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Slipping seatpost

Last week I went to go for a ride and noticed my seat post clamp had snapped. Not sure why I've never adjusted it after having a bike fit when I got the bike nearly 2 years ago. Its last service was a year ago.

I've ordered the same clamp again but after fitting it to the correct torque setting and going for a short ride on Saturday the seat post started slipping down. I looked rediculous by the time I got home.

I over tightened it sightly yesterday and had the same issue, although not quite so severe but it did still twist from side to side a bit.

Any advice on what can help sort this out?

Cheers

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18 comments

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Spangly Shiny | 3 years ago
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+1 for the drinks can shim method, shown to me more than 50 years ago and it still works. Just make sure it is an ally can, you don't want to induce galvanic corrosion and you might also want to use PVJC (Duralac) to keep the nasty white ally rot at bay.

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cyclefaster | 3 years ago
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Thought I had it sorted when I overtightened it some more but it was still slipping (less but still noticeable).

Bought a larger hope clamp and to see if that would work but after a ride out yesterday the same was still happening. 

As I'm only doing short loops at the moment I didn't get too far from home and could cut my ride short. 

What's annoying is that the numbers on the seatpost are getting worn and it's hard to be sure I'm getting it back in the right place

I guess I'll try the hairspray and slightly increasing the torque setting while keeping my fingers crossed. 

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ktache replied to cyclefaster | 3 years ago
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I managed to overtorque a hope QR seatpost clamp and broke the threaded bolt, the nut and part of the threaded bit shot across the room like a bullet.  They replaced it immediately, wondeful Hope, never had a problem with the replacement.  Though I was a little more careful, I had REALLY gone for it.

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Chris Hayes | 3 years ago
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I carry a spare (Thomson) in my saddle bag... but even quality clamps generally come with craply made, mild steel allen bolts that round off.  I have a compact frame which somehow seems to exacerbate corrosion in seatpost clamps - perhaps its because it is a bit more exposed to road spray, but anyway you can use carbon paste on alloy seatpost too if it is slipping and you don't want to risk over-tightening the screw...it helps.   

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Gus T | 3 years ago
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Have you tried a different seatpost?

 

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OnTheRopes | 3 years ago
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Is it a carbon frame and seatpost? If it is you need some Carbon Seatpost paste, also known as Carbon Assembly Paste, Grpper paste or Fiber Grip.

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srchar | 3 years ago
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What material are the frame and the seatpost?

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cyclefaster replied to srchar | 3 years ago
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srchar wrote:

What material are the frame and the seatpost?

Sorry should have mentioned both aluminium

 

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srchar replied to cyclefaster | 3 years ago
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Hairspray on the seatpost. If that doesn't hold, Ritchey Liquid Torque.

...and if neither of those work, you may want to measure the seat tube and seat post, to check that they are both within tolerance.

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cyclefaster replied to srchar | 3 years ago
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srchar wrote:

Hairspray on the seatpost. If that doesn't hold, Ritchey Liquid Torque.

...and if neither of those work, you may want to measure the seat tube and seat post, to check that they are both within tolerance.

Might give the hairspray a try. The annoying thing is it's the same clamp bought as a replacement so I assumed it would be fine when torqued to the right setti g

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ktache replied to cyclefaster | 3 years ago
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You may have less worries about a little bit more torque with both being ali rather than carbon.

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cyclefaster replied to ktache | 3 years ago
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ktache wrote:

You may have less worries about a little bit more torque with both being ali rather than carbon.

My main concern is I don't want it to snap again. The photo shows what the old one looked like. It was very random as I noticed it as I was getting the bike out for a ride so it must have snapped while put away in the garage. 

 

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Molteni Man replied to cyclefaster | 3 years ago
1 like

Hi cyclefaster,

I've had the very same issues with the identical seatclamp you have shown in the photo. I have an Orro Terra and guess you may have too?

My first one sheared in the very same way. Orro were good enough to provide me with a replacement- I wanted the same as I liked the design and found the small emergency light useful on occasion.
The new one worked fine for a while, but then kept slipping each ride. I tried everything including cleaning, carbon paste, checking tightness and torque etc without success. 
In the end I bought a more robust seat lamp and have had no issues since. Just think the original isn't strong enough for the job unfortunately.

BW Molteni 

 

 

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cyclefaster replied to Molteni Man | 3 years ago
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Yep it is from an Orro Terra. Hopefully the new hope clamp will be much better and can cope with my 90kg sitting on top.

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cyclefaster replied to Molteni Man | 3 years ago
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Molteni Man wrote:

Hi cyclefaster,

I've had the very same issues with the identical seatclamp you have shown in the photo. I have an Orro Terra and guess you may have too?

My first one sheared in the very same way. Orro were good enough to provide me with a replacement- I wanted the same as I liked the design and found the small emergency light useful on occasion.
The new one worked fine for a while, but then kept slipping each ride. I tried everything including cleaning, carbon paste, checking tightness and torque etc without success. 
In the end I bought a more robust seat lamp and have had no issues since. Just think the original isn't strong enough for the job unfortunately.

BW Molteni 

 

 

Yep it is from an Orro Terra. Hopefully the new hope clamp will be much better and can cope with my 90kg sitting on top.

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Rod Marton replied to srchar | 3 years ago
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If the seatpost is loose in the tube, and old trick I was once shown is to use a piece of old drinks can as a shim. Costs nothing, and it's probably worth a try.

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dave atkinson replied to Rod Marton | 3 years ago
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yeah that's a good hack. the other thing i'd suggest is just getting a beefier seatpost clamp. I've never really understood the drilling out of a seatclamp, it just makes it more liable to extend when you're tightening it. get a Hope one or something similarly chunky

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TheBillder replied to Rod Marton | 3 years ago
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Even a piece of card can be enough - years back I had a slipping post in a steel frame on a long trip. The card I found at the roadside cured the problem and stayed in for years. No worries about corrosion either.

These days the modicum of compressibility in the card would be lauded as a comfort improvement.

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