This is a quick sanity check.

I am fitting the Heim2 Chain Device to my Mojo and I just want to check a couple of things:

1. It is a 68mm BB shell on the Ibis, so before I was running 2 spacers on the drive side, now with the chain device on (BB Mount) I assmue this should now be one?

2. Therefore if question 1 is right – do I put the spacer on next to the BB shell or do I put the chain device to the BB shell? (If I look at the illustration below (fig 3) the chain looks like it has the right alignment when I put the spacer next to the BB shell)

3. It shows a 0.5mm washer next to the chain device (expansion on side of Fig 3) – do I put this in or will it throw my chainline out by 0.5mm?

Please just check my thoughts are right?? I had a bad accident once caused by a chain line being out (chain slipping) – so am slightly nervous about getting this wrong.

Thanks 🙂
Leon

It should just replace one of the spacers on the drive side – probably the one closest to the BB shell. That way the backplate is further away from the chainrings. As with any chaindevice, it will probably require a bit of of tinkering to get it perfect – make a cup of tea, put the radio on and try not to get too frustrated!

Yeah – thanks buddy. Patience never was one of my strong points. 👿

I started off by putting the chain device next the BB shell but then the chain ring looks like the right hand side (Bad side) of the illustration above. If I put the spacer next to the BB shell and then the chain device it looks like the left hand side (Good side) of the illustration? ❓

I’d say if it looks better, then go with it. As long as your granny ring bolts don’t rub against the backplate it should be ok.

it looks like the backing plate of the chain device is 2mm thick so they want you to fit a 0.5mm shim, which I am guessing is supplied with it, to maintain the 2.5mm spacing of one of the original spacers?

steezysix – Member

I’d say if it looks better, then go with it. As long as your granny ring bolts don’t rub against the backplate it should be ok.

Nothing rubbing and it seems to work ok.

andyl – Member

it looks like the backing plate of the chain device is 2mm thick so they want you to fit a 0.5mm shim, which I am guessing is supplied with it, to maintain the 2.5mm spacing of one of the original spacers?

I wondered if the plate was thinner? It looked about the same, but I suppose I wouldn’t see a 0.5mm difference with the naked eye.

Mmmm, I suppose I had better just ride it now and see if it behaves then??

put the plate on a flat surface with one of the original 2.5mm shims next to it. You will easily see 0.5mm as it’s quite a lot.

Its really very simple.

With a 68mm shell, 2 of the spacers on your BB are coverting it into a 73mm shell. The remaining spacer is for chain devices or etype front mechs. So your first thought that the chain device should be next to the BB is correct, or the chain device would not work for those of us with 73mm frames.

Since yours lines up fine like this then you dont need the extra 0.5mm spacers (note the * in the right hand picture, showing you only need it if your chain is not lining up.)

STATO – Member

So your first thought that the chain device should be next to the BB is correct, or the chain device would not work for those of us with 73mm frames.

Ah right! If you took one spacer away from a 73mm (i.e. leaving no spacers) to make it right, then that would be the same as removing one (i.e. leaving one spacer) to make it right. So, there is one spacer against the BB shell before the chain device – right?

I think I just made it very complicated in my head, as I have never had a 68mm BB before.

So, there is one spacer against the BB shell before the chain device – right?

Exactly.