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Looking for advice. I have just bought a new Easton EC90 seatpost. Sadly, the geometry on my bike means that I need to clamp it well above the maximum insert line. Above this line the post narrows slightly so although I can clamp it it keeps slipping.
I understand that I should really not clamp it above the max, but want to keep the post so need a way of achieving this. Has anybody got any innovative solutions?
Possible to trim a bit off your seat tube so that it clamps lower?
I did this on a medium El Guapo for Ed Oxley so his Reverb wasn't too high when topped out.
Sorry, hope I didn't explain the problem badly. It's not the MINIMUM insert it's the MAXIMUM insert.
Yes. Maximum insert. I understood. Shortening your seat tube will allow you to clamp the post lower.
Try wrapping some insulation tape around the area where the tube and post mate - one layer should be enough. Also good for stopping seat posts creaking.
Clamping the post in this area may result in it cracking as it's not internally supported correctly.
This is why there are limits and the reason it tapers.
Is this Brant of On-One and Shedfire fame? Thanks for the reminder of why I shouldn't even consider this, but the practical fact is I've just spent £100 on the post, now it has slightly scuffed decals from the first time it slipped, and won't be worth a dime second hand. It's on a road bike, so the risk of cracking is hopefully quite small. I'll try the insulating tape idea first ans see how it goes, but still open to some more suggestions. Thanks to all.
If you are aware of the risks and want to proceed then you could make some shims from coke cans to take up the slack between the frame and the post.
Sigh
Hello. Yes that's me.
The post will be internally reinforced in the area between min and max. Clamping outside this, even with such structurally stable and reliable items as insulation tape and coke can shims... Well...
I guess you are applying less leverage due to the lack of extension.
Ever had a seatpost snap on you?
...even with such structurally stable and reliable items as insulation tape and coke can shims... Well...
No one suggested they were structurally stable but don't let that stop you being a sarcastic prick, will you. It's no wonder you get on so well with some of the other users of this forum.
OP - It's worth paying attention to the insertion depth, of that there's no question. If you decide to use insulation tape and are using a torque wrench to tighten the clamp, be sure to back off by a NM or two. If in doubt work your way up in small increments or simply use a normal wrench, giving the post a gentle shove downwards every half turn or so.
Apologies if this is a grandma sucking eggs type post...
No one suggested they were structurally stable but don't let that stop you being a sarcastic prick, will you. It's no wonder you get on so well with some of the other users of this forum.
Indeed. The lowest form of wit. But truly... People suggesting nonsense like this, they can't actually be understanding what's going on. It's not a new design style. The early Bontrager, later Titec, posts used similar design. A very light carbon tube with an internal reinforcement "pushed up and glued in place" to support the stress concentration factors from the clamping area, and the bending load.
Only structurally sound way is to clamp the post within the limits, which may be possible by trimming the bike seat tube and extending the slot in the back too. But people can get jumpy about that too.
A torque wrench, even applied as you are suggesting isn't truly going to help.
Thanks again to all. Seems to be the nature of forums that simple queries end up in slanging matches.
Thanks Brant, I acknowledge your point, and I'm sure Easton would concur.
I fully understand 'what's going on'. I suggested a way of stopping the slipping without going to too much trouble. It's an easy fix if it works. If it doesn't then my next step, if it were me, would be to attempt to reinforce the clamped area.
Like I wrote, no one suggested structural integrity from insulating tape or Coke can shims, they were simply suggestions to stop it slipping. Maybe you should have suggested the slot extension idea in your third post instead of, lo and behold, once again being a bit of a prick and inquiring as to whether or not the OP has had a post snap on them.
OP - I'd look at getting a different seat post to suit your frame. Having a post snap isn't going to be fun, and even with shims/tape/whatever, you're clamping in an area not designed for clamping. Having spent £100 on a seat post I'd want it to be perfect and not be worrying about the fact I'd clamped it where I shouldn't, and it would certainly invalidate any warranty claim if the worst did happen. You may get more than you think for it second hand - folk often pay way over the odds for stuff on ebalg for example.
Don't see what he's being a prick about. Simply stating facts and a simple rolling of the eyes to anyone suggesting doing something warranty invalidating if not seatpost snapping.
As someone else already said, if you accept the risks, then go ahead.
Anyway, to the OP...
Personally for a £100 post I'd want to be covered by warranty for real failure. Clamp it as suggested then you'll get £0 back if it did snap.
The scratches on it still make it sell-able. Just not as new. So long as you don't mention where it's been clamped 😉
However if I understand it, you're saying the post doesn't fit due to frame geometry in that it's in as far as possible to the max line, and it's still not low enough? If that's the case is the frame simply too small?
Surely it would be too big. If it was too small the post would be sticking out beyond the minimum. I think we need some piccies to clarify.
And as far as eye rolling not marking out someone as a prick, we'll just have to agree to disagree on that one - 's condescending nonsense and overuse by some members of the emoticon variant just about sums them up as the same IMO. You simply wouldn't behave in that manner to someone's face, why behave like that when engaging on a forum.
My apologies for straying OT, OP...
🙄 Don't worry about those 'MIn' and 'Max' insert lines, they are only there to make the post seem more 'ardcore. 🙄
Final word (hopefully).
I've tried the insulating tape trick, and I also tried slipping a small metal circle under the seat clamp to 'open' it up a bit and allow it to tighten down more.
Result of all this faffing about, I have noticed that a small raised lump has appeared on the seatpost, and I believe this was caused by over tightening in this area. My conclusion is that no mount of tightening will clamp the seatpost in this area, it will just result in breaking the post.
I like the idea of stuffing a section of smaller seatpost (or similar) inside but that too sounds dodgy.
I have basically spent £100 on a post that I can't use, and probably ruined it trying.
Lesson: Maybe the online retailers or manufacturer should state the distance from saddle rails to max insert mark. I didn't consider it at all because my old EC90 Zero post was fine.
Lesson: Maybe the online retailers or manufacturer should state the distance from saddle rails to max insert mark.
No, the lesson was to check the seatpost when it was delivered and to realise it wouldn't fit so send it straight back for a refund.
That would have made sense obviously. However, if this information was readily available for all seatposts (and other items) then I would have saved myself a lot of time and money by not buying it in the first place.
Surely it would be too big. If it was too small the post would be sticking out beyond the minimum
Good point 😀
I'd be very surprised if there was a seatpost that is just simply too long from max insert line to seat rails to be practically useable on the correct fitting frame. Though maybe this is the case here.