke separately. Lot's of variation in there to explore what you are looking for.
For a while I ran the fork with near 25% sag, which would usually make a fork that dives into the weak midstroke, but not with the Runt, it stayed consistent. I set the mid/end to a higher value, and made an airspring profile that was very active, but would not blow through travel. Really good for lots of chunk.
I have since peeled things back with less sag, and am focused on a strong midstroke. This keeps the fork active, but with the midstroke being strong, holds up the fork. The front of the bike stays much higher now. This has been great for steep and smoother trails.
My biggest surprise is how it affects rebound. With less spring in the initial stroke, rebound slows down nicely as it returns to full travel greatly improving grip in corners (I run a fast rebound).
This is great info from all of you. Thanks
There’s a lot here to chew on- thanks for the input!
Ohlins Airspring video "why 95% of riders use it wrong" - figured i'd post here to hear your findings
If the pressure of the ramp up chamber stays higher than the main chamber when you hook up a pump, the ramp up piston shouldn't move correct?
I called Ohlins tech support yesterday after watching this video with that exact question and they confirmed. As long as ramp pressure is higher than main with pump attached you shouldn’t have issues. Obviously inflating the spring when neither have air do the ramp first.
good to know, thanks!
I have one on my Pike 150mm, and to be honest I run the chambers at essentially the same pressure. I'm 190 pounds. IDK how much benefit it actually gives for this use case on a trail bike.
I like a fork that rides high in its travel, so maybe I'm running more pressure than I need to in the primary chamber.
Where this could be an issue is if people were running much lower ramp up than what Ohlins suggests (haven't owned one but I believe their table is like 150% of main). So if someone was running 80 psi main and only 90 psi ramp (instead of 120 psi), then attaching a shock pump to the ramp without lowering the main chamber pressure could drop the ramp chamber pressure enough so that the main chamber pressure displaces the ramp piston.
This video is definitely a bit of a storm in a teacup, it has to be said. First of all, there is no air exchange between the main positive air spring and the ramp up chamber (they are separated by a piston), so even if you were to get things completely wrong, you could just pump up the ramp up chamber again and be back to square one. If you run the ramp up chamber super low you just end up with a very linear fork - similar to running no tokens in a classic set-up. Second, there is typically a 2-1 ratio between the main spring and the ramp up chamber pressure, so the ramp up chamber pressure is still significantly higher than the main air spring pressure even after you attach your shock pump. I run my chambers at about 105 in the main spring and 200 in the ramp up chamber, and when I attach a shock pump to the ramp up chamber it reads about 140 after the hose and the pump pressurize. "95% of riders use it wrong" sounds like a bit of a throw-away, inflammatory statement.
Thanks Johan. Regarding the negative chamber spacer. Sounds like it's worth leaving it in for my first few 38 rides? I'd be curious what you, Schroder and Jonny did with that white devil :D
Yes in theory - although if your pressures are closer than the normal recommended ratio theres a small chance if you top it back up seal friction would prevent it fully extending and you end up with a softer main chamber (volume is larger). I think this is generally no different to checking pressure in a single chamber fork - you don't really need to check anything unless it feels softer. If you do think its soft then deflate the top, pump up the bottom them pump up the top. As long as you note the pressure going in thats the main one to work with for set up, and follow the proper sequence for making adjustments - putting a pump on is always unreliable for checking. If there is an actual leak it will be very noticeable!
I did nothing with it, I left well enough alone and have been thoroughly enjoying my 38 in stock form since I got it. I think the air spring design and base tune is one of the things that really sets this fork apart. For me, as an aging 200-lbs hack, I see no need to fiddle with the negative air volume at all - this fork is one of the most dialed I have ever ridden, it offers a great mix of support and comfort that just gets better the harder you push it. If I ride flatter terrain, I run a few psi less in the ramp up chamber, and if I want more support for more demanding stuff, I run a bit more. That's about it.
I (re)set my pressures regularly because I’ve found ambient temperature differences can make a material difference (+\- 10psi). Where I ride 20 degrees F difference in temp ride to ride in the summer is frequent.
Excellent! I won’t touch it then. I’m similar in both hackiness and weight, so that’s great to hear.
It’s one of the few forks I didn’t feel like I needed the spacer out. The only gripe I have with mine, is the negative spacer can actually float up on compression and then tap the bottom on rebound.
You can hear it when bouncing around in a parking lot. I spoke with Öhlins USA about it, and that was what we determined the noise to be. You could probably put a small o-ring in there to act as a bumper but I haven’t bothered to try.
Some silicone grease helped hold it in place for a while and kept it quiet, eventually came back though. Otherwise it’s a phenomenal fork.
This is retarded. So what if your negative piston moves anyways, it moves all the time during operation...
And if your ramp chamber is normally 200 psi and you attach a pump to it and it then shows say 140 psi when you are "checking your pressure", then surely you pump it back up to 200 psi before disconnecting the pump? After re-inflating it, the ramp piston will move back to the top again.
I mean who checks the pressure, sees it is wrong and then leaves it at that pressure???
Seems like the Runt gets generally good reviews, but I did not get along with it at all.
I thought it felt worse than running 0 volume spacers in my 150mm Fox 36. I could feel the ramp up before the 2nd chamber started compressing. I messed with it for a couple of rides then pulled it.
I have issues with my wrists due to old injuries and certain types of bumps cause me more problems than most and the runt seemed to exacerbate those issues.
Anybody got solid miles on a new Fox 36 x2?
Lookin for longer term feedback. Thanks!
Do you think you had the pressure too high in the second chamber?
I had it lower than Dias recommends, I ran lower pressure in the second chamber, less pressure differential than standard. I emailed him and he was helpful trying to sort it out, I just never was happy with the feel.
It just felt like I could feel the ramp up, I prefer the feel of 0 tokens in the fork.
I'm surprised this doesn't get more attention, it indeed makes a "material difference" as you say. I always check pressure immediately before a ride, running a few PSI below my target if I'm starting early, and vise versa in the evenings.
The simple way for anyone to test how dramatic this truly is is to measure the PSI change in disconnecting/reconnecting the hose w/no temp change, then account for that difference after a dramatic change (say, set your PSI in the morning, then check it in the afternoon). I've run a coil shock for years so idk what kind of PSI differences you can expect out back, but I see (and feel) 5+ PSI changes in my 160mm fork regularly.
100% this, if I am riding with a pack I normally take a shock pump with me and check the pressures at the top of the first climb, give things a chance to warm up. In the Alps last year my rear shock pressure would be about 12psi lower in the cold basement of the apartment than at the top of the mountain on a hot day.
Not sure if we discussed alignment of forks here at all, I know we did in the tech rumors topic, but anyways. Sample of one.
I'm doing a 200h service on my MY23 Zeb and based on everything discussed about alignment and binding, I tested it out. Each stanchion in it's respective lower hole/bushings runs fine. Bith run fine in the top bushings, but bind in the lower ones. That is without a hub. Installing my wheel it runs smoothly. Empty owers fit very snugly over the hub while I can easily insert the hub with the fork fully assembled - apparently the lowers by itself are bent inwards a bit, but the dimensions of the fork are such that with the CSU with stanchions is installed, putting the hub in it everything is nicely parallel and nothing (appart from the hub axially a bit, which is clamped by the axle anyway) is preloaded in any way.
Solid video. I wonder how much of an impact that bleed shim makes on the compression adjusters. And is the bleed shim on the aftermarket shocks? I've mostly seen them on OEM shocks. Reports are that a bleed shim in an OEM Float X can make adding the LSC knob do almost nothing.
I have a NSR-racing valve in RockShock, this valve has a bleed and I can agree that LSC knob does nothing...
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