Seat post sleeve

chris folder

Well-Known Member
Hi :hello:anyone ever fitted a seat post sleeve on your Brompton? My seat post keeps slipping i have tightened seat post clamp up very tight cant tighten it up anymore and still slips when rideing. So will have to have a new sleeve fitted in the frame if you have fitted one yourself how is it to fit and what glue did you use?
 
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12boy

Über Member
Location
Casper WY USA
I tried DIY but failed. Used superglue for the sleeve and that worked but the sleeve was too big inside to allow the seatpost to pass. So I took fine sandpaper on a thick dowell amd sanded until it would pass and then had to tighten it way too much. My rear triangle hinge was also toast so I made a box, sent the bike to a dealer in Minnesota and they reamed the new insert and replaced the bushings and sent it back. My overtghtening the seatpost had ovalized it so a new one was in order, also. Works great now. If there is one thing I do not love on the B it is that seatpost arrangement. I have owned a lot of bikes and have refurbished some that had frozen seatposts but this was the worst seatpost PITA I have ever encountered. Don't know if the ream was truly necessary but my suggestion is pay a reputable shop to fix yours. Just wasnt worth the aggravation to do it myself.
 

reppans

Active Member
I found my seat post slipped due to skin oils from my hands when I grabbed the seat post to fold. Try removing the seat post and wipe it down with alcohol, including the mating surfaces of the plastic sleeve inside the seat tube. Then don't touch the seat post anymore and only fold the rear wheel by lifting the saddle.
 

mitchibob

Active Member
Location
London, UK
I think it's really important not to over-tighten the clamp, as on my first Brompton, putting a little too much into the seat-clamp stopped it working properly at all, and was replaced a few days later. I actually bought a cheap titanium seat post for my newer brommie this year, and while it's Brompton 'compatible', it lacks the finesse of a decent Brompton part (i.e. you can pull it straight out as it's not flanged at the bottom), but it's 300g lighter, and little more comfy and doesn't tend to slide much, once about a half turn was added to the seat post clamp nut, although, perhaps due to super firm suspension (near non-existant), I do have to stick an additional quarter turn in about once a month perhaps.
 

chriscross1966

Über Member
Location
Swindon
It's a service spare that really needs the shop to fit. If its slipping your first thing to do is thoroughly clean and degrease the post and the liner. I go through a liner every 2-3 years or so.
 
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chris folder

Well-Known Member
Hi guys ok :okay: i see you can buy the seat post sleeves but hard to fit them yourself i spoke to a Brompton dealer he said they need to fit them as it needs to be reamed and they have the tool for doing it. Chris when feel you need a new sleeve fitted have you got your seat post clamp nut screwed on quite alot from when the sleeve is new?
 

chriscross1966

Über Member
Location
Swindon
Not really, i use knurled nuts and do not expect it to be more than hand tightwhen open and not to take a lot of effort to close. When it starts to drop when riding and cleaning doesnt fix it i replace it. You need a 32mm reamer and rubberised superglue that needs to be refrigerated, its also important to clean the old glue off too. If you know what you're doing it takes about an hour. My first one took nearly four.
 

TheDoctor

Resistance is futile!
Moderator
Location
Stevenage
What others have said - try degreasing the seatpost first. I had exactly this problem, and a good wash with Mr Muscle did the trick.
 

Beter Poutakis

New Member
Location
North America
It hasn't been quite a month yet since picking my Brompton. The seatpost recently began to slip. Reading this thread, I've only 'slightly' tightened my clamp. Problem resolved... for now.
 

chriscross1966

Über Member
Location
Swindon
It hasn't been quite a month yet since picking my Brompton. The seatpost recently began to slip. Reading this thread, I've only 'slightly' tightened my clamp. Problem resolved... for now.
Check it with a torque wrench once you've cleaned it ... most new owners don't have a visceral understanding of how clean the seatpost needs to be, I certainly didnt.
 
Easy enough job. Break the old sleeve out and clean up the seat tube. Get the new one (mine came as a pair;; if so,, try them without glue and use the one that works best).

The glue I used was Unibond Repair Extreme Power Glue (Wilko sell it). The sleeve did not require reaming afterwards.
 

dagtontv

Member
Easy enough job. Break the old sleeve out and clean up the seat tube. Get the new one (mine came as a pair;; if so,, try them without glue and use the one that works best).

The glue I used was Unibond Repair Extreme Power Glue (Wilko sell it). The sleeve did not require reaming afterwards.
rogerzilla

My saddle is beginning to slip and move rather too easily and I need to get it replaced. It sounds as if you were able to remove the old sleeve cleanly enough, any special tools required? I have made other repairs to my Brompton how long will it take?

dagtontv
 
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