Print Page - 100/125 smaller chain?

Title: 100/125 smaller chain?
Post by: Mike Lenz on July 27, 2021, 01:52:34 PM

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.

Title: 100/125 smaller chain?
Post by: Larry Perkins on July 27, 2021, 03:17:07 PM

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

Larry P

Title: 100/125 smaller chain?
Post by: Mike Lenz on July 27, 2021, 04:49:48 PM

Larry,Where did you get the 420 sprockets?
Thanks

Title: 100/125 smaller chain?
Post by: Larry Perkins on July 27, 2021, 05:30:21 PM

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

Larry P

Title: 100/125 smaller chain?
Post by: JP Morgen on July 30, 2021, 12:08:10 AM

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...

Title: 100/125 smaller chain?
Post by: Mike Lenz on July 31, 2021, 05:59:43 PM

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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General Discussion => Penton Talk => Topic started by: Mike Lenz on July 27, 2021, 01:52:34 PM