alij2018

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.