Clydesdales/Athenas (200+ lb / 91+ kg) - Seatpost slowly lowering
Bikeforums.net is a forum about nothing but bikes. Our community can help you find information about hard-to-find and localized information like bicycle tours, specialties like where in your area to have your recumbent bike serviced, or what are the best bicycle tires and seats for the activities you use your bike for.
I have noticed that my seatpost slowly lowers itself (~1") over the course of a week or so of commuting. I weight ~275lbs and ride a stock LHT (as far as the seatpost tube is concerned). The local shop used grease in the tube as a protectant for the steel frame. The post is held in place via an allen bolt collar (torqued to correct spec). Any thoughts? Should I remove the grease where I'm trying to clamp? Yes, I know grease is slippery but I'm also concerned about developing rust inside my frame. Is this a Clyde issue where we just need to adjust saddle height every so often? Thanks!
04-12-10, 06:16 PM
you can always place a thin strip of duct tape just above the seattube-seatpost junction. it will provide extra resistance to the seat lowering
04-12-10, 06:17 PM
I would expect that when you grease up that area, you have to increase the torque to prevent the slippage. Unless you leave your bike in the rain, or commute in the rain and never dry it off or clean it, there shouldn't be excessive concern about rust.
04-13-10, 02:49 AM
no leave the grease cos thats what stops it welding itself to the frame!! seriously. you can get shims to fit your seatpost to get more grip or even make your own from a coke can;)
04-13-10, 05:36 AM
You could use a shim like Breadbin mentioned or you could just give that allen bolt another half turn to the right ;)
I had the same issue on my last frame. All I did was get one of those cheap seat post reflectors and set it at the union. It does not take much to stop that lowering.
Thanks everyone, I'll start with the tape trick and go from there. I -do- commute in the rain so I want to keep the protection :-).
04-14-10, 05:21 PM
If not too late, might I suggest instead?
Black 'friction' tape (AKA Electrition's tape) one tight loop so it will slide *inside* just enough so the tape does not show? Even the cheap plastic tape ought to do the trick for you. More binding than metal on metal, or, metel on lubed metal.
Just my $0.02 worth
04-14-10, 05:31 PM
You said it was an LHT? I'd contact the guys at Surly and ask their advice. And check out this post (http://www.surlybikes.com/blog/spew/spew_4_-_why_seatposts_slip/) on their website.
Surly also sells a super-duper seatpost clamp meant for heavier riders and MTB use.
Thanks for the link rockdog, I will try the tips in that article.
04-15-10, 04:50 PM
I had the same issue with the carbon seatpost on my Tricross Comp. I just tightened it up until it didnt' slide anymore. Didnt have a torque wrench...been ok for 2k miles.
04-15-10, 09:03 PM
Had the same problem with the carbon seatpost on my Sectuer Comp. Just tightened the crap out of it and it stopped moving.
Powered by vBulletin® Version 4.1.12 Copyright © 2013 vBulletin Solutions, Inc. All rights reserved.