Do you think I need a new cassette?

[OxygenJames]

So...... about 6 months ago something started jumping out of gear when the bike was in top (11T) - this is on my haibike - the problem seemed to go away if I cleaned the chain thoroughly and lubed it up well.

Well now it jumps out of gear quite a bit - but only in top - I can't tell for sure if its the chain coming off or what it is - but in top if you put pressure on it something is jumping out of the gear.

Have attached pictures - what do you think - does that top gear (11T) look worn to you? I have done around 3500 miles on it - must admit I have a dongle on the bike meaning we are doing quite a bit of 25mph+ riding - and if you think it does need changing ought I to change the chain at the same time?

Any thoughts welcome.

Cheers.

James.

PS. My paranoid fear is that its nothing to do with the cassette and something inside the crank engine is broken (though why it would only do it in top gear is beyond me).

 

[Deleted member 4366]

There's nothing wrong with your motor. Your top gear doesn't look worn enough to jump, so that leaves gear adjustment or worn chain.If you can get it on a bike stand, wind the pedals in top gear to see if the derailleur is holding the chain in the middle of the sprocket. you can apply the brake while your doing it to see what happens when there's a bit of load.

 

[Martin@e-bikeshop]

Sounds like you need to come and see me James?
Good excuse to see the new place too..

Martin

 

[Emo Rider]

Put your bike in first gear and try to pull the chain away from the gear teeth. If you can see more than 1/8" of space under the chain, it could be worn out. Sorry to disagree Dave, but the 11t looks scalloped out and a new cassette may be in order.

 

[Kenny]

As in the picture I thought my 11t sprocket looked worn out too.

On further investigation I discovered the teeth on a new sprocket were not symmetrical either.

Apparently there made that way for smoother gear changes.

( I never noticed your mileage and high speed usage in your original post. On second thoughts the cassette is probably due for replacement although its hard to tell unless you see it with a new one, side by side)

 

[Emo Rider]

Hope this helps

 

[D C]

It does look worn to me but as Kenny says it may just be the way they are designed.
At that mileage, if you do decide to replace the cassette I would consider changing the chain at the same time as they may not mate up with each other and still give a problem.
You will need new ones at some stage and if the problem isn't cured by fitting them you can put them back in the box till they are needed and go on to further diagnosis.

Dave.

 

[mike killay]

11t cogs always jump!
I have tried 3 now, both Shimano and Sram. They are simply too small to take the pressure.

 

[Emo Rider]

11t cogs always jump!
I have tried 3 now, both Shimano and Sram. They are simply too small to take the pressure.

Like Mike says, 11 teeth is small. The actual numer of teeth engaged by the chain can be adjusted slightly. The single screw that rests against the dropout can be turned out to let the mech engage more of the gear with the chain. This however can affect the smoothness of your shifting.

 

[SRS]

I decided to run my Haibike until the chain jumped. Started jumping in top gear. Left if a bit too long and the 11 tooth sprocket snapped in half one day.

Replacement cassette and chain soon sorted it. I think 2500 miles was the mileage for the cassette at the time.

 

[neptune]

It is often hard to see when a sprocket is worn, especially if like me, you have eyesight issues. If you think that a particular sprocket in a cluster is worn, compare the width of the flats on the tip of the teeth with those of an adjacent sprocket. It is often easier to see wear by this method. a worn sprocket has narrower flats.

 

[OxygenJames]

Thanks everybody. I think I need a new cassette and chain....... I've played around with the derailier - doesn't make much difference - the chain pulls off the lowest gear a bit but hard to tell (thanks for that tip)...... those teeth not only look uneven to me (designed like that so I am told) they also look very small/worn in places compared to the cog above.

I'm real happy nobody has said they think its the motor (Davey? even said for sure he didn't think its the motor - great).

Of course a trip down to see you Martin would be a nice day out - and you could look at it and tell me what you think and sort it out - and of course show me all the new bikes you have - which is tempting too.

SRS whoever you are well if you've found 2500 is about it with your Haibike - thats what I am thinking. Like I said - thanks to everybody who said anything and of course if anybody else has any further bright ideas feel free.

Cheers. James.

 

[RobF]

The cog looks worn to me, but as has been said, the different shaped teeth on Shimano cogs can make judging wear difficult.

I also agree it's a very small cog for the application.

With that in mind, could you put a larger ring on the front?

That might enable you to get the speed without using the smallest cog as often.

Martin has a range of sizes.

 

[Croxden]

When mine jumped I held it on by holding the gear changer down, that stopped it. But it was new then yours is wearing but might help. If the other gears are OK does it matter?

 

[Martin@e-bikeshop]

The cog looks worn to me, but as has been said, the different shaped teeth on Shimano cogs can make judging wear difficult.

I also agree it's a very small cog for the application.

With that in mind, could you put a larger ring on the front?

That might enable you to get the speed without using the smallest cog as often.

Martin has a range of sizes.

From memory Rob he already has a larger sprocket, good shout though.

A simple chain & cassette to resolve. Looking at about £65. Not bad over 2500 miles thats 65/2500= 0.02 a mile and a few charges

Look forward to the email James.

Martin

 

[D C]

I wonder if 10 speed stuff is a step too far, It seems that everything costs double compared with 9 speed. I do like a lot of gears as I use leg power as much as possible but it seems a lot to pay for the privilege of an extra cog. I've tried a friends 10 speed bike and I could certainly feel the difference but not enough to make me want to upgrade. It was a new bike and strangely enough he hadn't noticed it was a 10 speed!.
My last Sram 9 speed cassette and matching Sram chain cost just less than £30 for both though as Martin said, spread over the mileage, cost per mile and cost per smiles isn't that much.

Dave.

 

[Deleted member 4366]

The thing that gets me is that the top gear is removable so that you can replace it, but try and get the gear on its own!

 

[flecc]

Shimano have always been obsessed with fast gear changing and were first to introduce low peak reshaped sprockets and sprocket side profiling to assist chain lift-off. That does indeed speed and smooth changes, but sometimes at the cost of lift-off when it's not wanted. Of course they are not too concerned at customers needing to buy new cassettes more frequently!

I won't use any sprocket smaller than 13 tooth for this and excess wear reasons, but that means larger chain wheels. Since I like a high top gear, my current bike's 13 tooth top gear sprocket is coupled to a special purchase 60 tooth chainring. It's an expensive solution at the outset, but lasts many thousands of miles so saving much later cost.
.

 

[OxygenJames]

From memory Rob he already has a larger sprocket, good shout though.

A simple chain & cassette to resolve. Looking at about £65. Not bad over 2500 miles thats 65/2500= 0.02 a mile and a few charges

Look forward to the email James.

Martin

Where would I be without you Martin?

So is that £65 fitted? Which would mean me coming to you - which is possible but I have a lot on for the next few weeks and may or may not be able to get down your way. Or could that be £65 sent to me with a link to whatever Youtube video would show me how to do it myself (and I presume I would need one of those Cassette removal tools too...)

Thoughts?

 

[OxygenJames]

Where would I be without you Martin?

So is that £65 fitted? Which would mean me coming to you - which is possible but I have a lot on for the next few weeks and may or may not be able to get down your way. Or could that be £65 sent to me with a link to whatever Youtube video would show me how to do it myself (and I presume I would need one of those Cassette removal tools too...)

Thoughts?

Oh - and the other thought I had Martin - do they do a cassette that does up like one cog at a time - like an 11T, 12T, 13T etc - because I only ever use the top 5 gears - and that includes going up the hill to Wimbledon village with the dog on the front. Is that possible? Plus though we need to be aware you once told me that with the dongle and my 38T chainwheel (I think its 38) - you said there are certain cogs at the back I must not have if I dont want to mess with the dongle's function.

Thoughts once more?