contango 

My Rockhopper is now about 2 years old and I've covered about 3000 miles on it. Most of the mileage I do is on roads or easy trails (compressed gravel etc) with some stretches through heavy mud and rutted earth. I don't do fast technical descents or a lot of the kind of stuff that would normally be associated with mountain biking.

The chain is, not surprisingly, quite well extended. I think it's somewhere around 1% extended at the moment. The owner of my LBS said what he would do from here is to keep riding it until the chain started to skip and then replace both the chain and the cassette at the same time, on the basis a new chain won't mesh properly with the cassette.

Elsewhere I've read that a cassette should last as long as two chains.

Obviously I don't want to throw money around just for the sake of spending it but at the same time I'd rather spend a bit more and do it right than scrimp and save only to find I end up wrecking something, not least because saving now only to wreck later means spending more in the long run.

So the question is simple - to this cyclist who has only ever had to replace a single tyre once, what's the best course of action from here?

kycycler

Your LBS has the right idea, although at this point I would change both the chain and cassette. With 1% wear the chances of chain skip on the old cassette are pretty high. FWIT I change my chain at about 1800 mile and the cassette every 3rd time I change the chain. This is on a road bike. Next time try not to let the chain get so worn and you will save yourself $$$ by just changing the chain more often.

I know that I will hear from some who think that this is over kill but I do not have any problems.

dwellman

Cassette should definitely last as long as two chains. . . I've gone four and now starting over new.

FastJake

Not if you let the chain wear long enough that it ruins the cassette.

OP: when you get a chance, replace your chain and cassette at the same time. You should also inspect your chainrings because if your Rockhopper has a 22T granny ring as it is liable to wear away just as fast as a 22T cog on your cassette. Chainrings last (almost) forever on road bikes with 42/52T rings to spread out the load. But a tiny granny ring will wear out much faster. Next time keep a closer eye on chain wear.

contango 

The Rockhopper does have a 22T granny ring but I almost never use it. The vast majority of my cycling is in the outer chainring with the middle one used for a few large hills around here. I really need to get myself a chain wear tool and use it regularly - what I've tended to do so far is take it to the LBS every once in a while and borrow their tool.

The guy at the LBS reckoned that when I replace the chain and cassette I'll probably want a new outer chainring and possibly a new middle chainring within six months. The outer chainring on it is 44T and I'm thinking of swapping it for a 48T. It should fit in the space, it will give me slightly higher gearing for flats and moderate downhills and for the bigger hills I can shift to the middle chainring as I do now.

Is there any reason why swapping for a slightly larger chainring would be a bad idea?

contango 

One other question on chainrings, on the Specialized site it says the chainrings are "44A x 32S x 22S". I figure that means I've got 44/32/22 teeth but what do the A and S mean?

phoebeisis

aluminum steel is my guess on a and s
Smaller rings take a bigger load- so make them of tougher material-steel
Besides you save more weight making a big ring out of aluminum

dwellman

Right. They should but that doesn't mean they always do.

contango 

That makes sense, thanks

FastJake

You'll have to re-position your front derailer, but 4 teeth isn't that big of a deal. The swap should be fine

dedhed

The chain will have to be resized for the bigger ring also.

davidad

https://draco.nac.uci.edu/rbfaq/FAQ/8d.2.html

contango 

Thanks everybody, now we're almost at the end of our run of Bank Holidays in the UK (partly thanks to The Bill And Kat Show) it's time to go ahead and get myself a new cassette.

The one that was on the bike when I bought it was a Shimano Deore HG-50, 11-34t. I've been mostly happy with the gear ratios I have - much as I'd sometimes like them to be closer together in the middle I'd rather not lose the low end or the high end. But I've seen a few others that look functionally much the same, specifically the Deore HG-61 11-34t (which as far as I can tell is about 50g lighter and 50% more expensive) and the Saint/SLX HG-80 which is slightly more expensive again. I've ruled out the XTR M970 because it's many times the price and I'd need to be convinced I'd get value for money for a cassette that's £120/$200 or more.

Can anyone give me an insight into what I'd be getting for the extra money if I upgraded to the HG61 or HG80? From what I can tell they are a little bit lighter, but as a Clyde I'm really not bothered about saving 50g here and 25g there when I've got far more than that sitting around my belly.

FastJake

Slightly less weight. The lowest-end cassettes have individual sprockets with a spacer between each. These are nice because they can be disassembled and "custom" cassettes can be created. To save weight, higher end cassettes have the top few gears on a spider - all one piece. To further save weight, the high end stuff has the lowest (largest) sprockets made out of titanium.

If you want durability, stay away from the titanium. It will be slightly lighter but wear more rapidly. Personally I don't think I could ever spend more than $30 on a cassette. The tiny weight savings isn't worth it for me.

contango 

Great, thanks for that. From what I could see the more expensive cassettes seemed to be little more than more money for a lighter unit but good to have it confirmed.

If I want to save 50g I'll have a smaller piece of pie for lunch

Looks like the HG-50 it is. I did find it interesting that on the higher-spec Rockhoppers (mine is the Comp Disc) they put a different chain on them (the KMC X9 SL instead of the regular X9) but the same cassette. So that means £16.99 for the HG-50 instead of £24.99 for the HG-61 or £34.99 for the HG-80.

ETA: Having the largest cogs made from titanium would seem to be a bad thing for a Clyde, when I'm using the largest cogs it normally means most of my weight is turning the pedals because I'm going up a hill...

Now I just hope my LBS has one in stock when they reopen tomorrow....

dwellman

If not, there's an outfit on the ebay called threracksource (don't know the name of heir shop, though) that I've gotten as quick as 2nd day after placing the order, except the do mostly, if not all, SRAM. Good prices on 8 and 9, not so good on the 10.

HillRider

I believe the OP is in the UK so, while 2-day delivery is possible, it's going to cost more than the cassette.

contango 

I am in the UK so the US-based retailer probably won't offer 2-day shipping anyway. But since my location isn't obvious to those who haven't seen my other posts I still appreciate the pointer.

My LBS doesn't have it in stock but can get it within a couple of days. I could order it online and save a little bit of cash but for this time at least I'd rather let the LBS do it, not least because they'll fit it for no extra charge and it saves me buying the tools until the next cassette replacement.

dwellman

Ah. Well, that makes a difference.