When you bolt on big parts, it really starts to look the part, doesn’t it? It feels like it’s been a while since I’ve done work like this.
Since I got the swingarm used as just the arm itself, I also arranged for a chain guide.
The swingarm is from a Yamaha. After researching, I found that the chain guide cover part number is identical to the TDR250, which means the bushing will fit.
I could make one, but that’s too much trouble—if something already exists, why make it? That’s the spirit here.
I center it with a face plate TO clamp and start machining. I was surprised to find that the original bushing inner diameter has a clearance of only +0.06 mm.
Since it’s cast iron, it machines smoothly and easily.
I machine the inner diameter down to 20 mm and I’m done. Next up:
Of course, the swingarm side won’t fit either…
The dimensions here are pretty loose—even the original is over +2 mm. Since it’s a hassle to mount it on the milling machine,
I made a sliding guide and got to work grinding away.
Good old hand filing.
*Since it’s my own bike, I hand file it. If it were a customer’s, I’d definitely outsource the machining.
The pivot shaft is BITO R&D chromoly with electroless nickel plating.
The lightening holes look great and really sharp.
It’s really starting to take shape now.
