Fitting chain device

konadawg

Hasn't been a problem, but the chain does sometimes come off and for the price worth having a go:

http://superstar.tibolts.co.uk/product_ ... cts_id=336

Now I have some difficulty with this:

The ISCG (old) type (which, based on research only as yet is the one for a Giant Reign X) is advertised as also being BB mount.

Take it to mean that you take off the external BB and remove one of the spacers, replacing the spacer thickness with the backplate of the device.

Question - would this also mean that the dia of the hole in the middle is small enough that BB mount is inevitably mandatory with external BBs and securing via the tabs is just an extra?

Or am I missing something?

thel33ter

konadawg wrote:

Take it to mean that you take off the external BB and remove one of the spacers, replacing the spacer thickness with the backplate of the device.

Said it yourself. They aren't under a huge amount of force, so don't have to be incredibly tight.

The ICSG 05 ones go right over the bb cups, and bolt into the frame.

*AJ*

If your frame has ISCG guides, then you can remove the BB mount bracket and the chain device will fit over the BB and bolt straight to the frame.

If you do need to use the BB mount then it doesn't replace one of the spacers, the bracket is chamfered so it fits over the BB shell on the frame. This allows the tabs to be in the same place as they would had the been welded to the frame.
The actual ISCG adapter plate that sandwiches between the BB cup and shell isn't the same width as a spacer (2.5mm) it's actually only about 1mm so the same amount of spacers will have to be used as you are using now, otherwise the cranks rub on the back plate of the device.

konadawg

Thanks, so the "also" (as in BB mount) is not really an option with ISCG old combined with an external BB, it is fact, and if you wish, you could also use the bolts to secure the backplate to the tabs, making the ISCG the "also" option.

If that is clear...!!

*AJ*

If you have ISCG mounts you only use them, not the BB mount adaptor.

konadawg

*AJ* wrote:

If your frame has ISCG guides, then you can remove the BB mount bracket and the chain device will fit over the BB and bolt straight to the frame.

If you do need to use the BB mount then it doesn't replace one of the spacers, the bracket is chamfered so it fits over the BB shell on the frame. This allows the tabs to be in the same place as they would had the been welded to the frame.
The actual ISCG adapter plate that sandwiches between the BB cup and shell isn't the same width as a spacer (2.5mm) it's actually only about 1mm so the same amount of spacers will have to be used as you are using now, otherwise the cranks rub on the back plate of the device.

Regret not getting much of this - my bad or yours ?

Bike has ISCG tabs but what bb mount bracket do you refer to, or adapter plate?

The chain device is as per the link in the OP.

*AJ*

The BB mount that superstar refer too is a bolt on addition just for those of us that don't have ISCG tabs.

konadawg

*AJ* wrote:

The BB mount that superstar refer too is a bolt on addition just for those of us that don't have ISCG tabs.

I don't see any 'additions' - have you actually seen the pic in the link?

What I am trying to get at - a confirmation that you can't NOT bb mount.

*AJ*

Ahhh sorry, this is the dual ring device? I forgot they made that one... Ignore everything I've said above, yes you have to BB mount it, and yes you remove one spacer to accommodate it. The bolt to your ISCG mounts to stop it rotating.

Apologies for the above, I went off on a tangent because I've just fitted there laser chain device on my bike and it took a bit of trial and error.

konadawg

Thanks mate, I like to understand things before I commit to them.