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Rear clunk / donk
#1
Hello! - ohh i do hope you can help!

I am 8000Km in to a to a cycle tour. I have a condor bike. Recently my bike has developed a rear clunk. It seems to come from the rear - I experience it through the whole frame - It doesn't make an actual clunk sound bit is a physical 'donk' that jolts the whole frame - it is regular and speeds up when going faster - it happens even when not pedaling ie - glidding. Nothing is rubbing, the wheel is 'true', I tried the listening to the bearing through the seat thing and they are a bit gritty but do not seem irregular. Could it be the bearings anyway? I'm not sure how i'd check?

any other thoughts!!!!!!!!???

ta a heap
:-)
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#2
Sound like there's a problem with the rear wheel, something's sticking or catching when it spins (which probably explains why it happens more often at high speed).

My advice would be to take the rear wheel off and do the following:

turn the cassette/freewheel and see if at any point in the rotation it sticks or feels rough.

If that doesn't find it, try grabbing the wheel cones and turning them. if it sticks at some point in the rotation, there's your answer!

My thoughts are the bearings have gone, and possibly taken the cones with them.
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#3
Liz. I think Jon nailed it at the rear hub. That is the perfect description of bad bearing / cone.
You need to stop at the first bicycle shop that you find and have new bearings, HEAVILY GREASED, put in. Loose balls or Retainer does not matter. Your cones are already compromised. If it is a great bicycle shop, they will also have the Cones if needed. If the Cups in your hub get messed up - big $$$ maybe. Luckily, balls and cones are sacrificial.

I wish you the best on your ride!
Wheelies don't pop themselves. (from a QBP fortune cookie)
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#4
Thanks Guys!

We think it is the bearings too - I took the rear wheel off and spun just the inner bit - it is gritty and irregular.

My big problem now is that it is New Year in Vietnam and all the shops are closed. :-( How long /far do you recon I can go on it before something 'bad' happens... I'm not actually sure what will happen.

On a positive note it only really noticeable when loaded.... is that positive?
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#5
As I said, Cones and Balls are replaceable. On 90% + of hubs, the Cup is not. It takes more to score or damage the Cup, thankfully. A ruined cup means a trashed hub. Time for a new wheel or a rebuild.

You can ride it until the balls grind into dust, but then you'll be walking it. Why not just have a layover and enjoy the Viet New Year! That sounds pretty cool.
Wheelies don't pop themselves. (from a QBP fortune cookie)
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