Sllipping seat post -when you have tried everything?

Just built a rigid Cotic Solaris and for the first time in 25 years I have a slipping seat post issue. Thomson elite with hope QR.

I’ve googled the hell out of this and tried all the traditional remedies like clean and lube the seat clamp assembly and use mine minimal grease. I’ve even tried carbon slip paste. I’m tightening the QR as much as I dare (and I’m quite daring!)

I have read that Thomsons are notorious for this but it simply shouldn’t be the case for premium kit like this.

Anyone got any further ideas before I start buying different seatposts?

TBH I’ve no idea why Thomson are considered a premium brand. Their stems often fail on the face plate and the seat posts are distinctly average. Luckily people like them so if you stick it on eBay you’ll get enough for a cheaper, better post. Could try a different clamp. I like Salsa but Hope should be ok.

I once switched out a Hope for a Salsa seat clamp to stop this – carbon paste was a good shout too.

Carbon paste (on ali bits) sorted mine, couldn’t change the clamp as it’s an integrated part of the frame

I had exactly this. Thomson post,solaris frame and constant slipping. Swapped post for a hope eternity and problem solved. As you say this shouldn’t happen with a brand like Thomson.

Ditto Thomson, creaked like something awful on Soul, reverb doesn’t, raceface doesn’t. Sell the post 😀

Thomson posts often come in slightly small try a coke can shim. Also hope clamps aren’t great in my experience salsa is far far better.

Never ever had a problem with any of my thomson seatpost in any of my bikes…On One, Kona, Cove, Marin but have had poor experience with Hope seat clamp x1 and a salsa which I found to be utterly hopeless. A newer stripped down, lubed Hope clamp worked fine.

Xcracer shop has a thing for this- never tried it but it looks good

http://www.xcracer.com/shop/viewproduct.php?productid=351

Clicked this thread thinking “Thomson post” and what do you know….. Tried some calipers on the post to actually measure it?

Similarly if I see a thread about hubs not fitting in dropouts you just know it’ll be hope…

Xcracer shop has a thing for this- never tried it but it looks good

http://www.xcracer.com/shop/viewproduct.php?productid=351

One of these.
I had issues with a slipping Thomson post on my CX bike. I fitted the KCNC thing and it never slipped again. Well worth a fiver.

Double seatclamp, but you’ll lose the qr function.

Had the same problem a wile back I put some carbon past on the post problem solved aluminium frame and post

Despite being keen on most Hope stuff (apart from brakes) I have had issues with their QR seatclamps on two bikes with varied posts. Bolt through one has worked fine though. TBH I think all Hope QR fittings are crap.

http://www.xcracer.com/shop/viewproduct.php?productid=259

Try one of these, it’s basically a really light clamp, without any lip at the top of the clamp, meaning you can clamp it around the post itself just above the main clamp. It weighs bugger all, and also means you can whip the post out and get it back to the right height really easily.
I’ve been using it on a KCNC post in a Canyon frame and it’s worked brilliantly.

when you have tried everything

Have you tried changing the post?

got a thomson in my Ti road thingie and it’s perfect. put a use sumo in and
it’ll rattle around in the frame like it’s only 31mm instead of 31.6 !

coke can should sort you out though 🙂

Thanks for all the advice folks. I’ve taken a punt on anti-slip thing from xcracer for a fiver.

Fingers crossed.

Ive had a hope clamp where the lip at the top was thicker than the seat tube so just wouldnt work until id taken a file to it.

I have the same problem with a Thomson post in a Solaris. Going to replace the post when I’m not feeling so tight.

Grant – a cheapo Raceface Ride one cured the annoying creak that the Soul had with a Thomson, despite various carbon pastes.

I’ve taken a punt on anti-slip thing from xcracer for a fiver.

Fingers crossed.Fair enough. Keep trying to patch up the problem 😈

Only because I’ve done this……

Is the clamp the right way.. The split in the clamp is the same side as the split it the seat tube…

Had slipping seat post for ages until I turned clamp round. Solid as a rock now…

why you trying to make a super light build then using a QR ? bolt thru lighter and tighter.

Thanks Iain, sounds like a good idea.

Kcnc post to save some weight.

Anyways I’ve never had an issue with Thompson post but lots with hope qrs

hope QR

This is likely to be your problem, it’s not a great cam design ime. Takes a lot of force to clamp the post properly, eg compared to a salsa. Thomson posts have been good fits in the bikes I’ve had them in, a snugger fit than some others but a vernier will tell you if it’s undersized. The seat rail clamps can get creaky but that’s not realted to the frame fit.

Thomson posts also have that turned finish that if slipping isn’t caught quick it’ll wear quickly making the issue worse.

Fibergrip and bolt up clamp will sort it.

Hope seatclamps (be they QR or Bolt up) are a bit rubbish, salsa, thomson or Surly are much nicer.

In the first instance I’d be measuring both the post and the seat tube, as if both are at maximum (one oversized and one undersized) tolerance then you are asking a lot of the QR.

And if you want to save weight, look at a bolted clamp and an I-Beam post/saddle combo instead.

I’ve knurled seatposts to solve this issue. I’ve seen posts which are the right diameter, but the surface is so slick a normal clamp won’t hold it.

I once switched out a Hope for a Salsa seat clamp to stop this

This. I had some problems with various qr seat clamps including Hope on my Specialized full sus and ended up having to use a non-qr single bolt clamp, until a friend recommended trying a Salsa flip lock clamp. All good now.

Clicked this thread thinking “Thomson post” and what do you know

+1

1. Remove seat post.
2. Wipe it dry/clean.
3. Spray it with ordinary hair spray (not too much, just “pssst! pssst!”)
4. Insert seat post back into the frame.
5. Enjoy riding!

Tried and tested 8)

Only by replacing the Hope qr was I able to eliminate slippage, after already changing the post and using carbon assembly paste.

When i had this problem I read on here to put talcum powder on the seatpost ,try it,it actually works!

+1 to MartynS. Ensure slit to slit for proper action.

My Cannondale F29 with a Thomson seat post just fitted is slipping. The seat clamp has a pin in it, so you cant spin it round to be split to split with the frame. I also fitted a Thomson seat clamp, but it is too loose. They both fitted my Scandal without an issue. I might try that seat gripper by KCNC to see if it fixes it.

When the ribbed finish on Thompson seatposts wear down slightly, the slippage only gets worse. As stated above, carbon grease helps but its also worth seeking out a Cromag seatpost clamp as they have great clamping power which solved an issue i had with the Thompson post.

I ordered a KCNC clamp from Taiwan for £6 and also found that the lamping area in the seat tube was quite smooth, so used some very coarse emery cloth to roughen up. I also have coated the post in carbon grease stuff.

Carbon paste works wonders better than the other solutions as it means no new parts.