Ask the experts

[beaterdit]

Yeah, I’m super sensitive to setup and picky. Really hits me in the wallet.

[rideit]

The engineers got into an argument about it in the Pinkbike comments:

Attachment 461864

That’s some world class dick-swinging!

[Jtlange]

Any hack even with a manual mill and lathe can easily maintain a tolerance of .04 or .05". In modern production a .001" is quite normal if not even higher.

In fact direct from the source correct bushing tolerance is a diametric clearance of 0.0015”– 0.0090”.. Bushings are sized before installation and re-checked for size after installation

Bushings too loose are way more problematic than a bushing thats at the upper end of the tolerance range IE: 0.0015 Now that tolerance level is quite fine, there is no way anyone is going to maintain a tolerance of that without using special fixturing and you are way more likely to do more damage then good trying to do this by hand.

Now all of the bushing tools people are selling online ( Fox just sells installation and removal tools) are all sized .07mm over. Thats 0.027" which is way off the charts for the factory spec.

If you really insist on doing this, then purchase a good bore gauge and actually measure it before and after.

I was using the tolerance as an example not gospel. Not everyone understands tolerancing that well to get down in the weeds on it.

If you feel like your fork is smooth, you probably don't need it. If you put your tool in and it feels like not a lot of pressure required to get through, you probably don't need it. You test first. If your fork feels like shit no matter what you do, its probably a good place to check.

I wish I had $500 on a bore gauge that needs about a 8-9" depth to get the bottom bushing. I think you would find instances of bushings exceeding a .0075" tolerance range due to the bushing thickness and shape alone not to mention the cast diameter variation, and then halving the window doing two legs together. Stack ups are a bitch on concentric parts tied to another part that requires concentricity. If the upper tubes angles are off by a portion of a degree along the length of the stancion that could be over .01" alone.

I think those numbers highlight the exact reason the burnishing and leg alignment could be needed more than you would expect. Essentially you have ±.0018" range of acceptance on each part nominally in a dynamic assembly. That's tough to do across thousands of parts a year.

Too loose of bushings is exactly why they likely manufacture on the tight side for fewer first pass yield issues and scrapping less product.

[Meconium]

Just squeeze a bunch of Aquafresh in the lowers and call it good.

[climberevan]

Where are you seeing the P2Max spiders for sale?

Either I imagined it or can't find it again... I've done a TON of powermeter shopping lately trying to find one that Ms CE will be happy with.

I ended up ordering her one of the definitely-on-sale Rotor 2inpower cranksets. She wanted to run a 28t ring, so spider ones are out.

I also ordered an Xcadey spider for SRAM cranks from AliExpress. It was $255 and can't be any less reliable than the POS Stages one I'm currently using (see pics). I'll report back with whether it works after it arrives in a month or so.

[skinipenem]

100% fixed my problem. No more cold, purple, reverse circumcision nub of a dick. Best chamois ever!!! 100% insane, thought it was a gimmick. If no one vouched for this, I wouldn't have paid full retail to guinea pig.

Now here is some worthwhile beta. Will try on next chamois buy.

Sent from my SM-S908U1 using Tapatalk

[Roxtar]

Thanks. Before I go further down this rabbit hole, is there any simple test to see if your bushings may need to be burnished?

Not a test but a little example of the difference in smoothness burnishing can give you.
Keep in mind, this was a fork that was pretty good to start. Not one with real issues as described above.
https://www.youtube.com/watch?v=X6JOS58P2UU

[Roxtar]

I see no 'blades' or abrasive surface, is that right? Does this tool just sort of 'stretch out' the bushings?

Yes, "stretching" is a good description. There is no cutting or removing material in this process.

[Roxtar]

Direct quote from what you posted:

“With mass manufacturing the tolerances for the bushings is tight, opening the bushings does have an effect on the life of the fork, which would mean the fork would need servicing much sooner”


So if you want your fork to start to feel sloppy sooner than go for it. While you are at it shave down the inner side of the dust seals too as they provide far more friction.

I disagree with that PB statement. First off, it's not removing material, just compressing it slightly to get the correct sizing. Keep in mind, the tool that's being used is ground to the precise size that the bushing ID should be.
If the bushing is the correct size, it will have no effect, it's just slightly massaging an oversized bushing to get to that correct size.

[criscam]

son got a new (to him) bike a couple months ago. several times he's come to me about shifting/derailer issues and ea time i've had to adjust the b screw as the top derailer pulley was interfering w his cassette. i'm assuming it's "moving" on it's own? common issue or am i missing something? and is there a a fix?

edit-derailer is a shimano xt 11 spd

[californiagrown]

son got a new (to him) bike a couple months ago. several times he's come to me about shifting/derailer issues and ea time i've had to adjust the b screw as the top derailer pulley was interfering w his cassette. i'm assuming it's "moving" on it's own? common issue or am i missing something? and is there a a fix?

edit-derailer is a shimano xt 11 spd

blue loctite?

[criscam]

blue loctite?

Was wondering that.


Sent from my iPhone using TGR Forums

[Roxtar]

son got a new (to him) bike a couple months ago. several times he's come to me about shifting/derailer issues and ea time i've had to adjust the b screw as the top derailer pulley was interfering w his cassette. i'm assuming it's "moving" on it's own? common issue or am i missing something? and is there a a fix?

edit-derailer is a shimano xt 11 spd

blue loctite?

That's it.
Pretty common problem with Shimano 12sp. The plastic thingy that's supposed to put a little pressure on the B screw threads doesn't seem to hold it tight enough. Back it out far enough to get a good coating of locktite blue on the threads and it should hold.

[criscam]

That's it.
Pretty common problem with Shimano 12sp. The plastic thingy that's supposed to put a little pressure on the B screw threads doesn't seem to hold it tight enough. Back it out far enough to get a good coating of locktite blue on the threads and it should hold.

Thx!

[kathleenturneroverdrive]

Shop tech told me yesterday not to use my clutch (on my gravel bike) because switching between 2x chainrings with a clutch on is really bad for the rear derailleur. I've run a clutch for years now with no issue. Any truth to that?

[climberevan]

Shimano neutral service tech told me 2 weeks ago at a race that the clutch shouldn't affect shifting with GRX 2x or with Ultegra RX 2x, but anecdotally i disagree. My bikes all shift better with the clutches off, so I usually leave them that way. No major dropped chain issues.

[Meconium]

Shop tech told me yesterday not to use my clutch (on my gravel bike) because switching between 2x chainrings with a clutch on is really bad for the rear derailleur. I've run a clutch for years now with no issue. Any truth to that?

2x M9000 on my hardtail. I just adjusted the clutch for less clutch for lighter shifting. sometimes the factory setting is crazy tight, just pull little plug and back off micro hex screw.

Edit: GRX you might need to open clutch cover and back off with open end wrench?

[kathleenturneroverdrive]

Interesting. I've never really noticed a difference shifting with it on or off, but haven't spent much time with it off. I'll give it a shot and see if shifting is improved.

[Whiteroom_Guardian]

Last ditch effort before I go to the Shimano tent tomorrow (racing at Silver this weekend) and figure out why the fuck my bike will decide to not shift.

I rode the bike park VERY wet yesterday and it shifted fine (I put new cable/housing in a couple times in the last month). Washed bike and dried it last night. Today it takes TREMENDOUS force to shift and the mech seems "slow" like I shift up a bunch.....nothing happens. Shift down a bunch.....nothing happens. 5 seconds later it finally shifts.

Can a bent mech do this? Or do I need to degrease the mech (xt 12 spd btw) and lube it somehow?

The dirty/wet ride makes me think somehow the parallelogram whatever is sticky. The clutch is fine. I've opened it and looked. Clutch on or off it still shifts like this.

[climberevan]

WRG, I'd put money on it being the cable. Detach it at the der and see if it moves smoothly.

I've already reduced clutch tension on all of mine to almost nothing. Anyway I don't have big dropped chain problems so clutch existence for me is immaterial.

[Whiteroom_Guardian]

So I guess it's just a design flaw? Another dude posted further up that his Gnarvana shifts crappy too. I have to put new cable and housing weekly lol?

[EWG]

Ok, here's a weird one. Fox rear shock. Bushing kit has the two white bushings, the metal shaft, and black spacers on each side. But it also has a very thin o ring that fits into the white bushing on each side. I'm missing one. What is it's purpose? Keep crud out of the shaft/bushing interface? Do I need to go source one?

[Roxtar]

Last ditch effort before I go to the Shimano tent tomorrow (racing at Silver this weekend) and figure out why the fuck my bike will decide to not shift.

I rode the bike park VERY wet yesterday and it shifted fine (I put new cable/housing in a couple times in the last month). Washed bike and dried it last night. Today it takes TREMENDOUS force to shift and the mech seems "slow" like I shift up a bunch.....nothing happens. Shift down a bunch.....nothing happens. 5 seconds later it finally shifts.

Can a bent mech do this? Or do I need to degrease the mech (xt 12 spd btw) and lube it somehow?

The dirty/wet ride makes me think somehow the parallelogram whatever is sticky. The clutch is fine. I've opened it and looked. Clutch on or off it still shifts like this.

Check B-tension since it's easy.
By "tremendous force", do you mean thumb force? If so, I'd look at cable/housing. Possible you crimped the housing or got major contamination from the slop yesterday.
Somehow, the cable seems to be holding things up.
Lack of up-shifting would also point to this.

[Gerome]

I have this old 2010 S-Works 29er xc race bike for my wife that I occasionally ride on gravel rides. The frame is pretty worn out and the Brain doesn’t really work anymore. The rear shock was rebuilt by Specialized last year so I assume it is worn out bushings. How likely is it for me to find replacement bushings?

Also, the geometry is a little extreme for my wife. Is it possible to add a 1Up dropper post to this bike? Can I safely drill a hole in the carbon frame to route a dropper post cable internally? Can I shorten the stem without losing too much stability to the bike?


Sent from my iPhone using TGR Forums

[Whiteroom_Guardian]

Yep I have learned to constantly check B tension since running XT last few years. Yes lots of thumb force needed. I'll put a new cable in tonight or tomorrow and see if that helps.