lets go racing

The biggest deterrent to historic racing is eligibility rules. We have people on committees who tailor the rules to suit their own motorcycles. The first thing they do when writing rules is think about what should be excluded. They imagine that other guys who make modifications, are the reason they themselves are slow. Lap times don't mean much, some races are won by psychology in the pits. I usually try to help the other guys become faster. I do not care who beats me, they still have to ride the bike. I was really sad the first time I rode the Seeley 850 at Mount Gambier. There was a kid with a Honda 750 having a really good go at me, but when I put pressure on him, he gave up.
 
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acadian said:
It's very frustrating, I have spoken with a builder who ran in the same class and was told that he's "gotten by" inspection, but also gotten caught. In his opinion it's a crap shoot depending on who is performing the inspection. But in terms of actual legality, adjustable fork dampers are not permitted.

What's more aggravating is that lack of harmonization in rules between VRRA (canada) and AHRMA (usa), many guys race on both sides of the border and, in fact, a VRRA licence (obtained in Canada) fully qualifies you for AHRMA... so it's clear that they want cross border competitors.

I'm not sure what guys do... I mean, do they pre prep their bikes for two set ups (i.e. dampers, floating discs) and then swap on either side of the border??

edit: another example in carbs - VRRA smoothbore size limit = 31mm, AHRMA = 34mm
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If the respective committees didn't have territorial issues, (often the case) the intelligent thing to do would be to have AHRMA and VRRA representatives sit down with a case of good beer and hash out a set of North American rules, thus encouraging larger fields
 
Understanding the rules well, and building the most competitive machine that you can, within those rules, is all a part and parcel of racing.
 
Seat and fairing arrived

lets go racing


Next project is the gearbox rebuild, while I sort through the internals I'll also be trying to work out an outrigger, I've located a suitable deep groove ball bearing, it's 7mm deep with an ID of 29mm, the sleeve gear is 28.5mm so it will require a sleeve, the bearing that Steve supplied is 1.125 ID (28.55mm) which gives a bit of slop on the sleeve gear. All that being said, and since I don't have the ability to cast parts, this will have to be a bolt together unit. I've not found any references to other folks who've made their own outrigger so I'm in uncharted territory as best as I can tell. I anyone has any tips send them my way.

lets go racing
 
Difficult to find time to put into the project, but some progress made while waiting on close ratio gear set from RGM which just arrive along with rebuild kit, so that's next on the to-do list

lets go racing


I'm going to pin both of the bearings a'la dunstall's counterbore/washer procedure, so I made up some 5/8 OD x 1/8 thick washers (3 total, one for GB and two for engine case bearings). Locating the counterbore in the shell to provide just the right amount of overlap on both bearing outer races was a tad tricky, but the washer locates where I wanted it. Once the bearing are in I'll use a 5/8 deburring endmill to counterbore the outers (this will work better than a grinding stone IMO).

lets go racing
lets go racing


While I was waiting on the gear set I made up a pair of rearsets, I appreciate why a good pair costs so much

lets go racing
lets go racing
lets go racing


Fairings also arrived, decided to paint them blue because I don't have a blue bike

lets go racing


That's it for now, will post updates as the gearbox rebuild comes along
 
SteveBorland said:
Is that really enough engagement ? I always thought it would have to be about twice as much?
Fascinating to see this build, there's an awful lot of "if only I could also do that" here :)
Click to expand...

I think so, yes, the important function is to prevent the bearing rotating/walking, so the fit of the washer in the countrerbore is critical, and it's a tight fit.
 
Ran into a problem that's got me stumped. Began assembling the close ratio gear set I got from RGM, there were some fitment issues I had to resolve with a couple gears (1st gear bushing too tight on shaft, 2nd gear casting marks interfering with mainshaft splines), but aside form that everything goes together as expected until I try to get through all the gears. Note that the camplate and quadrant are timed as per Hemmings and I do have full range with clearance on the quadrant with inner cover fitted. The problem is with fourth and after disassembling and testing one gear at a time this is what I've found:

Quadrant/plunger in fourth

lets go racing


Third gear/selector fork in quadrant track, and the selector spindle does not line up

lets go racing


So I move the selector fork up so the spindle bore does align

lets go racing


And here's the resulting position of the camplate

lets go racing


Swapped with a standard gear and problem persists, swapped selector forks and the problem persists. Any (helpful) thoughts are appreciated
 
The standard troubleshoot is - disassemble, analyze, repair/adjust, reassemble.

You've done the disassembly and the analysis.. so from what you've shown the camplate detent is in the wrong place for the 4th gear forks to move. The way I see it, it seems like it could only be 2 things, the fork is bent somehow or the detent is located incorrectly on the cam plate.

The next step is repair/adjust. Needless to say making a new camplate from scratch would be a huge job,... but you could always buy a camplate and weld up the old detent and relocate it to where your testing showed that it needs to be. This solution only risks the cost of a new camplate and some of your time...

That's my $.02

Edited to add: Perhaps you have the wrong camplate.. (not really something I know about, but something that might explain what you are seeing)
 
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o0norton0o said:
The standard troubleshoot is - disassemble, analyze, repair/adjust, reassemble.

You've done the disassembly and the analysis.. so from what you've shown the camplate detent is in the wrong place for the 4th gear forks to move. The way I see it, it seems like it could only be 2 things, the fork is bent somehow or the detent is located incorrectly on the cam plate.

The next step is repair/adjust. Needless to say making a new camplate from scratch would be a huge job,... but you could always buy a camplate and weld up the old detent and relocate it to where your testing showed that it needs to be. This solution only risks the cost of a new camplate and some of your time...

That's my $.02

Edited to add: Perhaps you have the wrong camplate.. (not really something I know about, but something that might explain what you are seeing)
Click to expand...
Thanks, that's my conclusion as well. These are parts from a donor box I bought, after a few more disassembly/test procedures (i.e. inserting only one fork at a time), I've concluded that the issue is with the forks, The camplate, aside from being hardened at some point, seems OK, but I did polish the tracks to remove any burs and that only resulted in a moderate improvement.

I've ordered a new camplate, pair of forks and spindle bar from Andover. So this means the entirety of the box is now new parts (except for the quadrant which is the good brazed version). Given the intended usage I think that's probably a good thing,
 
You will find with close ratio gears, you can run higher overall gearing. But for clutch start races, you need the low first gear. The Commando first gear will usually fit the close ratio cluster, Even on short tight circuits, I have never had to go back to first gear while racing. With the Commando engine, the secret is to make them pull, but if you lose too many revs on upchanges, then you rely on throttle response. The heavy crank must be kept spinning high. I suspect some people do not know how to use the gearbox. My motor works between 5,500 RPM and 7,300 RPM.
 
Finally finished the gearbox, ordered two new shift forks from andover and that rectified the problem, though there's a lack of a definitive click going into the gears (except for neutral), so I'm thinking a new plunger and spring may be on order. Anyway, all installed with the DIY outrigger

lets go racing
lets go racing
lets go racing
 
Question for the gallery, if you had to choose between Molnar cases or barrels what would inform your decision? For context I was planning on reinforcing the stock cases I have which are otherwise in good shape, this will be mated to the short stroke crank from molnar
 
acadian said:
Question for the gallery, if you had to choose between Molnar cases or barrels what would inform your decision? For context I was planning on reinforcing the stock cases I have which are otherwise in good shape, this will be mated to the short stroke crank from molnar
Click to expand...
Mmmm. Maybe not what you want to hear but when I did race bikes my money went first into parts that made it strong and reliable.

After I achieved that then I worked on fast.

To finish first - first you have to finish. And that's a serious machine your building there.

Of course Colin Chapman famously went another way.
 

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