Suntour and Shimano playing nicely?

[KneesUp]

My MTB is secondhand, and quite old. The groupset is mainly Suntour XCT -I suppose it was roughly the equivalent of Deore at the time.

It works fairly well but I cannot get the gears to index correctly. For some gears is switches fine, but for others it's a bit of a clunk. Some times one 'click' up gets nothing, but two gets two gears up, so to go one gear up you have to go two up and then one down.

I've only had the briefest fiddle to get it right if I'm honest, but I think the issue may be that the freewheel (that's right, freewheel baby - none of this cassette nonsense) is spaced for Shimano (because it's a replacement, and where are you gonna get a Suntour spaced freewheel from?) and thus it will never quite work. If it wasn't for the potential spacing issue I'd put it down to lack of adjustment and sticky cables.

Just wondering if anyone has any experience of this? I have the original back wheel in the shed (just remembered as I'm typing this - came with the bike but has a few broken spokes) so I might see what the freewheel on that is.

 

[RebornBumbler]

I'd imagine the Suntour and Shimano freewheel sprocket-spacing is identical.
From the description, I reckon the derailleur and perhaps shifter need a good clean and lubricate - same with the cable, but personally I'd just replace it.
Then just make sure the limit screws are OK, tweak the cable barrel adjusters until it's quiet, and it's hopefully fine.

If not, your derailleur may be knackered, or mounting bracket bent.

 

[RecordAceFromNew]

I agree with RebornBumbler. In any case you can check both sprocket spacing and cable pull per click from info provided here.

 

[Mr Celine]

I recently scrapped a Raleigh Pioneer due to a seized seat post and cracked seat tube. It had Suntour XCT but had a 7 speed suntour cassette rather than a freewheel. The cassette was not compatible with Shimano due to the spline pattern being different, though I don't know about the spacing between sprockets. The indexing was never very good and even when properly adjusted the shifting was never as quick as newer systems, probably because all the sprockets were plain with no dropped teeth or ramps.

 

[KneesUp]

I recently scrapped a Raleigh Pioneer due to a seized seat post and cracked seat tube. It had Suntour XCT but had a 7 speed suntour cassette rather than a freewheel. The cassette was not compatible with Shimano due to the spline pattern being different, though I don't know about the spacing between sprockets. The indexing was never very good and even when properly adjusted the shifting was never as quick as newer systems, probably because all the sprockets were plain with no dropped teeth or ramps.

Not sure if it was originally a cassette or freewheel - the wheel that is on it is definitely a cassette. The last bike I rode regularly was a road bike with Shimano Exage downtube shifters that I used to use in friction mode, so when it works it seems quite snappy to me. I think it's best if I don't ride a new bike - could get expensive quickly!

Out of interest, did you keep the XCT crankset, and if so, would you be interested in selling it (assuming it's in good condition?)

 

[Mr Celine]

Not sure if it was originally a cassette or freewheel - the wheel that is on it is definitely a cassette. The last bike I rode regularly was a road bike with Shimano Exage downtube shifters that I used to use in friction mode, so when it works it seems quite snappy to me. I think it's best if I don't ride a new bike - could get expensive quickly!

Out of interest, did you keep the XCT crankset, and if so, would you be interested in selling it (assuming it's in good condition?)

I only kept the cranks and they aren't in good condition. The chainrings were done. It was a 48 38 28 triple with the big ring being round and the other two rings being oval, which I never liked anyway.

The cranks are square tapered so not suntour specific, any other square taper cranks would fit.