Re: [CR]On Topic Campag&Clone Cranks vs. "Modern" Bottom Brackets

(Example: Framebuilding:Technology)

From: "David Snyder" <dddd@pacbell.net>
To: "Classic Rendezvous" <classicrendezvous@bikelist.org>
References: <2304018.2632641199042363760.JavaMail.root@vms125.mailsrvcs.net>
Subject: Re: [CR]On Topic Campag&Clone Cranks vs. "Modern" Bottom Brackets
Date: Sun, 30 Dec 2007 16:02:00 -0800


Yes, I've measured the new and older Campy spindle ends to the thousandth and can't find any difference.

Even using JIS spindles, the arms go on all but a little less than 3mm of the normal depth, so effective spindle length is almost 6mm longer overall when substituting same-lengthed JIS spindles or bb's.

I bought an 11-yr-old NOS, Campagnolo Record8 Titanium-equipped off-topic (Boulder Bikes) road bike on Ebay (paid $725, 1/6th of retail) earlier this month, and it had a JIS titanium bottom bracket (made by World Class) as original equipment. This was used to allow chainline adjustment/correction due to the Paris-Roubaix air suspension built into the frame, with the extra effective length of the JIS bb spindle much needed to clear the swingarm pivot forging. The ti spindle is 113mm JIS instead of the specified 111mm ISO (Racing Triple here), so the total increase in effective length should be, and is, 4mm on each end (8mm overall).

I measured the spindle end size to confirm JIS, and inspected the inside of the Record crankarm's square openings. Clearly the spindle makes far less than full contact with the arm's bore, yet the cranks spin true and I've had no issue with the arms loosing during the first 300 hilly miles.

These ti spindles are flexy though. Even with ~2-3mm clearance between middle (42t) ring and the "chainstay", there is contact when I sprint up a local 18% grade in the 30t inner ring. Steel would be better, and would allow me to set a straighter chainline without fear of chainring rub. The original chainline was so severe I had to move the redundant (for me) 14t cog and spacer to behind the largest cog, leaving me with but 7 usable cogs. I also re-worked the axle spacing to move the hubshell 2.5mm over, gaining 7.5mm of chainline correction and full use of the cog stack while in the big ring. So, now I've still got a 13-26, with 30-42-52 in front, but I wish the frame's builder could have narrowed things down up front. This bike also has Union Ti spokes, but I only notice any difference when working at the truing stand. The weight sans pedals is 22.0 lbs. even has an air fork!

David Snyder Auburn, CA usa

smwillis wrote:


>I am pretty shore the taper is the same and Phil and some other ones will
>all work.
> http://netmail.verizon.net/webmail/static/images/spacer.gif
> http://netmail.verizon.net/webmail/static/images/spacer.gif>From: r cielec
> <teaat4p@yahoo.com>


>>Ahoy !
>>
>>I am writing from a service parts need to "keep 'em flying".
>>
>>I read or perhaps mis-read, an off-hand comment in a recent CR posting
>>that there is a difference of spindle tapers for the Campag NR/SR and
>>modern Campag bottom brackets. I thought the eternal difference was
>>only two: either one and only one type of Campag vs. one and only one
>>type of JIS. But, now what - there is more than one type of Campag
>>taper ?
>>
>>For On Topic cranks, specifically Campag NR/SR&Clones, what "modern"
>>Campag spindles/bb's have the wrong taper and will ruin On Topic cranks
>>?
>>
>>I was considering using the affordable and available ACH cartridge bb's
>>for my NR/SR cranks.
>>
>>Thanks.
>>
>>Richard Cielec