1896 Crescent Pedal Crank Thread Change

[GiovanniLiCalsi]

I have found a left hand pedal crank to replace my broken right side crank.
My question is what is the best way to modify the left side crank to accept a right side pedal?
I’m thinking about boring a larger hole and silver soldering a threaded busing into the bore. Does anyone know where I can find the bushing, with threads or should I just use a threadless bushing and thread it myself. I have new pedal taps, courtesy of Geobike.
Thanks

 

[TR6SC]

Giovanni, Google Heli-coil.

 

[GiovanniLiCalsi]

Not sure how that would change thread direction. Also there is not enough inside diameter inside threaded crank. Seems like it would be easy enough to bore threaded hole larger and silver soldering a bushing inside bore and thread it with a hand tap.

 

[TR6SC]

It sounds like you need right hand threads in a left hand crank. The Heli-coil is an insert of threads. You drill out the existing threads, tap the hole, and screw in the right handed Heli-coil. The coil is put in under tension. It will not come out once inserted. Google up on it. I'm fairly certain this is the fix you are looking for.

 

[GiovanniLiCalsi]

I’m going to nickel plate the crank.Wouldn’t it be better to silver solder a smooth steel bushing?

 

[GiovanniLiCalsi]

This story gets worse!
I finally compared the found crank with my Crescent crank and they are two completely different sizes. There is no way it can be used.
If I can’t find an original crank, I’m going to have to cast one in steel....

 

[tommydale1950]

This story gets worse!
I finally compared the found crank with my Crescent crank and they are two completely different sizes. There is no way it can be used.
If I can’t find an original crank, I’m going to have to cast one in steel....

Can you post a photo of the crank you need ? I have some loose ones Tom

 

[GiovanniLiCalsi]

Thanks!

1896 Crescent No.1 pedal arms.
• 9/16” bottom bracket x 1/2” pedal threads
• 7/8” profile width on bottom bracket end of arm
• 7-3/8” overall length of arm
• 25/64 smaller diameter of tapered arm
• 33/64 larger diameter of tapered arm

 

[Craig Allen]

I would weld up the hole, drill and tap.

 

[GiovanniLiCalsi]

The cranks that we’re sent to me are the wrong lengths. I will either need to find exact originals or have them cast in steel.