[eakins]

But I still have that odd b tension setup???
Mmm, do I ride as is or go thru the trouble of adding chain with the idea that I can set the b tension per the manual?
Will it really make any shifting difference in the end?

Ps since this is a 11spd chain I see there are connecting pins available too to add chain length.

 

[eakins]

Been doing some Google searches with results pointing back to other MTBR threads.

Seems I'm not the only one who has needed to move their b tension RD stop arm out of the way and have the screw just adjust off the hanger...even after having the correct chain length.

 

[eakins]

So I have a new spare chain.
Decided to pull it out and cut it longer to the next inner plate than the other one.

 

[eakins]

It's as long as it can go.

Put the RD b tension stop plate back in place per the manual.

Set the chain to big ring, no b tension and it will only adjust to here?
My hanger is not compatible - older 26" Blur XC with that plate in place even with the longest of chains.

So ...

 

[eakins]

And at zero tension ( and the need for less to adjust it ideally) this is what that length chain looks like.

It that ok for the chain to sit up inside the pulleys cage like that? I know understand why Shimano put a rubber guard there.

 

[eakins]

So where do I proceed?

Keep it as is? No added b tension and run it.
Keep the longer length but move the b tension stop plate and adjust b tension ideally?

Go back to the shorter chain and adjust b tension ideally?

 

[eakins]

Thats weird, my bike came setup wrong with the b tension stop moved out of the way like you have and chain too short. I finally got it to shift nicer and not drop off large cog when i put the b stop spacer as speced and chain lengthened as speced

Your read your post
Shimano 12 speed SLX problem

Looks like my longer chain setup now is very similar to yours with the chain real close to that rubber on the RD.

Still have a problem with my b tension.
With that stopper plate back in place and the b screw at no tension I am still a few mm below that 51t line on the RD.

I have yet to find any explanation of what that stopper plate does except for creating more b tension than a screw alone or it mimics a longer b tension screw.

Beyond that I don't see any negatives having my b tension screw hit my hanger direct so that I can set it up properly?

I'm chalking my issues to my older bike and thus hanger shape that was designed when everything was 9 spd.

 

[eakins]

Talked to a Shimano tech about the b tension issue.

He said there was not a fundemantal issue flipping that b tension stop out of the way to achieve my ideal b tension so the 51t line matches on RD.

He did caution using a 12spd RD - SLX, XT, XTR with this vs using the Deore RD-5100...
Since the 12 spd RD parallelogram is "slightly different" vs the 11spd 5100 one?

Is this a real concern since many have used a 12spd RD successfully with that 11spd 11-51 vs sticking with the down-spec Deore 11spd RD?

 

[DeoreDX]

I thought it looked fine in post #39. You can simulate chain growth by pulling the derailleur cage closer to the chainstay as you slowly turn the cranks. Make sure it's free to flex and doesn't have any collisions.

 

[eakins]

Ok gents it's dialed and shifting very well!
Even better than with the shorter chain.

There is just enough b tension screw to achieve and ideal line up. Chain is set at the max +6 sizing on the right image per the manual. This is the visual how it look.
Goes against all my prior knowledge in my head so thanks to those who persisted with me...I should have done this first thing as recommended.

This should also serve as a big heads up to anyone who can't get their b tension set perfectly...go screw direct to the frame.

 

[eakins]

chain is too short

Yes sir!

 

[eakins]

Looks fine, within parameters. Leave it, imo.

I should have left it as is but I've also learned alot here, thanks.

 

[eakins]

I thought it looked fine in post #39. You can simulate chain growth by pulling the derailleur cage closer to the chainstay as you slowly turn the cranks. Make sure it's free to flex and doesn't have any collisions.

Thanks.

It would have worked but these seem to be happiest with more chain than less.

The 12spd RD with my 11spd CS may or may not be a factor per Shimano but longer is working well.

The Shimano rep did say that frame variation does have an affect and they can only recommend the rd-5100 with 11spd.

My b tension is an odd one and probably just an older bike/frame variation thing.

 

[asilker]

Sorry about digging up an old thread, but this is exactly what I wanted to ask about

I've done plenty of work on hardtails, this is my first FS :12 speed m7100 SLX kit

On gear one there's so much chain sag it rests on the stays. This is with the recommended 6 links as screen shot earlier in this thread.

I realize we're talking about chain growth thru shock travel, but this seems kind of extreme to me

Should I size the chain down by 2 links or does this look right?

 

[J.B. Weld]

Sorry about digging up an old thread, but this is exactly what I wanted to ask about

I've done plenty of work on hardtails, this is my first FS :12 speed m7100 SLX kit

On gear one there's so much chain sag it rests on the stays. This is with the recommended 6 links as screen shot earlier in this thread.

I realize we're talking about chain growth thru shock travel, but this seems kind of extreme to me

Should I size the chain down by 2 links or does this look right?

View attachment 2006633

check b screw first, if it's correct I'd remove 2 links

 

[asilker]

check b screw first, if it's correct I'd remove 2 links

I can do that. Thank you for helping me

I'm assuming that even without sag, the chain on gear 1 will look relatively normal with maybe a slight sag. Is that reasonable?

 

[jochribs]

I'm assuming that even without sag, the chain on gear 12 will look relatively normal with maybe a slight sag. Is that reasonable?

Fixed above.

And no, properly sized and adjusted, the derailleur should hold the chain pretty straight.

 

[asilker]

Fixed above.

And no, properly sized and adjusted, the derailleur should hold the chain pretty straight.

Thank you, and thank you

I'll go back and take another look at things later today. Appreciate the help.

 

[Dictatorsaurus]

Just to get more understand, the Shimano 12 speed chain length is measured while the suspension is fully compressed (sagged) ?

 

[J.B. Weld]

Just to get more understand, the Shimano 12 speed chain length is measured while the suspension is fully compressed (sagged) ?

Nope, measure it unsprung but it's different for fs and hardtails.