Tyre replacement.....confused.

[lekyuk]

Hi,

I need a new rear tyre, I've settled on a like for like tyre as I'm not that sensitive to notice any difference in performance. But, what I can't quite understand is the mechanism for taking of the wheel and not re-tensioning the chain.

I asked my local bike shop if they checked chain tension when replacing the tyre and he said they and most garages just put back where it was.....but how is that possible? I can only assume when you take off the rear tyre you don't have to remove/release the things that position the wheel, is that right?

Ta,

Leky

[plumber02]

the axle just slides out without touching the adjustment simple job, but if they were any good they would check it anyway that's if it was a proper bike shop, that to me is just good business

[Joe Rocket]

I would not expect any bike dealer/garage to not check the chain tension/wheel alignment when putting the rear wheel back!

True, the wheel will just drop out when removing the axle but the whole rear wheel assembly has to be moved forward to drop the chain off, the spacers out and the rear sprocket carrier in order to get the wheel out. They can simply note the position of the alignment marks each side of the swing arm but as plumber02 says they aren't doing what they should do if they don't check it properly after re-assembly.

If you want to put their number up here I'd be happy to phone their workshop, along with others on these boards too, no doubt.

[Yoyo]

I would hope they would 'ask' if I'd like them to check the tension/alignment etc but I'm happy to check that kind of stuff myself as we all know how inaccurate those marks can be. 

[kwackboy]

When removing a rear wheel the chain adjusters are locked in position so the alignment will be the same when putting the wheel back in. The wheel spacers will only fit in their relevant sides, It's near impossible to get it wrong. Also, any decent tyre fitting shop will do this job for you . 

[Joe Rocket]

I must say I have never put a wheel back and relied on the adjusters locked in the previous position.

The chain is only correctly adjusted when the play is optimised and position of both adjusters are matched by small adjustments each side. That is done before the axle is bolted up and the adjusters are under tension when doing so. There is play between the adjusters, washers and axle but that is negated when all is pulled equally in the same controlled direction. That goes for whatever reason the wheel is removed; tyre, chain, brakes, bearings...........

You can put the axle back in and tighten it up on the locked adjusters (difficult in my opinion) but there is no cetrainty either side is correct, especially if the chain was too slack before, and if it was it will still be!

You can argue there's not much to worry about but quite honestly it's lazy and not good practice. The garage is your 'expert' when it comes to safety above all and it is only a couple of minutes to the well trained. 

[mrp192]

I am not a mechanic but if I adjust the chain on my Bandit I only use the swinging arm marks as a guide as mine are slightly out side for side.
I have a small cheap round LED torch which I lie on top of the top run of the chain just in front of the chain guard. It's just the right diameter to sit there between the side plates and not move side to side. I then look under the rear of the guard and the light shows you whether the chain is straight or not. Even if it's slightly out you can see the bend in the plates as the shadows are different.
I do this every week before checking the tension and the couple of times in my bikes life I've had to adjust it.
If the chain needs adjusting I find it easier to kneel behind the bike and push one knee against the tyre to keep it pushed tight against the adjusters, loosen the axle and then make the adjustment and retighten the axle  before releasing the pressure on the tyre.
I always then recheck both the tension and alignment as have found torquing the axle up can make it change.
Although my Bandit has not needed a lot of adjustment I've used this method since racing MX as a youngster where it would need doing two or three times a meeting.

[kwackboy]

The markings on chain adjusters are there to help you get your rear wheel alighned to the point where the wheel is pretty much straight, unless you're adjusters are buggered, that's good enough in my opinion. Now if people need to go to the extreme of meticulously measuring the wheel so it's exact then that's down to personal choice but splitting hairs if you ask me also 9 out of 10 people wouldn't even notice if was out when they are riding anyway
Who's to say that the swing arm is exact..?  Ponder on that thought. 

[Joe Rocket]

I agree with you kwackboy, it is personal choice and most won't know if the wheel is slightly out of line. However on my bike I do like to know it is correctly adjusted for wheel alignment and chain play even if the swing arm may not be exact............ 

Just a couple of points which might help any rider; Haynes Manual is fine for simple things but it has no 'Haynes Hint' for re-using the locked adjusters' position when remounting the wheel and I have that voice in my ears saying "have you put the wheel back in straight?" or "did you tighten all the nuts properly?".....yes my pillion/wife!