Strida noise (clicking? galloping?)

I’ve taken delivery of a Strida 5.0 and it’s making a galloping sound when pedalling:

https://www.youtube.com/watch?v=9aKKbNKOEmQ

Is this the ‘clicking’ sound I’ve read about or is it something different? I’ve greased the washers on the rear frame joint, but the noise seems like it comes the drivetrain. All help gratefully received!

I’d try to decrease belt tension first.

Thanks - will try that. Would it be too taut because of the unseasonably hot weather we’re having in the UK at the moment?

That is actually possible - Kevlar has a negative temperature coefficient, that means the belt becomes shorter if it is hot.

Edit: The correct term is “thermal expansion coefficient”.

Well, I managed to decrease the tension but only by hammering the bottom bolt, as the recess for the Allen key has been stripped out by the previous owner! Is the bolt a standard size that I can buy? Or do I need to go to Strida for it?

flic.kr/p/2jvLTN6

That happens if people don’t have a hook key :confused:

You could use principially a common Allen or hex headed bolt in size M8 x 16 mm.

I think I’ve worked out what’s actually making the noise - the outside edge of the rear sprocket is very close to the frame and it’s scuffing when under strain. The edge isn’t continuous, which was why the sound was intermittent (‘galloping’).

https://flic.kr/p/2jxy1mp

So now I have more questions: is it because the sprocket is slightly loose? Or is it something else? The belt shouldn’t pull so hard that it makes the sprocket ‘bend’ towards the frame.

I wonder why there are no collision marks left at the partial, flanged disc at the outside of the pulley.
But possibly they are just not visible on the image.

The sprocket must not be loose sideways (if it is I’d suspect worn out bearings).

Are you able to replace the freewheel?

Hmmm. So I loosened the belt a bit, and ended up replacing the wheel bearings in case it was them (surprisingly easy once you know how), but it’s still making the noise and I’m guessing it’s the freewheel now.

Is the removal tool for it Strida-specific? Or is it a tool that can be sourced easily?

No, that is a pretty common BMX tool :slight_smile:
Just check at my tool guide; scroll down to T.

I’m truly flummoxed now. I took the rear wheel apart - freewheel seems fine, and anyway the sound is happening when the freewheel is in motion, only when it is static (ie. when pedalling and the belt is turning the wheel). Also, I can make the noise stop if the freewheel is stopped in a different position on the wheel.

As it’s only happening when pedalling, it can only where a static part of the bike (the axle, frame, brake calliper) interacts with the turning wheel. So I’ve narrowed it down as follows:

  1. Definitely not the brake disc or calliper
  2. Not the bearings (replaced them)
  3. Don’t think it’s the freewheel for the reason above (although I’ve removed it, I can’t completely dismantle it at present)
  4. It’s not the crank or bottom bracket (checked that even though that’s not where the noise seems to be coming from)
  5. I’ve cleaned the belt and the teeth at the wheel and on the crank

So I think the noise is either coming from:

  1. Where the wheel bearing pushes against the big hexagonal bolt on the axle (part 340-08)
  2. Where part 338 pushes against the bearing (449) - maybe I’m overtightening it? (I have no torque wrench)

It’s so annoying because I’m loving the bike but the noise is annoying me no end!

Could you possibly record that noise somehow?

Chris, the first post contained this video, youtube.com/watch?v=9aKKbNKOEmQ

I think it would be a good idea to change the freewheel as I think that is where the noise is coming from.

Bill

Hi Bill,

thank you!
Sorry, wasn’t attentive and too fast.
:blush:

Yes - the video has the sound on it!

Thanks - I got as far as removing the freewheel, but the pins on my 2-pin removal tool were too big to unscrew the bearing race. I’ll get a better tool and then rebuild it - I’m guessing you think it’s the bearings from that sound and not something else that has worn out?

Yes, I think so.

Just why do you want to rebuild and not replace?

Because as far as I can see, a rebuild would cost pennies for the new bearings, but a replacement seems to be GBP50 wherever I look! The teeth aren’t worn at all which is another factor.

Pardon me, but which way would you replace the bearings ?
It seems one could just replace the balls.
(Which does not make sense for me.)

That’s what I meant - ‘bearings’ can also refer to the balls in English. To be honest, I’m still sceptical that it’s the freewheel making the noise, as it is in a locked position when the sound is happening, but it’s another thing to tick off the list.

A little bit further along - I wondered if the noise might be from the bottom bracket rather than the hub, and the noise was being transferred down the bottom tube to make it sound like it was at the back of the bike.

So I removed the bottom bracket and took the bearings out. I found this mess on one side:

I’ve ordered a new set of bearings. It’s important to note that, although the bearings in the bike are labelled ‘6002-2RS’, they aren’t the same size as those with the same name offered for sale on eBay etc. The dimensions are 31(outer dia.)x16(inner dia.)x10(width)mm so I’ve ordered some 163110-2RS bearings instead.