On my 1986/87 F1(B) there is installed the earlier 38mm front fork. I consider upgrading this to the "standard" 40mm fork for the F1B-models. Are there any other except Ducati who used this forklegs and trippel tree, or is this a Ducati only fork?

Is the Paso M1R fork/TT a straight bolt-on? Not correct for the F1B, but maybe a periode correct upgrade?

I believe the 40mm on the F1b were unique to Ducati. But there are at least three variations, from plain-jane to very fancy (endurance) and some 42mm (GP) versions (see Lou's Moretti). I think many were sold as after-market items.

No, no way is the M1R a bolt on. Especially for you, going from a 38mm set with 195mm tube centers to 41.6 that are 205mm apart. Sit and look at your bike and all the needed changes.

Even more versions of M1R's out there too.

A good way to upgrade a Marzocchi 38mm fork is to install Sports Valves (available from Sports Motorcycles in New Zealand). Those valves permit to adjust damping and rebound. I have done this conversion and I am very satisfied with the result. Glyn Robinson sells everything you need to convert your 38mm non adjustable fork into a fully adjustable one.

Beside providing his Sports Valves, nicely made fork caps and the adjusting tool, Glyn can provide the adaptors needed to make a perfect installation. Glyn was also very cooperative and always available to provide advices and instructions during my installation.

Gilles

Thanks for your kind words Gilles.

And, you can use all the others parts on the front end now! MikeV

I am not an expert, but my reasonning is that a 38mm Marzocchi fork is strong enough for a 300 to 350 pounds bike with a not too heavy rider.

My 750F1 in race condition weights approximately 300 pounds and is very happy on race tracks with its original 38mm fork (modified with Glyn's Sports valves).

Gilles

I agree, 38mm is certainly big enough. I run 35mm forks with my valves on two of the TT2's with no issues. The most important issue is not the diameter of the tube. That bit we can all see. It's whats happening inside that we can't see that really matter the most.

Well said. Next priority is to set those adjustments and utilize the range of useful function to suit the tracks one likes. So many riders never touch the adjusters we need more track event workshops. Get those track engineered motorbikes out on the track wherever you may be!

Best wishes,
FMcD