Have questions or want to discuss cycling? Join Now or Sign In to participate in the BikeRide community.

New: Take Part in the October Giveaway to Win the Qiolor TIGER Retro Electric Bike


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
(02-25-2012, 09:16 PM)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...

Forum Jump:

[-]
10 Latest Posts
Schwinn trike NOISE
Today 05:20 PM
Schwinn meridian rear drive axle
Today 04:36 PM
What was your first bicycle?
Yesterday 04:11 PM
Great UK Cycle Camping Map, For E-Bikes,...
Yesterday 05:38 AM
Charging at campground
Yesterday 05:33 AM
Failure to stop at stop sign means $500 ...
Yesterday 05:27 AM
Bicycle enthusiast located in California
Yesterday 04:15 AM
Moving in Style: Beyond Regular Transpor...
Yesterday 01:29 AM
Do you plan or random ride your MTB ride...
11-02-2024 11:43 AM
Cycling is Anti-Aging, But There's a Cat...
11-02-2024 11:36 AM

[-]
Join BikeRide on Strava
Feel free to join if you are on Strava: www.strava.com/clubs/bikeridecom

[-]
Top 5 Posters This Month
no avatar 1. Jesper
18 posts
no avatar 2. enkei
18 posts
no avatar 3. GirishH
13 posts
no avatar 4. Flowrider
12 posts
no avatar 5. Talha
10 posts