Bicycle Mechanics - Gunnar Rockhound Slipping Seatpost

Hi All!

I hope someone can give me some tips on this one. I have a circa 2002 Gunnar Rockhound with what is, from what I understand, a bad case of Gunnar Rockhound Disease: a slipping seatpost. This one is determined to slip. So far I've gone with a 27.2 Thomson Elite seat post and I've replaced the original seat collar with a Salsa Liplock spaced with four or five wraps of aluminum can (good excuse to have another beer!) to make certain the collar doesn't "bottom out". I've got the collar so cranked down that I'm worried about stripping. On yesterday's ride, you guessed it, it still slipped. My next thought is to switch to a Salsa flip lock and see if I have any better luck with a quick release (I'm not optimistic). Could this be a symptom of a problem with the frame?

Other than this one problem, I absolutely LOVE the bike! This thing basically reads my mind when I'm on it, which makes it an absolute joy to ride.

Anyone have any experience with this? Any ideas I haven't thought of?

Thanks!!

Hi All!

I hope someone can give me some tips on this one. I have a circa 2002 Gunnar Rockhound with what is, from what I understand, a bad case of Gunnar Rockhound Disease: a slipping seatpost. This one is determined to slip. So far I've gone with a 27.2 Thomson Elite seat post and I've replaced the original seat collar with a Salsa Liplock spaced with four or five wraps of aluminum can (good excuse to have another beer!) to make certain the collar doesn't "bottom out". I've got the collar so cranked down that I'm worried about stripping. On yesterday's ride, you guessed it, it still slipped. My next thought is to switch to a Salsa flip lock and see if I have any better luck with a quick release (I'm not optimistic). Could this be a symptom of a problem with the frame?

Other than this one problem, I absolutely LOVE the bike! This thing basically reads my mind when I'm on it, which makes it an absolute joy to ride.

Anyone have any experience with this? Any ideas I haven't thought of?

Thanks!!

What size is the collar?

Have you checked the Message Board over at the Gunnar site? There are at least a couple of threads discussing this, though there doesn't seem to be one universal fix. Some have luck with different posts, friction paste, different collars, etc.

I've got three Gunnars, none of which slip. On the other hand, my Marin Pine Mountain suffers from seatpost slippage, and I have yet to cure it. I tried friction paste, which didn't help. I tried different seatposts with no luck. The only thing that did work was using a bolt on collar cranked on as tight as I could get it.

Unfortunately, this is not the best solution, since the first collar I tried had the bolt snap in half before I could get it tight enough. I replaced it with a stronger bolt, but I still get nervous every time I tighten it (that bolt breaking was really loud and scared the crap outta me---kind of like blowing a tube).

I might try moving up to a 27.4 post (spec is 27.2), but I'm hesitant to put out the extra money if it's not going to help.

I did not read the Gunnar threads, but an ugly/temp solution would be to secure wrap or shim at your seat post height above the clamp. The wrap would rest on top of the seattube hopefully with enough friction to keep the post from slipping.

I hope you find a solution you like.

I've had seat post slipping with carbon seat post in carbon frame and alu seat post in steel frame. Remedy for me is Permatex Hylomar HPF available at auto supply stores. It's a sticky gasket dressing that doesn't harden. Provides protection between the frame and seat post and remains sticky to prevent slipping. I suspect that the Tacx, FSA et al frame prep products work the same way.

I've had seat post slipping with carbon seat post in carbon frame and alu seat post in steel frame. Remedy for me is Permatex Hylomar HPF available at auto supply stores. It's a sticky gasket dressing that doesn't harden. Provides protection between the frame and seat post and remains sticky to prevent slipping. I suspect that the Tacx, FSA et al frame prep products work the same way.

The Tacx paste actually has small granules in it, giving it a gritty feeling. I guess it would be akin to the old method of roughing up a post with sandpaper, but without having to actually rough up the post.

I tried using this stuff to alleviate my Marin's slippage issue, but it did not fix the problem.