Slightly crunchy drivetrain mystery
Discussion
I keep my drivetrain clean and well adjusted but still I get what I can only describe as a slightly 'crunchy' feeling on a semi-regular basis. It comes and goes apparently at random, just started doing it again the other week, has persisted after fitting new chain and cassette about a week ago.
There is no accompanying noise, it is felt through the pedals rather than heard. Gears are indexed and shift smoothly, derailleur stops adjusted. Crunch is worst in lower gears (biggest sprockets on the cassette). Chain ring (single) is not brand new but only a few months old and not really worn. Cleaning seems to make it worse if anything;)
In a week or two more it will probably go away of its own accord if history is anything to go by. But I would rather not wait for that - I like a smooth pedalling bike and it is starting to get quite annoying...
There is no accompanying noise, it is felt through the pedals rather than heard. Gears are indexed and shift smoothly, derailleur stops adjusted. Crunch is worst in lower gears (biggest sprockets on the cassette). Chain ring (single) is not brand new but only a few months old and not really worn. Cleaning seems to make it worse if anything;)
In a week or two more it will probably go away of its own accord if history is anything to go by. But I would rather not wait for that - I like a smooth pedalling bike and it is starting to get quite annoying...
The pedals may feel ok when spun by hand. With leg force on them things might be different. Can you borrow a set to swop & try? Otherwise strip them and knock out the bearings, check the bearing surfaces for wear. You feel this through your feet, start with the parts nearest them and work back.
Somewhat inconclusive update on this for anyone who might be interested.
Stripped, regreased and adjusted both pedals and rear hub. Small improvement and the worst crunchiness is now in the higher rather than lower gears which may be preferable;)
One thing that has impressed me is the quality of the hubs, which are Shimano and really supposed to be for MTBs. They maybe a bit on the heavy side but they are very well sealed. Pristine when I opened up the rear one although it is 7yrs old and it's 2yrs since I last serviced it.
Ridden year round in all weather. So long as I keep the cones well adjusted i think they will last forever!
Stripped, regreased and adjusted both pedals and rear hub. Small improvement and the worst crunchiness is now in the higher rather than lower gears which may be preferable;)
One thing that has impressed me is the quality of the hubs, which are Shimano and really supposed to be for MTBs. They maybe a bit on the heavy side but they are very well sealed. Pristine when I opened up the rear one although it is 7yrs old and it's 2yrs since I last serviced it.
Ridden year round in all weather. So long as I keep the cones well adjusted i think they will last forever!
It could be derailleur hanger alignment ? -- most decent bike shops will have the right tool to check and align this for you
https://www.parktool.com/blog/repair-help/rear-der...
https://www.parktool.com/blog/repair-help/rear-der...
upsidedownmark said:
Recently traced my driveline issues to an exceedingly worn (prematurely so) jockey wheel on the RD, which the chain was no longer following properly. Not something I've seen even in many years of riding, so unlikely, but maybe worth a check.
I have some spare jockey wheels so will give that a whirl, tks. Also checked alignment but only with a straight edge by eye. Might drop by LBS and ask them to pop it on the gauge.
Its a bit of a poser. Albeit only a minor thing but I do like a smooth drivechain so it grates, literally and metaphorically!
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