Why is chain Riding on cassette when back-pedalling
I've got a snag I cannot fathom out on my Focus Mares CX, it has a thru-axle set up.
When I try to back pedal the chain is riding up on the rear cassette rather than running smoothly backwards. I have checked for restriction in the freehub (all cleaned and spins freely), the jockey wheels are free running too. BB is all good and cranks spin when chain is off. I have the QR set at the absolute minimum but when it's closed the chain won't run backwards.
I'm at a loss as this has developed for no reason I can see. I haven't changed anything? I have attached link to show what I mean if I haven't explained it very well.
https://youtu.be/Ju3CkIreZxs
Thanks for any help.
When I try to back pedal the chain is riding up on the rear cassette rather than running smoothly backwards. I have checked for restriction in the freehub (all cleaned and spins freely), the jockey wheels are free running too. BB is all good and cranks spin when chain is off. I have the QR set at the absolute minimum but when it's closed the chain won't run backwards.
I'm at a loss as this has developed for no reason I can see. I haven't changed anything? I have attached link to show what I mean if I haven't explained it very well.
https://youtu.be/Ju3CkIreZxs
Thanks for any help.
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Not sure if it's different on thru axle bikes but on normal stuff with qr that generally means a Jeffed freewheel.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 -
Don't think it's the freewheel as it seems ok when you loosen the lever. Are you actually unscrewing the thru axle or just flipping the lever over? I didn't think flipping the lever would release any tension. Looks like there is some side load on the freehub causing drag when it's tightened up. Could there be a spacer missing or in the wrong place. I only have experience of a front thru axle so am no expert only hypothesising. It looks like a Novatec hub, or one they've rebranded for someone else. Were the wheels supplied with the bike? Does it have the correct end caps? I discovered they changed the design of the front end caps on hubs with the same model number and late QR end caps caused an early hub to lock up when fitted.0
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I think this is as simple as "Don't do it"? An offset chain line will take a chain up/down the block if back pedaling. This is why you need to ensure the chain line is straight before back pedaling for oiling the chain, etc., (so ideally something like small ring at the front, middle of the block at the back). If the chain was moving up/down the block when freewheeling then there would be an issue, but I don't think this is the case?0
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Why would you back-pedal?ROAD < Scott Foil HMX Di2, Volagi Liscio Di2, Jamis Renegade Elite Di2, Cube Reaction Race > ROUGH0
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Are you actually unscrewing the thru axle or just flipping the lever over? I didn't think flipping the lever would release any tension.
It's just very lightly tensioned. It does apply pressure on the axle slightly and that's enough to cause friction to prevent the back pedalling. I think it might be a spacer issue so I've asked for a schematic to see if something is missing. The front axle is not any help with the setup.
It does it with the chain straight or offset. It doesn't do that on my 11s Ultegra on the road bike.An offset chain line will take a chain up/down the block if back pedaling
- because it always has done it fine , all the bikes i own do it, it's how it should operate.Why would you back-pedal?0 -
Pilotdavo wrote:
- because it always has done it fine , all the bikes i own do it, it's how it should operate.Why would you back-pedal?
Why should it operate that way? A bike isn't designed for the chain to run in the wrong direction. It is designed for the chain to go in one direction or be stationary.ROAD < Scott Foil HMX Di2, Volagi Liscio Di2, Jamis Renegade Elite Di2, Cube Reaction Race > ROUGH0 -
I'm just trying to find the source of the friction that is preventing the rear wheel running freely. One of the symptoms is the chain won't run smoothly over the cassette when back pedalling. The resistance is noticeable when pedalling and this is not optimal for riding the bike. It didn't used to do it. I admit I don't have to back pedal but something is still malfunctioning which I'm trying to identify with the help of people on this forum.0
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It may be a symptom of your TA issue. Does your wheel look aligned? Is your cassette properly torqued up?ROAD < Scott Foil HMX Di2, Volagi Liscio Di2, Jamis Renegade Elite Di2, Cube Reaction Race > ROUGH0
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All looks good. Shifts easily, across the cassette and the rotor is sitting plum in the calliper for the brakes.0
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I'm suspicious of the hanger alignment in this scenario. I have a bike that always did that and having it aligned solved it - I could get it to index okay but the whole RD was just slightly off and that cause the chain to be at an angle going backwards.
Worked for me. Eyeballing it isn't good enough - you need the tool to do it.I'm left handed, if that matters.0 -
Looks to me like it would be brake pads, take um out an try it. If so align caliper last.The Wife complained for months about the empty pot of bike oil on the hall stand; so I replaced it with a full one.0
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I don't think it's brake pads or hanger issues as it's changing according to tension on the hub. Checking the schematic as you say and having a good look to see what's causing the drag is the key.
If it is excess side loading of a bearing as I suspect it could be it will cause the bearing to fail prematurely so you do need to sort it.
Just be methodical and eliminate one thing at a time. Good luck.0 -
meanredspider wrote:Why would you back-pedal?
To lube chain
To position cranks correctly before starting off
Unless at extreme chainline the OP should be able to back pedal.0
