A mix of M952 and M953 on my 'new' bike - help please!

[alex1981]

Hello,

I have bought a new bike for the girlfriend, picked it up today. Before picking it up, the seller noticed that it had 9 speed (M952) shifters but an 8 speed cassette. So he swapped over a 9 speed cassette before I arrived. No problem, apart from the chain was too short for me to test it properly (it locked out) but he kindly supplied me with a new chain.

But...getting home trying to get the chain length right I notice a few things...the cassette he fitted is a 36T. But the rear mech seems me be a 953 Short cage - and I just don't think the mech is long enough as it rides on the cassette on the bigger cogs?

So I have a couple of questions...

Do the M952 shifters work OK with the M953 rear mech (which is the reverse type)? Is this normal to do this? I thought maybe you'd have to pair the rapid rise mechs with rapid rise shifters, or does it make little difference? I have not used a reverse RD before.

I need a 9 speed cassette if I want the indexing to be right on the shifters...but before it had a 30T 8 speed cassette. What should I do there? What is the max size cassette the M953 RD can have?

Am I better off getting a regular cage M952 RD and a 34T cassette, or will a a 952 RD work OK with a 36T cassette?

Trying to figure out the least amount of components I need to but to get it working correctly! To me...it seems to just need a 30T 9 speed cassette? As the 952 shifters *seem* to work with the mech OK?

 

[ishaw]

Re:

Hope the following helps. I've built many a bike with m95x gearing.

Shifters and rear mech will work fine together, you just have to get used to shifting the opposite way you would normally.

Cage wise, short cage mechs will only work well with shorter range cassettes. Usually a mech will have a max tooth count somewhere. If you think 30t is max, then you have the 2 options you've mentioned. New longer cage mech or new cassette.

If you go down the mech route, I've got a longer cage m952 rear mech I can sell for a decent price as it needs new jockey wheels, and you can pinch them from your m953.

You'll need a longer chain as you've discovered to cover the extra teeth and longer cage. Probably have a chain I could throw in with the mech if you want (not trying to sell you anything, I just could if you decided to go this way).

Have you tried adjusting the b screw? This is the screw that pushes against the mech hanger on your frame. This screw adds or removes space between the top mech cog and the largest cassette ring. You might be able to get away with screwing this in, pushing the mech away from the largest cog. If this works, no need for a new mech, only a chain.

Changing the rear cassette to a shorter range would negate the need for a new mech, and you might get away with using the same chain you already have. Depending on the riding planned, the shorter range may or may not be ideal, only you will know that.

I sexing wise, if somehow it was set up to work with 8sp cassette, the indexing will likely be out. Simple job of turning the barrel adjuster on the rear mech until indexing is as you want it. Shifters also have barrel adjusters so you can do this there too.

In short, you might just need a new chain, or you have other options.

 

[alex1981]

Re:

Thanks for your reply and that is a help

The chain I have is a new 116 link Shimano HG and is plenty long enough certainly for the short mech.

Glad to hear that the shifters work OK in reverse.

So on reflection it looks like a 9 speed 30T cassette will sort out the woes. Is there one that would be best suited to what I have?

 

[alex1981]

Re:

Now ordered an 11 30T from SJS. Only an SG50 but it will do the job

Now...where's that cassette tool I've not used for 10 years!

 

[mk one]

isnt the max tooth stamped on the arm plate?

 

[hamster]

One other thing. The rapid rise (reverse action) rear mechs rely on the spring tension to push the chian onto the larger sprockets. It has to oppose chain tension. On conventional high-normal mechs the spring drives the shift to a smaller sprocket, assisted by the chain tension.
As a result, when the mech spring gets old and weakens, shifting can get erratic, slow and even start gear skipping.

In my view it's lovely until a weak spring, then bin-bound garbage. I used to use one on a road bike with bar-end shifters as it kept the shifters out of the way of my knees when climbing out of the saddle.

 

[alex1981]

That's interesting to know. If I find it weak or difficult to tune up I might just swap it for a 952 - they seem to last forever and shift perfect, every time.