Chain Roller Question

[Dennis Jones]

From 77 to early 80's the rear motor mount spacer has a place to mount a chain roller. I don't think I have ever saw one of these intact. Without it if you run the chain loose enough to not be to tight on full compression it is floppy loose and can come off on full extension. What are some of you other Guys that are racing these bikes doing to keep your chain right? A thrown chain at the Marion PV CC caused me to go from 3rd to 4th [xx(]

Thanks for any imput.

Dennis Jones

[Larry Perkins]

Dennis,

I can match that up for you but have lost what size the roller needs to be.  Give me a measurement and I can fix you up.

Larry P

[Dennis Jones]

Larry I don't know the size, I've never had one. The mounting arms are 1" apart with a 6mm axle hole. It looks like 1 1/4" diameter is as large as will fit. From pictures it looks narrow enough to ride between the sidelinks. I'm thinking there may be a problem with running them because I see very few bikes in the pits with them [?]
Maybe someone else can supply measurements or share some tips.

Thanks

Dennis Jones

[454MRW]

I bought a complete assembly from Al Buehner a while back and need to put it on my 78 MX-6 that has the roller worn flat on one side where it evidently stopped turning. The roller part is 1" in diameter with a raised center part to help center the chain that is 1 1/4" in diameter. The raised center portion is 5/16" wide.
The roller on this new one is 27/32" wide with a washer on each side and the mounting arms are 15/16" apart. Donny Smith has a new center bushing (sleeve) on eBay right now, eBay # 250002553361 so if Al doesn't have any more, you might check with him for some of the pieces. Mike

Michael R. Winter
I enjoy rebuilding and appreciating Pentons!
1974 250 HS Pentons-1980 KTM 250'S

[Larry Perkins]

I have some Malcolm Smith Racing ones that have sealed bearings that I think will work.  The original roller helped on the MC5 and GS6 bikes alot with chain probs.  I will check these rollers with one of the mounts and let you know.  If they are right size they would be far better than the originals with just a bushing.

Larry P

[Dennis Jones]

Mike, thanks for the measurments. Did you put this piece on a racer or resto?
Larry, that would be cool. If the origanals had bushings instead of bearings its no wonder they are missing on most bikes.
Anyone else have any ideas? A few of us POGR's talked about this at the Marion CC without any good answer. What are the rest of you guys doing [?]

Thanks

Dennis Jones

[Lew Mayer]

Some of us ride with 4 inches of suspension and don't have that problem. Back problems, maybe.

Lew Mayer

[454MRW]

Dennis,
I originally bought it for the restoration of the 78 MX-6 I bought back in December, but as it turns out, I am going to have to use it on another 78 MX-6 I just got in preparation of The Park Hills Enduro in October (my first endeavour of this kind) in many years. I will have to find another for the other bike, but I would definitely go for one with sealed bearings for the competition bike. Mike

Michael R. Winter
I enjoy rebuilding and appreciating Pentons!
1974 250 HS Pentons-1980 KTM 250'S

[Kip Kern]

Dennis  I just bought a NOS roller from Al B for a "78" MC-5 250.  He may have another for you to check out as there are two sizes.  CIAO

[Dennis Jones]

Hey Larry, Did you get a chance to see if one of your MSR rollers will fit?

Dennis Jones

[Dennis Jones]

Hey Larry, Did you get a chance to see if one of your MSR rollers will fit?

Dennis Jones