I could do with so advice. Got new bike just before Xmas, due to work I’ve only been out four times but I noticed that after each ride the cassette is showing signs of surface rusting. Spoke to LBS and they said to re-lube after each ride. Have done this and it is still the same, if not a little worse. It’s a Shimano CS-HG20, 9-speed, 11-34.

Not sure if I’m concerned about nothing but never had this issue on my previous bike with a SRAM drive train.

Anyone had similar issues or advice for me.

Cheers 😀

No doubt this goes against all other advice, however I try and squirt my chain and cassette with GT85 after wet rides, displaces all the water meaning it shouldnt show any rust marks.

FWIW, I’ve also just fitted a new Shimano HG50 (I think) 9 speed cassette, and its fine 🙂

Google doesn’t show anything with that model number but almost all Shimano stuff these days has a nickel coating to stop it corroding. Yours may be a Friday afternoon job with a very light coating that has failed.

Chase it with the bike shop as it’s sub standard, my Shimano cassette doesn’t get lubed after every ride and has never rusted.

HG20 really is the bottom of the food chain so to speak, so not really surprising in current conditions

somo uk – try HG20 cassette – not plated

If it gets wet it’ll rust. As you say, it’s just on the surface, so won’t affect things too much.

What are you lubing with? Might be worth giving the whole drivetrain a clean off and starting again. I use Squirt and reapply after every ride in current conditions, although I know others others don’t like Squirt.

your worrying over nothing, unless you plan to lie it up for a long time without lubing, as it’ll brush off with use.

+1 z1ppy and njee, its superficial surface rusting that will wear off as soon as its used. And a ghetto-level cassette unlikely to have any form of coating.

Sure it’s not rust transferred from the chain?

Thanks for the replies. I’m using Epic Ride lube as recommended by LBS. All surface rust was brushed off after last ride and then the lube re-applied. Chain is pristine so it’s not coming from that. Strange that it’s showing these signs after such little yes even in the crappy weather at the moment.

It’ll rust. It should just be surface rust. I wouldn’t worry about it.

CS-HG20

I don’t wish to sound snobby, but that’s your problem.

Bottom of the food chain, as described above.

I wouldn’t worry too much about it – just keep it clean, keep your chain lubed and replace with something plated when it wears out.

I guess the cassette has black sprockets so as per comments above isn’t plated. This black coating will wear quickly and then rust will appear I doubt it’ll be an issue if you keep the bike clean and lubed, a little surface rust won’t be any issue in use.

When you’ve cleaned and dried your drivetrain, then apply lube and run through all gears at the front and back, which will make sure you get a little lube everywhere, and stop it rusting.

Thanks guys, spoke to LBS earlier, they’ve said same as some replies above, the cassette isn’t coated but shouldn’t cause any problems. They also recommended an upgrade but said to call them if I start to have shifting issues and they will sort me out.

You’d probably be better off with something a bit “wetter” than Epic Ride if you do want to slow down the rust bloom a bit. The flip side is that it will get muckier quicker.

I use this

I spray the chain after washing it and then cycle through all the gears. This helps get rid of any excess water and leaves a coat if oil on the drivetrain.

I then use a rag and wipe off any excessive oil and dirt off the chain so it doesn’t attract grit.

Worked for years.

HG20 really is the bottom of the food chain so to speak, so not really surprising in current conditions

This exactly. It’s probably cheaper to buy another one of these cassettes than it is to buy chain lube (Well, nearly… 🙂 )

Don’t worry about it. Clean your bike after each ride and lube the case tee with GT85. That’s all you can do.

This is one of those obvious cost-cutting parts that manufactures put on bikes, like cheap tubes, cables and low end M475 hubs.

It will also weigh the same as a boat anchor. Dump it as soon as practical for an XT and marvel at the weight saved. Which will be considerable.

Keep the chain well looked after and you’ll be fine.

/edit

Dump it as soon as practical for an XT and marvel at the weight saved. Which will be considerable.

While not untrue, this cassette is an insight in to the components on the OP’s bike. Without wanting to sound snobbish, the cassette isn’t likely to be the only budget component on the OP’s bike. I wouldn’t likely start throwing all of my upgrade pennies on what is essentially a wear item.

Typical Shimano crap. You would never have this problem with Sram.

Why the hell do people ‘lube’ a sheet of steel , such as a cassette ?. Seen muppets at Swinley just smog the area just spraying anything and everything, whether it moves or just sits there. It does nothing other than attract dirt. Just clean it and replace with a better cassette when the chain goes down. You only need to lube chain links, gears and the like.

I had the same cassette as stock on my Specialized Camber Elite. Rusted after a couple of weeks despite religiously lubing and cleaning after every ride.

I think that particular cassette is a bottom-of-the-rung Altus one, usually found on £150 Halfords bikes and doesn’t have the same nickel coating as higher models.

I managed to pick up a decent Deore HG50 for £15 in a Chain Reaction sale so swapped it out fairly quickly. I’d suggest you do the same. After two months the original cassette looked like a barnacle-encrusted boat anchor.

Why waste time with a rusting HG20? Chain Reaction has HG50s on sale for £10.99

http://www.chainreactioncycles.com/shimano-alivio-hg50-9-speed-mtb-cassette/rp-prod443

Shimano cassettes only get the nickel coating on deore and upwards I think HG 62 and above .

HG50 on my hardtail, complete bargain at CRCs prices, used in the worst weather and conditions for a year now.
Still shifts well and no sign of rust, the chain is at the point where I should replace it, but will be going 10 speed in the spring so providing it does not start to skip or shift badly I will leave it on till then.

Typical Shimano crap. You would never have this problem with Sram.

Worked for years.

And that’s just one coat!

I used to use it while overseas – it’s the gungiest wet lube I’ve ever come across! But it’ll stop your cassette rusting… 😉

Otherwise something a little thinner like Finish Line XC will do a good job, but need reapplying more often (but also be less gungy).