how in the hell does this happen?

hillhudson · Post by **hillhudson** » Wed May 06, 2015 1:38 am

how does one go about running a cb77 dry clutch style? this photo blew my mind a bit.

http://www.vf750fd.com/vf750f/ian_munro/0001.jpg
http://www.vf750fd.com/vf750f/ian_munro/0001.jpg
http://www.vf750fd.com/vf750f/ian_munro/0004.jpg

G-Man · Post by **G-Man** » Wed May 06, 2015 5:40 am

Hill

I have heard that it is possible to run a TZ350 clutch by using an extended gearbox mainshaft. You obviously need a modified primary cover to keep the oil in.

http://home.comcast.net/~eholman/repspec.html

I acquired a CR72 primary cover a while back to look at how it was done by Honda back in the day. This one came up on UK eBay, rather surprisingly. It won't fit a CB72 engine but is very interesting.....

The other pictures of a gear primary conversion using a CB500 clutch drum with gear and the idler gear (actually a gear from a Honda gearbox) with mounting plate.

G

hillhudson · Post by **hillhudson** » Wed May 06, 2015 11:49 am

Oh man, thanks for the info! It might be nice toget that primary cover molded and replicated!

G-Man · Post by **G-Man** » Wed May 06, 2015 12:28 pm

Hill

That's the plan. Typically Honda, all of the screw holes are in the wrong places, despite the fact that the original CR72 was based on a CB72 design. Last month I picked up a CR72 gear shift lever and linkage with some CB72 stuff so I'm edging ever closer.

It should be possible to come up with something based on that cover for a CB72. There have been a number done like the one you showed and Ellis Holman's. I think there is also something on Michael Moore's Eurospares site.

http://www.eurospares.com/graphic2.htm

G

hillhudson wrote:Oh man, thanks for the info! It might be nice toget that primary cover molded and replicated!

MBellRacing · Post by **MBellRacing** » Tue May 12, 2015 1:36 pm

So I MIGHT be working on a top secret project that is 100% unrelated to gasoline-powered motorcycles, but I have been making connections in the aluminum casting world. If someone could gather some [small] crowd funding for it, I'd love to invest some time in creating a new primary cover that accommodates the dry clutch. That would be my kind of project, with some help!

G-Man · Post by **G-Man** » Tue May 12, 2015 1:44 pm

I've used these guys, about 3 miles from me to do patterns for iron castings.

http://patternsderby.com/index.php/patt ... sting.html

Last time I visited they were repairing a quantity of cylinder head patterns for the Ford engine plant at Dagenham. There are plenty of people around here who do castings for Rolls Royce aerospace and Formula 1 teams.

This is going to be part of my CR72 replica......

G

MBellRacing wrote:So I MIGHT be working on a top secret project that is 100% unrelated to gasoline-powered motorcycles, but I have been making connections in the aluminum casting world. If someone could gather some [small] crowd funding for it, I'd love to invest some time in creating a new primary cover that accommodates the dry clutch. That would be my kind of project, with some help!

Airmun · Post by **Airmun** » Tue May 12, 2015 4:14 pm

I have the patterns for the early type primary case. They may be modified to suit standard cases, I am not sure. The photos from a couple of posts ago will show the part.