Double Chain Device alignment issues

[chimp007_uk]

Unfortunately Ive turned to the darkside of modern biking, after selling my 99 GT XCR STS... :cry:

I've got a 2010 Trek Remedy 8, and converting it from a 22,32,44T triple to a 22,32T double. I've fitted an E13 bashring and a DMR chain device. However I'm having some issues with alignment... I have a 73mm BB casing with XT cranks and a single 2.5mm spacer on the drive side as per.

The dmr chain device has replaced the drive side space, but then I'm left with this for alignment to the granny and middle ring...

I played with the BB spacing adding another 2.5mm spacer and ended up with this...

Obviously this isn't a good thing to do.

I'm stumped! All of this type of chain device is the same, a steel or ally plate with a roller at the end.

Anyone got any ideas?!

Cheers
Chris

 

[unkleGsif]

Take the roller off and turn it round?



G

 

[chimp007_uk]

The shoulder is bigger on the right to the left, so only makes it worse

 

[unkleGsif]

Surely with the roller turned round, so the smaller shoulder is more "inboard" (or to the left in the pictures, the chain will run straighter
(and I'm NOT calling you Shirley )

Does it run straight if the chain sits on the larger shoulder?




G

 

[chimp007_uk]

I can have a play, but the roller is designed to be that way so the decrease in chainring diamter is taken up in the roller.

If I have the chain on the granny ring, it rubs against the inner shoulder whilst on the larger part of the roller.

 

[gradeAfailure]

Would say that the chainrings need to be further out still - I've got a similar chain device on my Pitch with a double/bash so will take a pic tonight if I can.

 

[Mindmap3]

Does the frame have ISG tabs?

I always have issues with bb mounted chain devices on 73mm shells because here aren't enough spacers to much about with like with a 68mm shell.

Only thing I can think of is trying a Blacksmith Stinger because the don't have the step in the roller, so may be easier to set up.

 

[cyfa2809]

You have 73mm shell? You dont need any spacers. Yes how a bout a different device? Is the wheel in in the pictures?

 

[Mindmap3]

Are you desperate to run the chain device?

I never had any issues when I can a dual ring, even in the peaks.

The other (extreme) option is Race Face cranks because they come with axle spacers, allowing you to fiddle with the chain line and axle spacing.

Personally, I'd take the easy option and ditch the DMR chain device and run it like that.

 

[cyfa2809]

Is it iscg?