# New seat post clamp - to stop slippage.



## Kell (6 Jul 2019)

I’ve been reasonably happy with my seat post after it was initially slipping when I got it (4 years ago). 

But recently, it’s been dropping by about an inch whenever I ride it. 

Doesn’t seem to get any worse that that, but definitely does it every time. 

All those years ago, I bought another clamp as that seemed to be the advice at the time. But I never got around to fitting it as I scuffed up the seatpost and gave it a good degreasing and that seemed to cure it. 

So today, while I remembered, I got that seat clamp out and filed down the lip with a metal file then used 240>500>1000 wet and dry to make sure it was smooth and there were no jagged bits. Took about an hour in total. 

When I took the seatpost out I could see that the shin is in need of replacing as it’s coming apart at the back edge. 

Forgot to take any pics and I didn’t want to take it apart again just to shoot it. 

Hoping this will cure it until such a time as I can get the shim replaced. 

Anyone have an idea of cost?


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## Cycleops (6 Jul 2019)

Isn't there a paste you can buy that limits slip?
That premium Brompton sticker is looking a bit tired .


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## Kell (6 Jul 2019)

Cycleops said:


> Isn't there a paste you can buy that limits slip?
> That premium Brompton sticker is looking a bit tired .



There may be a paste that does that, but having taken the seat post out, I can now see that the problem is definitely with the shim. 

I have a sneaking suspicion that moving the seat as far back as it will go on the rails will have contributed to this, if not directly caused it. 

That sticker’s been like almost since I got it.

I think i might have kicked it as I stepped through the frame.

I keep on meaning to remove it completely as it does look rubbish.


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## chriscross1966 (6 Jul 2019)

Sounds like time for a new post liner, four years is a long time on those, my daily rider eats one a year now at about 10 miles a day


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## Kell (7 Jul 2019)

chriscross1966 said:


> Sounds like time for a new post liner, four years is a long time on those, my daily rider eats one a year now at about 10 miles a day



Am I right in thinking you replace yours yourself?

I seem to remember you saying that you do, but it’s not for everyone.


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## Schwinnsta (7 Jul 2019)

I basically did that too. It works. If the dealer option for replacing the shim was less expensive, I might have done that. It works. Only downside is it is one more clamp to fuss with when your folding it up.


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## Kell (8 Jul 2019)

Well, I can confirm there was no slippage this morning.

oo-er


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## 12boy (9 Jul 2019)

I tried to do it myself and that didn't go well. I wound up mailing it to a Brompton shop 1200 miles away and had the rear triangle spindle done too. They used a reamer and the seat post has worked well for months..if you have tightened the QR tighter and tighter to avoid slippage you may have ovalised the seat post just like I did before I got it fixed by the shop.. The double QR thing does work, although I am too anal to accept that long term.


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## chriscross1966 (9 Jul 2019)

Kell said:


> Am I right in thinking you replace yours yourself?
> 
> I seem to remember you saying that you do, but it’s not for everyone.


Yeah it's probably not for everyone, i have a 32mm reamer in my workshop and that thing isn't cheap unless you get lucky on ebay... plus the rubberised superglue they use is pretty odd.. it's not a hard job and i will likely be doing one this weekend as i have some longer rides coming up


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## Kell (14 Jul 2019)

Well, I got lucky and managed to get the sleeve replaced in a couple of hours.

The guy said that the sleeves now come pre-reamed and therefore his £500 reamer is now pretty much redundant.

Although I have to say, I assumed the reamer was for the seat post. Shows how much I know. 

He also confirmed that there was pretty much no material left on the rear of the sleeve.

Definitely should have replaced it before now.


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## Kell (15 Jul 2019)

Having ridden it this morning I can also confirm that the awful squeaking that I thought was the rear triangle has also gone.


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## ukoldschool (6 Aug 2019)

Where did you get it done @Kell ?


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## rogerzilla (10 Aug 2019)

I replaced mine and it worked perfectly without reaming. However, Brompton are utter swine now and won't allow the majority of parts to be sold to end users, so you have to pay a dealer to fit everything. I wouldn't buy another one because of this. You used to be able to get everything, which was the big advantage over a Far Eastern folder. What do you do if your nearest dealer is 50 miles away?


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## RegG (11 Aug 2019)

My daughter has just bought a (brand new) Brompton and I borrowed it to take on holiday last week.

I was disappointed to find the seat post slipping 2-3cm after just 2 or 3 miles. I didn't want to tighten the clamp bolt at this stage as it is a new bike.

I've emailed Brompton but am still awaiting a reply. My daughter hasn't got a lot of faith in the dealer as they didn't even know how to fold or unfold the bike when she went to look at one!

Surely this should not happen on a brand new bike?


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## rogerzilla (11 Aug 2019)

Pull the post out (remove the saddle, pull it out from the bottom) and degrease it and the sleeve with meths or similar. A bit of grease or oil on the post can cause slippage. If this doesn't work, tighten the nut just enough to prevent slippage when you bounce on the saddle.


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## RegG (12 Aug 2019)

rogerzilla said:


> Pull the post out (remove the saddle, pull it out from the bottom) and degrease it and the sleeve with meths or similar. A bit of grease or oil on the post can cause slippage. If this doesn't work, tighten the nut just enough to prevent slippage when you bounce on the saddle.



Thanks for that...... we will give it a try.


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## sdawila (12 Aug 2019)

I am currently having this issue !, I purchased the bike brand new and today it is not even 3 weeks old and I have already broken the seat post clamp. after bringing the bike back to the store where I finally got it replaced for free at the end. Guess what ?, I broke the replacement after 2 rides (around 60 Km). I still use the bike but the bike cant be folded since I secure the seat post clamp manually by twisting the bolt with a spanner.

Brompton is not my first folding bike, my first folding bike is the Dahon Vitesse D7 and I still have it and loving it, folding and unfolding the bike is not new thing to me, but I was blamed by a Brompton distributor in Jakarta that I folded and opened the bike in an incorrect way and oh boy it did insult my experience for commuting daily by a folding bike for a year plus. Long story short, I am not a happy customer and I am not going back there for the same problem.

Maximum bike payload is 110 Kg. and I weight 92 Kg. what do I do next to overcome this problem ?


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## rogerzilla (12 Aug 2019)

Which part broke? The lever?


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## sdawila (12 Aug 2019)

the lever looks good as new but it does not do the job when you tighten or loosen it. This happened both to the old and the replacement ones.


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## rogerzilla (13 Aug 2019)

I wonder if they've redesigned them in poor materials? It sounds as if the cam has rounded off or something.


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## Kell (13 Aug 2019)

ukoldschool said:


> Where did you get it done @Kell ?



Got mine done at Saddle Safari in Marlow. 

It’s where I bought it from. 

I’ve left the second clamp on for now too as it adds about half a second to the the fold/unfold time. And hopefully will stop me over tightening in the future.


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## sdawila (13 Aug 2019)

rogerzilla said:


> I wonder if they've redesigned them in poor materials? It sounds as if the cam has rounded off or something.



I have just discussed with long term brompton owner about this issue, more or less about the seat post clamp material, according to him, the stock seat post clamp does the job better than the 3rd party branded ones that cost a lot. 

It seems like I’m facing a dead end if I’m stucked with another replacement which will brake after few rides.


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## RegG (13 Aug 2019)

sdawila said:


> I have just discussed with long term brompton owner about this issue, more or less about the seat post clamp material, according to him, the stock seat post clamp does the job better than the 3rd party branded ones that cost a lot.
> 
> It seems like I’m facing a dead end if I’m stucked with another replacement which will brake after few rides.



I've had a reply from Brompton re the seat post slipping on my daughters 3 week old Brommy.....

We've been advised to return it to the dealer for adjustment and, if that doesn't work, Brompton say they will have it back to the factory to rectify it. Trying to do it ourselves could invalidate the warranty.

I've no idea how the warranty works in Indonesia but I would suggest an email to Brompton to see what they say.

Good luck.


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## rogerzilla (13 Aug 2019)

sdawila said:


> I have just discussed with long term brompton owner about this issue, more or less about the seat post clamp material, according to him, the stock seat post clamp does the job better than the 3rd party branded ones that cost a lot.
> 
> It seems like I’m facing a dead end if I’m stucked with another replacement which will brake after few rides.



The Brompton seat clamping arrangement is a fairly unique hybrid of an old-fashioned steel frame seat lug (the type that has "ears" for a binder bolt or short QR skewer) and the separate collar type of seatclamp found on most modern frames. Not many off-the-shelf clamps would work very well.


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## sdawila (15 Aug 2019)

RegG said:


> I've had a reply from Brompton re the seat post slipping on my daughters 3 week old Brommy.....
> 
> We've been advised to return it to the dealer for adjustment and, if that doesn't work, Brompton say they will have it back to the factory to rectify it. Trying to do it ourselves could invalidate the warranty.
> 
> ...



well thanks for the respond. Turned out our problem is the same. on my way to work this morning I decided to stop over to one of the Brompton workshops owned by friend of a friend just to obtain a way out from this seat post clamp headache. According to one of the technicians the seat post clamp material is far poor compared to the previous version/batch. He had actually weighted both the new stock clamp and the old ones, the old ones in indeed a lot tougher and weight almost double than the new ones. He suggested to get the titanium replacement for a power user who'd rather abuse the bike for more than 120 km weekly. The stock ones are great for weekend rider but not for user like me.


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## rogerzilla (15 Aug 2019)

Brompton do tend to use customers as beta testers. They've had a few notable failures over the years: aluminium seatposts and cracking M-type bars spring to mind.

Much of the specification is also suspect. The hinges and clamps are well made but a hi-ten steel frame is a bit cheap on a £1000 bike and there are some really cheesy components that you'd expect on a £200 bike.

They do fold smaller than anything else but you're mostly paying for the brand (and London labour costs).


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## sdawila (26 Aug 2019)

To update the issue, i finally found a cure. I’ve ordered a titanium seatpost clamp from ebay and it will take sometimes to arrive in my possession. While waiting for it to get to me, i ended up buying a alloy seatpost clamp which cost lots cheaper than the original ones. It did look good and paid it, installed it and it is a cure for my problem. But....

The slipping issue is still happening but it’s not as bad as it was. I will try to borrow someone’s seatpost just to see if the gravity of this mess is actually the seatpost.


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## bikegang (28 Aug 2019)

We have worked with KCNC with this aluminum CNC machined Groovy seatpost, test ride pretty convincing and will lose -140 g in the process... iso certified to 120kg.


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## rogerzilla (28 Aug 2019)

Brimpton tried an alu seatpost after they discontinued their own titanium one. I think it marked too readily - it didn't last long as a product.


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## sdawila (9 Sep 2019)

rogerzilla said:


> Brimpton tried an alu seatpost after they discontinued their own titanium one. I think it marked too readily - it didn't last long as a product.



The slipping issue is still happening. The first problem I have I thought it was the defected seatpost clamp but it turned out I still have the same problem after replacing the clamp with a titanium. Does anyone reckon if I replace the seat post with a titanium one would end this problem ? or should I replace the shim first ?


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## RegG (9 Sep 2019)

If the bike is still under warranty get it back to Brompton.


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## sdawila (9 Sep 2019)

RegG said:


> If the bike is still under warranty get it back to Brompton.



good suggestion, I will visit the Brompton store this weekend.


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## Tenkaykev (9 Sep 2019)

bikegang said:


> We have worked with KCNC with this aluminum CNC machined Groovy seatpost, test ride pretty convincing and will lose -140 g in the process... iso certified to 120kg.
> 
> View attachment 482375
> 
> ...



I've just spent an informative 20 minutes on Wikipedia leaning about the properties of various aluminium alloys. 

The aluminium alloy used in the seat post looks to be an excellent material.
The price did make me cough though. 
If it was half the listed price I'd be tempted.


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## sdawila (10 Sep 2019)

Tenkaykev said:


> I've just spent an informative 20 minutes on Wikipedia leaning about the properties of various aluminium alloys.
> 
> The aluminium alloy used in the seat post looks to be an excellent material.
> The price did make me cough though.
> If it was half the listed price I'd be tempted.



but comparing apple to apple between aluminium alloy and titanium alloy, without a doubt everyone will opt for the titanium one. i am sure you will find fair prices on the titanium in ebay or some other chinese marketplace.


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## chriscross1966 (13 Sep 2019)

sdawila said:


> The slipping issue is still happening. The first problem I have I thought it was the defected seatpost clamp but it turned out I still have the same problem after replacing the clamp with a titanium. Does anyone reckon if I replace the seat post with a titanium one would end this problem ? or should I replace the shim first ?



You have thoroughly cleaned the post and the liner haven't you?... it's really easy for things like chainlube to get on there and until you've had it apart and cleaned everything it will slip. When it's clean it won't... even touching the post will transfer enough skin oil to cause the problem if you keep doing it.... I bought myself a fun ten minutes earlier this summer when I unfolded having just applied suntan cream....


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## sdawila (14 Sep 2019)

chriscross1966 said:


> You have thoroughly cleaned the post and the liner haven't you?... it's really easy for things like chainlube to get on there and until you've had it apart and cleaned everything it will slip. When it's clean it won't... even touching the post will transfer enough skin oil to cause the problem if you keep doing it.... I bought myself a fun ten minutes earlier this summer when I unfolded having just applied suntan cream....



oh my God ! I have never thought of the remaining skin oil that may have left there while cleaning the post. 

Thank you very much, I will try it out as soon I've got some medical/rubber gloves. Have a nice weekend !


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