Any suspension servicing gurus here?

Hi all

Just bought a (lightly) used MTB. It has 2020 Rockshox Rebas fitted with a remote lockout. The fork worked nicely on my quick test ride before buying, but since getting the bike home and setting the air pressure for my weight, I’m having 2 problems and I’m not sure if they’re related to each other or not:

  1. The remote lockout doesn’t seem to spring back/return. You can apply the lockout with the remote lever or by hand using an allen key, but there’s no “snap” back in to position. If done with the cable, the lockout on the fork stays fixed and I end up with lots of slack in the remote cable. I removed the damper and checked/refitted the spring and the problem persists.

  2. With the correct pressure for my weight (120psi, 81kg) the fork is suuuuuper stiff. Feels like it’s locked out. However if I drop the pressure down to 60psi then the fork will compress. What’s even stranger is that whilst out riding a few days ago (first ride on the bike) the fork seemed to stiffen up and then loosen up again at various intervals throughout the ride.

I’m not sure if the default setting (i.e no cable tension from the remote) is unlocked or locked on these forks?

Really appreciate any help. Thanks

I don’t know RS stuff that well but it sounds like either the entire damper or that upper lockout assembly needs to be replaced. You might give them a call, they used to have good customer service in my experience and may be able/willing to send something or at least give you better guidance.

For the air spring, I always thought their recommendations for PSI were high. But, don’t default to 60, try 100, 110 for instance and see how that feels.

Thanks, I’ll get in touch with them.

I’ve read similar about pressure recommendations being high, but I’m having to set it at 50% of the recommendation to get 15 or or 20% sag.

That’s an indication that’s somethings wrong, probably with both air spring and damper.

Yep, that’s why I’m here…

Reba doesnt seem to be RS’s best fork…I had similar issues…I ran 70 psi and im 165 lbs…never got full travel.

Yes, sorry - there’s no way of knowing exactly what I’m afraid unless you’re up for taking it all apart. My honest answer is don’t invest too heavily in that fork and be ready to replace it possibly.

Happy to do that. Let me know what I need to do. Thanks

You’ll need to do a basic lower leg service to gain access to the air shaft (which is what I suspect is wrong). The process isn’t hard but requires a few specialty tools as well as specific oil.

Before you take this on yourself make sure you have the needed items, shock pump, the oil, a hammer, a flush ground 24mm socket, and I believe you’ll need a pair of c-clip pliers. If you’re missing any of that, decide if you want to invest in those items. You’ll have to research that.!

Call Rock Shox on Monday and talk to them first. They’ll be more sympathetic to someone who has not gotten half-way through a service. Not knocking your mechanical aptitude, just telling you my experience as a former suspension tech with limited experience on that brand.

The best I got for you, good luck.

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Thanks. What’s the suspected issue with the air shaft? Am i looking for a fault? Replacing the shaft? Replacing a seal?

Here is a service manual…not sure if it is exactly your model but they all are very similar. You can see what is involved in a servicing your fork.

Well, I’ve fixed the lockout. And this serves as a very good example (among many other on the internet) of when the forums win and the manufacturers guidance doesn’t.

The cause of my sticky lockout was friction between two parts of the lockout mechanism (where there shouldn’t be friction) that the lockout return spring is not strong enough to overcome. I simply solved it by sanding away the black anodising on the inside of the 24mm nut where the threaded lockout nut sits on top of the damper.

Here’s the video I followed, with a much better explanation than I can write. Note that my damper looks slightly different to the one in the video but the fix was exactly the same - my Rebas cartridge is white instead of red, and instead of a half moon on the bottom, mine has a blue disc with 2 holes for oil flow that are closed when the lockout is engaged.


Hi All,

Hijacking this thread as it seems closest to what I’m after.

I’ve just picked my bike up from the shop after having the lockout remote swapped out and new cables installed. The bike has a super weird feeling and doesn’t seem to have the three separate modes (definitely on the front).

The front seems to have open, open, and locked which isn’t rigid but has about 30mm travel. The rear seems to have open, traction, and traction (that’s always how it’s felt though).

One thing I learned while picking the bike up was that the “positions” are all at the remote end, and there’s no detents or anything, just infinite adjustment on the top of the fork. How do the different “modes” work if that’s the case? Does that mean you could use two-position and have “Open” and “Traction” and that the traction would be ever so slightly firmer than factory?

Hopefully that makes sense.

2020 Scott Spark 910 with Fox 34 Performance Elite and Fox EVol

Unless you’ve bought a specific proprietary damper from Scott, then you won’t have this on the front. I tried to buy this damper and Scott told my LBS that they had 3 in stock and were reserving those for warranty replacements only. So I assume, like me, you bought a 2 position fork (open/locked). Which is fine, because all the front fork is doing is dampening. Imagine open holes to allow oil to pass through. As you dampen/close off the fork becomes firmer and firmer.

To set up the “3 position” of sorts on this fork it comes down to cable tension. What you’re after is Open, some dampening, more dampening. It’s subtle and not as noticeable as the proper original damper. On my new 2022 SID Ultimate SL (2 position) fork I’ve basically have that hack. I also don’t have a true lockout. While seated, the lockout is firm, but if I stand and put enough pressure/weight on the fork, the “blow off” releases and allows about 30mm of travel like yours. This is intended behavior to protect the Race Day damper. There is no fix for this unless you get Scott’s damper. To be honest, I don’t miss the true lockout as I’m 99% in traction control.

My rear has a true lockout. If yours doesn’t, then either cable tension is too loose or you need to service the shock.

2018 Spark RC 900 WC

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Thank you!!! That makes so much sense! I had my original damper replaced with a 120mm one when I got the bike. That may have had a true 3-pos?

I wonder if I should just remove the front cable then. I use full lockout so, so rarely.

My rear has never had a 100% (zero movement) full lockout. Could it be a tuning difference between the 900 and RC series (mine is a 120mm travel Spark)? I will get both ends serviced in September before the racing season.

Do you know how the valving works? If one were to set up a rear lockout with a 10mm pull, instead of the standard 7mm, would that give you a slightly stiffer Traction mode? Or does the valving line up at specific points along the control?

Also, thanks for the recent uploads, I’ve been enjoying the long XCM coverage to jump in and out of to finish off sessions :ok_hand:.

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Sorry, I don’t know the specifics of the dampers and exactly how they work, I just understand the concept. Regarding the rear shock, the bolt holding the cable should be about at 9:00 when fully open, 12:00 in traction control and at about 3:00 locked out. This is when looking at it from the front like a clock. My rear has about 5-8mm of movement locked out if I’m really cranking on the pedals. I run my rear shock at 138psi and I weigh 177lbs.

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Thanks. I’m going to have another play this afternoon.

Definitely seems to all make a lot more sense after your explanation.

I think I need to redo my settings. I had the bike running really well before I took it to the shop and have mucked about with it the last few days too much.

Currently ~100psi front and 200psi rear at 170lbs (77kg). Seems way too high …

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