Slipping seatpost, HELP!
07-13-20, 01:34 PM
#1
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Slipping seatpost, HELP!
So, I have the Cannondale Trail 5 2020 bike, alloy frame and alloy 31.6mm seatpost with a standard quick release seat clamp. I am having a big issue recently, which is slipping seatpost.
Well, everything was OK since I bought the bike in February. I adjusted the height of seatpost after buying and all good. Recently, last week, it was the first time I completely removed the seatpost and cleaned it with a cloth as it had dirt. And the seatpost had scratches too.
I put a very thin of lithium grease so that next time it does not stuck in the frame. i applied the grease below the label of minimum insertion. I put it back, tightened the quick release with a normal force which I used to do before.
While riding, I noticed it slipped gradually after some time by 2 or 3 centimeters. I put it up again, and tightened a bit harder. It was OK but slipped by 1 centimeter only.
I retightened it again and rode some offtrack, and it slipped by 2 centimeters after some time. This was frustrating. So, I overtightened it more and it slipped by just 1 or 2 millimeters instead of centimeters.
I came back home, removed the seatpost and seat clamp as well. I inspected the frame and all good. No sign of defect etc. I sprayed the quick release with penetrating oil from Abro to eliminate corrosion or whatever. I removed the lithium grease and applied standard grease. Yes, a thin layer. I cleaned the seat tube inside a bit with a cloth. I put it back again and this time, almost overtightened the quick release. I did not test it yet. Maybe it will work or not, soon will know.
So, what are the solutions I can apply if it slips again?
1/ Should I change clamp to a bolt one?
2/ Is it slipping because of the scratches on the seatpost?
3/ Should I tighten it with more amount of force?
I am afraid to overtight it. Maybe overtightening it will work too. But I still want to use normal pressure. I'm considering buying a seat clamp with bolt. Maybe that quick release is crap.
Well, everything was OK since I bought the bike in February. I adjusted the height of seatpost after buying and all good. Recently, last week, it was the first time I completely removed the seatpost and cleaned it with a cloth as it had dirt. And the seatpost had scratches too.
I put a very thin of lithium grease so that next time it does not stuck in the frame. i applied the grease below the label of minimum insertion. I put it back, tightened the quick release with a normal force which I used to do before.
While riding, I noticed it slipped gradually after some time by 2 or 3 centimeters. I put it up again, and tightened a bit harder. It was OK but slipped by 1 centimeter only.
I retightened it again and rode some offtrack, and it slipped by 2 centimeters after some time. This was frustrating. So, I overtightened it more and it slipped by just 1 or 2 millimeters instead of centimeters.
I came back home, removed the seatpost and seat clamp as well. I inspected the frame and all good. No sign of defect etc. I sprayed the quick release with penetrating oil from Abro to eliminate corrosion or whatever. I removed the lithium grease and applied standard grease. Yes, a thin layer. I cleaned the seat tube inside a bit with a cloth. I put it back again and this time, almost overtightened the quick release. I did not test it yet. Maybe it will work or not, soon will know.
So, what are the solutions I can apply if it slips again?
1/ Should I change clamp to a bolt one?
2/ Is it slipping because of the scratches on the seatpost?
3/ Should I tighten it with more amount of force?
I am afraid to overtight it. Maybe overtightening it will work too. But I still want to use normal pressure. I'm considering buying a seat clamp with bolt. Maybe that quick release is crap.
07-13-20, 01:37 PM
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I have clean and slightly roughened the first inch of seat tube with sandpaper. They sell some seat post lube with grit in it also.
A friend of mine used a second collar that used an allen key on top of the first.
A friend of mine used a second collar that used an allen key on top of the first.
07-13-20, 02:45 PM
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07-13-20, 02:49 PM
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Good advice^^
I have also 'knurled' the seatpost with a punch where I think the clamp grabs the most. I bunch of punch marks around the post. Also clean out all the grease, degrease and use carbon fiber assembly paste... has grit in the paste. Also... get a better clamp... I like Salsa brand clamps.
I have also 'knurled' the seatpost with a punch where I think the clamp grabs the most. I bunch of punch marks around the post. Also clean out all the grease, degrease and use carbon fiber assembly paste... has grit in the paste. Also... get a better clamp... I like Salsa brand clamps.
07-13-20, 02:49 PM
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Try using anti-seize instead of grease. Available at your local auto parts store or good hardware store.
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07-13-20, 02:52 PM
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I highly recommend: https://www.parktool.com/product/sup...compound-sac-2
07-13-20, 03:07 PM
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Owner's Manual
Please read your owner's manual (especially p. 26, and p. 75, but the rest too) and/or contact your dealer.
Excerpts:
-mr. bill
Please read your owner's manual (especially p. 26, and p. 75, but the rest too) and/or contact your dealer.
Excerpts:
Originally Posted by Cannondale
1. Ask your dealer to help you make sure you
know how to correctly clamp your seat post.
2. Understand and apply the correct technique
for clamping your seat post
know how to correctly clamp your seat post.
2. Understand and apply the correct technique
for clamping your seat post
Originally Posted by Cannondale
If you can fully close the cam lever without
wrapping your fingers around the seat post or a
frame tube for leverage, and the lever does not
leave a clear imprint in the palm of your hand,
the tension is insufficient. Open the lever; turn
the tension adjusting nut clockwise a quarter
turn; then try again.
wrapping your fingers around the seat post or a
frame tube for leverage, and the lever does not
leave a clear imprint in the palm of your hand,
the tension is insufficient. Open the lever; turn
the tension adjusting nut clockwise a quarter
turn; then try again.
Originally Posted by Cannondale
■ Seat Post Lubrication Clean and apply the following to a seat post before inserting into the frame.
- Is a gel like lubricant formulated for use with carbon fiber components (Cannondale p/n KF115/).
- Alloy Seat Tube & Alloy Seat Post = Grease
- Alloy Seat Tube & Carbon Post = Carbon Gel
- Carbon Seat Tube & Alloy Seat Post = Carbon Gel
- Carbon Seat Tube & Carbon Seat Post = Carbon Gel
- Is a gel like lubricant formulated for use with carbon fiber components (Cannondale p/n KF115/).
Last edited by mr_bill; 07-13-20 at 03:15 PM.
07-13-20, 03:52 PM
#9
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I have a folding bike, seat post pushed down locks the fold, so It has to be QR, in my case they're stacked so I open both levers @ once..
07-13-20, 09:00 PM
#10
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07-13-20, 09:03 PM
#11
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Thread Starter
Owner's Manual
Please read your owner's manual (especially p. 26, and p. 75, but the rest too) and/or contact your dealer.
Excerpts:
-mr. bill
Please read your owner's manual (especially p. 26, and p. 75, but the rest too) and/or contact your dealer.
Excerpts:
-mr. bill
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07-13-20, 09:05 PM
#13
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You sandpaper last inch at the bottom fully until the entire paint came off? What this will do?
07-13-20, 09:43 PM
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07-13-20, 09:58 PM
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07-14-20, 07:48 AM
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Good advice here but really the bike is under warranty and this shouldn't be your problem to fix. You shouldn't have to purchase a new seat post clamp or anti-seize or knurled the seat post. It is fine if you want to but I would be taking the bike back to the bicycle shop where you bought it and have them deal with it.
07-14-20, 02:00 PM
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Clean the goop off from both areas & smear some extra hold hair gel on the post. Tighten it down & let it sit for 30 minutes while you clean your chain, wheels, & check psi while also getting the mail. After 30 minutes, your seat should stay at height. To remove the seat post, loosen the flange of all its tension, & with a rapid twisting motion while lifting up, it should remove freely. Cleaning & Reapplying gel is needed when the hardware tension has been released.
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07-14-20, 03:04 PM
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Crazy thought. Are you actually riding down trails now that the weather is nice? Get out of the saddle. (I would think this is self teaching on hard-tails, hell, self teaching on any tails, but....)
-mr. bill
-mr. bill
07-14-20, 05:45 PM
#20
Senior Member
As is so often the case, the answer may be beer. Drink a can, then cut a strip of the aluminum can approx. 1/2" wide and 2' long. Use this as a shim to firm up the clamp's grip on the post.
Good luck
Good luck
07-14-20, 10:38 PM
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I use the second collar on top of the seatpost clamp also. Works great, easy, and looks good.
07-15-20, 06:08 AM
#22
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I highly recommend: https://www.parktool.com/product/sup...compound-sac-2
07-15-20, 11:11 AM
#23
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Frame's seat tube 31.8? , seat post 27.2?
these look excellent : https://www.sjscycles.co.uk/seat-pos...18-mm/?geoc=US
these look excellent : https://www.sjscycles.co.uk/seat-pos...18-mm/?geoc=US
07-15-20, 11:31 AM
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Can we just file this as yet another “Everything worked great until I 'fixed' it” thread?
-mr. bill
-mr. bill
Last edited by mr_bill; 07-15-20 at 12:08 PM.
