Got a On One Inbred 29 er with a Thomson layback post and a Hope qr clamp. The bike is 4 years old. The post keeps slipping, not huge but some. Yep I am nearing Clydedale weight

However given Thomson and On Ones legendary quality control at either ends of the spectrum, how do I stop it slipping.

I was thinking acollar round the seatpost to stop it slipping

You can get double clamps, one part claps the seat tube the other part clamps on the seatpost.
Or try a dod of grease on the qr cam.

Thomson posts are notorious for slipping, buy a cheapy Decathlon one and it’ll be solid. Or even a RaceFace or any other brand really 😀

Is the split in the QR clamp (the bit where the bolt goes through) the same side as the split in the seat tube?
I had them opposites once and had a Thompson post slip, Line up the splits and all was good!!

Hope that makes sense!

Get a salsa clamp that will sort it out. Hope clamps aren’t great I find.

Put a wanted for a flip lock

Flip locks require greasing in my experience.
Other than that they work.

found one of these works fine – https://www.sjscycles.co.uk/seat-posts/307-272-mm-gold-kcnc-sc13-twin-seat-post-clamp/?sessionid=a2c4af599719c6241d37f614b1f9892d5bcc83e8 or if you have a spare clamp same as seatpost diameter clamp that above seatpost clamp

Try some carbon assembly paste. Worked on my Thomson/Inbred combo.

Not heard of QC issues with the inbred, my bet is on the hope clamp and/or Thomson post.

Clamp is cheaper fix, salsa flip lock would be my bet but not sure they still sell them so would go second hand. A new post wouldn’t break the bank so would be worth a shot.

Thomson posts are notorious for slipping

+1 Just won a bet with myself that this would be about a Thomson before opening the thread. I should’ve doubled on a hope seat clamp too.

Different seat post and a salsa clamp. If you stick your hope and Thomson on eBay you’ll likely come out with some beer money too

Cheers all, whats the deal with Thomson seatposts?

I like the lining of slits up idea,makes sense mechanically. I will try that first.

Clean and lube the clap bolt.

Notorious combo for slippage that.

Hope clamps are a bit shit, Thomson posts are slippy, in a steel frame particularly from what I’ve read, all elements combined do not make for a secure post.

Salsa clamp cured the problem on my Soul, and also barely greasing the post at all. Just remember to move it regularly so it doesn’t seize.

+1 for the Salsa clamp – an accidental discovery on my part, as the gold one appealled to my inner jackdaw.

As above, Thompson Seatpost plus Hope Seatcollar = much slippage.
Ditch the Hope for a Salsa and a touch of carbon paste.

Hope clamps need a good taking apart and thorough cleaning every year or so including possibly even a very very fine sanding on the parts that move against each other.

Otherwise you think you’re doing it up really tight but it’s actually just the friction of it’s own action you’re working against.

You can convert hope qr to bolt only with a few quids worth of bolt.