Scratching on Reverb shaft

Th3P

Good evening

I'm hoping someone can help, I've just finished cleaning my bike ready for an upcoming race and noticed a scratch down the rear on the Reverb shaft very light in feel.
This must have happened on my last ride as I have photo from before with no scratch.
What could cause this?

I've checked and doesn't seem to be any debris around the seal and I have loosened off the seat post clamp encase this could be the case?

Th3P

Sorry forgot to add a few other details its a Reverb Stealth that came on a new Whyte 129 works which I've only had 2 months.
Its cleaned after each ride and I apply Fenwick's suspension lube weekly

Here's some photos

https://www.dropbox.com/sh/5gaohvkrjmyc ... DprBksGzoa

stubs

Looks a bit terminal that if the black anodising has come off that quick I would say assembly fault. If its only 2 months old take it back and you should be given a new one I dont think it looks rebuildable though I am not an expert on Reverbs never having seen inside one.

Contact the seller straight away with plenty of pics if bought online or take it back to shop. Be polite but firm that is totally unacceptable on a 2 month Reverb people have used them for 3 years plus and had no wear on the shaft.

stubs

I have just blown it up and it looks really bad it is a gonner that grey goo on the seal is aluminium and oil by the looks of it. I wouldnt use it till your sorted or you could have to pedal home with the saddle right down

rockmonkeysc

Either it's bent or something is dragging inside.
Worth trying for a warranty repair/replacement. If that fails you can get spares for a diy rebuild or TF Tuned do Reverb repairs.

marcus'73

I had a similar issue some grit got into the collar and scored the shaft -no where near as badly as the example here and although it still functioned it leaked air and sagged slightly in use. Took it in to my LBS and they looked up the parts prices to repair it and reckoned that it was over £100 in parts alone -I guess because the RRP is so high. They recommended using it till it died and then buying another. I ended up buying a new one as it was only an extra £65 on CRC at the time. I didn't think I'd get anywhere on a warranty claim as even though it was only six months old it wasn't really a manufacturing fault as such. I think you need to stay on top of keeping the top nut tight as when it works loose during use and you get movement between the shaft and main body it must let crap in past the seal.

The Northern Monkey

Does look like some crud/grit has got in there and scratched as it goes up/down.

These things baffle me a bit, forks take a huge amount of abuse and with stand mud, grit, water etc etc so why cant the same tech be put into seatposts?!

Dick Scruttock

A dropped post takes a huge amount of abuse, arguably more than a fork due to the forces applied to it.

Th3P

The Northern Monkey wrote:

Does look like some crud/grit has got in there and scratched as it goes up/down.

These things baffle me a bit, forks take a huge amount of abuse and with stand mud, grit, water etc etc so why cant the same tech be put into seatposts?!

This was exactly my thoughts when I saw this.
Anyway, Great news I was riding in Ard Rock Enduro this weekend (yesterday) so took the bike over to the SRAM tent and showed the guys who asked if they could dis-assemble and take a look.
I returned twenty minutes later and there it was with a new Reverb fitted, He explained this is the first he and his colleague have seen this issue so would rather replace and investigate so really glad i took it over. They wanted no money for this so i made a donation to World Bicycle Relief on behalf of SRAM so great result and if you get/see anything similar get the manufacturer involved

Great to see manufacturers presence and support, I realise this fault shouldnt occur or develop but I do really appreciate hassle free support!

Thanks to all that posted, I now need to find a replacement rear tyre as the Nobby Nic just doesnt seem to cut it 2 rears (and therefore two new rear tyres) in 2 months!

stubs

Rick Draper wrote:

A dropped post takes a huge amount of abuse, arguably more than a fork due to the forces applied to it.

Huh :? a fork is sliding up and down thousands of times in a ride takes a hell of a lot of bending force and is always takng your weight. A dropper post moves a few times and when its steep or bumpy and dropped its not even taking your weight. If a set of forks lasted as many cycles as a post we would be fitting new forks every ride.

rockmonkeysc

stubs wrote:

Rick Draper wrote:

A dropped post takes a huge amount of abuse, arguably more than a fork due to the forces applied to it.

Huh :? a fork is sliding up and down thousands of times in a ride takes a hell of a lot of bending force and is always takng your weight. A dropper post moves a few times and when its steep or bumpy and dropped its not even taking your weight. If a set of forks lasted as many cycles as a post we would be fitting new forks every ride.

Ricky is correct. The bending forces on seat posts can be massive and the shaft is tiny compared to the diameter of a fork stanchion. If your frame has a slack seat tube the bending forces through it as you hit big bumps or compressions while seated (we try not to, but it happens) can be greater than your forks are likely to see. Plus, a fork see's it's greatest bending forces usually when at least partly compressed.
Personally I have bent three or four 27.2mm seat posts, I haven't measured it but I would guess that a reverb post's piston shaft is a similar diameter.

The Northern Monkey

So why hasn't my normal 27.2mm seatpost bent yet?

I put it up and down all the time (albeit manually)... I don't see the difference.
Although, that's a non-argument as reverbs don't come in 27.2.