I have just bought new SLX M660 10 speed shifters but I am having a devil of a job finding the right end caps on my cable housing that fit snug in to the barrel adjuster. i have some housing and caps but they seem too thin (end cap appears to be about 5mm) so i found a slightly bigger end cap which is too big (end cap is 6mm). What the heck is going on? Can anyone tell me catergorically what size I need?

Are you sure you have GEAR cables and end caps and not BRAKE parts?

Definately gear cables it has the wire core in there. It just cant seem to find an end cap that fits the barrel adjuster its either too loose or too big, so annoying. Even had some old XT cable housing and end cap and that was too small.

Does it actually matter if they are a little loose? The cable tension will stop them coming out.

I can’t even remember if mine are tight loose or snug tbh.

Looking at the Shimano tech docs, they look pretty standard to me
http://www.shimanoservicecentre.co.uk/SSC/shimano_parts/Shift%20Lever/SL-R660.pdf

That link does seem to work. Does it say what width the barrel adjuster is?
Its not just a little loose though and the caps dont fit too well in the stops either so they have a tendency to rattle and jiggle about and its very annoying. I think i may just put a bit of black insulation tape round them just to fatten them up.

Do the caps fit the cables? If so than I can’t see the problem. The rattling reason doesn’t wash with me as I said it will all be tight when the inner is fitted. I’m as OCD as the next person but surely you woon’t notice two small movements in the cables when riding off road? Also if they were tight the barrel adjusters wouldn’t rotate easily.

have you checked your other bikes, if you have any to see how tight they are? I can’t get down my garden at the moment to check, can anybody else see how snug theirs are.

I dont have another bike to check as they were stolen! This is a new build. The caps fit the housing fine but they really arent a good fit in the barrel adjuster or all the mounts on the frame. I know what you mean about the tension keeping them in place but i would like at least a decent fit rather than slopping about in there.

Off to the LBS tomorrow to pick up something else so taking shifter with me in the hope that they tell me I have gone mad or doing something wrong! It doesnt seem right but like you said it doesnt affect anything so not much to worry about to be fair.

The housings fit loosely so that the outers don’t twist when using the adjusters to take up cable slack – don’t worry about it!

Bad news on the stolen bikes, sorry if I rubbed salt in the wounds.

Thinking back I seem to recall the cables falling out of the shifters rather easily.

It’s obviously something that is worrying you and as your off to the LBS tomorrow anyway you may as well ask. Won’t do any harm.