Bike keeps shifting by itself!
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Sounds like a worn cassette to me, as mambo80 said, try refitting the old chain and see what happens.~~~~~~Sustrans - Join the Movement~~~~~~0
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My SRAM cassette is somewhat worn now and it's done 4,500 miles, I'll probably change it next time I change the chain.Bungle73 wrote:
After such a short time? Are SRAM cassettes really that fragile?Graeme_S wrote:Still sounds like a worn cassette to me.
How would I know? And that means I'll need to buy a new cassette, plus the tools needed to put it on.
Wear rate dependent on so many things. In my experience if you've fitted a new chain, the shifting is fine in a stand, but when you're riding the chain moves by itself from a cog in your cassette with more teeth, onto a cog in your cassette with fewer teeth then your cassette is probably worn and will need to be replaced.
You may as well buy a new cassette and the tools and try it. If it's not that you can fix it some other way, and your cassette will eventually need replaced.
Trying the old chain back on it as Mamba says is a good idea.0 -
Right, I stuck the old chain back on (which I had to dig out of the bin btw), went for a short ride, and now it seems fine. I guess that means I now need to go and place an order for a new cassette+plus tools.
Thanks for the help.0 -
So what happened to the 'I've been maintaining my bikes for 20 years' then ?
You've never seen a worn cassette in all that time ?0 -
oof..!0
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Fenix wrote:So what happened to the 'I've been maintaining my bikes for 20 years' then ?
You've never seen a worn cassette in all that time ?
No. There was a long period where I wasn't riding.
When I changed the chain on my MTB a couple of years ago, that's all that needed doing, Despite it being on there since I bought the bike in 1999. It had been sitting in the garage for a quite a few years though.
I never said I'd done everything. I've done other bits of maintenance though, like changing stems and handlebars and grips, replacing cables, indexing gears and setting up brakes, and servicing and regreasing a headset and cup and cone bb and hubs, I even put a full new group set on one bike years ago.0 -
Bungle73 wrote:
After such a short time? Are SRAM cassettes really that fragile?Graeme_S wrote:Still sounds like a worn cassette to me.
How would I know? And that means I'll need to buy a new cassette, plus the tools needed to put it on.
Have you not built up a collection of tools over those 20 years maintaining your bikes?0 -
Dinyull wrote:Bungle73 wrote:
After such a short time? Are SRAM cassettes really that fragile?Graeme_S wrote:Still sounds like a worn cassette to me.
How would I know? And that means I'll need to buy a new cassette, plus the tools needed to put it on.
Have you not built up a collection of tools over those 20 years maintaining your bikes?
I've a box of tools, yes. But I've never needed the ones necessary for removing a cassette.0 -
Have you routed the cable wrongly to the bolt at the rear mech when you replaced the cable?
(EDIT. Scrap the above, you say it works fine in the stand).
Failing that:
- something's worn, cables etc
- something's broken, shifters, mech
- something's not setup properly
Take it to someone who's been doing bike maintenance for 20 years, it will be obvious to them whatever it is.0 -
Veronese68 wrote:Could be a bent derailleur hanger. With the worn chain there was enough slop in the chain that it wasn't an issue, new chain being laterally stiffer would highlight the issue. Only a guess of course.
I was going to say this or a bent rear mech.
How does it all look lined up?
Nothing utterly daft like rear wheel in drop out correctly?Postby team47b » Sun Jun 28, 2015 11:53 am
De Sisti wrote:
This is one of the silliest threads I've come across.
Recognition at last Matthew, well done!, a justified honoursmithy21 wrote:
He's right you know.0 -
You will need a cassette tool and a chain whip. Rather than a conventional chain whip the tool from Decathlon gets very good reviews, that would seem to be the way to go. I don't have one as I have a chain whip I've had for about 30 years, but I will be getting one. This is what you want:Bungle73 wrote:I've a box of tools, yes. But I've never needed the ones necessary for removing a cassette.
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I had to google that to see how it works. Man that's neat.
https://www.youtube.com/watch?v=7WeGW4U ... 3A6jfeStVW0 -
Yes, every time I use a chain whip I sit and have a think about which way round it has to go as I don't use one every day. With that it just looks so simple. Still might need a chain whip if seperate cogs have chewed into an ali freehub body though.Fenix wrote:I had to google that to see how it works. Man that's neat.0 -
I went for a standard Park Tools chain whip. Decathlon didn't have the cassette I needed and it's far easier to order it all from the same place. Their one isn't available anyway
Everything is fine.Matthewfalle wrote:Veronese68 wrote:Could be a bent derailleur hanger. With the worn chain there was enough slop in the chain that it wasn't an issue, new chain being laterally stiffer would highlight the issue. Only a guess of course.
I was going to say this or a bent rear mech.
How does it all look lined up?
Nothing utterly daft like rear wheel in drop out correctly?0 -
Bungle73 wrote:Right, I stuck the old chain back on (which I had to dig out of the bin btw), went for a short ride, and now it seems fine. I guess that means I now need to go and place an order for a new cassette+plus tools.
Thanks for the help.
Nice one, satisfying when you get to the bottom of an issue, no one was born a skilled mechanic so dont take any notice of the wee wee takers, the main thing from all this is that you took the advice offered and figured it out.0 -
People would have more sympathy with him if he hadn't told us that he knew more than most of us about fixing bikes as he's been doing it for 20 years... Just not anything tricky like er cassettes.
Ffs we used to do them as schoolies changing sprockets to suit the ride.0 -
mamba80 wrote:Bungle73 wrote:Right, I stuck the old chain back on (which I had to dig out of the bin btw), went for a short ride, and now it seems fine. I guess that means I now need to go and place an order for a new cassette+plus tools.
Thanks for the help.
Nice one, satisfying when you get to the bottom of an issue, no one was born a skilled mechanic so dont take any notice of the wee wee takers, the main thing from all this is that you took the advice offered and figured it out.
Hopefully. But there is still a chance that after I've done it it will be the same, but hopefully not.
You know who are probably one of THE most annoying types of people on an internet forum? That's right, it's people who selectivity quote parts of previous conversations in order to make someone else look bad. Well done.cougie wrote:People would have more sympathy with him if he hadn't told us that he knew more than most of us about fixing bikes as he's been doing it for 20 years... Just not anything tricky like er cassettes.
Ffs we used to do them as schoolies changing sprockets to suit the ride.0 -
It was a fairly good flounce. Tempered only by your having to come back and ask for help from us the next day. I'm rating it 8/10.0
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I don't think anyone is trying to make you look bad.
You managed to make a fool of yourself by saying you had 20 years bike fettling behind you and you probably knew more than most on here, then ask why your rear mech is ghost shifting.0 -
Tell me, does everyone who comes on here asking for help, or says that they don't like something that you obviously think is the best thing since sliced bread, get "the treatment" or am I a special case?cougie wrote:It was a fairly good flounce. Tempered only by your having to come back and ask for help from us the next day. I'm rating it 8/10.
If you speak to me like I'm some kind of idiot, and with the contempt that I was shown, why act surprised when you get back the reply that you deserve?
But answer me this, why are you trying to derail this thread in the same manor as the other one was?
I have all I need from this thread (for now), so I will bit it farewell.0 -
Qube wrote:I don't think anyone is trying to make you look bad.
You managed to make a fool of yourself by saying you had 20 years bike fettling behind you and you probably knew more than most on here, then ask why your rear mech is ghost shifting.
Lets get one thing straight. The 20 years thing was said after I was talked down to like I was a damn child, and all because I was having trouble with one of those bloody quick links. It really is pathetic the response I got just because I sad I didn't like them. So I suggest you go elsewhere with your trolling.0 -
I think I'm beginning to learn who the trouble makers are here now. It's funny how the previous two posters have contributed NOTHING of worth to this thread, except attempts to rile me up.
I shall not be replying to this thread now, until I try what has been advised. So thank you again to those to did assist me.0 -
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Two flounces in a row.....0
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The workshop entry for 'thread of the year'...0
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To the OP.. I want to be helpful.. the cassette is 'slightly' worn by the sound of it. that means it has mated with your existing chain so a brand new chain is not a perfect match to some of the sprockets - the ones you used the most. You will probably find that the new chain would eventually 'mate' with the old cassette after a couple of hundred miles and the skipping will stop and normal shifting will be resumed. You probably don't need that new cassette as badly as you think.
Obviously there is a limit to how much wear on the cassette you can get away with. if your transmission has never been cleaned and bike ridden in bad conditions for 2000+ miles then you have already had your £££ worth from the cassette. If you've only done half that mileage and kept the bike clean i'd be pretty confident the new chain will bed in nicely for you.0 -
If you have a tool for checking chain stretch, something like: http://www.wiggle.co.uk/x-tools-chain-w ... -one-size/
Then I think the rule is that if you replace the chain at around 0.5% stretch, your cassette will last longer. You can wait until stretch hits 0.75% but your cassette will get worn more quickly and if you go beyond that you will probably need to change the cassette every time you change the chain.
Another thing that can happen, as an alternative to cassette wear, is if your hub is loose and there is side to side play in the freehub or the wheel, the cassette can move slightly from side to side and jump onto another ring. I had this when I took my freehub off to grease it and didnt tighten it up again properly.0 -
Veronese68 wrote:
You will need a cassette tool and a chain whip. Rather than a conventional chain whip the tool from Decathlon gets very good reviews, that would seem to be the way to go. I don't have one as I have a chain whip I've had for about 30 years, but I will be getting one. This is what you want:Bungle73 wrote:I've a box of tools, yes. But I've never needed the ones necessary for removing a cassette.
Oh I'm having one of them. Actually had a 'moment' there when I seen how to use it on youtube.
I'm easily pleased.0 -
@Semantik A hundred miles? I can't even ride it a hundred yards down the road.
@apreading How can it be chain stretch when it's a brand new chain? And I've never even touched the freehub. And wouldn't explain why putting the old chain back on fixed it.0 -
The old one had stretched, that's why you replaced it wasn't it?0
