Powerfly What grease or spray lube won't rot rubber?

[Expidia]

One month old 2022 Powerfly and I’m still getting an annoying crackle/creaking sound which I thought greasing the seat rails would help, but it's not coming from the rails (or the dropper post).

It sounds like the sound of the cheap thin store plastic water bottles making a crackling sound in the cage.

I found I can now replicate it replicate it by standing on the side of the bike and leaning over with my weight forcing the rear frame up and down. Closest I can pinpoint the sound is the top eyelet of the Rockshox. I think it's called a DU rubber bushing that is in the eyelet. Rather than lose the bike for two weeks at a Trek store under warranty I'm thinking of removing the bushing, inspecting it and check with Trek C/S to see if they recommend a lubricant for it.

If it’s bad, I can have Trek send me a new bushing (or just order one online). But I also I want to rule out that it’s not a defective shock itself. The reason it’s taken me so long to complain about the noise is that I always thought it was coming from a rear rack bag. Now that I use a back pack I know it was not from the bag.

Anyone else experience a creaking issue where the rear shock attaches to the frame on a Powerfly?
Thx

 

[slomtbr]

Silicone based lubricant.

 

[RustyIron]

I'd be surprised if the bushing is rubber. More than likely, it's Delrin or some other high-zoot plastic. Usually clearances will be really tight. You can use whatever petroleum based grease you'd use on any other bike part. Since you already have the bike apart, do both ends of the shock, and the pivots, as well.

 

[Expidia]

I'd be surprised if the bushing is rubber. More than likely, it's Delrin or some other high-zoot plastic. Usually clearances will be really tight. You can use whatever petroleum based grease you'd use on any other bike part. Since you already have the bike apart, do both ends of the shock, and the pivots, as well.

Thx for your reply. It's not apart yet as I was waiting to bring it over my son's house in a few days. Then I can sit on it and bounce up and down replicating the sound while he uses this automotive stethascope that I have to pin point where the creaking is coming from.

 

[steve_sordy]

............while he uses this automotive stethascope that I have to pin point where the creaking is coming from.

Now that's cool!

 

[TheRealPoMo]

I had very similar symptoms....did the usual seat post and rails, headset, cables but cured it (no doubt temporarily) by showering the rear suspension linkages and shock with a gentle hosing. I guess dust gets in there. If I didn't avoid using water as much as possible it probably would not occur.

 

[Expidia]

Post updated with vid of the noise: https://youtu.be/YWXzJT9TQ3E

 

[Expidia]

Update: Ya , my son figured it out tonight. It was two loose screws under the back of the seat that hold it tight to the rails. I never knew they were under there! When these bikes come into the stores they are partially unassembled and they probably have kids putting them together. No more clicking noises now