Strange sound

[Grandad]

The sound is similar to the "twanging" of spokes bedding in on the first couple of revolutions of a new wheel.

Bike is an Orbea Gain with 32 spoke wheels so this was my first check. No problems there, even after 18 months regular use. I use the motor for less than 10% of all rides.

Next thought was the drive train, but it also occurs when freewheeling.

Now stuck for ideas.

[Jdsk]

Can you hear it when the bike's on a stand?

Can you put a recording on YouTube or Dropbox or somewhere?

Jonathan

[cycleruk]

If it still does it when freewheeling then logically it's going to be the wheels. I used to have a wheel (rear) that made a noise when the tyre pressure dropped. (drive side spokes weren't tight enough). Started doing it after I had it some time, not when new.
Other thoughts would be the bearings or freewheel?

[Richard of York]

Had a spokey type pinging sound start going up a 10% hill the other day. Never happened before on this bike. RD "spare" cable had just got close enough to brush against spokes. Always worth checking for the easiest options first.

[cycle tramp]

I had the exact same thing this weekend. Lots of twanging from my rear wheel. Couldn't find the issue - then it occurred to me I left my wallet chain unclipped from my shorts and it was just long enough to reach the inner edge of the rear wheel....

[531colin]

The sound is similar to the "twanging" of spokes bedding in on the first couple of revolutions of a new wheel. ......

If it walks like a duck and quacks like a duck........

[Valbrona]

Bit of spoke bedding in, loosening, twisting, re-confabulation ... you know the thing.

Might be worth dropping in the wheels for a re-tension/true when there are more miles on them.

[CREPELLO]

My old Gal had a wheel that did this. It was an Elesa Endeavour rim, double-walled with those spoke well cups that rivet the two walls together. If they are made with cheap plated steel they can corrode leading to noise. On my wheel they had rusted. A squirt of PTFE spray applied sparingly* around the top of each cup joint and excess wiped away - this soon cured it.

* too much spray lube and it risks migrating to the inner tube then...............bang!
There's always dry PTFE lube as well.

[531colin]

viewtopic.php?t=131049
I think those wheels have "history".

[Grandad]

Definitely spokes. It is now more constant and as I stopped after the last ride I stood astride the bike then sat back on the saddle with one foot on the ground and got the twanging.

The spokes are much thinner than the ones on my other bikes and there's only 32 of them. This seems a flimsy setup for a hub motor so I will get the wheel rebuilt with more substantial spokes.

I've since learned that a club member with the same bike has already been through this procedure.

[rogerzilla]

Spokes only ping on a first ride if the wheelbuilder left twist in them. If that is the case, you need to find a new wheelbuilder!

[Grandad]

Spokes only ping on a first ride if the wheelbuilder left twist in them.

Agreed, but this has occurred after 2000+ miles. They ping when I just sit on the bike and if I then stand up and then sit down again they ping again - this rules out any other source of the noise.

I doubt that Orbea have a wheelbuilder as such but my LBS has

[rogerzilla]

Does the rim have eyelets? These can corrode a little where they are pressed into the rim, and cause the rim to creak in a similar way. The cure (apart from buying a different rim next time) is a drop of oil on each one, which shuts it up for a while. DRC ST19 rims are terrible for it.

[Grandad]

Will check - that could be a cheaper option!

[rogerzilla]

https://yarchive.net/bike/rim_noise.html

The late Jobst Brandt on the issue.