bikertoqut

Hi everyone,

I appreciate your help on this issue. I bought a Kettler exercise bike a few months, ago. It is quite old, though I think it has quite a lot of life in it and I want to avoid replacing it if I can.

It starts emiiting a "squeeking" noise once I start using it. (video in link below). ThIs gradually changes to a "clink" or "clud" sound once on each rotation. It is quite loud and easily enough to put me off using it.

I have pulled the case off of it to get a better look at it, tried oiling it (that does not work) and checked the crank socket - which is tight enough. So I am still trying to figure out what is causing the noise and how to fix it.

If anyone has experience with a similar issue, and is able to point me to the issue, I will greatly appreciate your help. i really want to fix it (if possible) as it is a good exercise bike, save for one small drawback.

Link to bike noise: https://streamable.com/kwn95w

Andrew R Stewart 

Gosh that noise is awful! It is rhythmic with the cranks so the first thing I think of is a BB that needs lube. You could detach the drive belt and only turn the cranks to see if it is there. Andy

Iride01 

Might also sound like the belt is slipping a little somewhere. They make belt dressings you can probably get still at auto part stores or elsewhere. Might just be a temporary solution if the belt is too dry.. so to speak.

And possibly the belt is just too tight.

bikertoqut

Thanks for the reply and advice guys. Most helpful !
The noise is awful Andrew! I have some good over ear headphones, even whilst having them on listening to something at a lound volume, the noise is persistent and loud enough to distract and disturb anything I listen too !
I too thought the same Andrew, unfortunately I don't have the right size ratchet piece to get the crank off at the moment, likewise getting the drivetrain shall be a feat as the bolthead is so awkwardly placed and hard to get at I may have to improvise to find a way to get some leverage on it to move it ! A friend of mine should have some tools to help so I will be trying to get them next time I can when I am over that way.

After taking a closer look, with the eye and ears only, I suspect that the belt is rubbing on either side of the guide rollers pictured. (In fact I know it is, see both pictures below) But this is what I suspect is causing the noise, because:
A: Part of the belt is fraying on the left, - this is from friction rubbing up against the left side of the guide rollers as it moves forward. (I peddle forward alot)
B: The belt is not fraying on the right side as I don't peddle backward all that often.
C: Fraying is an obvious sign of friction - which can result in noise.
D: The noise occurs as the belt comes in contact with the roller to the left or right and stays in contact with it - not when it is moving from left to right (the roller is wider than the belt, so it has a small portion of time when I rotate the pedals from forwards to backwards or vice versa, that the belt needs to transfer to the other side of the roller.) You can see this in the picture as the belt is rubbing up against either side depending on which direction I am peddling. Forwards - it rubs left, backwards, it rubs right.
E: The sound does sound like something that would be caused by these materials colliding.
F: The noise seems to "echo" near the spring at the back, so when I put my ear close, that is where the noise appears to be coming from. Not the crank.

Picture of belt going forward (rubbing on left side of roller where fraying has occured on that side of the belt.) https://streamable.com/wp3mcy
Picture of belt going backward - friction now on right side of belt. https://streamable.com/lhgrkh
In the picture of the belt going forward, you can see a small gap between the belt on the right and the right side of the roller (which catches it and rubs when the peddles are moving backwards).

I think the way the bike is designed is intentional for the belt to rub on either side of the roller. So my main question for me ot resolve now is, do I replace the belt? Or is it a case of lubrication, I suspect there should be some way of fixing it. I might have a look at contacting Kettler and see if I can get any tips from them.

I will keep this thread updated as I progress. Cheers guys.

bikertoqut

I finally heard back from Kettler. She said she cannot help by sending the email data to the analysis team, but did say she thought the issue is the ball bearings.
Which I guess is probably a positive considering they should not be expensive to replace. Just disassembling the bike in order to make the change is probably going to be the hard part
as it may require tools I do not have at the moment. I don't know when I will be able to do this, hopefully sometime soon and will aim to post here once I have some more progress.

FBOATSB

Looks to me like the pulleys are out of alignment and are eating the belt. Like somebody once took it apart and didn't reassemble correctly or somethings bent.