Cycling and bicycle discussion forums. 
   Click here to join our community Log in to access your Control Panel  

Go Back   > >

Bicycle Mechanics Broken bottom bracket? Tacoed wheel? If you're having problems with your bicycle, or just need help fixing a flat, drop in here for the latest on bicycle mechanics & bicycle maintenance.

User Tag List

Thread Tools Search this Thread
Old 08-22-11, 04:59 AM   #1
Senior Member
Thread Starter
Join Date: Jul 2010
Posts: 483
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
How does a square tapper tandem crank differs from a regular crank?

I'm looking at a vintage crank I'm interested in but it is listed as a tandem crank. How is that different from a regular crank?
abdon is offline   Reply With Quote
Old 08-22-11, 06:41 AM   #2
Senior Member
Join Date: Aug 2005
Location: Pittsburgh, PA
Bikes: '''96 Litespeed Catalyst, '05 Litespeed Firenze, '06 Litespeed Tuscany, '12 Surly Pacer, All are 3x8,9 or 10. It is hilly around here!
Posts: 30,227
Mentioned: 20 Post(s)
Tagged: 0 Thread(s)
Quoted: 636 Post(s)
If it's the Captain's crank it will have a spider on the left side for a single synchronizing chainring and no spider for any chainrings in the right or normal drive-side. Also, the crankarm with the spider will have left-handed pedal threads like a regular non-drive-side crankarm, which is why you can't just turn a standard crank around 180 to get the chainring on the left. The pedal threading would be wrong.

If it's the Stoker's crank it will have a both a spider for the synchronizing chainring on the left side and a regular spider (usually for a triple) for chainrings on the normal drive-side.

A Captain's bottom bracket will have to be long enough on the left to accomidate the synchronizing ring and the Stoker's bb will have to be long enough to allow chainrings on both sides.

Last edited by HillRider; 08-22-11 at 06:46 AM.
HillRider is online now   Reply With Quote
Old 08-22-11, 06:43 AM   #3
Senior Member
Join Date: Mar 2008
Posts: 7,204
Mentioned: 25 Post(s)
Tagged: 0 Thread(s)
Quoted: 600 Post(s)
A tandem has two pairs of cranks, and a synch chain running between them. A front/captain tandem crank will have a chainring spindle for the synch chain on the left arm, while the rear/stoker crank will have chainring spindles on both crank arms.
It's not just a question of flipping them over, as arm orientation is coordinated with pedal threading. Get it wrong and pedals may unscrew while JRA.
dabac is offline   Reply With Quote

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

All times are GMT -6. The time now is 10:51 AM.

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to and affiliated sites.
  • Ask a Question
    get answers from real people!
Click to start entering your question.