Iron Motors Tech

panic · Joined: 04 Dec 2005 Posts: 179 Location: Hempstead NY USA

Very nice!

Curious - any idea why the oil tank is mounted so low on the frame?
Seems to me that it has more exposure to heat from the rear cylinder, plus it masks the back of the cylinder from streaming air.

Piet Jan · Joined: 24 Nov 2005 Posts: 78 Location: Netherlands

Am now half way the shake down (I hope). Here's a short movie of the bike going through the gears (BSA 4-speed with left side controls using a push-pull cable to the right side of the box). The exhausts are KR type 1 3/4" open pipes with 8" baffles inside. Maybe not ideal from a performance perspective but great noices. Have no compaints at all in the performance department, compared to the standard WLA I am used to this thing really goes. Have to limit myself because it has only 40 miles on the clock right now.

http://www.youtube.com/user/GT3RSlover#p/a/u/0/pzmEN2awIeU

George Greer · Posted: Fri Jul 09, 2010 9:53 pm Post subject:

Piet...

That rocks...

Sounds nice and strong.

Once you get it broken in, what do you estamate top end?

Interested in your foot shft mountings. Gets my interestest in mounting the M21 on my bike again.

I do have a set back on the KH cylinders that I got....what I thought was hardned up grease.......was covering some pitting that I don't think will clean up, and I may have to either look for another set of them, or consider having them sleeved.

George

panic · Joined: 04 Dec 2005 Posts: 179 Location: Hempstead NY USA

Just about 100, with enough gear. It takes 30 hp or so.

Piet Jan · Joined: 24 Nov 2005 Posts: 78 Location: Netherlands

George, Uh.... I think about 100 mph Smile

The gearing was calculated to be the same as a WL with a 34 motorsprocket, so on the tall side. That calculation was based on the use of a 18T (BSA) gearbox sprocket. I have changed that to 19T mainly to improve chain-frame clearance, so is now a bit taller even.
The gearing feels pretty good with good acceleration and 4th on the tall side with low rpm's at 50. Haven't been above 50 yet, have to carefully run it in. I plan to install an accurate bicycle speedo for trials when that's completed.

The K is advertised as having 30 hp. This bike has KH cams and Mikuni carb and should have a bit more than that (the KHK set is waiting on the shelf).

All in all the promise of 100 mph sounds good. So far I've only covered 40 miles (have been inactive for about two months due to neck problems). The coming months should complete the run in. Ofcourse depending on the shortcomings I may find.

Next years Spa track days should be doable - if there's competition from our French and German friends ofcourse. I believe it should be pretty close to WR performance and with 4 gears and big front brake should have an advantage. We'll see.