[Closed] SRAM GX 1x11 mech, hits...itself when on 10T cog. Issues on 125x12? (Pic!!)

What's the jockey wheel doing that high up? I'd check the chain length and b screw first.

I had this issue with sram 10-42 set up. Seem to remember the b screw sorted it

starting to wonder if I should have gone Shimano.

yes, yes you should have. 😆

I cant help thinking that on a bike with 142 dropouts there wouldnt be this issue.

What's the jockey wheel doing that high up? I'd check the chain length and b screw first.

Its on a full susser so have to allow for compression and chain growth... but mainly its just got to be that high to take up chain slack as the chain needs to be that long to go upto the 42T cog. Chain length worked out as per SRAM tech sheet for this 1x11 GX setup.

To get the cage pulled down enough to clear the cam I would have to remove so many links it would rip the mech apart well before it got upto the 42T. 🙁

I had this issue with sram 10-42 set up. Seem to remember the b screw sorted it

Yeah, been messing with that, but not sure its going to help. At the moment anyway.

Did your frame happen to be 135mm too?

Thanks for help guys!

Can you take a photo of the set up from further away?does look like incorrect B tension

Uuuh... Have you got the chain routed through the mech properly? That's a confusing photo, but if that's the upper jockey I think the chain should be on the other side...

If it IS just a weird photo, chain too long?

Nothing wrong with the mech, check the b-tension first then shorten the chain.

Have tried the 11 speed XTR and I am not impressed, SRAM X01 works and looks better.

What frame is it?

i know i put up a sarcy comment about Shimano earlier, but i have also run Sram X01 and X1, both had the same issue on 142 dropouts. it was cured with a massive dose of B-tension (maximum) and careful chain length adjustment and even then it only JUST cleared (we are talking 1/2mm).

To me it seems that on some bikes, the maximum B-tension setting on SRAM mechs is where they should START.

You probably need 1 more link than you think, then wind the B tension in a bit to compensate. Do remember that under load (assuming FS) the mech will be stretched out so you need it roughly in the middle of the gap when static to ensure no problems.

To help heres your photo marked up. You need to slacken the mech until the part thats clashing (marked in red) moves into the 'ok zone' (Green) when static.

[img] [/img]

Thanks for comments, reading them and taking notice!

Will reply to them in a bit.

Just uploading pics to clarify.

BRB, thanks for help as always!

You probably need 1 more link than you think, then wind the B tension in a bit to compensate. Do remember that under load (assuming FS) the mech will be stretched out so you need it roughly in the middle of the gap when static to ensure no problems.

To bring the cage down you mean remove a link, not add one?

Also, in that pic, the bike is in a stand, so suspension unweighted.

That said this Marin has very small chain growth any way. Will get pics up asap.

Bike, 32T NW and oval front:

[img] [/img]

Mech in context:
[img] [/img]

In 10T/12T (ignore B screw... had it in, out, shake it all about... just happens to be in this position when I took pic):

[img] [/img]

In 42T:
[img] [/img]

i know i put up a sarcy comment about Shimano earlier, but i have also run Sram X01 and X1, both had the same issue on 142 dropouts. it was cured with a massive dose of B-tension (maximum) and careful chain length adjustment and even then it only JUST cleared (we are talking 1/2mm).

To me it seems that on some bikes, the maximum B-tension setting on SRAM mechs is where they should START.

Hey, no offense taken, I like banter! lol

Your post gives me hope too! Was just about to go get some washers from Homebase in a bit. :/

Thanks for all the help guys. Genuinely appreciated and its why I love this forum. Such a vast amount of knowledge and help.

To bring the cage down you mean remove a link, not add one?

1. Wind your b-tension right out, if you have enough wound on already
2. Add a pair of links. Bear in mind this will add way too much chain and so you'd need to increase the b-tension to compensate - you probably only really want about 1 links worth, but of course you must add 2.

SRAM mechs run much more horizontal than Shimano, so can look a bit funny if its your first one. The angles are a bit wonky on the pictures so its hard to tell but as a guide you're looking for the center of the lower jockey wheel to be horizontal with the arm pivot (The bit with Roller clutch written round it) in smallest cog, and vertically aligned in biggest cog.

No sorry I meant slacken the chain, you need to add a link to make the arm tuck up a little farther into the mech. The bit that is catching is designed to sit in the 'OK Zone' in my pic. In order to get it into that you can either:

I get what you mean by the OK zone but to get there I have to extend the cage down (even with B tension all the way in) which means shortening the chain?

I mimicked lengthening the chain by taking it partially off the front ring... sure enough the mech curls further into itself, further from the OK zone. To get into the OK zone I can only see that shortening will do that, not adding links?

I think ben must be holding his laptop upside down.

So your last two (10/42) pictures look just about right and the cage doesn't hit the pulley...

Here's mine, if it helps: http://imgur.com/a/7qTN7
B-Screw about 2/5ths in, chain was set up for 30T + 4, now I run a 32, so it is 2 links shorter than SRAM spec.

So your last two (10/42) pictures look just about right and the cage doesn't hit the pulley...

Here's mine, if it helps: http://imgur.com/a/7qTN7
B-Screw about 2/5ths in, chain was set up for 30T + 4, now I run a 32, so it is 2 links shorter than SRAM spec.

Thanks for those pics. Any chance you could take one showing the cam in relation to the cage when in the 10T? That would be really helpful! 🙂

Still tinkering but apart from the brand new chain being no good for anything other than testing now (got a bit too merry with the chain tool...using 2 power links on the chain now, lol)I havent achieved a whole lot.

That said, Ive learnt a few things on the way:
1
The tolerances are tiny and being on a full sus means your juggling a few variables all at once. B tension, chain growth, position of cage etc.

2 Trying to do this entirely on a work stand is a no go. It needs to be on the floor on and off, to check the effect of the chain growth on the cage position.

3 NW chain rings make an odd noise. lol

4 I may still end up buying some washers...

If the cam were a couple of mm smaller I would have had this setup hours ago and been out riding. As it is I have to order a new chain and possibly still get some washers for a bodge.

The "ok zone" mentioned by benpinnick makes sense and I did manage to get the cage into that position. Basically the cam rests in the gap where the cage narrows... BUT... my ocd noticed an issue with that. If your going over bumps etc it might cause the cage to extend enough (even with the clutch)to allow the cage and cam to still hit. As the cage extends the top of it would hit the cam. Theoretically, if the clutch didnt stop it in time.

That last point [b]MIGHT[/b] be the key. If my ocd is unfounded then getting the cam to rest in that "ok zone" looks to be the only way to resolve this... washers bodge not withstanding!

Anyway, a pic of the cam in relation to the cage in the 10T would be massively helpful mate!

Thanks again all. 🙂

You probably need 1 more link than you think, then wind the B tension in a bit to compensate. Do remember that under load (assuming FS) the mech will be stretched out so you need it roughly in the middle of the gap when static to ensure no problems.

Ah!! Sitting down and mulling it over I see why you say lengthen the chain! We want the cage to contract more so the cam enters that ok zone.

Makes prefect sense now. Annoys me when I cant get my brain around a concept so at least I get that now. 🙂

Ill check back on here later, but if you get a chance of forwarding that pic of the cam/ cage (like my first pic) I will forever be in your debt!

Going to have a cold beer now and forget about bikes and gearing for an hour. 🙂

Ha I thought you Would get there in the end. Not sure how you sized the chain but 1x sram needs shortest +3 links rather than the normal 2.

Ha I thought you Would get there in the end. Not sure how you sized the chain but 1x sram needs shortest +3 links rather than the normal 2.

Followed the SRAM pdf initially which says 4 links for the GX.

Yep, understand your edited pic properly now [b]benpinnick

. Do you find the clutch cuts in before the cage can extend going over bumps etc?

Im just concerned that if it doesnt the cam will still foul the cage as it extends downward over rough ground?

I understand the concept you use now, but still need to put it into practice . 😉

Just ordered another chain from Amazon which will be here tomorrow guaranteed and its cheaper than CRC, so might get out this weekend after all.

Oh, and a pic like my first one on here (would still be really handy [b]otsdr[/b], when your not busy.)

Thanks for help guys!

 

My cage is in a position similar to yours (and I consider my chain 'short' now) and if I force it down it rubs slightly on the (slack) cable: http://imgur.com/a/RNJ3F
I can see it being a pain on a full suspension, but I think there is enough room to play between the chain length and the B-tension.
If the cage hits the guide itself, it might be down to 135x12 vs 135x10, although I thought the distance between the small cog and the hanger should be the same...

Hi, thanks for pic. Much appreciated.

So looking at the pic benpinnuck kindly edited with the "ok zone" marked on it, is that where your mechs plastic cam is positioned when on the 10T? Kind of between the 2 jockey wheels where the cage narrows?

The cage on mine his that plastic cam the cable runs round just after the plastic wheel.like you say, it skims the cable at that point too, just as it enters the cam.

Yes, the guide/cam ends up being in the "ok zone", and Ben's advice is correct.
Try out a new chain and start with the longest you can, using the discarded powerlink of the current (short) chain for testing. Once you find the correct length you can use the powerlink that came with the new chain.

Thanks mate for confirming.

Now I have an idea what to do thanks to you guys.

Yeah, going to use the knackered chain to experiment with to get it right then swap on the new chain.

The irony here?

I strongly suspect that when I fitted all this gx gear initially today that I had it all set up and running fine and just like you describe.

It was changing gear fine all was good... then I noticed the cam near the cage and thought it was a potential problem, just looked wrong and started to mess around with EVERYTHING to try and get the cage away from the cam. Though it seems in reality that being in that safe space between the jockey wheels IS as far away as you can get the cage anyway!

Got to laugh. 🙂

Massive, massive thanks to you guys for the help with this. Will post up with an update tomorrow.

First thing to try is just wind the b tension right out. That might buy you enough movement without buggering about with the chain.

Will do mate, the chain length is about right in theory now after bodging it back together so will try all the other tinkering options first.

Ill have a far better idea of the effect of them now I really understand where the cam part of the mech needs to be tucked away to.

Ill do a lot more of the adjustments off the stand tomorrow too.

I don't think you've got your mech installed right, yours looks rotated round too far clockwise on its mount, see this pic. The cable entry should be pointing up more - yours looks almost horizontal.

[img] [/img]

As an aside to this thread; my gx rear mech which looked like a bargain compared to my previous x01 (it looked the same etc) - is now on the scrap heap. After about 300 miles it started to tighten up on itself. Until I couldn't remove it from the hanger without breaking something. Which I did it as it fell apart ! Also I could never get it to set up exactly right as per the x01. w

Anyway I came on here saying how good it initially was. It's been returned and replaced now.

I don't think you've got your mech installed right, yours looks rotated round too far clockwise on its mount, see this pic. The cable entry should be pointing up more - yours looks almost horizontal.

No. she's fitted ok. You can see the mechs lug resting on the hangers "cam" for want of a better description. 🙂

[img] [/img]

Not fitted new chain yet etc yet been a bit busy. Will sort tomorrow for last bit of fettling before a first ride!

rone - Member

As an aside to this thread; my gx rear mech which looked like a bargain compared to my previous x01 (it looked the same etc) - is now on the scrap heap. After about 300 miles it started to tighten up on itself. Until I couldn't remove it from the hanger without breaking something. Which I did it as it fell apart ! Also I could never get it to set up exactly right as per the x01. w

Anyway I came on here saying how good it initially was. It's been returned and replaced now.

Ouch, thanks for heads up, hope that was a one off. How on earth did it tighten up on the hanger?

OK, quick update.

Took the bike out for a short shakedown ride.

Put the new chain on, including the lock link its about 5 links overlap and might try a shorter length in the future (with the knackered old chain) but ran well straight off.

Shifted well under load, didnt hear and noises and on a QUAD Marin the swingarm amplifies chain noise so thats a good sign.

Might need to swap out the oval 32T front as the gearing felt really low, but will wait till |I ride some more typical trails next time.

Over all, quite impressed. Runs great with the Gx Gripshift too.

Sorry, used gripshift since the 90's and everything else just feels wrong!

Bonus is Im using the 2x front gripshift to control the dropper post so looks/ feels symmetrical on both sides and done away with the dropper control of course.

Thanks for help all, fely like jacking the idea in after the initial problem I had.

STW saves the day again!