An odd question perhaps, but I'm currently looking at an 853 frame I fancy. It takes a 27.2mm post and a 28.6mm collar. Now I probably wouldn't have taken any notice of this except that, in a discussion on the Kinesis UK Virsa Prestige, someone mentioned the same dimensions and suggested that this left the seattube walls very thin and that there might be flaring issues.
My current 853 Inbred takes a 27.2mm post and is quoted as taking a 29.8mm/30.0mm collar, although I have to say that the collar closes almost to the point of touching on the 853 whereas the same kit on my DN6 Inbred have a large gap between the collar ends.
Maybe 853 seattubes are thinner and I'd assume that the collar itself would limit flaring and with plenty of post still in the frame I'd hope that it wouldn't crack either (and of course there's the warranty) but I was wondering what people think, I'm 15 stoneish so will it be an issue?
my DMR's those dimensions (26.8 and 28.6mm). It'll only flare if the seatpost isnt inserted past the bottom of the top tube.
Cheers, but it's 27.2 (post) and 28.6 (collar) that I'm looking at, which would leave thinner walls than 26.8/28.6. It's probably fine but I'd be interested to know what people thought before committing. The Virsa Prestige has the same post/collar sizes and I haven't heard of problems there, but I have had someone suggest that it could be problematic. It might be find with a 853 seattube though.
I just put my faith in assuming that theres someone out there who's thought about it and selected those tubes, so it must be ok.
Any other thoughts, or do I just put my trust in the designers and the warrant?
It will be fine steel bikes have been running those dimensions for nearly 20 years. I had a Kona explosive from 92 and it had the same size seatpost and seat collar and that is still being used now.