Shimano 10 speed gear set up

[Deleted member 23692]

I hope someone can shed some light on this as it's driving me mad.

I recently bought a 2nd hand Cube LTD that had approx 3 months light use and then was left in a shed for a couple of years until I bought it a month ago. As such it's in excellent condition but a bit dry and crusty. I've been slowly cleaning, fettling and replacing bits as needed and it's all there apart from setting up the gears.

The high and low limits are set perfectly, as is the B tension. However when I take all the slack out of the cable but just pulling by hand (no pliers or 3rd hand's used) before snugging up the cable clamp bolt it changes up 2 sprockets with the 1st click of the shifter and then one sprocket per click after that.

The only way it will move from the 1st to 2nd sprocket is if I deliberately introduce quite a bit of slack in the cable when on the small sprocket. With the slacker cable it changes through all the gears perfectly.

It's running XT mechs and chain with SLX cassette and shifters, which is a compatible setup according to Shimano Tech Docs. I've replaced all cables (inner and outer), the mech hanger and inner plate of the mech cage as it was tad bent.

My previous bike was also an LTD, but a 9 speed version and that worked perfectly without this 'excessive' amount of slack as does my 9 speed road bike, as has every other bike I've owned or worked on.

So the question is.. is this slack cable a characteristic of 10 speeds or is there some problem I've overlooked?

 

[Kbrook]

When its on the small sprocket there is a little slack as the cable is de tensioned. You say that when its slack it changes perfectly, so there's your answer, turn the barrel adjuster clockwise to make it slacker, anti clockwise to tension it. My 10 speed is certainly not tight when on the small sprocket.

 

[oliglynn]

sounds like it's indexing is out by one sprocket - i.e. your high limit sets the position on the smallest sprocket, but you have tensioned up the cable (by barrel adjusters) by about 1 sprocket witdth.

To fix this, shift in onto the third sprocket (using one shift), and then loosen barrel adjuster until it's comfortably on the second sprocket. It should now index properly, but could require a little fine adjustment. A bit of slack is not a problem when on the 1st sprocket.

 

[Deleted member 23692]

[QUOTE="oliglynn, post: 3251070, member: 7697"To fix this, shift in onto the third sprocket (using one shift), and then loosen barrel adjuster until it's comfortably on the second sprocket. It should now index properly, but could require a little fine adjustment. A bit of slack is not a problem when on the 1st sprocket.[/QUOTE]That's what I ended up doing, but to do so (and to get all the gears indexing properly) I need to slacken the cable by approx 4 full turns at the barrel adjuster - this means the cable is that slack I can pull it about 30mm from the cross bar without the rear mech moving.

Granted the shifter takes in the slack to move up one sprocket from top gear, and then all subsequent gears work OK, but it'd just the amount of slack that concerns me. If that's the norm then so be it but it does seem a little excessive.

 

[oliglynn]

not too au fait with xt shifters. That does sound a little slack though, so understand your concern. Don't really want cables slapping about when out on the bike.

Another thought- sounds like excessive movement in the indexing between 1st and second sprockets. Perhaps it'd be worth opening up the shifter and checking that the anchor on the end of the cable is seated properly in the indexing barrel, or if there's any damage in there causing it to move too far when on the first sprocket (cable slack). Look at what happens in there when changing gear.

 

[Deleted member 23692]

I've stripped the shifter into many parts, inspected, cleaned and reassembled it. It's a fascinating piece of machinery, but also I couldn't see any worn/bent/broken bits. I'm happy the shifters and mech and cabling are all in good fettle.

I've treated myself to a mech alignment tool and found the new one to be quite a bit out - around 4 inches across the rim between 3 and 9 o'clock. So with that tweaked and the indexing reset from a fresh, the slack in the centre of the top tube is down to 15mm, which I can live with. Oddly it looks worse than it did before but it is deffo dead perpendicular to the axle now.

On a couple of forums I've read that 10speeds do need to run with more a slack that 9's to ensure that in top the mech is on the limit screw and not held in place by the cable.. which seems to be the case. However I can't find any' official' word on the subject.

Thanks for you help anyhoo