Swing arm bearings

[Grumpy old man 4,673]

Hi

Out on a ride today and the bike ( Nc750x) developed horrible vibrations,  like  a very exaggerated engine throb at certain revs, revs were it normally vibes but really exaggerated.  On inspection at home while checking chain tension I discovered play in the swing arm bearings, when pressing up on the chain slack I could see the arm moving. Now! Could this be the cause of the said vibes? Funnily enough the bike passed it's MOT last week.

 

Cheers 

Lloyd 

Edited June 1, 2020 by Grumpy old man

[outrunner 4,457]

I wouldn't have thought so, worn swing arm bearings are more likely to make the bike handle funny. Could be the chain, but I could be wrong, it has been known. 

 

Andy.

[Grumpy old man 4,673]

4 minutes ago, outrunner said:

I wouldn't have thought so, worn swing arm bearings are more likely to make the bike handle funny. Could be the chain, but I could be wrong, it has been known. 

 

Andy.

Hi Andy 

New chain and sprockets 500 miles ago. I removed the swing arm and greased all the bearings at the same time and they all looked good then.

[outrunner 4,457]

Well, in that case it's knackered and I would sell it if I were you. On the other hand I have no idea what is wrong with it, sorry.

 

 

Andy.

[Slowboy 20,426]

I'd run a spanner over the engine mounting bolts, just in case they've come a bit loose. Other than that, I'd fix the swing arm bearings anyway and see what difference that made.

Brian

[Grumpy old man 4,673]

52 minutes ago, slowboy said:

I'd run a spanner over the engine mounting bolts, just in case they've come a bit loose. Other than that, I'd fix the swing arm bearings anyway and see what difference that made.

Brian

Thanks Brian that was the plan. Any suggestions on sourcing bearings? 

Cheers 

[Slowboy 20,426]

3 hours ago, Grumpy old man said:

Thanks Brian that was the plan. Any suggestions on sourcing bearings? 

Cheers 

 

Not really, I try and buy decent ones (SKF) from a decent supplier, like Bearing Services Limited but don't really buy them often enough to know what's current. Any one else?

[rjp996 1,091]

i changed my bearing - its a needle bearing and only source for the size I could find was Honda. They were not crazy expensive, but were hard to get out - I ended up using a die grinder bit in a dremel to grind the outer ring until thin and then broke it out easily with a screwdriver - once I wen this route it was a 10 min job (using a blind bearing puller / slide hammer too all day before I gave up - if I do this again, its the Dermil from the outset

[djsb 491]

39 minutes ago, rjp996 said:

i changed my bearing - its a needle bearing and only source for the size I could find was Honda. They were not crazy expensive, but were hard to get out - I ended up using a die grinder bit in a dremel to grind the outer ring until thin and then broke it out easily with a screwdriver - once I wen this route it was a 10 min job (using a blind bearing puller / slide hammer too all day before I gave up - if I do this again, its the Dermil from the outset

Not something I'd like to risk myself as too much risk of damaging the bearing seating and a lot of flying fragments of steel that could cause injury. Surely this would only work on the roller bearings for the dog bone linkage and NOT for the ones in the main swing arm pivot. I did think about how I would remove the bearing when I had my swing arm off. They were OK but I would use a blind bearing puller myself.

[rjp996 1,091]

2 minutes ago, djsb said:

Not something I'd like to risk myself as too much risk of damaging the bearing seating and a lot of flying fragments of steel that could cause injury. Surely this would only work on the roller bearings for the dog bone linkage and NOT for the ones in the main swing arm pivot. I did think about how I would remove the bearing when I had my swing arm off. They were OK but I would use a blind bearing puller myself.

I think you are correct - the roller bearings were in the dog bone block and normal in swingarm - I did all at the same time and forgot what was in what ;-) the non roller bearings came out ok - I would have pulled one side and used a long bar to get the other out once I had access (my side hammer is not large enough really...)

[Grumpy old man 4,673]

38 minutes ago, rjp996 said:

I think you are correct - the roller bearings were in the dog bone block and normal in swingarm - I did all at the same time and forgot what was in what ;-) the non roller bearings came out ok - I would have pulled one side and used a long bar to get the other out once I had access (my side hammer is not large enough really...)

Looking at the manual the swing arm has a mix of roller bearings and needle bearings.  As it happens I took a torque wrench to to it and got another 2 - 3 turns before hitting the correct torque and it took up all the free play and sorted the excessive vibes.👍.

[outrunner 4,457]

1 hour ago, Grumpy old man said:

Looking at the manual the swing arm has a mix of roller bearings and needle bearings.  As it happens I took a torque wrench to to it and got another 2 - 3 turns before hitting the correct torque and it took up all the free play and sorted the excessive vibes.👍.

Glad you got it sorted Lloyd but I find it strange that it was the cause of vibrations at certain revs.

 

Andy.