Axel issue

[Carlos the jack daniels]

Noticed a knocking sound on my back wheel thinking it was the axel may be bent but unsure. Is it worth fixing or just order a new hub ? I’ve got an eskute m100( I know) bought just to commute to and from work. Any advice would be appreciated thanks

 

[saneagle]

Noticed a knocking sound on my back wheel thinking it was the axel may be bent but unsure. Is it worth fixing or just order a new hub ? I’ve got an eskute m100( I know) bought just to commute to and from work. Any advice would be appreciated thanks

I very much doubt that it's a bent axle unless you've done something really daft.

Can you give us a better description of the knocking noise? Is it continuous or does it come and go? Is it a deep knocking or a tapping noise or what?

When did it start?
Have you taken off the back wheel, and did it start after that?
What happened to cause it to start or did you just get it out one morning and it was doing it?
How old is the bike and how many miles has it done?

Without giving us all this information, we've got no chance of helping you.

 

[Carlos the jack daniels]

I very much doubt that it's a bent axle unless you've done something really daft.

Can you give us a better description of the knocking noise? Is it continuous or does it come and go? Is it a deep knocking or a tapping noise or what?

When did it start?
Have you taken off the back wheel, and did it start after that?
What happened to cause it to start or did you just get it out one morning and it was doing it?
How old is the bike and how many miles has it done?

Without giving us all this information, we've got no chance of helping you.

It’s a sort of low clunk/ knocking every 1 wheel rotation, it started after I changed my brake pads about 2weeks ago!! The bike is not a year old yet ! It’s done about 700miles just on a road back one for to work(trying to avoid the potholes) is it my hub ? My crank shaft or something else ? It’s my only transportation to work so I’m getting a little worried. Cheers

 

[sjpt]

It could be the wheel out of true, and hitting the brake pads once every revolution.
I wouldn't expect a clink from that; but could maybe be called that.
Very easy to check. Spin the wheel and see if it has a wobble from side to side.
If it does, it needs truing, or has a broken spoke. A bit more difficult but plenty of instructions on the web.

BUT, I see you have disk brakes, so probably not that. A bent brake disc could cause it.

 

[matthewslack]

The online specification says 'mechanical disc brakes', and the noise started when you changed the pads.

Most of this type of brake have one pad fixed and one pad moved by the cable and mechanism. Did you adjust the fixed pad position when you replaced the pads? If not, it may be contacting the disc once per revolution, causing the noise.

Can you get the bike stood up with the rear wheel off the ground and rotate the wheel while you look carefully at it? Check the front as well if you changed those pads too.

A little bit of wobble in the disc is not harmful, and can be put right by carefully bending the disc straight. Only needs finger force.

 

[saneagle]

It’s a sort of low clunk/ knocking every 1 wheel rotation, it started after I changed my brake pads about 2weeks ago!! The bike is not a year old yet ! It’s done about 700miles just on a road back one for to work(trying to avoid the potholes) is it my hub ? My crank shaft or something else ? It’s my only transportation to work so I’m getting a little worried. Cheers

That's pretty easy then. Almost certainly the caliper is rubbing on the motor or the disc is rubbing on the caliper. You need to get your head down by the caliper to see what it is. Once you see what's touching, you should be able to determine what to adjust.

It could also be that the disc is rubbing on the pad, which you can solve by adjusting the caliper:

• First get the caliper straight by loosening the two screws that hold it to the adapter; pull the brake lever on as hard as you can and hold it like that while you retighten the screws
• Screw in the adjuster on the back pad (normally an allen screw that you access from the other side through the spokes) until the pad rubs on the disc when you spin the wheel.
• Back it off until it no longer rubs - no more than necessary.
• Turn the cable adjuster until the moving pad rubs on the disc.
• Back it off until it no longer rubs.
• That's it

One other problem I've seen is the top edge of the disc touches the top of the caliper because the washers aren't thick enough. the difference between hitting and not hitting can be microns. A good indication of that being the problem is when it's worse immediately after you used the brake because the disc expands a bit when it becomes warm.

 

[Carlos the jack daniels]

I very much doubt that it's a bent axle unless you've done something really daft.

Can you give us a better description of the knocking noise? Is it continuous or does it come and go? Is it a deep knocking or a tapping noise or what?

When did it start?
Have you taken off the back wheel, and did it start after that?
What happened to cause it to start or did you just get it out one morning and it was doing it?
How old is the bike and how many miles has it done?

Without giving us all this information, we've got no chance of helping you.

Also, this knocking noise is only when you ride the bike !! But nothing when you don’t.

 

[saneagle]

Also, this knocking noise is only when you ride the bike !! But nothing when you don’t.

When an axle bends on a motor like yours, it bends on the right side outside the motor and results in the gears jamming against the side of the motor so it doesn't freewheel anymore. To bend it, you'd have to be doing 6 foot jumps on one of those off-road courses. You don't bend an axle by replacing disc pads. Use logic and keep a clear and unbiased head.

 

[Carlos the jack daniels]

When an axle bends on a motor like yours, it bends on the right side outside the motor and results in the gears jamming against the side of the motor so it doesn't freewheel anymore. To bend it, you'd have to be doing 6 foot jumps on one of those off-road courses. You don't bend an axle by replacing disc pads. Use logic and keep a clear and unbiased head.

Have I put everything back together unaligned then ?

 

[saneagle]

Have I put everything back together unaligned then ?

How would I know? You haven't shown us anything and you've told us virtually nothing.

 

[Carlos the jack daniels]

That's pretty easy then. Almost certainly the caliper is rubbing on the motor or the disc is rubbing on the caliper. You need to get your head down by the caliper to see what it is. Once you see what's touching, you should be able to determine what to adjust.

It could also be that the disc is rubbing on the pad, which you can solve by adjusting the caliper:

• First get the caliper straight by loosening the two screws that hold it to the adapter; pull the brake lever on as hard as you can and hold it like that while you retighten the screws
• Screw in the adjuster on the back pad (normally an allen screw that you access from the other side through the spokes) until the pad rubs on the disc when you spin the wheel.
• Back it off until it no longer rubs - no more than necessary.
• Turn the cable adjuster until the moving pad rubs on the disc.
• Back it off until it no longer rubs.
• That's it

One other problem I've seen is the top edge of the disc touches the top of the caliper because the washers aren't thick enough. the difference between hitting and not hitting can be microns. A good indication of that being the problem is when it's worse immediately after you used the brake because the disc expands a bit when it becomes warm.

It’s only happening when there’s weight on the bike. Ie when I’m riding

 

[thelarkbox]

#1

Use logic and keep a clear and unbiased head.

If you suspect the brake pad exchange? temporarily remove the calliper and and test ride the bike for 40m or so or until the knock occurs.

#2 If a suggestion is proposed, report back on how testing the theory went or what detail omitted earlier rules it out.

#3 photos and pictures can illustrate a LOT. ib this case a sound recording or short vid may even prove fruitful.

#4 reconsider post #11

I dont know your bike, does sitting in the saddle change the bike geometry due to suspension? can you emulate this wih a ratchet strap? or something when the bike is up turned?

 

[saneagle]

#1

If you suspect the brake pad exchange? temporarily remove the calliper and and test ride the bike for 40m or so or until the knock occurs.

#2 If a suggestion is proposed, report back on how testing the theory went or what detail omitted earlier rules it out.

#3 photos and pictures can illustrate a LOT. ib this case a sound recording or short vid may even prove fruitful.

#4 reconsider post #11

I dont know your bike, does sitting in the saddle change the bike geometry due to suspension? can you emulate this wih a ratchet strap? or something when the bike is up turned?

Yes, that's it. Undo the two screws that hold the caliper, then tie the caliper up out the way, while you try the bike up the road and back. If the noise persists, it's not the caliper, so let us know.