Sliding #$!@$~! seatpost!

[bdinger]

Okay, I found one minor annoyance about my LHT :). Like my Hardrock, for some reason the seatpost refuses to stay in one position without gradually sliding down. Any suggestions on how I can combat this? The seatpost clamp looks pretty good - it's a "Surly Constrictor" - and it's tightened down pretty darn tight. I just.. am at a loss on how to get it to "stay". Any suggestions?

[bigwies]

I have a similar problem last year when I picked up my bike. I tightened down the QR clamp, but the thing just wouldn't stop sliding. Then after about 4 to 6 weeks it suddenly stopped. I think it had to do with getting some road grit to stick to the grease on the seatpost, which then gave the clamp something rougher to grab onto.

I would check with your LBS. I think there is a type of grease that has some type of "friction enhancer". I would also check the Mechanics Forum for suggestions.

Good Luck

BTW, I love your new LHT. I have been looking at the Cross Check, the LHT and the Salsa Caseroll. Tough but fun dilemma to have.

[Air]

Some things to try here (http://www.bikeforums.net/showthread.php?t=28574) - could be a bunch of stuff.

[dewaday]

See if your LBS has some carbon assembly compound. It's basically a light grease with some tiny plastic abrasion added to increase adhesion. Works like a charm.

[The Historian]

Okay, I found one minor annoyance about my LHT :). Like my Hardrock, for some reason the seatpost refuses to stay in one position without gradually sliding down. Any suggestions on how I can combat this? The seatpost clamp looks pretty good - it's a "Surly Constrictor" - and it's tightened down pretty darn tight. I just.. am at a loss on how to get it to "stay". Any suggestions?

Could you replace the QR seatpost with one that tightens with an Allen wrench? QR seatposts and Clydes don't mix, IMHO.

[bigwies]

The Surly Constrictor is not a QR clamp.

http://www.surlybikes.com/parts/popup_images/parts_prodConstrictor.jpg

It sounds pretty heavy duty from the description.

[Air]

Could you replace the QR seatpost with one that tightens with an Allen wrench? QR seatposts and Clydes don't mix, IMHO.

Have one on my folder - never been an issue. Not a high quality one either.

When I did have a problem I found it wasn't seated right.

[fc_]

I have a lht as well, and have had zero problems with the seatpost slipping. First thing that I'd check is if the seatpost was over greased. You really only need a thin layer of grease to prevent bonding. Mark where you have your seatpost inserted to (a taillight or reflector clamp works without making a permanent mark on the seatpost). Take the seatpost out, clean it well with a degreaser, and then lightly apply grease to the area below the insertion mark, re-insert the seatpost and tighten things up. If you have grease coming up out of the seattube/seatpost junction, you've applied too much! Aside from that, you can try a different seatpost to see if that solves the problem (in case the tolerance on the original one is a bit off).

[Tom Stormcrowe]

Aluminum can be stopped from sliding by a light application of talcum powder to the seat post. This can cause the post to seize in the frame as well, though. I'd suggest the stuff they use for carbon seatposts as well.

[bdinger]

Okay, come to find that on the LHT Complete they don't use the Constrictor, but rather a cheaper allen-bolt type. Hrm, I think that's likely the problem right there, so I'll hit up the LBS over lunch and pick up a constrictor.

Also, I do think she was over-greased just by a quick inspection. I'm going to wipe it down to get rid of the excess on the seatpost, which hopefully should help the problem further.

Bike.. I love 'em! :D

[fc_]

Okay, come to find that on the LHT Complete they don't use the Constrictor, but rather a cheaper allen-bolt type. Hrm, I think that's likely the problem right there, so I'll hit up the LBS over lunch and pick up a constrictor.

Also, I do think she was over-greased just by a quick inspection. I'm going to wipe it down to get rid of the excess on the seatpost, which hopefully should help the problem further.

Bike.. I love 'em! :D

Interesting that they don't use a constrictor with the lht complete. I know the frame/fork on its own comes with a constrictor (at least mine did). Good catch on that. From their website, you need the 30mm version (they also have a 31.8mm size). Good luck with the new clamp!

[Wogsterca]

Okay, come to find that on the LHT Complete they don't use the Constrictor, but rather a cheaper allen-bolt type. Hrm, I think that's likely the problem right there, so I'll hit up the LBS over lunch and pick up a constrictor.

Also, I do think she was over-greased just by a quick inspection. I'm going to wipe it down to get rid of the excess on the seatpost, which hopefully should help the problem further.

Bike.. I love 'em! :D

Okay, an Allen bolt is actually better then a quick release, a quick release just make it easier for some bloke to steal your saddle, you can put a lot of clyde power behind an Allen bolt, just tighten that sucker as tight as it will go, without using an extender or lever to gain mechanical advantage..... I knew someone in the old days who had this problem, back when seat posts were steel, it was an old beater bike and he tack welded the sucker in place..... Solved the problem, hard to do with a modern AL or CF post though:D

Method one, remove the lube, put on just enough that the dissimilar metals don't corrode together (steel frame and AL post), and tighten that sucker down hard.

Method two, if the post is black, get some black spray paint, and add a thin coat to the post, this will increase the diameter of the post slightly, which should make it harder to slide up and down, and less likely to move on it's own.

Method three, go back to the LBS, tell them the problem, and let them figure out a way around it.....

Method four, get a second seat post clamp, mount it just above the existing one, on the seat post itself, and tighten that down, you may need to add a thin metal shim (like a piece of a pop tin) to make the post big enough for the clamp to work, but for the seat to move, it needs to move both the seat post binder, and the second clamp, which is much less likely.

Method five find a piece of the same alloy as the post, wrap it around, and tig weld it onto the post. That sucker has slipped it's last....... Of course, you may need to reharden the post, to give it strength.

I have always wondered, why adjusting the height of the seat is so easy, but the height of the bars isn't, as raising one, usually means you need to raise the other as well.

[Brad G]

Sounds crazy, but I have always used a little bit of pump hairspray on seatposts that do that to me. Just a little, let it dry and put it in. No more slipping. I have never had one seize on me. I still grease the lower portion of the seat post. I only use the hairspray on the small area in which the post contacts the clamp

[Air]

Hairspray is also great for putting grips on the handlebars - spray it on, slide them on when wet and when it dries it'll be stuck fast (if you need to get them off just work some water in there).

[George]

I went to the hardware and got some Loctite and it did the trick for me, good luck.

[idig]

This was one of the most annoying aspects of my Big Sur. I haven't had an issue with my LHT, at least not yet. I did replace the stock seat post with a Thomson Elite, so maybe that's what is saving me. I hope you get it fixed. It's a frustrating problem to have.

[tpelle]

Okay, come to find that on the LHT Complete they don't use the Constrictor, but rather a cheaper allen-bolt type. :D

Well, I didn't know that! When I read the title of this thread, I was going to suggest a Surly Constrictor, as I'm a 260 LB Clyde riding a Surly LHT, and have no problem with seat-post slippage. I just checked my LHT, and I have the Constrictor, but my bike was built up from a frame/fork.

[Torrilin]

Okay, an Allen bolt is actually better then a quick release, a quick release just make it easier for some bloke to steal your saddle, you can put a lot of clyde power behind an Allen bolt, just tighten that sucker as tight as it will go, without using an extender or lever to gain mechanical advantage.

Actually, that's one of the problems with Allen screws. A small female wimp like me can tighten 'em down enough to break the screw, with the standard tools, which means they give me enough mechanical advantage to bend hardened steel. If you've got an Allen driver instead of a key, it gets even easier. That'd be why I bought an Allen multitool. Less leverage so I'd probably break the key out of the case before I overtightened a screw.

Dunno if a Surly Constrictor or the stock LHT seatpost clamp have a stop to prevent over tightening. If they do, it's fine to whale away. If they don't... be leetle more careful *g*.

[idig]

For the record, my LHT looks like it has a Surly Constrictor as well. If it isn't a constrictor, it's a Surly something.

[tpelle]

I just looked at the Surly web site, and the specs for the LHT Complete. What is says for seatpost clamp is "Surly Stainless Natural Silver". It doesn't actually specify the "Constrictor". My seatpost clamp is not silver in color, but black, which matches the picture on their web site for the Constrictor.

I wonder if they get the Constrictor made to their spec in the U.S., but the complete bikes come from their vendor in the far east, who uses something different?

[bdinger]

I just looked at the Surly web site, and the specs for the LHT Complete. What is says for seatpost clamp is "Surly Stainless Natural Silver". It doesn't actually specify the "Constrictor". My seatpost clamp is not silver in color, but black, which matches the picture on their web site for the Constrictor.

I wonder if they get the Constrictor made to their spec in the U.S., but the complete bikes come from their vendor in the far east, who uses something different?

I'm not sure what the deal is, but the clamp is definitely not a Constrictor. I saw one in person, and it's MUCH MUCH MUCH beefier than the one on my LHT. Granted, the one on my LHT is pretty decent - and it has a nice surly logo stamped into it :) - but it's no Constrictor. The LBS has a Constrictor on order for me, though, and after getting some long-arm allen wrenches at Lowes my current one is tightened enough that it's not slipping too terribly bad. Once the new one is here I'm going to use the hairspray method and then really constrict the snot outta it.

As a sidenote, the Salsa clamps are awesome! I saw one, and MAN are they sweet. I'll probably order one to have around as a spare.

[idig]

I have a constrictor on order for my Big Sur. I should have it today, and will see how different it is from the stock clamp on my LHT.

[idig]

I stand corrected. I ordered a Surly Stainless clamp, which is what came on my LHT. I opted for it over the Constrictor because I figured stainless steel was stronger and more durable than aluminum. The Constrictor does have a stainless bolt, but I wanted an all steel clamp. I also figured if Jenson was charging $5 more for it then it must be better. Silly reasoning for sure, but that went in to my decision, so take it for what it's worth. I ordered it prior to picking up my LHT, so the fact that it had a stainless clamp did not figure into my decision. I now have the stainless clamp on both my LHT and Big Sur. I don't know when I'll get the Big Sur back out there to test the clamp, but it likely won't be anytime soon. The seatpost on my LHT has not budged at all. I don't think it's going anywhere. I can't believe you can't get yours to hold. I tightened mine until it started creaking, and then a nudged it a few more creaks.

[fc_]

As a sidenote, the Salsa clamps are awesome! I saw one, and MAN are they sweet. I'll probably order one to have around as a spare.

Oddly enough, one of my other bikes is a Salsa Casseroll, with the stock seatpost collar, lip lock I think, and the seatpost hasn't slipped either. :D

[Alathea]

Is there a magic formula for not overtightening the QR skewer? I had my seat post and saddle out this weekend adjusting the saddle and checking inside the tube and what not, but when I put it back in I realized that I didnt' count how many turns I had used to take it off. A website I read said "the lever should be tense at about the 1/2 way point before levering the rest of the way over". Is that the best im going to get? I don't want to over tighten it-Ive already deformed the barends a bit from when I put the locking collars on my Ergon grips. :-(

[Air]

To the point it doesn't slide around anymore ;)

I don't think you can crush the seat post with the QR skewer unless you really ape it - the skewer will strip first. If you have to ape it and it's still sliding then you may have to use a shim (cut a piece of aluminum can) or something similar.

[Alathea]

Cool. Ill stop analyzing about it. One bike only so I don't want to mess it up too much.

[Grandpa_Biker]

I've searched through several threads, following several links, trying to learn how I may remedy my sinking seat post. My LBH (I suspect that means Local Bike Shop :twitchy: ) only tightened the constrictor so that now, when the seat post continues to slide down the frame and I go to open up the clamp, I almost need to pull the lever with both hands:(

I find that I need to re-heighten my seat rougly every 10-15km (10 miles) as it has sunk 1 - 1 1/2 inches.

I did read that the problem may correct itself if I am patient and wait a few more weeks (my bike is barely 3 weeks old (Ironhorse Warrior), and has roughly 150 miles on it.

Any suggestions would be greatly appreciated.

[Wanderer]

Get a seatpost clamp that will only fit on the post itself. Then reinstall and tighten as normal. Then tighten the one on the seatpost after sliding it down to the tube it resides in. It will be a block.

[Grandpa_Biker]

Get a seatpost clamp that will only fit on the post itself. Then reinstall and tighten as normal. Then tighten the one on the seatpost after sliding it down to the tube it resides in. It will be a block.

THANK YOU That certainly makes sense :)