Chainline problem

EssexCyclist

Hi,

I have recently changed the rear wheel on my 2005 Specialized Allex Elite, due to budget constraints I opted for the shimano WH-R500 wheel (Tiagra) which I believed would be a suitable replacement. However since the change the chainline doesn't appear quite right. When riding on the inner chainring (42t - double) and the largest sprocket the chain catches the spokes, in other gears when watching the chain it appears to catch the sprocket teeth very slightly on one side. The bike itself rides OK, there is no skipping of gears and the indexing is all OK. I've checked chain wear etc and nothing is out of the ordinary, the bike hasn't done that many miles so I wouldn't expect it.

Am I missing something obvious :?:

At first I thought I may have needed a 1mm spacer between the hub body and the cassette but doing that meant I couldn't get the lock ring on, since checking on the shimano site I know this is not needed.

I'm doing the Essex tunner the weekend after next and would like it running smoothly as things like this bug me!

Any help greatly appreciated.

Thanks in advance

PS These are the specs, all components kept the same only the rear wheel/hub have been changed.

CASSETTE
Shimano 105, 9-speed, 12x25t
CHAIN
Shimano HG 73
CRANKSET
Shimano 105
CHAINRINGS
53Ax39A (double)
BOTTOM BRACKET
Shimano 105, Octalink spline, 68mm shell, 109.5mm spindle (double)

keef66

The chain hits the spokes?? :shock:

Is your inner chainring a 39 or 42? (you mention both)

Did you re-index the gears and adjust the limit screws on the rear mech when fitting the new wheel? Sounds like the new one is dished slightly differently from the original. Does the wheel rim sit centrally between the stays? I'd set up the rear mech from scratch, paying particular attention to the lower limit screw; you don't want the chain jamming between the cassette and the spokes or the mech going into your nice new wheel.

desweller

I have this problem when swapping from my PX Model B to my R500. The hub flange is a little closer to the freehub.

Easily solved by tweaking the bottom limit screw.

EssexCyclist

The chain brushes the spokes, not much but you can hear it providing the wind isn't blowing!

I did re-index the gears as a matter of course but haven't adjusted either limit screw.

The inner chainring is a 39, my apologies for the confusion there.

I guess I'll need to Google the limit screw adjustments as my knowledge there is a little sparse.

Thanks for your quick response, much appreciated.

EssexCyclist

Thanks Des, there's a theme forming here

desweller

The limit screws are very crude. There are a couple of lugs on the parallelogram mechanism, it's easy to figure out how it works if you examine it closely enough.

keef66

Please don't ride it until you've sorted it out! If my chain or rear mech was brushing the spokes I'd be off the bike like a shot. Once you've ripped a rear mech off a bike you don't ever want it to happen again. Just make sure you don't do it the wrong way, otherwise it sounds like you'll be guaranteed to put the rear mech into the spokes!