RE: [CR]Campag Spindle Taper Mates with ?

(Example: Racing:Jacques Boyer)

Content-class: urn:content-classes:message
Subject: RE: [CR]Campag Spindle Taper Mates with ?
Date: Mon, 19 Mar 2007 21:18:46 -0700
In-Reply-To: <20070320034435.62285.qmail@web52012.mail.re2.yahoo.com>
Thread-Topic: [CR]Campag Spindle Taper Mates with ?
Thread-Index: AcdqoiLX8xymONqAReqnrjq4hFoLDAAAsIHQ
References: <20070320034435.62285.qmail@web52012.mail.re2.yahoo.com>
From: "Mark Bulgier" <Mark@bulgier.net>
To: "r cielec" <teaat4p@yahoo.com>, <classicrendezvous@bikelist.org>


All cotterless axles use the same taper angle, with only very rare exceptions. All the brands you mention use 2°.

The differences are in the size at the beginning and the size at the end of the taper (and the length of the taper), plus how far from the frame the taper begins and ends.

In my opinion, it is always safe to find out compatibility by simply trying it.

If the taper on the axle is too small, it may pass all the way through the crank - just check by removing the bolt after fully tightening it. The axle must be recessed at least little down into the square hole in the crank - not hitting the washer under the bolt. 1mm is probably enough there, providing you really did tighten the bolt as much as you ever will in use. Also look at the big end of the taper, where the axle gets abruptly bigger - that cannot be allowed to touch the back of the square hole in the crank.

If the taper is too big, it won't go far enough into the crank and the amount of surface area where they mate will be too small. Test the same way as above - mount the crank then take the bolt out. This may be harder to judge by eye, but I'd like to see less than 5mm of remaining square hole, that isn't filled up with the axle.

If you pass the two tests above, then you just need to see if your chainline comes out OK. With most brands this can be adjusted a little, for example with washers under the fixed cup if the chainline is too close to the frame. Some brands, like Phil or OMAS have more adjustability because of having no fixed cup.

There are probably more specific guidelines out there, brands that do and don't work together, but I think the guidelines I've given you here are general and will always work, though the trial-and-error method may be too slow for you.

Good luck, hope it helps.

Mark Bulgier Seattle WA USA

r cielec wrote:
>
> Have a Campag NR/SR/GS bottom bracket.
>
> Do not have a Campag crank. So, a non-Campag may have to be the
> alternative. The usual European suspects: Omas, Ofmega, Galli,
> Gipiemme, Mavic, Zeus, long shots = Stronglight, TA (I do not think the
> French are compatible).
>
> Can someone point me to a reliable cross-reference table ?
>
> Is there a reliable method for measuring the crank to determine the
> required spindle spec' (ISO; JIC; proprietary: ?).