Re: [CR]re: cranks bottoming out. Am I in trouble?


From: "Donald F. Dunstan" <donalddunstan@wtconnect.com>
To: "classic list" <Classicrendezvous@bikelist.org>, "Roy H. Drinkwater" <roydrink@ptd.net>
References: <OFAABFAC05.59239BA6-ON85256DA9.006150F4@mail.gm.com> <a05200f00bb95258ecd62@[192.168.1.1]>
Subject: Re: [CR]re: cranks bottoming out. Am I in trouble?
Date: Mon, 22 Sep 2003 18:19:20 -0500


When crank arms bottom out chain line becomes an issue. Crank arms bottoming out are a sign the crank arms have been overtightened, deforming the crank. The axle end should be ~1/8" from the end of the taper hole on a properly tightened and torqued crank. If they are even with the end, you will have ~3-4mm chainline displacement, and you will also have a higher probability of the cranks loosening on a ride. FWIW. (It doesn't matter whether the crank bolt is painted or not.:)

Donald F. Dunstan
Winters, TX


----- Original Message -----
From: "Roy H. Drinkwater"
To: "classic list"
Sent: Monday, September 22, 2003 5:22 PM
Subject: [CR]re: cranks bottoming out. Am I in trouble?



> Marcus asked:
>
> >So today's worry is that the Campy SR cranks are bottoming out on the
> >spindle. The crank arms are tight, but I am not loving the chain line.
> >Are my cranks toast? The spindle is a Campy steel. I can't remember the
> >numbers on it, and it took awhile to get the BB adjusted right, so I would
> >prefer not to take it apart again if I can help it. I know, I should have
> >written it down when I had the chance, but here we are.
>
> Measure the chainline as per
> <http://www.sheldonbrown.com/chainline/index.html>. It should be
> 41mm from the center of the downtube to the center of the small ring,
> and 46mm from the center of the downtube to the center of the big
> ring. You might of reversed the axle.
>
>
> Roy "don't ask me how I know about reversed axles" Drinkwater
> Lititz, PA