Allmtn 7 chain replacement?

[JC1982]

Hi all

Two things really.

When I am in the highest gear the chain is looking a little slack to me with a slight drop between the cogs, top and bottom. Anyone experiencing that? I am not really experiencing the chain suck issue.

Has anyone changed their chain yet and what have people used and found a good replacement and what number of links have people used?

I push some heavily and tech climbs.

Thank all.

 

[fenwick458]

if the chain looks a little slack, is it too long?

 

[JC1982]

It's the stock chain ar the moment. That's the bit that threw me with it looking slack. It's done 300 miles.

 

[All4Fun]

I would check the derrie, remove the chain and check the derrie for free movement and spring tension.

 

[JC1982]

Thank you.

 

[Jackware]

Hi all

Two things really.

When I am in the highest gear the chain is looking a little slack to me with a slight drop between the cogs, top and bottom. Anyone experiencing that? I am not really experiencing the chain suck issue.

Has anyone changed their chain yet and what have people used and found a good replacement and what number of links have people used?

I push some heavily and tech climbs.

Thank all.

Is the derailleur clutch engaged as this helps tension the chain?

 

[All4Fun]

The clutch does not affect the tension, it dampens the movement of the cage, it is a kind of band brake.
The spring behind that pivot point provides the tension, sometimes there is a second hole to hook the spring in to develop more tension.
It may be the case that if the coupling does not work properly, the spring is counteracted and the cage is therefore not pressed against the end stop.
Hence check without chain and clutch on and off.

 

[JC1982]

Thank you both,

From what I can see the derailer tension is ok.

Can I just check what length chain people have on there allmtn 7, mine is currently 126 links.

 

[All4Fun]

I check the chain length in the following Shimano way: in case of a fully release the pressure of the damper and find the point where the distance crankshaft-rear axle is greatest, then the chain from the largest chainring at the front to the largest at the rear and that outside the derailleur, determine the length and add 2 links.

Btw, i checked mine 122 links, 38-42 tooth, chainstay 470 mm.
If i'm right yours has 38-51, chainstay 460 mm.
Quick calculation: 51 - 42 is 9, that makes 4.5 links, chainstay 10 mm, upper and lower makes 20 mm.
4.5 x 12.5 = 56.25 - 20 = 36.25 / 12.5 = 2.9, that makes 4 links, so 126 could be right.

Another thing, is the B-tension right, does the cage catch the chainstay?

 

[All4Fun]

I check the chain length in the following Shimano way: in case of a fully release the pressure of the damper and find the point where the distance crankshaft-rear axle is greatest, then the chain from the largest chainring at the front to the largest at the rear and that outside the derailleur, determine the length and add 2 links.

Btw, i checked mine 122 links, 38-42 tooth, chainstay 470 mm.
If i'm right yours has 38-51, chainstay 460 mm.
Quick calculation: 51 - 42 is 9, that makes 4.5 links, chainstay 10 mm, upper and lower makes 20 mm.
4.5 x 12.5 = 56.25 - 20 = 36.25 / 12.5 = 2.9, that makes 4 links, so 126 could be right.

Another thing, is the B-tension right, does the cage catch the chainstay?

Owwwwwww........

Big mistake, the standard Sram was 11-42, i'm running a XT 11-46 now.

So, new quick calculation:
51 - 46 is 5, that makes 2.5 links, chainstay 10 mm, upper and lower makes 20 mm.
2.5 x 12.7 = 31.75 - 20 = 11.75 / 12.7 = .95, that makes 2 links, so 126 could be 2 links too long.

 

[JC1982]

Thanks I am starting to think the chain is too long at 126.

Its is riding OK but will occasionally not change gear requiring me to shift twice. Could thay be attributed to the chain length. As I have check the cable tension and indexing, plus had it serviced and it still does it.

 

[All4Fun]

Did you finetune the cable tension while riding, it may be that the outer cable cannot move freely in the frame and is therefore "pulled longer" by compressing the rear suspension.
I had a bike that ghost-shifted on strong compression, made some changes to the cable routing and it was over.

Chain length will not be the problem in this case I suspect.