RodTi Posted March 17, 2011 Author Posted March 17, 2011 If the supplied seatpost really is 27.2mm, it will be worth your while to stick with its present dimention. It is a standard, after all. Have your seat tube reamed out. A framebuilder can do it for you and since you are in the Province, you are in luck. South Africa's last surviving framebuilder lives there somewhere - Frans du Toit. Call him, ask him if he has a ream and do the seat tube for once and all. Thanks JB - dropped him an email already - and will have a chat with him in the morning... Here's hoping he can clean my pipes.No wait. That's wrong.
Skylark Posted March 18, 2011 Posted March 18, 2011 (edited) I have a similar seatpost problem with a Morewood Shova 2005 Its needs 31.8mm - measured with a vernier....Previous owner tighten the clamp to fit an undersized 30,9mm postI have re-flared the seatpost entry slightly and lightly sanded the inside - No weld marks etc And a 31.8mm KNC seatpost is a real bastard to push in , first bits pretty easy as in RodTi's experience then you gotta really twist it in with quite some force and its very difficult to get out - Like oh my gosh will this ever come outDid lubricate it with Q20 to help it in but made very little difference Should a correctly fitting seatpost slide in and out relatively easily? ie only mild effort need to move it in and out and/or change the height Edited March 18, 2011 by SkyLark
RodTi Posted March 18, 2011 Author Posted March 18, 2011 Should a correctly fitting seatpost slide in and out relatively easily? ie only mild effort need to move it in and out and/or change the height Difficult to convey in words what constitutes 'relatively easy'... But allow me to go roundabout in an attempt to formulate an answer... In my 27,0mm seatpost frame, given the difficulty in sourcing that size, I was running a 26,8mm post... I was young ( ), and didn't think much of it... had quite a lot of slippage on the post though, during the course of a ride... LBS put things into perspective upon inspecting the seat clamp, when he pointed out how flexed the lips on the sides of the seatpost slot were, as the clamp was in effect forcig the lips to close around the post... He maintained that were mine an Alu frame, it might have cracked already... Which saw me order a 27,0mm through CRC... It would not go in. Rather, with much cursing, it went it - but then no amount of cursing saw it come out again... Picture a plank, some bolts, a bike with everything removed save the cranks, an insane amount of twisting, pulling and swearing - and a badly scratched Thomson post back in the hand... Plenty of sanding later - and it now fits. It might have something to do with me having had something too small on there before, which result in the opening of the tube being mishapen? I don't know... It now still requires twisting and a bit of elbow grease - but nothing serious. There is no slippage - but it moves freely enough that that when I am mid-ride, I can hop off, undo the clamp - and quickly drop the height for those tricky ST sections... Once through, hop off and raise again - no problems. I also use plenty of Q20 - but to give you an idea, if I undid the clamp, and turned the bike over - I don't think the weight of the saddle would pull the post out - I'd probably need to give a light twist - and then it would probably drop... Hope this helps!
RodTi Posted March 18, 2011 Author Posted March 18, 2011 Oh wait... With this being said... Now to my present dilemma... What's that Afrikaans saying about "met genoug geweld kan jy jou eie vinger in..."? Well - clearly, I'm not using enough force... Took it in to the LBS this morning... Techie looked at me like I was slightly mad... He simply said - if it's a 27,2mm tube, then a 27,2 post will fit. He took another standard 27,2mm - and slid it in... It did appear to go in easier than the Thomson - I'm beginning to be convinced that not all Thomsons are equal He made me put the saddle back on - one doesn't appreciate how much difference using the saddle for leverage on the seatpost actually makes... Would also explain why trying to force the plain seatpost (sans saddle) in, was so difficult... He greased it up - but it still took a fair amount of elbow grease.... But it's in... He's convinced I'll be able to get it back out, albeit with a bit more effort than my previous one... I won't necessarily be making adjustments on the fly initially, but maybe it will improve over time, possibly as the tube takes up the new flex?... Will see how this pans out. It's in like a glove - and quite clearly is meant to go in, since you don't get a 27,195mm seatpost... But will report back here when the bike is assembled - and give you an indication of how tight it is in comparison to my other bike... Guess the bottom line is, it really depends?
LeTurbo Posted March 18, 2011 Posted March 18, 2011 You can probably pick up a good Vernier from Cash Converters - I bought a lovely one in 100% condition for under R100. One of those tools that you just find more and more uses for. I'm a great believer in shims; it's amazing what you can do with an old jam tin to make things work. Both my Le Turbos have odd-sized seatposts.
RodTi Posted March 18, 2011 Author Posted March 18, 2011 You can probably pick up a good Vernier from Cash Converters - I bought a lovely one in 100% condition for under R100. One of those tools that you just find more and more uses for. I'm a great believer in shims; it's amazing what you can do with an old jam tin to make things work. Both my Le Turbos have odd-sized seatposts. Mr. Bornman is a great advocate of the foreign (aluminium) beer can shim... He's popped up a few posts on how best to do it... Will remain an option should I choose to drop down to the 27,0mm - and then shim it - but as mentioned, hopefully my problem has now disappeared! Ps - will keep a look out the next time I pass a CC store - thanks for the tip!
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