REAR WHEEL - IS IT POSSIBLE to MOVE SPROCKET?

[ANLAF]

Fellers

I have a 140 rear tyre. The chain runs near to the tyre wall. Is it possible to move the rear wheel sprocket by, for instance, removing the six retaining nuts, removing the sprocket, putting some form of spacer(s) between the hub, and replacing the sprocket and (longer) bolts?

I imagine it is possible, but what is the consequence of changing the angle of the chain from rear sprocket to engine spocket? My chain is longer to accommodate the hardtail, so if I can do it what size spacer can I get away with without compromising metal and flesh?

ANLAF

 

[weaselbeak]

You can do this if you can space the front sprocket out as well. They just need to line up well..

 

[jd750ace]

Ideally you would space both sprockets the same to keep the direct run of the chain. Mis alignment can cause rapid wear of the chain, sprockets, and your output shaft seal. Spacing them is not a huge deal, but the sprocket bolts are a very unique thread pitch for the size of the bolt. Finding longer ones would be a challenge I would think.

 

[5twins]

Actually, they're not that hard to come by. I was able to get a 10 pack of 5mm longer ones from McMaster-Carr. M10 are available in 3 thread pitches. There is the normal (considered "coarse") 1.5 thread pitch, a fine 1.25 pitch, and a really fine 1.00 pitch. I think these were the really fine ones but don't hold me to that. Check the bolts with a thread gauge.

My advice would be to put the proper size tire on.

 

[DIRTY DOG]

I run a 150/80/16 on my hardtail and still have about 1/4" of clearance a 140 should fit
with out too much problems

 

[ANLAF]

Thanks fellers

I got the bolts (6) anyway as the wheel had one missing. That's how it came, and I wouldn't run a bike unless I'd gone over everything myself and checked all the bolts and nuts and washers were there and correctly tensioned.

Weaselbeak and jd750ace, yes, I had better not just think of spacing the rear without adjusting the drive sprocket, too.

5twins, I just happen to have been given this new 140 tyre so I will give it a try. And if Dirtydog runs a 150, wow! then there should be plenty of room.

Dirtydog, do you have a chain tensioner on your bike? I imagine that would go a long way to prevent the chain going near the tyre wall or 'slapping' it.

ANLAF

 

[DIRTY DOG]

Thanks fellers

I got the bolts (6) anyway as the wheel had one missing. That's how it came, and I wouldn't run a bike unless I'd gone over everything myself and checked all the bolts and nuts and washers were there and correctly tensioned.

Weaselbeak and jd750ace, yes, I had better not just think of spacing the rear without adjusting the drive sprocket, too.

5twins, I just happen to have been given this new 140 tyre so I will give it a try. And if Dirtydog runs a 150, wow! then there should be plenty of room.

Dirtydog, do you have a chain tensioner on your bike? I imagine that would go a long way to prevent the chain going near the tyre wall or 'slapping' it.

ANLAF

ya I run a tensioner but it's to slow down the the chain flopping up and down and eating the rear fender more than the hitting the tire there is about a 1/4 -3/8 of an inch
betweenthe tire and chain ( I run a 17-31 with a 110 link(I think) 530 chain )

 

[FrkyMnky]

Keep in mind, when running your tire will actually get narrower. So while the chain is flopping around without a chain tensioner and it looks bad when you think about the tiny gap you have while sitting, the gap is actually a bit larger.

 

[XSLeo]

I ran a 140 tire for awhile, it hit the chain some. If you look at the edge of the tire you will see that it comes to an edge that sticks out past the side wall by quite a bit. It does this to give a maximum lean angle and help prevent tire damage if it rubs up against a curb or some such.
I put my bike up on the center stand and with the bike running and in gear I used my 4 inch angle grinder to grind off a bit of this edge. About an 1/8 inch off both sides.
Leo

 

[ANLAF]

Thanks Dirty Dog and FRKY.

XSLeo I admire your tyre re-modelling techniques. I got a new Continental rear wheel with a big 'lean-over' lip. The nice chap at the tyre place swapped it for a Bridgestone with no lip. Phew, I can put away the grinder.

ANLAF

 

[jamesgs4]

if you go to a 520 chain you will gain some clearance

 

[ANLAF]

Thanks, jamesgs4, but now you're talking technical - the pitch of both the 520 and 530 is 5/8 (the pitch is the distance from centre of one pin in any of the 8-shaped plates to the centre of its neighbour in the same plate), BUT the width of the 520 is 1/4 (the width is measured at the narrowest gap between two outside plates) and the 530 is much larger (relatively) at 3/8. The important factor is that the chain should have some side play. The 530 fits the sprocket with that side play. True the 520 will fit on the sprocket, but yikes, without that side to side room.

Have you seen a 520 on the XS650 sprocket up close, James? Interesting to know.

ANLAF

 

[jamesgs4]

I meant a 520 conversion, sorry. I did the 520 conversion a few years ago and I have plenty of room now.

 

[ANLAF]

Thanks jamesgs4, I got yer!

ANLAF