Buzzing gears

Alibran

Sorry this is long, but I'm trying to cover everything.

A few weeks ago, I took my bike to my new LBS for a few things, including new chain, cassette, gear and brake cables. He kept the bike longer than he said he would, and when I got it back it was so quiet without the rattling I'd been getting from my worn drivetrain. After a couple of rides, I realised I was missing a couple of gears, so checked the cassette to find he'd replaced my 12-25 with a 14-25. While I was looking at the cassette, I noticed the jockey wheels on the rear mech were clogged up with gunk. I cleaned the chainset - it appeared he'd smothered it in wet lube, despite it not having rained here since April - and relubed.

On my next ride, I started to get a buzzing noise from some of the gears - it's worse in the lower selection of gears for each chainring, and gets louder as the cadence increases. I also started to notice occasions when the gears didn't select properly (particularly when changing to a larger sprocket) and the cranks would spin freely for half a revolution before the gear "engaged".

The bike is a 9-sp triple, with Tiagra shifters and Sora front and rear mech. I know how to ride it correctly, only use appropriate chainring/sprocket combinations, and always ease off when I change gear.

Things I have checked are:

1. Indexing is the best I can get it - it changes up and down smoothly through the gears when I test it
2. Cable outers are seated correctly
3. Cage isn't rubbing
4. Top jockey wheel is clear of the largest sprocket and rear mech hangar is not bent
5. Cassette is not loose
6. Chain is routed correctly through the rear mech

I'd originally intended to do the work myself, but I mistakenly thought it would be cheaper and less hassle (since I didn't have any of the tools needed, and it would be my first foray into bike maintenance) to take it to the LBS. I was obviously wrong! I'm now hoping to figure this out and sort it myself. In any case, I don't intend to take it back to the same LBS. He told me he'd need the bike for a day, and kept it for 3 days. I told him to change like for like, and he sold me a cassette that doesn't have anything like the gear range I want. Also, the only reason I can see to have smothered it with wet lube was to disguise the noise it was making. To be honest, I think he saw me coming.

So .... any suggestions?

The noise is irritating, and I also find it rather embarrassing. The cranks spinning is very irritating, especially when you're trying to maintain cadence/momentum on a climb. But neither of them make the bike unrideable. I've just run out of ideas of what to try next.

chiark

i'd just go back, and politely ask him for the 12-25 rather than the 14-25 he's mistakenly fitted, and ask about the buzzing. You paid for a service, part of the reason for doing that is for support: the shop will know what they're doing one way or another, so I wouldn't be too paranoid that they saw you coming!

Also, my understanding is that wet lube isn't called wet lube because it's for wet conditions, but more what it's made from... I use wet lube year round after having no success with 'dry' lube, specifically Finish Line wax ceramic stuff. It made my chainset damn noisy!

I'd give them a call, book a time to nip in, and see if he can look at it there and then, and sort out the cassette.

merak

My guess (only a guess mind) is that something is not correctly assembled in the cassette or that an 8 speed chain has been fitted. 14-25 is a pretty rarely seen cassette, I think - and only available in Ultegra afaik. Perhaps one or more of the cassette sprockets has been fitted back to front which might prevent the Hyperglide function working. Anyway, why don't you take it back and complain - having a different range cassette from what you ordered is reason enough.

wombar

First off, if you'd like to get into doing your own maintenance, and don't have a workstand, I'd advise you invest in one. I picked up one of the cheap ones from Lidl, but Ribble sell one for about £50 that is highly recommended on here. One of the most useful things I ever bought for my bike.

Then you just need some basic tools, or you could buy one of the tool kits from Ribble/Wiggle etc for around £40. Anyway, I'll try not to turn this into the merits of DIY thread.

Sounds like your indexing could be a little out, but it really depends what you mean by buzzing. Simplest thing to try is turning the barrel adjuster on the rear derailleur a quarter turn at a time and seeing if that fixes it. Much easier to do with a workstand btw.

Could be any number of things though, so I'd also take it back to the shop and get the mechanic to take a look at it. You paid for a service, and your bike should have come out running smoothly.

centimani

The buzzing and difficulty shifting may not be connected it may be two seperate issues...
i fitted a new chain some time ago and retained the original cassette and chainrings. There was a distinct buzz from the chain for a week or so, then it disappeared. Changed plenty of chains before, never had that happen before, i didnt have any shifting problems.
Why ? i dont know, maybe just the new chain meshing in ?

Alibran

chiark wrote:

i'd just go back, and politely ask him for the 12-25 rather than the 14-25 he's mistakenly fitted, and ask about the buzzing. You paid for a service, part of the reason for doing that is for support: the shop will know what they're doing one way or another, so I wouldn't be too paranoid that they saw you coming!

Yes, I know I should go back and I should be able to expect good service, but tbh expecting good service in Spain is setting yourself up for disappointment. You're just pleasantly surprised and pleased if you get it.

chiark wrote:

Also, my understanding is that wet lube isn't called wet lube because it's for wet conditions, but more what it's made from... I use wet lube year round after having no success with 'dry' lube, specifically Finish Line wax ceramic stuff. It made my chainset damn noisy!

From what I've read, wet lube goes on wet and stays wet, which means it doesn't wash off so easily, but dirt and dust sticks to it easily. Dry lube goes on wet and then dries. It's thinner and washes off much more easily, but once dried doesn't attract dust. I used wet lube year round in Cornwall, but changed to dry when I came to Spain because I now never ride in wet conditions, but do ride in dry, dusty conditions. I'd never had any problems with noise until recently (apart from when my old chain/cassette got worn).

Alibran

merak wrote:

My guess (only a guess mind) is that something is not correctly assembled in the cassette or that an 8 speed chain has been fitted. 14-25 is a pretty rarely seen cassette, I think - and only available in Ultegra afaik. Perhaps one or more of the cassette sprockets has been fitted back to front which might prevent the Hyperglide function working. Anyway, why don't you take it back and complain - having a different range cassette from what you ordered is reason enough.

I was wondering the same thing about the chain. If he could fit the wrong cassette, he could just as likely fit the wrong chain. Is there any way to tell, or is the difference in width so tiny that you don't really notice it? Of course, I don't have the old chain to compare.

The cassette is an HG50, which does come in 14-25. I don't see the point of it tbh. I was tempted to get a 12-27 in the first place because some of the hills around here are pretty steep, but decided to save myself some money (that is only available in Ultegra, at least according to what I can see on Wiggle), so that's probably what I'll do now.

I'll take a look at the sprockets. I assume the little grooves would be pointing in the wrong direction if one of the sprockets was the wrong way round.

Alibran

wombar wrote:

Anyway, I'll try not to turn this into the merits of DIY thread.

Sounds like your indexing could be a little out, but it really depends what you mean by buzzing.

I learnt the merits of DIY already. If you need something done, you can do it yourself, and know it will be done properly. And if your bike breaks, you can fix it.

The buzzing is very similar to the noise high voltage cables make. It does have that one benefit in that I hate the things, and every time I ride under them now, I can tell myself the noise is just my bike

merak

Yep - there is little triangle stamped on one side.

As for the chain - I don't know how you'd tell what's fited short of measuring it with a micrometer (unless the speed is stamped on the plates) but it also occurred to me that if he put a 10 speed chain on that could also result in poor shifting.

Alibran

merak wrote:

As for the chain - I don't know how you'd tell what's fited short of measuring it with a micrometer (unless the speed is stamped on the plates) but it also occurred to me that if he put a 10 speed chain on that could also result in poor shifting.

Thanks for that. I'll get a new chain, and try that as the first thing. I was going to get a couple of extra ones anyway, since I've read about the benefits of rotating chains to reduce cassette wear.

wombar

Does the new chain have any writing (might be really small) on it? Most decent chains will have something written on them but this will depend on make/quality etc. That might tell you whether he's fitted the wrong chain if you can find a model number etc.

Personally, it doesn't sound like there's anything catastrophically wrong to me. If the gears aren't indexed properly, they won't sit square on the cassette which might be the cause of the "buzzing". If you can turn the cranks and the barrel adjuster at the same time, give the adjuster a few turns in one direction, then the other and see if it gets quieter/louder.

The difference between 3 turns can make all the difference to the performance of shifting.

chiark

Sorry, I didn't twig you're in Spain! Ah, I can see why service expectations may be a little different then... Also explains the dry lube, but I really couldn't get on with it at all

I must admit I'm now wondering about the chain/cassette combo, as it sounds like you've got everything adjusted nicely but it just isn't playing the game. Can you ID the chain at all? Mine has the part number (HG-5701) stamped on it - it also says it's asymmetric, so if it's fitted the wrong way around it'll cause issues.

If it's an HG50-9, chainwise you need a CN-7701, or HG93,73 or 53 according to...
http://bike.shimano.com/publish/content ... le.html/01)%20Drivetrain%20Compatability%20Chart.pdf

I don't know if this helps at all... Apologies

keef66

Do both the chain and cassette look brand new? I'm wondering if he's drowned it in wet lube to disguise the fact he's bunged on a pre-owned cassette??

(14-25 is a bit unusual; perhaps he keeps trying to get rid of the thing!)

+2 on the possibility of a mismatch between chain and cassette.

I use Squirt wax-based dry lube in the "summer" here in the UK. Put plenty on and let it dry, and it keeps the drivechain smooth and quiet. Also has the benefit that it constantly flakes off taking the dirt with it.

As soon as it starts to get cold and wet I switch to Finish Line Wet lube which seems much better at protecting the chain from rust, but needs frequent wiping down to remove the worst of the inevitable black gunk.