Chains and sprockets, whats the rules for replacement?

[nzspokes]

How do I check wear of both and when to replace?

[MSTRS:Me]

There's no real rule of thumb, but there are several ways to get a guide...
If you can pull the chain out from the rear sprocket far enough to almost clear the teeth - it's fucked.
If the chain has (extreme) tight spots and/or causes a regular 'thump' to be felt when riding - it's fucked.
If you can see sprocket teeth that are deformed on one side or are 'bending over' - they're fucked.
Generally, it is good practice to replace the lot together.

[jaffaonajappa]

nzspokes - mate are you checking the chains sag/tightness whilst sitting on the bike?

[nzspokes]

nzspokes - mate are you checking the chains sag/tightness whilst sitting on the bike?

No, is that the correct way to check it?

Asking because I dont know. My chain looks worn but not sure.

[jaffaonajappa]

No, is that the correct way to check it?

Asking because I dont know. My chain looks worn but not sure.

yeah man - reasonably common rule of thumb. 2 to 3 cm slackness whilst sitting on it.....ie rear end slightly compressed - which usually has the back wheel at its furtherest point.

[nzspokes]

yeah man - reasonably common rule of thumb. 2 to 3 cm slackness whilst sitting on it.....ie rear end slightly compressed - which usually has the back wheel at its furtherest point.

Cool, thanks for that.

Now if I want to lower the gearing, any reason I cant? CBXs seem to be very overgeared. Reviews also say this. Any rules for it?

[MSTRS:Me]

Now if I want to lower the gearing, any reason I cant? CBXs seem to be very overgeared. Reviews also say this. Any rules for it?

If you can get bigger/smaller sprockets - then yes.
Rule of thumb - 1 tooth less on front = 3 teeth bigger on rear (for gearing down purposes).
Usually best to go for a bigger rear sprocket, but note that you will need a chain with more links.

[nzspokes]

If you can get bigger/smaller sprockets - then yes.
Rule of thumb - 1 tooth less on front = 3 teeth bigger on rear (for gearing down purposes).
Usually best to go for a bigger rear sprocket, but note that you will need a chain with more links.

Cheers. I will ride it for a bit once ive got my licence then work out how much I want to change it. May as well do it once Ive got to change chain and sprockets.

[Flip]

There's no real rule of thumb, but there are several ways to get a guide...
If you can pull the chain out from the rear sprocket far enough to almost clear the teeth - it's fucked.
If the chain has (extreme) tight spots and/or causes a regular 'thump' to be felt when riding - it's fucked.
If you can see sprocket teeth that are deformed on one side or are 'bending over' - they're fucked.
Generally, it is good practice to replace the lot together.

There are some very good and easy to measure wear limits on chains. The chain makers will list out a maximum elongation measurement for any given chain. Simply get this measurement and it usually refers to 10 or 20 links and measure the length of the number of links with a ruler. Its OED.

Tight spots can be a pain in the ass, they are actually loose spots in reality. So check the chain in several places.

If the sprockets look worn and the teeth are worn on one side it time for new ones. The front sprocket usually goes first because it is smaller and spins faster. It is best for the chain if you put a new chain on an un-worn sprockets, however its only a good engineering practice thing to do not really a super critical necessity.

[MSTRS:Me]

There are some very good and easy to measure wear limits on chains. The chain makers will list out a maximum elongation measurement for any given chain. Simply get this measurement and it usually refers to 10 or 20 links and measure the length of the number of links with a ruler. Its OED.
Need to remove the chain, and measure on a flat surface, which can be a chore...
Tight spots can be a pain in the ass, they are actually loose spots in reality. So check the chain in several places.
Too right.
If the sprockets look worn and the teeth are worn on one side it time for new ones. The front sprocket usually goes first because it is smaller and spins faster. It is best for the chain if you put a new chain on an un-worn sprockets, however its only a good engineering practice thing to do not really a super critical necessity.
It is 'super critical' if you want your chain/sprockets to last the maximum mileage. They wear together, and putting a new one with a worn one (either way round) - the worn part simply accelerates the wear on the new part to try to mesh properly.

[Corse1]

There are some very good and easy to measure wear limits on chains. The chain makers will list out a maximum elongation measurement for any given chain. Simply get this measurement and it usually refers to 10 or 20 links and measure the length of the number of links with a ruler. Its OED.
Need to remove the chain, and measure on a flat surface, which can be a chore...
Tight spots can be a pain in the ass, they are actually loose spots in reality. So check the chain in several places.Too right. both my bikes manuals have a measurement of approx 202mm for 11 links I think that can be measured along the bottom run in situ when the chain has been adjusted tight.

If the sprockets look worn and the teeth are worn on one side it time for new ones. The front sprocket usually goes first because it is smaller and spins faster. It is best for the chain if you put a new chain on an un-worn sprockets, however its only a good engineering practice thing to do not really a super critical necessity.
It is 'super critical' if you want your chain/sprockets to last the maximum mileage. They wear together, and putting a new one with a worn one (either way round) - the worn part simply accelerates the wear on the new part to try to mesh properly. Yep agree with that too. Should change altogether

Been looking at my chain condition recently. I think I am good to go for a little while yet

[Chancebmx25]

replace when they go shark teethed!