| T.R | Title | User | Personal
Name | Date | Lines |
|---|
| 862.1 | | GANSU::CAPTURE | Rod MacFadyen, in Ferney | Tue Sep 13 1988 15:49 | 11 |
| 862.2 | ANybody think indexing's NOT worth it? | MARVIN::MACHIN | | Tue Sep 13 1988 16:31 | 13 |
| Well, I went into Berkshire Cycles (I've bought 3 bikes from them,
all great/great service etc), and tried out a Saracen. I thought
it was very good -- and I was surprised, since I've seen a few Saracen
racing bikes and the bits and pieces weren't good. In fact I tried
one at 290, and another at 390 to see what the difference was. (The
more expensive one had more expensive wheels, chainset and block).
But I'm not as aware of the do's and donts in ATB bikes as I am
in tourers/racers (for example, the golden rule about welded/brazed
lugging on tourers is broken by even the more expensive ATBs).
Richard.
|
| 862.3 | Wouldn't say no to one, tho' | GANSU::CAPTURE | Rod MacFadyen, in Ferney | Wed Sep 14 1988 12:12 | 13 |
| 862.4 | brazing/welding | MARVIN::MACHIN | | Wed Sep 14 1988 15:35 | 9 |
| Frames withour lugs (i.e. tubes are butted directly onto one another)
need welding together. The high temperature produced in welding weakens
the steel. Lugged frames (i.e. tubes slide into joints) are brazed,
which uses muck lower temperatures and so doesn't have adverse effects
on the structure of the metal.
At least, that used to be conventional wisdom.
Richard.
|
| 862.5 | when is a lug not a lug? | SUSHI::KMACDONALD | loose chips sink mips | Wed Sep 14 1988 15:46 | 17 |
| > Frames withour lugs (i.e. tubes are butted directly onto one another)
> need welding together. The high temperature produced in welding weakens
not quite - various custom builders (English WITCOMBs for example) made
occasional lugless frames that were brazed together. The mitering of the
tubes has to be VERY precise in order for this to work, but when it does,
it's really beautiful. Looks a bit odd, but produces a very strong, very light
frame.
typically the really cheap department store bikes were welded, using very heavy
"sewer pipe" tubing so that the welding wouldn't weaken it to the point of
failure. Toward the beginning of the "bike craze" (early 70's) the wisdom
on the streets was "buy a lugged frame" so some cheapos came out with a
welded frame and plastic "lugs" that had no purpose, other than to sucker
the consumer. Urp.
ken
|
| 862.6 | As long as it doesn't collapse beneath you... | MARVIN::MACHIN | | Wed Sep 14 1988 16:03 | 4 |
| So why are ATB frames so often welded? 'Cos they're thick? To avoid
weight?
Richard.
|
| 862.7 | There's welding and welding | RDGENG::VAL_K | Kassessinoff, now you know a foreign language | Thu Sep 15 1988 10:27 | 8 |
| I have seen it written down in several publications that some makers
like Peugeot, employ a modern computer-controlled welding machine
which ensure only enough heat to effect a weld, and the resulting
joint is claimed to be at least as strong as the braised lugged
one, but much lighter. Makes sense to me; I believe it.
Val.
|