storm42
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- Jul 20, 2011
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Right, spurred on by the best improved competition I though I would do a build thread on my Commando. I hope you all like what follows.
When I was in my late teens, my mate bought a Dunstall 750 Commando and because he had one, I had to have one and I ended up with a Mk1a 850 Interstate.
I don't seem to have any pictures of it when I bought it but it went through a lot of changes and was my only form of transport for many a year. I fitted clip-ons, rear sets a 2 into 1 pipe and thrashed it mercilessly for years, became an expert at rebuilding the gearbox as that wouldn't stay together for long at all.
Anyway I have done previous restorations on it and it has been in various guises over the years, it has been a roadster and a Gus Kunn lookalike, but always money, or lack of it, has meant that any rebuild has been a bit of a compromise, I remember one incarnation in 1978 as a Roadster complete with third Isolastic under the gearbox and a rear disk conversion, I ran out of money before I got the rear disk working and ran the bike for over a year without a back brake.
The reason for the rebuild !! I visited the Bikers Classic meeting at the Spa Francochamps circuit in Begium and decided that, although it was a brilliant weekend, It looked a lot more fun on the other side of the fence. This meant that I needed a pre 1980 bike to enter with and although the Norton was in a sorry state it was duly nominated for classic parade duties.
And now to the present, The next couple of pictures are of the bike as it was in January this year.
I was going to seal the old Gus Kunn tank and with that in mide I cut the bottom out to make sure the job was done properly, gave up in the end as I wasn't sure if a glass tank would be allowed on the track. I bought an aluminium one.
I have never liked the Norton fork dust seals so I altered the seal holders to accept Harley ones.
I went down the twin disk route which like a lot of things for the bike created major problems. The Hub, Disks and callipers came from RGM, the fork bottoms came from Norvil.
As they are all for the same bike I didn't think there would be any fitting problems but, the calipers are Grimica copies of the old AP callipers and apparently the Novil fork bottoms are designed for the later type of AP calliper when the 12” disks are used.
As the price difference between the the Grimica and AP callipers would heat a small town for a year, the only option for me was to machine the disks down by 5mm
Looking at the picture of the hub and disks in the forks above, I wasn't confident that the spokes would clear the calipers but I built the wheel anyway and all fits so a bit of a result after all the trouble making the disks fit.
I cleaned the crank cases up in the bead blaster which was well worth the £90 ($145) it cost,
The crank was worn on the drive side journal so I had it re-ground, chromed over size and then ground to spec, I got them to radius the shaft where it joins the web as recommended by Jim Schmidt.
As you can see, I also bought a couple of Carrillo rods off Jim. Obviously I bought the pistons too.
Quite a difference in the rod lenth.
They stick out of the top a bit though
I had the barrels bored and the cam followers surfaced.
Had to go for a belt drive.
New chain and new Avon race rubber (more about that later)
I read a thread from beginning to end by Jeandr and the rose joint links made a lot of sense to me so!!
Didn't have time to make one for the top so I ended up with a Norvil one.
I picked up a close box from the classic bike show which was supposed to have been built by Pete Lovel, doesn’t hurt to make sure everything is OK though. It was.
Did some work on the rockers.
As you can see from the photos, I had the frame and other painted bits powder coated. But when it came to matching the paint for the tank ect to the fairing and front mudgaurd, the paint shop had trouble getting it right so I bought some pearl yellow and painted the lot. Because the seat was old and battered it was a nightmare to paint and still isn't right. I will be replacing it with a Norvil one.
I also went with the flatties that Jim sells although I wish I had waited a bit as he now has some 34mm ones. Might have to put them in the lathe.
If I had written this as I did the build, there would have been a catalogue of disasters similar to the disk débâcle.
As I said at the top, the reason for the build was to enter the Bikers Classic meet, and I thought that starting in January would allow enough time for the build seeing as the meet was in July.
Well, the crank and barrels were dropped off at the engineers at the beginning of February with a promise that they would be ready at the end of Feb. When I went for them they hadn't even started work on them, anyway to cut a long story short I got them back in April.
The tank was late and when I got it, the cap would spring open at the slightest tug, I found this out by picking the tank up by the cap and it sprung open and I dropped it.
.
Even things like the chain guard didn't fit without persuasion, I mean, how hard is it to punch holes in tin in the right place ???
The 4s cam was machined badly ie the taper in the end for the ignition rotor was out of true, this caused the Pazon Ignition to only fire on one cylinder, I found this out the day before I set off to Belgium. That along with the carbs being so rich the bike was missing badly nearly ruined the Bikers Classic meet. I cured the one cylinder thing with a rotary file in the paddock at Spa but I didn't get to the bottom of the rich mixture until I got it on the dyno the day before doing the Day of a Thousand Bike meet at Mallory.
That showed that the mix was going off the bottom of the scale at about 3000 rpm, the annoying thing was that taking the very restrictive filters off almost cured the problem, in the end I ended up 5 down in the main jet with no filters.
I would say that I do not place any blame at Jims door for that as he couldn't know about the cam or the gas flowing that I have done, also there will be a difference in atmospheric pressure between here and California.
The fairing bracket fouled the top yolk so that had to be cut.
The list goes on and on but the memory doesn't so I will stop moaning about it. Just noticed in the pic above that I fitted the internals from John at Lansdowne engineering. This is a very worthwhile mod and John even met me at the classic bike show with only a few days notice to build them.
Top man and a top product.
The day before we went to Belgium was spent rebuilding the rear wheel with a 19” rim as with the race tyre on the 18” rim it was over an inch lower and I figured there would be ground clearance problems. There still was but that is for another day.
The weekend at Spa was brilliant and I will be there again next year.
Wet first day.
Sorry about the poor quality from the front camera especially the sound, but it gives you an idea of what the meet was about. The bike had only done 70 miles before the event.
When I was in my late teens, my mate bought a Dunstall 750 Commando and because he had one, I had to have one and I ended up with a Mk1a 850 Interstate.
I don't seem to have any pictures of it when I bought it but it went through a lot of changes and was my only form of transport for many a year. I fitted clip-ons, rear sets a 2 into 1 pipe and thrashed it mercilessly for years, became an expert at rebuilding the gearbox as that wouldn't stay together for long at all.
Anyway I have done previous restorations on it and it has been in various guises over the years, it has been a roadster and a Gus Kunn lookalike, but always money, or lack of it, has meant that any rebuild has been a bit of a compromise, I remember one incarnation in 1978 as a Roadster complete with third Isolastic under the gearbox and a rear disk conversion, I ran out of money before I got the rear disk working and ran the bike for over a year without a back brake.
The reason for the rebuild !! I visited the Bikers Classic meeting at the Spa Francochamps circuit in Begium and decided that, although it was a brilliant weekend, It looked a lot more fun on the other side of the fence. This meant that I needed a pre 1980 bike to enter with and although the Norton was in a sorry state it was duly nominated for classic parade duties.
And now to the present, The next couple of pictures are of the bike as it was in January this year.
I was going to seal the old Gus Kunn tank and with that in mide I cut the bottom out to make sure the job was done properly, gave up in the end as I wasn't sure if a glass tank would be allowed on the track. I bought an aluminium one.
I have never liked the Norton fork dust seals so I altered the seal holders to accept Harley ones.
I went down the twin disk route which like a lot of things for the bike created major problems. The Hub, Disks and callipers came from RGM, the fork bottoms came from Norvil.
As they are all for the same bike I didn't think there would be any fitting problems but, the calipers are Grimica copies of the old AP callipers and apparently the Novil fork bottoms are designed for the later type of AP calliper when the 12” disks are used.
As the price difference between the the Grimica and AP callipers would heat a small town for a year, the only option for me was to machine the disks down by 5mm
Looking at the picture of the hub and disks in the forks above, I wasn't confident that the spokes would clear the calipers but I built the wheel anyway and all fits so a bit of a result after all the trouble making the disks fit.
I cleaned the crank cases up in the bead blaster which was well worth the £90 ($145) it cost,
The crank was worn on the drive side journal so I had it re-ground, chromed over size and then ground to spec, I got them to radius the shaft where it joins the web as recommended by Jim Schmidt.
As you can see, I also bought a couple of Carrillo rods off Jim. Obviously I bought the pistons too.
Quite a difference in the rod lenth.
They stick out of the top a bit though
I had the barrels bored and the cam followers surfaced.
Had to go for a belt drive.
New chain and new Avon race rubber (more about that later)
I read a thread from beginning to end by Jeandr and the rose joint links made a lot of sense to me so!!
Didn't have time to make one for the top so I ended up with a Norvil one.
I picked up a close box from the classic bike show which was supposed to have been built by Pete Lovel, doesn’t hurt to make sure everything is OK though. It was.
Did some work on the rockers.
As you can see from the photos, I had the frame and other painted bits powder coated. But when it came to matching the paint for the tank ect to the fairing and front mudgaurd, the paint shop had trouble getting it right so I bought some pearl yellow and painted the lot. Because the seat was old and battered it was a nightmare to paint and still isn't right. I will be replacing it with a Norvil one.
I also went with the flatties that Jim sells although I wish I had waited a bit as he now has some 34mm ones. Might have to put them in the lathe.
If I had written this as I did the build, there would have been a catalogue of disasters similar to the disk débâcle.
As I said at the top, the reason for the build was to enter the Bikers Classic meet, and I thought that starting in January would allow enough time for the build seeing as the meet was in July.
Well, the crank and barrels were dropped off at the engineers at the beginning of February with a promise that they would be ready at the end of Feb. When I went for them they hadn't even started work on them, anyway to cut a long story short I got them back in April.
The tank was late and when I got it, the cap would spring open at the slightest tug, I found this out by picking the tank up by the cap and it sprung open and I dropped it.
.Even things like the chain guard didn't fit without persuasion, I mean, how hard is it to punch holes in tin in the right place ???
The 4s cam was machined badly ie the taper in the end for the ignition rotor was out of true, this caused the Pazon Ignition to only fire on one cylinder, I found this out the day before I set off to Belgium. That along with the carbs being so rich the bike was missing badly nearly ruined the Bikers Classic meet. I cured the one cylinder thing with a rotary file in the paddock at Spa but I didn't get to the bottom of the rich mixture until I got it on the dyno the day before doing the Day of a Thousand Bike meet at Mallory.
That showed that the mix was going off the bottom of the scale at about 3000 rpm, the annoying thing was that taking the very restrictive filters off almost cured the problem, in the end I ended up 5 down in the main jet with no filters.
I would say that I do not place any blame at Jims door for that as he couldn't know about the cam or the gas flowing that I have done, also there will be a difference in atmospheric pressure between here and California.
The fairing bracket fouled the top yolk so that had to be cut.
The list goes on and on but the memory doesn't so I will stop moaning about it. Just noticed in the pic above that I fitted the internals from John at Lansdowne engineering. This is a very worthwhile mod and John even met me at the classic bike show with only a few days notice to build them.
Top man and a top product.
The day before we went to Belgium was spent rebuilding the rear wheel with a 19” rim as with the race tyre on the 18” rim it was over an inch lower and I figured there would be ground clearance problems. There still was but that is for another day.
The weekend at Spa was brilliant and I will be there again next year.
Wet first day.
Sorry about the poor quality from the front camera especially the sound, but it gives you an idea of what the meet was about. The bike had only done 70 miles before the event.
