Rear Cassette noisy

[Ronnyuk]

I am after a bit of advice, I have travelled about 50 miles on my synergy 250 and I had a battery fault, this was repaired under warranty and I just went to refit it to the bike, on fitting it I notice that there is a clunking sound when you drop the rear wheel on the floor, it is coming from the rear cassette?? I asked a friend to have a quick look and you can move the top two gears left and right very easy, they almost seem to be independent of the actually gear cog assembly <does this make sense>

I phoned my local bike shop and they have said the whole rear cog mech is riveted together so none of it should move, is this correct and if so what could have caused this to happen after approx. 50 miles use?

Thx

 

[flecc]

If it is a cassette, the top two sprockets are frequently separate and changeable from the rest of them, held tightly in place by a threaded collar. It could be that is loose, but it shouldn't loosen in use. Alternatively it could be missing a spacer ring in manufacture.

That's not always the case with multi-sprocket freewheels where the sprockets are often a monobloc.

 

[Ronnyuk]

Thanks Flexx your the man, I thought it a bit weird the whole assembly would be broken, why would my bike shop tell me it couldn't be fixed...in the defence they didn't look at it I just phoned them. Do you know if I can buy the tool?

 

[Aushiker]

The cassette can work loose over time. It has happened to me and I am aware of at least one other rider on a group ride who had the same problem.

Suggest you take a look at the Park Tool repair guide. Hopefully should point you in the right direction to sorting the problem. Should be a quick and easy fix.

Andrew

 

[flecc]

Is this the Burisch Synergy GT 250? If so I'm fairly sure it has a multi-sprocket freewheel rather than a cassette since it has spindle centre cable entry to it's rear wheel motor.

Those freewheels have sprockets assembled by screwing in together to form a monobloc so it seems unlikely the outer pair would work free. There are a variety of tools choices as you'll see on the Park Tools site that Andrew has linked to. You'll need to check visually which engagement yours has at the centre, and in which way those sprocket are loose.

To use one of the tools you'll need to separate or detach the cable at one point to pass the tool over it.

 

[Ronnyuk]

Is this the Burisch Synergy GT 250? If so I'm fairly sure it has a multi-sprocket freewheel rather than a cassette since it has spindle centre cable entry to it's rear wheel motor.

Those freewheels have sprockets assembled by screwing in together to form a monobloc so it seems unlikely the outer pair would work free. There are a variety of tools choices as you'll see on the Park Tools site that Andrew has linked to. You'll need to check visually which engagement yours has at the centre, and in which way those sprocket are loose.

To use one of the tools you'll need to separate or detach the cable at one point to pass the tool over it.

Thanks for the advice both of you, yes it is GT 250 Flecc, I have spoken to Ryan and he is going to check it out tomorrow, he hasn't heard of it happening.

 

[Deleted member 4366]

Free-wheels are very cheap, just get a new one. I doubt that yours can be repaired anyway. You'll need a special free-wheel removal tool to get it off. It has to have a hole through it of at least 12mm to go over the axle. You should consider replacing it with a DNP one from Cyclezee so that you can get a 11T top gear for more relaxed pedalling.

 

[Kenny]

The cassette can work loose over time. It has happened to me and I am aware of at least one other rider on a group ride who had the same problem.

Andrew

I was replacing my chain on my Pro Connect recently and noticed the cassette had loads of play.

I assumed the cassette carrier bearings were "shot" and the cassette knackered (had done over 3k miles).

It turned out that the cassette securing ring had come loose and after cleaning all the cogs and reassembling , it was still working fine.

I wouldn't have thought your rear cogs are the freewheel type as they are in one piece and the chain naturally tightens them when pedalling.

Hopefully it's just the securing ring that has loosened.

 

[Deleted member 4366]

I wouldn't have thought your rear cogs are the freewheel type as they are in one piece and the chain naturally tightens them when pedalling.

Hopefully it's just the securing ring that has loosened.

i think that you're misunderstanding. This is a free-wheel gear set as opposed to free-hub (your type). It doesn't have a locking ring like yours. There is a sort of locking ring, but it's not one that you'd normally use. I've never heard of one coming loose because they're done up tight in the factory.

 

[trex]

they are riveted together.

If one of the sprockets moves, it's broken free and cannot be repaired.
Chuck it. The OP has the bike only a few days, I'd ask for a swap out replacement.

 

[Ronnyuk]

Well after all your kind advice I thought I would video the movement and post it on here, so brought my bike into the lounge for a bit of extra light , this was a great idea until my 3yr old son wanted to help, so he was trying to show you how it moved and how he could get his hands dirty touching the chain while I recorded him..

So while I was checking the sprocket he "accidentally" turned on the key and turned the throttle, I watched in horror as the bike flew into our brand new Samsung 46" 3D TV. So this little episode has just cost in excess of £1000..on the plus side I never swore ha-ha and I video'd the whole bloody thing

 

[flecc]

You have my sympathy, really bad luck. In a moment of carelessness a few years back I launched a powerful e-bike the same way, but in my case it only punched a hole in a panel door.

It's surprising how much damage a nominal 250 watts can do.

P.S. Maybe that video could recover £250 from ITV's "You've Been Framed".

 

[Ronnyuk]

Something to give you a laugh.. Fortunately we have insurance how the hell do you explain that heh

My missus mentioned YBF...I could never live it down

 

[mountainsport]

The cassette can work loose over time. It has happened to me and I am aware of at least one other rider on a group ride who had the same problem.

Suggest you take a look at the Park Tool repair guide. Hopefully should point you in the right direction to sorting the problem. Should be a quick and easy fix.

Andrew

Very good that, nice one Andrew.

MS.

 

[Aushiker]

So while I was checking the sprocket he "accidentally" turned on the key and turned the throttle, I watched in horror as the bike flew into our brand new Samsung 46" 3D TV. So this little episode has just cost in excess of £1000..on the plus side I never swore ha-ha and I video'd the whole bloody thing

You need to keep all this his the 21st BTW when do we get to see the video?

On the positive side you can now get a bigger TV

Andrew

 

[Ronnyuk]

Will put the video up soon

Here is the cassette from the rear view, apparently there is a tool that slips between the wheel and top sprocket that can tighten up using the locking ring shown, anyone seen anything like this?



Here is the locking ring on the bike

Would this work?

http://www.halfords.com/webapp/wcs/stores/servlet/product_storeId_10001_catalogId_10151_productId_1003443_langId_-1_categoryId_242558

 

[flecc]

There may be a manufacturer tool for that purpose, but basically an appropriate size C spanner could be used. If it's not a left hand thread it would have to be tightened against a freewheel removal tool in the other end held fast.

 

[Ronnyuk]

Flecc, I know it's a new bike but would it be easier for me to just go to Halfords and buy the removal tools and a new 7 speed cassette? how much of a job would it be for a noobie like me? and what would it cost me?

 

[flecc]

New cassette is the easiest as d8veh advised early in the thread. I'm not sure if Halfords will have a 14 to 34 tooth Megarange, but if not they can be got online.

If you've already got the freewheel off as it seems from your photos, you don't need a removal tool to put one on. If you do need one, make sure it's the freewheel removal one and not the almost identical cassette removal tool.

Also many of these removal tools don't have a big enough centre hole to go over the spindle, so make sure the one you get has a 12 mm or larger hole in the tool.

 

[Deleted member 4366]

The freewheel is cheaper than the tool:
http://www.ebay.co.uk/sch/Bike-Components-Parts-/57262/i.html?_from=R40&_nkw=freewheel+14+28&_sop=15

Do yourself a favour and use the opportunity to upgrade to a 11T top gear
http://www.ebay.co.uk/itm/like/261309204326?hlpht=true&ops=true&viphx=1&lpid=95&device=c&adtype=pla&crdt=0&ff3=1&ff11=ICEP3.0.0&ff12=67&ff13=80&ff14=95&ff19=0