I noticed something about my 3spd wheel and chain and all that. When pedaling the chain gets real tight, then real loose. Usuall that means there is a wobble somewhere, like the sprocket isn't lined up right? I would assume that the culprit would be the crank and sprocket. Any ideas?
So uhhh has anyone else experienced this?
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i've had a few old bikes that due to wear etc the hole in the sprocket is a little larger than it should be. if your not careful to center the sprocket, you run into the problem you got.
now this usually isn't the case. most main sprockets are press fit. wheres no room for error, but i have ran into the exception that bolts on. the rear sprocket could be worn.
now if the main sprocket has recieved an impact and is no longer circular, same problem.
a loose rear drop out (specially those presss fit tack welded type) or a loose rear wheel nut would do the same.
a loose rear hub (ie bearings) will do the same. (see if you rear wheel wobbles from side to side
and the worst of the worst. bent crank
now this usually isn't the case. most main sprockets are press fit. wheres no room for error, but i have ran into the exception that bolts on. the rear sprocket could be worn.
now if the main sprocket has recieved an impact and is no longer circular, same problem.
a loose rear drop out (specially those presss fit tack welded type) or a loose rear wheel nut would do the same.
a loose rear hub (ie bearings) will do the same. (see if you rear wheel wobbles from side to side
and the worst of the worst. bent crank
icyuod2 said:
Yeah I feel a wobble in my wheel. When I jam it down into 3rd I definitely feel it and also a little in 1st. So this thing will need some bearings huh? Makes sense since this thing was sitting outside for who know how long. It's a shimano 3spd hub, but that is all I know.
I've done some research on the hub, and I might have one of those Shimano 333 hubs. If that's the case, according to Sheldon Brown, once they go bad, it's better to scrap them. I'll need to check closer once I get home.
depending on his riding technique, leaning from side to side would tighen then loosen the chain, all in one rotation(as he leans from one side to the other.)
it could be as simple as tightening your hub. sometimes with old threads, when ya tighten the hub it free's up the other side. ya might need 2 wrenches to tighten one side of the hub (holding the bolts on both sides of one rear drop out)
try this, loosen both rear bolts (hub) then tighten the inner rear bolts (not too tight or the wheel won't turn, especially if the bearings are bad)
when you tighen the outer bolts, keep an eye on your axle/inner bolts to see if there moving.
then ajust accordingly.
sometimes if the threads are bad, the axle with have a mind of its own. if the nut jams up it can turns the axle out of the other 3 nuts.
i know it sounds a little nuts, but it happens.
it could be as simple as tightening your hub. sometimes with old threads, when ya tighten the hub it free's up the other side. ya might need 2 wrenches to tighten one side of the hub (holding the bolts on both sides of one rear drop out)
try this, loosen both rear bolts (hub) then tighten the inner rear bolts (not too tight or the wheel won't turn, especially if the bearings are bad)
when you tighen the outer bolts, keep an eye on your axle/inner bolts to see if there moving.
then ajust accordingly.
sometimes if the threads are bad, the axle with have a mind of its own. if the nut jams up it can turns the axle out of the other 3 nuts.
i know it sounds a little nuts, but it happens.
CCR
Mouth-Breather
i recently redid an old english style bike for a friend, stripped it down and painted it, reassembled and i thought id adjusted the chain slack but it was too tight when i went to put the chainguard back on, turns out the crank sprocket was "egged" ... some 70s polish bike with cottered crank and pressed on sprocket. may be the wheel if you notice knocking or play from side to side in the rear wheel, but if its the chain getting tight and loose and tight and loose its the sprocket.
one other thing was if you forced the crank through the tight spot it was enough force to pull the rear wheel forward in the dropouts and then the chain would slip of the sprockets when it loosened up again.
one other thing was if you forced the crank through the tight spot it was enough force to pull the rear wheel forward in the dropouts and then the chain would slip of the sprockets when it loosened up again.
what he said ^^^^
you could have a stretched area of chain.
that being said, if your rear hub is rattleing around on the axle like ya said the rear sprocket is def. moving. we tend to lean our weight when we peddle. this will actually move a loose hubbed wheel from one side to the other,which inturn moves the sprockets closer and further apart.
the same holds true with bad crank bearings. (does the crank wiggle?)
even 1/16 of an inch slop at the axle will transfer to 1/4to 1/2" movement at the sprocket
it is quite possible you have a few of these issues all working together.
the list goes on and on though, a few missing/worn/incorrect sized bearings will set a crank/hub crooked.
you could have a stretched area of chain.
that being said, if your rear hub is rattleing around on the axle like ya said the rear sprocket is def. moving. we tend to lean our weight when we peddle. this will actually move a loose hubbed wheel from one side to the other,which inturn moves the sprockets closer and further apart.
the same holds true with bad crank bearings. (does the crank wiggle?)
even 1/16 of an inch slop at the axle will transfer to 1/4to 1/2" movement at the sprocket
it is quite possible you have a few of these issues all working together.
the list goes on and on though, a few missing/worn/incorrect sized bearings will set a crank/hub crooked.
