What a day, seatclamp issues and seat slipping on MTB.

[Kingfisher101]

So I was tightening up my seatpost clamp and the nut pinged and went off somewhere into bushes, no chance of getting it back. The seat of the bike is now right down and obviously the clamp wont work because the nuts gone. I had to ride home about 6 miles all really uphill standing up out of the saddle obviously in the harder gears. I'm not that type of rider more sitting and spinning in low gears is my style. It was really hard work and I was getting some funny looks from pedestrians. I couldnt sit on the seat and pedal because it was way too low down.
I was boiling hot by the time I got in and it was a good job I'm fairly fit as otherwize I would'nt have been able to do that. I'm having an issue with the seat slipping down and I've been assured its the right size post for the frame etc. I've got a Hope seat clamp on not the qr the allen key one. The clamp part is turned to the front for extra tightening and it still slipped down a bit.
Any advice would be welcomed. I'm not really big or doing mad jumps or anything either. I've ordered a new Hope screw off Ebay and I've put a QR clamp back on the bike for the time being.

 

[Kingfisher101]

That was worse and the shop said it was more effective with the bolt twisted to the front.Thank you for the suggestion though.

 

[8mph]

Try shimming the clamp rather than the post. Try it with the clamp bit around the back. Hopefully all will be well once your replacement clamp arrives.

 

[Drago]

Well, look on the bright side. Kinky sorts pay good money for those sort of jollies.

 

[wafter]

Sounds like fun

It's my understanding that the bolt on the clamp should be oriented to be in the same place as the cutout in the seatpost tube on the frame.

I also vaguely recall something about the Hope bolts being a weak point (hollow shank in an effort to save a pointlessly low amount of mass..?) so you might have more luck with a standard item; assuming you can get one that fits.

Were you tightening to the specified torque? Have you measured and compared the OD of the seatpost / ID of the frame? What materials are involved; if it's a placcy frame and / or tube are you using grip paste?

 

[Kingfisher101]

No Its not a carbon bike its an alloy bike with an alloy seapost.
I've put the standard QR back on now, but I dont have much luck with those as the seat always twists about and also the seat drops a bit.
I'm informed the seatpost is the correct size for the frame.There doesnt seem to be much play when I take the clamp off.
No not tightening to any specific torque or anything, just tightish, obviously I dont want it to be so tight it damages the frame. The grease on the seatpost has been cleaned off as well. To help prevent slipping issues.
I put a piece of parcel tape on the post on Monday to see if the post dropped when I went for a ride and it didnt. So I thought it was now o.k, but it did a bit today so thats when moved the seat back up and retightened.( I'm going to take a spare clamp out from now on). I dont want to have to ride out ofthe saddle for miles again. It was really tiring.
I'll have a think about getting some of that Fibre Grip. Thanks for your reply.

 

[wafter]

Good work and no worries.

It's worth tightening to the specified torque to be sure all's as it should be. My Brompton saddle was a bit migratory until I actually torqued the bolt to the recommended value rather than just doing it by mechanically-sympathetic feel. One less thing not to have to worry about having got right

 

[Ajax Bay]

No not tightening to any specific torque or anything, just tightish, obviously I dont want it to be so tight it damages the frame.

Tighten it proper tight. How on earth will you "damage the [aluminium] frame" (provided the seatpost is the correct diameter)?
You must generate enough friction to hold the load.
Agree with @wafter "the bolt on the clamp should be oriented to be in the same place as the cutout in the seatpost tube" but suspect there is no "specified torque". And if there is and the bolt is so torqued and the seatpost slips, then what?

 

[rogerzilla]

Those Hope clamps use an alloy bolt. It's a stupid idea - I wish I'd read the reviews online. Same happened to me on the way to the Moulton club event in April, luckily only a mile from home.

I have now put a standard 8mm steel seatbolt in the clamp.

 

[ianrauk]

Another Hope bolt breaker here....

 

[Kingfisher101]

Those Hope clamps use an alloy bolt. It's a stupid idea - I wish I'd read the reviews online. Same happened to me on the way to the Moulton club event in April, luckily only a mile from home.

I have now put a standard 8mm steel seatbolt in the clamp.

View attachment 699303

That bolt is rubbish, in the middle its like some type of cement?
Anyway It appears thankfully that its no longer slipping down. I've put a piece of masking tape on the seatpost to measure any slipping.

 

[wafter]

Those Hope clamps use an alloy bolt. It's a stupid idea - I wish I'd read the reviews online. Same happened to me on the way to the Moulton club event in April, luckily only a mile from home.

I have now put a standard 8mm steel seatbolt in the clamp.

View attachment 699303

Good work - however I'm somewhat concerned by the orientation of the saddle. Don't want to raise a sensitive subject but have you been checked out to confirm your arse isn't on wonky?