Bicycle TutorBicycle Tutor

Show off your bike!

Related video tutorials:
Replacing old cottered cranks/bb
#1
trying to replace the bb and cottered cranks on an old murray road bike (early-mid 80s is my best guess on date) - i want to replace them with modern parts (square-taper spindle and cranks). took the bb off and measured it, and it's something like 78 x 149mm (78mm being the length from outside of one cup to the other, 149 being length of the spindle). this seems really weird... am i measuring it wrong? if it's right, can i use a normal 68 x whatever bottom bracket (i'd assume not, but)? how do i size it? or do i have to track down a bb of the same size? thanks!
Reply
#2
I really can't answer this one, but I am intrigued on how you got the cotters out though?
Good maintenance to your Bike, can make it like the wheels are, true and smooth!
Reply
#3
BP - pictures please !!! Ignore the overall length - it will have to match up with the new crankset you get. Remove the existing stuff from the frame (cups, axle, etc) the measure the housing on the frame.

Hi Bill - I always used a center punch and hammer after removing the nut and washer.
Nigel
Reply
#4
(02-26-2012, 01:16 AM)nfmisso Wrote:  BP - pictures please !!! Ignore the overall length - it will have to match up with the new crankset you get. Remove the existing stuff from the frame (cups, axle, etc) the measure the housing on the frame.

Hi Bill - I always used a center punch and hammer after removing the nut and washer.

Hi my friend. I have a couple of older bikes ,as everyone here knows lol, that have the cottered cranks. Hammer and punch is a way to do it with a block just under the spindle on the side of the cotter that is being driven out. I use this neat little tool... http://www.bikesmithdesign.com/CotterPress/index.html .

Sorry didn't mean to high jack the thread.
Good maintenance to your Bike, can make it like the wheels are, true and smooth!
Reply
#5
Bill - you are the Nut on the threaded end of a 9 mm cotter. Smile
Wheelies don't pop themselves. (from a QBP fortune cookie)
Reply
#6
LMAO!!!! Your the cap at the end of the bar tape keeping everything smooth and together in a neatly fashioned lol.
Good maintenance to your Bike, can make it like the wheels are, true and smooth!
Reply


Possibly Related Threads...
Thread Author Replies Views Last Post
  Upgrading BB and cranks set compatibility? anotherjeff 7 15,462 06-29-2011, 03:52 PM
Last Post: anotherjeff

Forum Jump:



ISSN 1918-3445 © Copyright 2007-2010 Bicycle Tutor / Privacy Policy / Created by Alex Ramon

feed