KX-100 Are 420 and 428 sprockets the same?

[snb73]

I'm putting a new chain and sprocket set on my son's old bike before I sell it. I'd like to put a 428 chain on it again. Are sprockets for a 420 and 428 chain the same size? Isn't the 428 a bit wider than the 420, but the same distance from link pin to link pin?

Thanks, Steve.

 

[Amber Farris]

No they are not the same. You will need to by 428 sprockets as well. I don't know the specs, but the regular 420 will not work.

 

[Jaybird]

Isn't the 428 a bit wider than the 420, but the same distance from link pin to link pin?

You got it.
All 4 series chains are 1/2" in pitch.

 

[MikeT]

Jaybird, what do you know about chains? :laugh:

 

[Jaybird]

All the CT 70's have 420 sprockets. You should be able to use a #428 chain on it.

 

[snb73]

So If the chains have the same pitch, I sould be able to use the "420" sprockets with a "428" chain?

Thanks, Steve.

 

[Jaybird]

You can probably use the 428 chain on the 420 sprockets. Not the other way around though.
428 sprockets are too thick for a 420 chain.
Depending on the sprocket cut. Not only does the 428 have a wider pin and plates, it also has a roller that sets about .325mm different in the tooth valley than the 420 roller does. (larger roller dia.)
Even though the two chains have the same pitch, the transition from the roller off the working face of the tooth may be enough difference that there may actually be more "noise" when using a 428 on 420 sprockets.
420 chains are cheap...why not get a quality new chain to go with the sprockets?
Your best possible solution would be to go with a 428 conversion for the KX100 sprockets, then you can use the 428 chain you have, and the whole set-up will have more integrity.

 

[snb73]

Jay,

I understand what you mean by," different tooth valley", that makes sense. I will be replacing both sprockets and chain. I've been having a hard time finding a 428 kit. The only place I can find the conversion kit is at Chapparal.

Thanks for the responses, Steve.

 

[Jaybird]

I may know another place to obtain what you want. E-mail me.

 

[83MX80]

holy crap some dinky sprockets on the KX100. my quad has 41-520 rear and 11T front sprockets. i know the front on my quad was $26.00 and the rear was $50.00