Modern Buddy

When I rock the bike side to side it makes a knocking sound. I removed the cotter pin and castle cover and checked the hub nut. It didn't seem loose. I tried to give it a good snug just for good measure but that didn't seem to do much. So I put it all back together with a new cotter pin. It still makes the knocking noise. I've linked to a video of the knocking sound below.

Is this normal?

What else should I check that could be making the knocking noise?

Thanks!

http://youtu.be/ngFMFSWJuLc

I think mine did that. As long as it doesn't knock when you spin the wheel you're likely fine.

If you grab the rear spring/damper assembly can you wiggle it? Is it loose at the upper mount?

That is crazy. And when you stop wiggling the bike, the sound has to slowly slow down and get quieter and taper off even though the bike is still sitting still. That is weird.
Does it do the same thing if you just grab the wheel and wiggle it and not wiggle the entire bike? Put your stella up on the center stand with the rear wheel off the ground grab the wheel and wiggle it slowly and see if you can get the same sound.

jimmbomb wrote:Put your stella up on the center stand with the rear wheel off the ground grab the wheel and wiggle it slowly and see if you can get the same sound.

Yup, agree with this. Also, does it still make the noise if you step on the rear brake while wiggling the scoot?

Have you pulled the wheel all the way off? I'd remove it, check the rear drum/hub and brake shoes. I'd check the shaft and make sure that the drum fits properly and that nothing is stripped. Then slap it all back together and make sure to torque that rear axle nut to spec (93Nm/about 69 ft. lbs.).

But… hard to tell where the knock is coming from. Are you sure it's the wheel?

Sounds like a loose shock/shock with a brittle bushing.

I jacked the rear wheel up and gave it a wiggle. It doesn't make the same loud knocking sound but it does feel like something is ever so slightly loose...almost unnoticeable.

I will try it with the rear brake applied. If it does still make the sound will that be an indication that something is wrong with the brake?

I am picking up a torque wrench this week so I will remove the wheel and check everything out. While I'm at it I will check out the rear spring / shock too.

Thanks for all the advice! I'll post an update.

Sounds like a loose shock/shock with a brittle bushing.

After listening to the video - this sounds like a potential reason because there needs to be some significant flex & mass (like suspended scooter weight) that continues to cause the continued rocking back and forth like that - rather than just stopping.

Mike Zero wrote:I will try it with the rear brake applied. If it does still make the sound will that be an indication that something is wrong with the brake?

It might just mean that the drum/hub isn't on right. More of a "easy to rule out" check than a "highly likely" check because you'd probably feel it while riding if this was the case.

fisher1 wrote:

Sounds like a loose shock/shock with a brittle bushing.

After listening to the video - this sounds like a potential reason because there needs to be some significant flex & mass (like suspended scooter weight) that continues to cause the continued rocking back and forth like that - rather than just stopping.

You might be able to check this by moving the shock or holding it while rocking the scoot. It seems like it doesn't take much force to make the noise happen. The shock's easy to remove and check as well.

That sounds like the hub is not properly tighten or the wheel bearing have play. The wheel brake hub will act as an amplifier even the slightest movement and a well greased axle might allow the rocking after you quit pushing. Old drum type brakes on cars routinely made this type of sound. The sound difference a metal on metal shock will sound sharper as a banging, this is giving almost a base drum sound with sound resonating through the tire and hub.

its play in the hub mine dos the same thing and it only has 1800 miles on it