RE: [CR]need raleigh 753 info


Example: Racing:Beryl Burton

From: Mark Bulgier <mark@bulgier.net>
To: 'Rick Chasteen' <rchasteen@kc.rr.com>, classicrendezvous@bikelist.org
Subject: RE: [CR]need raleigh 753 info
Date: Wed, 19 Dec 2001 23:36:46 -0800


Rick Chasteen wrote:
> Since I doubt a 753 tube COULD be ovalized without being
> painfully obvious (and certainly not that close to the lug),
> I'd be willing to bet that seat tube and/or the opening of
> the seat lug have not been properly relieved.
> Before I reamed the tube, I'd take a flex hone or a brake
> cylinder hone and make a couple of passes through the seat
> lug opening and seat tube. [snip]

Not sure what you mean by "properly relieved", could you elaborate?

BTW, in my experience all tubing is oval to some degree, although usually it's too little to mention. I just mentioned in case the unlikely happened, and an oval tube combined with a cheap caliper made him think he had a 28.0mm seattube when it was really 1-1/8" or vice versa. Normally the two are far enough apart in size that any decent measuring instrument should be conclusive.

A flex hone is a cool tool, I've flex-honed hundreds of frames (maybe a thou?) but as far as I know it's impossible to do on a painted frame without wrecking the paint, at least a little, right at the opening - do you know a technique for preventing that? On a frame that's going to be repainted anyway, it's pure benefit, can only help, as long as you can wash the cutting oil out before painting.
> If a 27.0 post fits after honing, then that is what I would use.

He said 27.0 fits now; did you mean the flex-hone might make a larger post fit? In my experience, a flex hone won't take any appreciable metal off, it just smoothes the finish. I don't think I've ever seen it allow the next larger size post to fit. Maybe I just didn't run it long enough.

I've also rigid-honed maybe a hundred frames - also an extremely cool tool, but rare to non-existent in bike shops or frame shops. It *can* make a larger post fit, but it takes an expensive machine and a fair bit of skill, to do pretty much what a reamer does. (It's wonderful for 853 or AerMet 100 Alloy, where the metal is too hard for a reamer.)

Reamers and rigid hones take metal off of the "high points" only, truing up the distortion and returning the bore to closer to a cylindrical shape. Flex-hones on the other hand take metal off more or less evenly all around - luckily not much - they improve the finish but don't make the hole effectively larger.

I'm not sure, were you saying that if he has a nice 27.2 post he wants to use, it's still a bad idea to ream? Is that based on having tried it and having had bad results? I claim, based on having done it numerous (maybe dozens?) of times, that it can work out just fine, especially on a frame that should have had a 27.2 post to begin with - metal removed by the reamer will be minimal.

Note, we still don't know for sure what size seat tube Jack has; if it's metric (28.0mm outside diameter) then 26.6 is normal, 26.8 is OK, and 27.0 is pushing the limits, so he better not try it.

Mark Bulgier
Seattle, Wa
USA