Street legal Norton Manx? Has anyone done it?

speirmoor

speirmoor

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Any lucky contributors here have a street legal Manx? If so I'd love to see it and tell us how you got around the "legalities"
 
Not me, but I do recall a mechanic of almost 45 years ago who regularly rode his Manx to work. It was great watching him start it up in the evening. Sat back on the rear stand He would put it in gear, rotate the wheel backwards to compression, then he’d spin the back wheel by hand to start it up. Never failed, started every time. Open megaphone, no lights. Wonderful.
 
Several examples of G50 and 7R models but I don't recall Manx based bikes.
 
Hi
Yes 1955 short stroke, back in 1971, biggest issue I had was vibrations at road legal speeds, no problems with getting past for roadworthy back then.
Fitted a Lucas alternator and dominator primary case.
Other issue was the standard Manx gearbox not much fun starting off on hills or starting and stopping in traffic.
I fitted a 99 gearbox with a kick starter to get around this, also used the kick starter, that was a lot better than pushing.
Fitted an Amal Concentric carby, on one trip to Easter Bathurst races the float bowl screws came out and the float went flying.
Since then I have restored the bike back to original spec.
If I was doing it again I would balance the engine so it was smoother at legal road speeds, and run total loss on electrical side.
Forgot oil leaks from valve push rods, spong was good for a short trip but longer trips not much fun.
Burgs
 
Burgs said:
Hi
Yes 1955 short stroke, back in 1971, biggest issue I had was vibrations at road legal speeds, no problems with getting past for roadworthy back then.
Fitted a Lucas alternator and dominator primary case.
Other issue was the standard Manx gearbox not much fun starting off on hills or starting and stopping in traffic.
I fitted a 99 gearbox with a kick starter to get around this, also used the kick starter, that was a lot better than pushing.
Fitted an Amal Concentric carby, on one trip to Easter Bathurst races the float bowl screws came out and the float went flying.
Since then I have restored the bike back to original spec.
If I was doing it again I would balance the engine so it was smoother at legal road speeds, and run total loss on electrical side.
Forgot oil leaks from valve push rods, spong was good for a short trip but longer trips not much fun.
Burgs
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I talked to Patrick Walker of Works Racing ( vg replica engines) about this last year. He said that a standard AMC box is fine, and he can supply an electric button decompressor for kick starting, and a small alternator for LED lights. Engine runs on modern semi or synthetic oil.
 
My late brother in law had an early version garden gate Manx brought off a racing gentleman in the 1950s, don't know how he mounted the dynamo for lights, it might have been a mag/ dynamo.
In the UK you can get away without lights ( or used to) provided you ride in daylight. If you get caught out with the fog from the Mull of Kintyne you are buggered. He used to kick it over and if it didn't start, it meant putting it in gear and rolling it back to get the piston in the right position. This is why Norton fitted a plate between barrel and c/case to lower compression ratio and fit softer cams on Inter, which he didn't have. Also Amal GP carb was no joke as it didn't have a pilot jet, but I think the TT carb did.
 
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I don't have a street legal Manx and I would never contemplate making one. Handling is about the same as any other featherbed Norton. Brakes a bit better. Weight is significantly lower (dry about 140 kg). The tall first gear combined with the lack of low end torque makes it problematic in low speeds. Fitting of a silencer reduces power significantly. Being old and stiff, I must admit that the riding position is not very comfortable for longer trips.. The inbuilt rust prevention system (open hairpin valve springs) makes it look a bit untidy. Oily rear tyres are not fun.
A Molnar engine with encapsuled coil springs is 99.9% oil tight. One single drop of oil from the rev counter gearbox in a racing season.
So personally I am building a street legal 650SS close to the Manx look and feel to get more riding.
 
Bill Anderson had an original one on the road in the 70's. He lives in the US now and goes to a lot of the speed meets. t El Mirage/Bonneville etc. I think he has a weslake engine in the Manx now
 
Landspeedracer said:
Not me, but I do recall a mechanic of almost 45 years ago who regularly rode his Manx to work. It was great watching him start it up in the evening. Sat back on the rear stand He would put it in gear, rotate the wheel backwards to compression, then he’d spin the back wheel by hand to start it up. Never failed, started every time. Open megaphone, no lights. Wonderful.
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I suspect it was fitted with detuneing mods, the same way Norton did to their Internationals. Softer cams and a plate between c/ cases and barrel to lower c. r. No way could you turn a standard Manx engine over compression by hand.
 
We usually started the JAP and JAWA speedway bikes that way, c.r. between 14 and 16. So I can't see why it couldn't be done on a Manx.
A properly setup Manx c.r 10.5 starts with max. 4 strides run and bump. Only question is how he fitted the stand, Manx frames have no lugs for it.
 
speirmoor said:
Is that the same law that allows race bikes on the street occasionally?
No, there is a ‘daytime’ version of the MOT ( roadworthyness) test, so no lights are OK, but then only daytime use.
Road racing is not allowed on mainland Britain, hence the Isle of Man races, where it wasn’t banned way back when.
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Mike40M said:
We usually started the JAP and JAWA speedway bikes that way, c.r. between 14 and 16. So I can't see why it couldn't be done on a Manx.
A properly setup Manx c.r 10.5 starts with max. 4 strides run and bump. Only question is how he fitted the stand, Manx frames have no lugs for it.
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Lugs? What lugs? Didn't the centre stand bolt to the engine plates?
I couldnt turn over a 370 single without a valve lifter, so I guess there must be a knack to it.
 
speirmoor said:
Is that the same law that allows race bikes on the street occasionally?
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No that's completely different, road closures allow races on otherwise open public roads, to ride a racer on open public roads without the need to have the roads closed you can get an Daytime MOT. The Daytime MOT allows you to ride on the open public roads only when the sun is up and visibility good, plus you have other requirements such as a working horn. The pre 65 trial bikes use it mainly, not much call for racing bikes with daytime MOT.
 
I’ve had bikes without lights MOT’d before. But does anyone know the process with an old bike now they no longer need to have MOT tests?
 
My MOT bloke says all that's required is a horn & rear reflector, but no MOT if older than 40. I have two old bikes with no lights & am in the process of building another.
 
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