Anthony":10ir0avn said:I'm puzzled that it takes a 29.4 post. Normally, butting is external so a 31.8 x 9-6-12 tube would have an internal diameter of 31.8 - 2 x 0.6 = 30.6 and it might take a post of 30.4 ED. The 29.4 post seems to imply that the butting must be internal. In which case the post is in contact with the tube only for the butted part of the tube. In which case, there may be no advantage from using a long post as I advocated earlier?
Yes, 29.4 with an internal butted section to the top of the tube. The butted section is fairly long so running a longer post makes perfect sense. Certainly better than an original USE with a 2cm tall shim.
ededwards":10ir0avn said:Lovely looking frame and kudos for the eclectic build - the tyres and stem/seatpost combo are nice subtle touches. Isn't it a bit small though with only that stump of post standing proud?
Got to take exception to this though- how on earth are you going to successfully ovalise the tube if you don't use a too small shim and some Red Bull can? Of course, the real experts use a too large shim (bashed home with a lump hammer so that the top is nice and splayed and all but impossible to remove without scoring the seat tube) and then 'screwing' in the post. If you get this right the shim overlap does a great job of ovalising the tube, you score the post beautifully so that it's easier to cut it lengthwise if you need to do so when you come to get it out plus, if you are really skilled, you can bulge the seattube and bend or (oh heaven) even snap the seatpost binder bolt. Or so I'm told.John":10ir0avn said:Running a decent direct fit (ie not shimmed) post and seat collar is the way forward.
Your mind tricks won't work on me Edwards!
There is only one other man on the site who could pull off the mismatched stem/post and tyre combo, he looks like Lewis Collins.
You know it fits me too. If I do move it on sure I can mangle the tube suitably, always good to repay favours.