Penton Owners Group

General Discussion => Penton Talk => Topic started by: cag33 on August 04, 2006, 12:16:42 AM

Title: 78 KTM
Post by: cag33 on August 04, 2006, 12:16:42 AM
Will forks from a newer ktm fit on a 78? How about an aluminum swingarm  from a 79? any ideas? Anyone have these parts if they will fit?
Title: 78 KTM
Post by: 454MRW on August 04, 2006, 07:31:40 AM
The 1980-81 forks are the same 38mm as the 78-79, but offer around an additional inch of travel 11.8" vs. 10.8" and I have installed a 79 swingarm on my 77 MC5 frame, so it should work on the 78, although the shock length would most likely need to be changed. The only problem is the clearance for the lower portion of the airbox, which originally fits into the opening on the stock swingarm when the suspension is compressed. Hi-Point made an Acerbis replacement airbox that didn't have the lower portion which would work with the aluminum swingarm. Mike

Michael R. Winter
I enjoy rebuilding and appreciating Pentons!
1974 250 HS Pentons-1980 KTM 250'S
Title: 78 KTM
Post by: Mike Lenz on August 06, 2006, 07:08:10 PM
I put a 79 alum swing arm on a 78.  You have to modify the front top of the swingarm to get engine clearance and I moved the shock mount back to be in line with the 78 arm.  If using 79 or 80 forks use a longer top out spring or a spacer to keep the travel the same or it wont turn well. The forks with the "fluted" damp rods from 80 and 81 work alot better.