Converting 1975 Cr Frontend To 77/78 Forks Steering Etc

I have a 1975 cr250 early ML frame with standard cup and ball steering stem but have been given the complete frontend with triple trees from a 1977 cr250 (9" suspension as opposed to 7" which I can use for my racing class). Problem is the early frame wont accept the tapered bearing setup from the later bike. Any advice from someone who has done the swap would be appreciated. Thanks in advance Dave

Knock out the races from both top and bottom of steering stem. You can get the cups you need for the tapered bearings from John at www.vintagehusky.com

Cheers

'77 uses the loose balls, '78 was the first year of tapered bearings.

Not a problem.The cups have the same OD as the ID of the 76 frame I have. I had to dress the OD of the cups took out of the 78 OR frame I have so I could use them in my 78 Auto frame.

The problem with this swap is the increased travel and the 77 triple trees will cause the front tire to make contact with the front down tube on the 75 frame when the front suspension is fully bottomed out. Ask me how I know.

Marty

The cups that John at Vintage Husky were made with the triple clamps he had made for the MAG. The 1975 & 1976 CR ML frames have a 32° rake. The 1977 has a 29°rake. I got a 77 360WR frame that has a set of Frontera forks on it (32°rake) and I heard it worked well.

Right, but my comment was that if he indeed has a 77 stem he does not need to worry about knocking out bearing cups, just slide the 77 clamps in place.