model 18s frame ,s

[bostonted]

Hi is there a huge difference between a 1950,s 18s frame and a model 20 frame , could any parts from the 18s frame be used on a model 20 rebuild? thanks

[Rob Harknett]

I can only think of one difference on the actual frame. The single frame will not have the twin head steady bracket on the front down tube. Although I am not really sure about that for the 1950 frame. You can always check your parts list.

[dave16mct]

No, the 1950 twin headstay was clamped on. Only difference is the casting behind the carb on the twin with hole for air filter tube. The singles didn't have this casting, just a plain tube.
Dave

[alanengineer]

Dave,
Just to be difficult, the parts book shows the same frame for the single and the twin. ie no extra hole for the carb tube. I thought that only arrived about '53 but on this, i could be wrong

[dave16mct]

You're right, I just checked with the Roy Bacon book (and that's never wrong! ahem.....) He says the twin's casting came in 1951. So it seems that the 1950 single frame was the same as for singles.
Dave.