Old bike, 9 speed setup issues/chain length

coomber

Replacing old cassette chain etc on old rock hopper...

Its obvious the chain is too slack.



But I followed usual guidance of putting it in 'big big' plus two links. Any advice?!



Help please!!

coomber

Lx rear mech, new cassette and chain and stx rc front

bikaholic

That's an RD-M570, capacity 43T.

Calculate the chain slack take-up required for your bike:

Cassette teeth (largest - smallest) + Chainring teeth (largest - smallest) = X,

If X > 43T, then there will be chain slack as shown in the picture.

If X =< 43T, then it will work as intended.


From the equation and choosing the easiest option, either reduce the size of the biggest chainring or reduce the size of the largest cog on the cassette.

Or, don't shift into the small/small combinations - but, this is not a proper fix.

cooldad

Looks OK to me. You wouldn't be riding in those two combos anyway.
Ignore the nonesense above, which has nothing wharsoever to do with the length of the chain. It realtes to the capacity of the mech.

Although your front mech looks far too high.

coomber

Wow that was quick.

11-34 rear cassette, need to check front think its 22-42.

If its a case of new cassette any tips to buying one without a dishplate at the rear? Couldnt find one on crc

coomber

cooldad wrote:

Looks OK to me. You wouldn't be riding in those two combos anyway.
Ignore the nonesense above, which has nothing wharsoever to do with the length of the chain. It realtes to the capacity of the mech.

Although your front mech looks far too high.

Ok!

Well I wont be using big big or small small so maybe I will just go with it. Its a hack bike anyway.

Now for first go at indexing in 15 years! Should be fun.

Front mech hasnt been adjusted at all. Will move it lower.

cooldad

What's a dishplate?
But if you are right about the sizes, that's 43 and so fine. Even a tooth or two out generally works fine.
Just drop the front mech a bit.

You should never be using the extremes of the cassette and chainrings anyway. Puts too much strain on the chain due to the angles. You have the same ratios elsewhere anyway.

cooldad

For indexing and pretty much anything else read 'Read this first' link below - really useful site.

coomber

Thanks cooldad great help.

Looks like a plate the biggest rear cog on the cassette. Poor Devon humour I apologise

bikaholic

cooldad wrote:

... Ignore the nonesense above, which has nothing wharsoever to do with the length of the chain. It realtes to the capacity of the mech...

What a numpty not to recognise the words of the bearded cycling guru.

Dérailleurs usually are rated in terms of "tooth-difference capacity," a number that represents the dérailleur's capacity to take up slack in the chain. To find the minimum tooth-difference capacity needed for the gearing you have selected, subtract the number of teeth on your smallest rear sprocket from the number of teeth on the largest. Do the same for the front sprockets, and add the two numbers.

http://sheldonbrown.com/derailleur.html

mcnultycop

coomber wrote:

If its a case of new cassette any tips to buying one without a dishplate at the rear?

You just remove it.

coomber

mcnultycop wrote:

coomber wrote:

If its a case of new cassette any tips to buying one without a dishplate at the rear?

You just remove it.

Sorry... Don't mean the plastic plate rubbish, I meant the massive rear cog. The old one was probably 28 teeth these new equivalents are massive - 34 in this example.

mcnultycop

http://www.merlincycles.com/bike-shop/m ... sette.html

coomber

Thank you very much

cooldad

bikaholic wrote:

cooldad wrote:

... Ignore the nonesense above, which has nothing wharsoever to do with the length of the chain. It realtes to the capacity of the mech...

What a numpty not to recognise the words of the bearded cycling guru.

Dérailleurs usually are rated in terms of "tooth-difference capacity," a number that represents the dérailleur's capacity to take up slack in the chain. To find the minimum tooth-difference capacity needed for the gearing you have selected, subtract the number of teeth on your smallest rear sprocket from the number of teeth on the largest. Do the same for the front sprockets, and add the two numbers.

http://sheldonbrown.com/derailleur.html

Well done, I am quite familiar with mech capacity, but a slightly slack chain in small/small is to be expected, and the sensible solution, if necessary, is to fit the mech to the required gearing, not the gearing to the mech.
But you do manage a certain consistency of idiocy in your posts.

bikaholic

cooldad wrote:

bikaholic wrote:

cooldad wrote:

... Ignore the nonesense above, which has nothing wharsoever to do with the length of the chain. It realtes to the capacity of the mech...

What a numpty not to recognise the words of the bearded cycling guru.

Dérailleurs usually are rated in terms of "tooth-difference capacity," a number that represents the dérailleur's capacity to take up slack in the chain. To find the minimum tooth-difference capacity needed for the gearing you have selected, subtract the number of teeth on your smallest rear sprocket from the number of teeth on the largest. Do the same for the front sprockets, and add the two numbers.

http://sheldonbrown.com/derailleur.html

Well done, I am quite familiar with mech capacity, but a slightly slack chain in small/small is to be expected, and the sensible solution, if necessary, is to fit the mech to the required gearing, not the gearing to the mech.
But you do manage a certain consistency of idiocy in your posts.

So says The forum clown responsible for driving away more newbies than there are grains of sand in the Sahara.

In case you still didn't notice, I hinted at all possible solutions. It just so happens I gave the easiest.

43T is the SGS capacity for the RD-M570, newer SGS RDs have max capacity 45T, but this is all meaningless if the bikes required capacity is not known - which is why the OP was asked to calculate it.

I can visualise the solution from more than one approach - it is not my fault if you're unable to follow along.

cooldad

Er Ok. Feel better now?