100/125 smaller chain?

[Mike Lenz]

I am building some 100 and 125's for mx and im wondering...Why not use an HD 420 chain and sprockets. Sprocket Specialties will allow me to order 420 front sprockets for a Sachs and KTM 125, and 1973 Penton Rear 420 sprockets, on line. If I can get those the chain would be lighter than 428 (or520). Plus the sprocket should be narrower than a 428 sprocket also. So weight savings there too. They got HD420 chains rated for 40 HP which are still lighter than 428 and 520 medium grade chains. Of course they may call me and tell me this isnt avib when I act try to order?? What do ya all think on this? Any rotating weight savings on a 100/125 is easy HP! Of course a light tire and tube makes an even bigger difference. Already got that sourced.

[Larry Perkins]

I have always run 420HD on my 420 sprockets with no problem.

Larry P

[Mike Lenz]

Larry,Where did you get the 420 sprockets?
Thanks

[Larry Perkins]

I told you wrong.  428H on stock 428 sprocket.

Larry P

[JP Morgen]

I run the DID 420 Gold race chain on a 1995 Honda CR125 with no issues. I would doubt S.S. will make you Sachs countershaft sprockets...

[Mike Lenz]

Mr. Morgen, Would you be interested in setting up a 100 engine or bottom end with your shifting mods for a 100 I want to build? I built a 100 using a 73 175 ktm bottom end (and whole bike) but AHRMA wont let it run in it's 100 class.
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