[troy]

Hey guys, maybe someone here is familiar with the problem of rock shox forks feeling a bit notchy at like 15-25% of the travel (talking about used ones, not brand new forks)? Kinda hard to describe this feeling, found it on multiple forks. Anyone knows the cause? Problem keeps comming back after lower legs service. F*cked up bushings? Something with Charger or Debonair seals?

Picture above is not related to the issue (or is it?)

 

[jonKranked]

well, that's the Boxxer L-Turn. not sure if RS ever made an L-Turn Pike or Lyric.

 

[Happymtb.fr]

Did you check how tight the bushings are? It has to be done without seals either with both legs like in the linked video or one at a time.

Madbikes on Instagram: "Because good is not the best (before and after video), from now: all forks gets our bushing treatment! We got custom made tools for all sizes bushing! We are still searching to give you the best possible feel on your suspension! #suspensionservice #bushingtool #bushingresizing #goodandbetter #madbikes"

65 likes, 5 comments - madbikes.be on April 28, 2022: "Because good is not the best (before and after video), from now: all forks gets our bushing treatment! We got custom made tools for all sizes bushing! We are still searching to give you the best possible feel on your suspension...

www.instagram.com

 

[Happymtb.fr]

Sick bushing sizing tool from Andreani by the way. Price is apparently 435€ + vat...

Andreani Group International on Instagram: " Avete già visto il nostro nuovo tool per calibrare le boccole MTB ⁉️ Ecco a voi un service completo utilizzando il nostro nuovo attrezzo. Disponibile con 6 diverse misure di boccole e da 2 a 4 tolleranze per singola misura Facile, veloce e preciso Have you already seen our new MTB bushing sizing tool ⁉️ Here you have a full service using our new equipment. Available with 6 different bushing measures and from 2 to 4 tolerances each Easy to use, fast and precise #mtb #bushing #service #workshop #reel #video #fork #tool #tools #equipment"

2,348 likes, 42 comments - andreanigroup on February 7, 2024: " Avete già visto il nostro nuovo tool per calibrare le boccole MTB ⁉️ Ecco a voi un service completo utilizzando il nostro nuovo attrezzo. Disponibile con 6 diverse misure di boccole e da 2 a 4 tolleranze per singola misura...

www.instagram.com

 

[Sandwich]

 

[toodles]

Sick bushing sizing tool from Andreani by the way. Price is apparently 435€ + vat...

Andreani Group International on Instagram: " Avete già visto il nostro nuovo tool per calibrare le boccole MTB ⁉️ Ecco a voi un service completo utilizzando il nostro nuovo attrezzo. Disponibile con 6 diverse misure di boccole e da 2 a 4 tolleranze per singola misura Facile, veloce e preciso Have you already seen our new MTB bushing sizing tool ⁉️ Here you have a full service using our new equipment. Available with 6 different bushing measures and from 2 to 4 tolerances each Easy to use, fast and precise #mtb #bushing #service #workshop #reel #video #fork #tool #tools #equipment"

2,348 likes, 42 comments - andreanigroup on February 7, 2024: " Avete già visto il nostro nuovo tool per calibrare le boccole MTB ⁉️ Ecco a voi un service completo utilizzando il nostro nuovo attrezzo. Disponibile con 6 diverse misure di boccole e da 2 a 4 tolleranze per singola misura...

www.instagram.com

Full bushing sizing tool kit - LABA7

Our bushing sizing tool has a full range of sizes and four precise increments—a perfect set to resize or burnish any current fork.

laba7.com

That set is 1500 EUR. Bloody hell.

Be nice if the fork manufacturers actually did it in the factory.

 

[troy]

Well, I've got a set 38mm +0.04/+0.07/+0.10 for my ZEB, that I will use in the near future, although my zeb has no such problem (yet).

If anyone is interested, local company makes those tools way cheaper than laba/andreani. ~100usd for 3 tools and ~130usd for the holder (but you can make your own easily). They heve no coating whatsoever, so I keep them in a jar full of oil. They do make some other suspension tools. Very nice quality, bargain pricing compared to other fancy tools.

DO AMORTYZATORÓW- FK - BITUL - narzędzia rowerowe

Lista produktów kategorii DO AMORTYZATORÓW- FK

bitul.pl

Anyway, back to the topic, those are probably bushing issues on those forks.

 

[Udi]

Never felt it on Zeb but definitely experienced it on older RS forks, it seems to be from the bottom of the bushing mushrooming against its seat - seemed to develop in-use rather than from new. Possibly under heavily-loaded hits (eg. under braking) the stanchion/bushing friction forces it downwards causing slight deformation. You could test it by measuring the stick point.

Resizing would help in minor cases, but I found once it developed the fork was never the same again.

 

[bullcrew]

Fork Bushing Sizing / Burnishing Tool

Remove unwanted harshness permanently with the best performance upgrade for your fork. Why waste money on damper or spring upgrades when those aren't targeting the root cause of a harsh feeling and unresponsive fork? Sizing / burnishing fork bushings removes friction and stiction from the fork...

rmsuspension.com

Buddy Mike makes these and has a burnishing removal and replacement tool coming out soon that's pretty badass...just got approval for manufacturing...he's in Canada , actually he's here for another 4 days then back in Canada..just rode.

 

[Muddy]

Spoke w/ a Tuner over the weekend and it was made mention the port to balance chambers (provided this is an air fork) finds wear over time. Unsure if this is a wear for service or a wear as part of the casting.

Disclosure - I have no idea what I am talking about other than repeated words... I don't touch dampers

 

[troy]

Fork Bushing Sizing / Burnishing Tool

Remove unwanted harshness permanently with the best performance upgrade for your fork. Why waste money on damper or spring upgrades when those aren't targeting the root cause of a harsh feeling and unresponsive fork? Sizing / burnishing fork bushings removes friction and stiction from the fork...

rmsuspension.com

Buddy Mike makes these and has a burnishing removal and replacement tool coming out soon that's pretty badass...just got approval for manufacturing...he's in Canada , actually he's here for another 4 days then back in Canada..just rode.

 

[djjohnr]

I had multiple '19/'20 Lyriks. One had the issue you described; bushing sizing helped quite a bit; however that fork also had a slight mis-alignment of the lowers which caused it to never be quite as smooth as the others.

 

[troy]

I had multiple '19/'20 Lyriks. One had the issue you described; bushing sizing helped quite a bit; however that fork also had a slight mis-alignment of the lowers which caused it to never be quite as smooth as the others.

what kind of misalignment are we talking here?

 

[Redwood Mulch Chucker]

The stanchions are not parallel with the lowers.

Sometimes the stanchions are splayed in/out or fore/aft, sometimes it's the lowers.
Same as checking for bushing fit; everything has to be clean/dry with the air spring, damper and seals removed.

Bolt a wheel in the lowers, drop a stanchion in one side at a time to check bushings, then drop both sides in to check alignment.
Should drop to the bottom out bumpers in all cases.

 

[djjohnr]

what kind of misalignment are we talking here?

As RMC posted above. The service center reported that when I sent it in to have the bushings sized; I wasn't able to tell visually.

 

[troy]

Friend of mine came today with his Lyric with this issue. Servicing it by the book didn't help. I took the fork apart, step by step, once again, checking every part on its own. Bushing/uppers were not great, but i've narrowed it down to an Air spring issue (at least in this case). Adding 3ml of lube in the positive air chamber, like the service manual says, was not enough. Ended up with 10ml of Motorex Supergliss 100 in the positive air chamber. Worked like a charm.

 

[Happymtb.fr]

Adding 3ml of lube in the positive air chamber, like the service manual says

Since when does RS recommend adding oil in the air spring? It seems that the oil added to the positive will slowly end in the negative...

From my own experience, mixing oil and grease in air spring build up a very sticky compound. That was on an old 36 with a coil negative spring, slick honey and Fox Float fluid.

 

[6thElement]

Since when does RS recommend adding oil in the air spring? It seems that the oil added to the positive will slowly end in the negative...

For ages.

 

[Happymtb.fr]

For ages.

From 2019 year models apparently. Not sure that would count as gor ages in RM years?

 

[Happymtb.fr]

For those who follow the instructions and mix grease with oil, does it work better than just grease?

 

[two-one]

For those who follow the instructions and mix grease with oil, does it work better than just grease?

There has been a time when RS advised a dollop of 'pm600 military grease' in the air spring... the red stuff. After that came the slickoleum years, which Fox copied. And recently they started advising their more expensive PTFE grease (green) in combination with a few ml of oil.

In my experience, the grease sometimes has the tendency to be pushed away from the sealing surfaces. I'm guessing the oil is intended to keep the grease moving around a bit more.

 

[troy]

Since when does RS recommend adding oil in the air spring? It seems that the oil added to the positive will slowly end in the negative...

From my own experience, mixing oil and grease in air spring build up a very sticky compound. That was on an old 36 with a coil negative spring, slick honey and Fox Float fluid.

I've been using Fuchs Titan Supergear 85W (85W-140 iirc) oil on air shock for at least a decade. Workes fantastic imho. It is very viscous, it stays where it should and coats the stanchions and seals with nice film for long time, not beeing excesively sticky at the same time.

 

[Redwood Mulch Chucker]

Slick honey and Supergliss 68k is a good combo, stays nice and free.

I usually put 3-4ml oil on top of the air piston. It does eventually get sucked into the negative side.

 

[Westy]

I put a bit of oil on top of the piston on my Mezzer and just make sure to flip it over when attaching a pump to prevent it from getting into the negative chamber.

 

[Leafy]

Full bushing sizing tool kit - LABA7

Our bushing sizing tool has a full range of sizes and four precise increments—a perfect set to resize or burnish any current fork.

laba7.com

That set is 1500 EUR. Bloody hell.

Be nice if the fork manufacturers actually did it in the factory.

I could design them a machine and get it built to do this for roughly 350k, would be able to do probably 40-50 forks an hour. Operator puts upper and lower in machine, machine laser mic's both stanchions, adjust variable burnishing tools to size for each stanchion, burnishes them, release parts. Would be pretty sick, also probably wouldn't add too much cycle time or cost if this machine also installed the seal.

 

[jrewing]

Slick honey and Supergliss 68k is a good combo, stays nice and free.

I usually put 3-4ml oil on top of the air piston. It does eventually get sucked into the negative side.

Thats my recipe too.