1" headtube with 1-1/8" fork adapter

[Papa]

I'll order the shortest BMX/MTB cranks I can find, but if you have any recommendations for a great brand, style, or size, please share them with me!

The man knows his s**t... none better.

BikeSmith Design and Fabrication

 

[PaPaSteve]

A picture is worth a thousand words . . . this explains a lot.

It's common for recumbent riders to run short crank arms, 150~155mm lengths even for tall riders.
There are a number of crank length discussion on the web.
Such as :

Crank Length Calculation

Crank length calculation is important to use the correct length of crank to ensure that your legs can work efficiently. Knee damage is a risk otherwise.

highpath.co.uk

If a used set of arms can't be found JB Importers has a nice line of BMX cranks in shorter lengths.
JB Importer parts can be ordered in most bike shops and often found on eBay and Amazon.

 

[2Phast2Delirious]

I ordered 1" threaded 26" forks. It appears that I will have to cut and rethread the fork steerer. I am considering installing the fork on Juanito first, then do the same with DookieCati.

 

[docw009]

I ordered 1" threaded 26" forks. It appears that I will have to cut and rethread the fork steerer.

I once tried to add threads to a 1" Capa RST suspension fork, but I used a low cost $29 pipe thread die. It wasn't hard enough. Instead, I converted it to a threadless fork as I had plenty of uncut steerer tube above the head tube. Much easier too.

 

[Papa]

Bicycle steer tubes are, as the name implies, "tubing". "Tubing" is dimensioned by OD. "Pipe" is dimensioned by ID. Therefore, the threading dies are completely different - in diameter, thread profile and TPI. Using one in place of the other will permanently damage the steer tube's existing threads, and likely render the fork unusable.

 

[Ianhill]

I swapped an old razor e300 scooter from threaded to threadless and went with a cartridge bearing rather than a open ball race but that was already 1-1/8 so i used an alloy stem clamp didnt have no issues with it coming lose on the threads but im sure they impinted the stem so i wouldn't use it on a threadless fork afterwards.

 

[Barncat]

2Phast- I did the mod in question to my Mongoose Pug build in the ebike build section here. It's not easy and ideally requires a lathe, and accurate TIG work. It turned out well and I have a lot of miles on it. The description starts at post #20...

 

[2Phast2Delirious]

2Phast- I did the mod in question to my Mongoose Pug build in the ebike build section here. It's not easy and ideally requires a lathe, and accurate TIG work. It turned out well and I have a lot of miles on it. The description starts at post #20...

Yes, I gave up on it and went ahead and bought a 26" Capa Racing suspension instead.

I was on the verge of doing something similar to what this guy did. Someone here could find this useful.

Here's Juanito finished.