New chain slippage

-liam-

Ok, done a search but can't really see an answer or the answer I want lol !

Spent the afternoon fitting a brand new rapid rise deore rear mech, a 9 speed xt cassette(was 8 speed), some deore shifers and a brand new sram pc971 chain.

All works perfectly, well almost except for that on the smallest cogs on the cassette I am getting the chain jumping. Now this isn't an issue as I can see that the mech is out of line at the bottom so I obviously need to adjust the stop position as it is jumping when under no pedal pressure(I know this cos I am still suffering with a foot injury so couldn't apply pedal pressure if I wanted to )

Actual question I have is, whether or not there is a possibility that the chain may need reducing in length as when on the smallest sprockets on both the front and rear (I know you don't ride like this) there appears to be a fair amount of slack. Is this normal and the chains are supplied at a pretty reliable length or can I take a link or two from the chain?

Andy B

You need to make the chain the correct length (the same as your old one, provided it's the same mech cage length)

-liam-

Andy_B wrote:

You need to make the chain the correct length (the same as your old one, provided it's the same mech cage length)

Same cage length but a 9 speed cassette instead of an 8 speed.

So is the only difference the thickness of the chain and not the length ?

Andy B

8 & 9 spd chains have a different thickness.

New chains are supplied to a longer length than you will need.

You will need to shorten the chain if you haven't.

-liam-

Thanks boss, thats what I wanted to hear.

Something to do tomorrow, I'm off for beer

warrerj

wrap the chain around the largest chain ring and rearsprocket (without runing it through the mech!) add a complete link and that should be the right length.

The only exception is on some FS you'll need to add and extra link to give enough length for the suspension to have it's full travel.

-liam-

Gutted.

Shortened the chain as it was a good 2 inches to long. Chain is still skipping though. From what I can see while riding, it skips from where the chain comes out of the mech and rides around the cassette before sitting back onto the sprockets again and it is under no pressure, just rotating the pedals but I can't simulate it with the bike upside down. The movement of the chain from sprocket to sprocket is perfect so I can't believe playing with the barrel adjuster will make any difference. Is there anything else ? I thinking that as the cassette is used, that is the problem.

Does this look ok tension wise small sprocket to small sprocket?

supersonic

New chains do not always take to old chainrings and cassettes. Could well be the problem.

If the chainset is 8 speed, will need replacing too.

-liam-

Seems to run fine around the chainset, well doesn't appear to be causing any issues anyway but will look at getting a new one anyway. Recently fitted a new bottom bracket so I want to get some use from it, at least a winters worth anyway lol.

supersonic

Is the axle the right length? Correct chain line?

andrewjoseph

Have you indexed the rear deraileur?

Doesn't really matter what chain ring on the front but middle is easier, change all the way down to the smallest cog at the rear, then back up one (from 9 up to 8).

now turn the barrel adjuster until the chain is trying to jump up to the next largest cog, back off until the chattering noise is gone.

the deraileur should now be indexed.

if you still have problems, check the 'B' screw is correct, not too far out or in.

Make sure you have put the cassette together properly, i.e. you don't have one cog reversed.

-liam-

supersonic wrote:

Is the axle the right length? Correct chain line?

Can you describe what you mean ?

-liam-

andrewjoseph wrote:

Have you indexed the rear deraileur?

Doesn't really matter what chain ring on the front but middle is easier, change all the way down to the smallest cog at the rear, then back up one (from 9 up to 8).

now turn the barrel adjuster until the chain is trying to jump up to the next largest cog, back off until the chattering noise is gone.

the deraileur should now be indexed.

if you still have problems, check the 'B' screw is correct, not too far out or in.

Make sure you have put the cassette together properly, i.e. you don't have one cog reversed.

I haven't indexed it. Just seemed to be really easy to set and didn't require messing with. I'll go index it

I did think of the cassette but it all looks ok.

supersonic

If the axle is too long, the chainrings would be too far out (or too far in if too short). This means that in certain gear combos the chain will be at an angle and can make it jump and slip.

Also shouldn't be using gears like the big/big chainring/cassette combo for this reason.

-liam-

supersonic wrote:

If the axle is too long, the chainrings would be too far out (or too far in if too short). This means that in certain gear combos the chain will be at an angle and can make it jump and slip.

Also shouldn't be using gears like the big/big chainring/cassette combo for this reason.

I'm not sure how that could be an issue when we are talking about one extra sprocket and narrower spacings inbetween the sprockets. Its not like anything is going to be out of alignment by 10mm or anything is it ?...I'm clearly not an expert though But I am an engineer by trade so with regards alignment etc, it all looks cool.

I've just put the 8 speed cassette back on and although it sounds a bit clacky probably cos I did nothing to set the mech, it doesn't jump on the small sprockets.

Also tried "Indexing" with no success and the cassette can only go together on the free hub one way....its idiot proof Thats ok then.

supersonic

It can be a big issue if the axle is that far out! Really looks like they are 8 speed chainrings too. Using the big/big small/small combos should be avoided full stop.

Also 8 speed cassette will never index with a 9 speed shifter.

nicklouse

as sonic says it sounds like you are trying to mix and match two incompatable set ups.

8&9 and not mixable.

-liam-

I always do avoid pedalling in those gears, understand the stresses it can put on a chain.

The issue is occurring on the underside of the cassette where the chain leaves the mech if you know what I mean ? I can see it skipping. The cassette has wear on the edges of the sprockets and where the steel is wearing on the teeth it is feathering out on the edges. I think the new chain doesn't like it. When I put my 8 speed cassette back on which isn't actually as badly worn as the 9 speed it behaves as it should.

nicklouse wrote:

as sonic says it sounds like you are trying to mix and match two incompatable set ups.

8&9 and not mixable.

Nope. There is no issue with the front pulley. Everything else is 9 speed as you suggested last week

nicklouse

-Liam- wrote:

I always do avoid pedalling in those gears, understand the stresses it can put on a chain.

The issue is occurring on the underside of the cassette where the chain leaves the mech if you know what I mean ? I can see it skipping. The cassette has wear on the edges of the sprockets and where the steel is waring on the teeth it is feathering out on the edges. I think the new chain doesn't like it. When I put my 8 speed cassette back on which isn't actually as badly worn as the 9 speed it behaves as it should.

so you have an 8spd shifter?

you can not use a 9 spd cassette.

-liam-

nicklouse wrote:

-Liam- wrote:

I always do avoid pedalling in those gears, understand the stresses it can put on a chain.

The issue is occurring on the underside of the cassette where the chain leaves the mech if you know what I mean ? I can see it skipping. The cassette has wear on the edges of the sprockets and where the steel is waring on the teeth it is feathering out on the edges. I think the new chain doesn't like it. When I put my 8 speed cassette back on which isn't actually as badly worn as the 9 speed it behaves as it should.

so you have an 8spd shifter?

you can not use a 9 spd cassette.

Erm...no.


I have 9 speed deore shifters.

I have a 9 speed xt cassette (used)

I have a 9 speed sram Chain

I have an issue where the chain is jumping on the small sprockets of the cassette

I have just put back on the 8 speed cassette and rode around the garden to try and isolate a problem with regards worn teeth on the 9 speed cassette and it runs fine.

I believe I have an worn 9 speed cassette.

Would you agree?

supersonic

What size is the large cog on each cassette?

Horton

Nick, I know you like your lists, but I think he's changed his shifters. Liam, have you tried tweaking the lockring on the cassette up a a couple of clicks - I had a similar problem and found that i hadn't tightened the lockring up nice and tight - the teeth on the inside sometimes make you think you've tightened enough when infact you can get a few more "clicks" out of - just be careful not to overtighten though.

Horton

Another thought, Nick/Supersonic, could running the 9spd chain on an 8spd chainset damage the chain?

supersonic

It works, but not very well. Some brands work better than others. They will wear different. I wouldn not recommend it.

Any ideas on what the large cogs are on the two cassettes? I am wondering if the B tension screw needs adjusting. If not, then it will be cassette wear and new cassette time.

-liam-

Horton wrote:

Nick, I know you like your lists, but I think he's changed his shifters. Liam, have you tried tweaking the lockring on the cassette up a a couple of clicks - I had a similar problem and found that i hadn't tightened the lockring up nice and tight - the teeth on the inside sometimes make you think you've tightened enough when infact you can get a few more "clicks" out of - just be careful not to overtighten though.

I'll try that tomorrow thanks bud. You are correct in that I like you tightened it a few clicks and thought it was tight enough.

-liam-

supersonic wrote:

Any ideas on what the large cogs are on the two cassettes? I am wondering if the B tension screw needs adjusting. If not, then it will be cassette wear and new cassette time.

Both 32 chap.

supersonic

I think we can safely say it is the cassette that has worn then!

-liam-

haha !

supersonic

Lol, got there in the end! I think we misunderstood what you were saying and vice versa!

-liam-

I've tried that many bits and peices and odds and ends it was hardly surprising.

Shame the only combination that was supposed to work was the only combination that didn't

-liam-

yay, closure !!

I ordered a new sram 9 speed cassette on thurday night. Thought there might be half a chance I'd get it for saturday morning but no such luck. Tonight, I'm mooching about in tidying up the back garden and we keep a bin bag behind the back gate in which we dump all cans and bottles to take down to the recycling centre at the weekend. I catch a glimpse of a blue bag just inside....The ba****d postman must of just lobbed it over the back gate on saturday morning and it landed in the binbag...he certainly didn't knock at the bloody door ! Lucky I looked otherwise my 24 quid cassette might of been sat in a skip by now. I'll have the shit in the morning :x

Anyway, all fitted and works perfectly. Chuffed.

Just need to fit a new chainset now.....I'll be back