Chain size for 350 scrambler

[Dave L]

Can anyone tell me the correct chain size and link number for my 1978 ish scrambler? I thought it was 120 link, did 420v when I compared the old one with different chain at my bike shop but it isn’t!

[Ventodue]

Hi Dave,

1978, you say? So it's a Mototrans Scrambler?

Afraid I can only give you the spec from the parts books for the Bologna SCRs and for the Barcelona Roads. And either of which may, or may not, be different from yours

SCR: 428 x 120 links
Road: 428 x 121 links.

But ...
In any case, unless you're thinking of changing these too, you need to first check what size your sprockets are. Otherwise you could buy a chain which doesn't match them. So, 'measure before buying'. This may help:

A 428 chain has a ½" pitch and a roller width of 5/16" (yes, all imperial, not metric).
A 420 chain has the same pitch, but a roller width of ¼".
A 530 chain has a 5/8" pitch and a roller width of ¼"
Etc.

As to the number of links ... well, that does depend on the number of teeth you have on the sprockets. But unless you're radically different from spec (e.g +/- 3 on the back), you can normally use the standard length. And if you use a spring link, you can always buy long and adjust.

HTH

Craig

[Dave L]

428 is the magic number. Thanks

[Dave L]

I’ll keep you posted!!!

[Dave L]

It's actually 122 links