[Hudnut]

I was banging my head trying to get the shifting dialed on my Eagle setup. the hangar was true, the housing was fresh, and almost everything was adjusted correctly. The problem turned out to be that the B gap was not correct. Sram makes a handy tool to set the distance but you can also set it by measuring 14mm between the cog and pulley in the highest gear. I found it difficult to do this with calipers or a measuring tape because you have to contend with the chain, wheels, frame, etc. the trick I found was a simple wooden carpenter pencil. the width measured exactly 14mm and can be fit through the wheel to take the measurement. If the pencil is bigger than 14mm you can just shave it down to the correct width.

 

[subyrally]

interesting, I will have to try that next time I mess with an eagle drivetrain.

 

[Hudnut]

In practice

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[chadbrochills]

Don't forget to measure B gap at SAG. So you either need someone to check it while you're on the bike or compress the suspension enough to hit close to your SAG and then check it.

 

[Hudnut]

Don't forget to measure B gap at SAG. So you either need someone to check it while you're on the bike or compress the suspension enough to hit close to your SAG and then check it.

Good point. My initial measurements were at sag but it was the same unloaded on my bike. Others may vary

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[Lone Rager]

I use SRAM's red plastic B gap tool.

 

[Forest Rider]

OP posted a red pencil first, then a green pencil in operation.

Is the red pencil a better one?

 

[Miker J]

Good tip as I've always got a few of those pencils laying around in the shop and tool box.

We all know that red bikes are faster than green bikes, but then why does red mean stop...

 

[Hudnut]

OP posted a red pencil first, then a green pencil in operation.

Is the red pencil a better one?

As you may notice, my bike is also green. Always coordinate tools with bike color. You don't want to have a fashion fau pax

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[angelo]

Good tip as I've always got a few of those pencils laying around in the shop and tool box.

We all know that red bikes are faster than green bikes, but then why does red mean stop...

Green=go
Yellow=speed up
Red=keep going

 

[farfromovin]

This will work for AXS as well, but it has to be a purple pencil and they are NOT the same size as red pencils.

 

[BujiBiker]

I tried this tonight as my middle gears were slow to shift down the cassette. It worked! The only problem I see is that I had to back the screw out enough to see the blue loc tite sticking out about 1/8”.

Would a longer screw be ok? Or don’t worry about it. I don’t have b gap tool.

 

[Hudnut]

Ya it's fine. As long as the screw has threads it in knuckle it's not going anywhere

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[BujiBiker]

Thanks! It cleaned up the shifting quite a bit. I have eagle nx. It shifts slow but much more precise now.

On the other hand I did notice the chain would sometimes start to peel off the 50 tooth ring if I backpedaled in the stand. Never did that before. Doesn’t do it riding either.

 

[mfa81]

http://instagr.am/p/B6eHbDgH5D4/
this works for me and shifting is as good as it gets! no need to tools or measurements!

 

[Lone Rager]

The upper pulley needs to be enough below the cog so that when shifting to the next larger cog, the chain and pulley doesn't get jammed into it. The optimal distance depends on the size of the jumps between adjacent cogs. On typical road cassettes a number of years ago, 6mm was sufficient. Current wider range cassettes, particularly 1x mtb cassettes, need a larger gap...like 16-17mm.