TW wrecks a perfectly good Commando etc.

I doubt anyone would put an engine commissioned by Dulux in a TR5T in place of one the best engines to come out of the UK (Late unit 500), I did get a B50MX seat for the one at the back though along with a 1970's Malcolm Smith tank.
The head is done (Kibblewhite / new valve seats etc) cylinder rebored and a bunch of NOS parts from rockers to replacement shafts and gears.
It should look something like this depending on the tank used.

Medal winners at the 1973 ISDT which was quite a feat against the two strokes of the time.
Only 929 built for the red 1974 version.


TW wrecks a perfectly good Commando etc.
 
Nearly time to pack my bag ready for the morning.

Some pics for folk who like shiny things.

Kubota alternator - 14 amp / 168 watts ( 20 amp / 240 watt as a future option) to 1949 Sunbeam S7 Deluxe.
I sold my 1954 S7D a year or so back.

TW wrecks a perfectly good Commando etc. TW wrecks a perfectly good Commando etc.

Machine an OD thread the units rear mount
Machine an ID threaded mount for that to thread in, the mount cap screw lock the two together after tightening.

TW wrecks a perfectly good Commando etc. TW wrecks a perfectly good Commando etc.

Coupling is a four prong drive with soft flange insert (The engine drives the coupling, the coupling drives the alternator indirectly)
The outer shell is the same dimensions as the original Lucas dynamo, its end cap reused.

TW wrecks a perfectly good Commando etc. TW wrecks a perfectly good Commando etc.
 
Time Warp said:
I doubt anyone would put an engine commissioned by Dulux in a TR5T in place of one the best engines to come out of the UK (Late unit 500), I did get a B50MX seat for the one at the back though along with a 1970's Malcolm Smith tank.
The head is done (Kibblewhite / new valve seats etc) cylinder rebored and a bunch of NOS parts from rockers to replacement shafts and gears.
It should look something like this depending on the tank used.

Medal winners at the 1973 ISDT which was quite a feat against the two strokes of the time.
Only 929 built for the red 1974 version.


View attachment 110978
Click to expand...
Sweet example of a sweet bike there dude…
 
Now , twin 30s on it , and 40 over 650 pistons , and youll start to get somewhere .

TW wrecks a perfectly good Commando etc.


Was said they detuned it , due to the bronze rear wheel gear . NOW , a new gear,
or a modern swing arm with it , and itll be safe to double the horsepower !

Was a S8 on a cruise , manadged rural roads & 70 mph no sweat , was in the first bunch to pull in shortly after the throttle merchants , always .

TW wrecks a perfectly good Commando etc.


Ever seen anything else in them ? .
 
Yes I am quite familiar (perhaps every square mm) with that model.

I was lucky enough to find a NOS worm wheel and worm screw in the UK. (bought in 1962 by the seller)

TW wrecks a perfectly good Commando etc. TW wrecks a perfectly good Commando etc.

They are a very enjoyable motorcycle to work on and have little in common with anything.
Perhaps the two wheeled version of a Morris Minor. (My second car)
 
Matt Spencer said:
Was said they detuned it , due to the bronze rear wheel gear .
Click to expand...

Apparently there was a cross flow head version built (100 mph) but was not put into production.

I had read part of the problem with the bronze worm wheel was the wrong oil recommended by the factory , you can adapt a Ural centre to the final drive but the Ural wheel hub would need to be used (The wheels on the S7D are interchangeable)


Sunbeam 500 twin- 70 mm x 63.5 mm
Late Triumph 500 unit 69 mm x 65.5 mm
Norton Commando 750 73 mm x 89 mm
Triumph pre unit 650 71 mm x 82 mm

Surprisingly the Sunbeam does not have the 'worst rod ratio.

TW wrecks a perfectly good Commando etc.
 
p m was supposed to be a link to a rebuild , Id tripped over . Shiny new bits !

WHAT happens on the overun with that worm gear , Is throttle off like putting on the brakes .
Youd think it would take more kilojewles to turn it from the other end , as in the wheel , pehaps .
 
Matt Spencer said:
p m was supposed to be a link to a rebuild , Id tripped over . Shiny new bits !

WHAT happens on the overun with that worm gear , Is throttle off like putting on the brakes .
Youd think it would take more kilojewles to turn it from the other end , as in the wheel , pehaps .
Click to expand...

That thread went pear shaped with the demise of Photobucket but might update it one day, not being able to back edit it does not help.

I would imagine the worm drive would add some friction but never noticed anything obvious but the engine is low compression.
 
Time Warp said:
I doubt anyone would put an engine commissioned by Dulux in a TR5T in place of one the best engines to come out of the UK (Late unit 500), I did get a B50MX seat for the one at the back though along with a 1970's Malcolm Smith tank.
The head is done (Kibblewhite / new valve seats etc) cylinder rebored and a bunch of NOS parts from rockers to replacement shafts and gears.
It should look something like this depending on the tank used.

Medal winners at the 1973 ISDT which was quite a feat against the two strokes of the time.
Only 929 built for the red 1974 version.


View attachment 110978
Click to expand...
I'm sure I read somewhere the unit single BSA and later CCM was the most successful competition MX ever in terms of years in production and trophies won
For a road bike I'd definitely prefer the triumph twin in the bsa chassis
 
The TR5T is not that great on road with the stock gearing unless you want to doddle along (close 1/2 - stock T100 3/4 along with the short final ratio)
Prices for them have risen drastically in the last few years world wide.

As far as 4 stroke singles I think I would rather have the best of both worlds with more HP and torque than an 850 Commando to boot.

Procycle DR780 big bore (110 mm), KW big valve cylinder head (Phil Tainton Racing did the machining) Web #190, TM40 pumper, FMF Powerbomb header, TB C2 muffler (off one of my TL1000S's)
Billet 3rd gear (I got Nova racing in the UK to make them) along with everything else inside the engine/gearbox replaced with new.

That project went into Commando territory ($$) but was well worth it being a keep forever bike.

TW wrecks a perfectly good Commando etc.
 
Time Warp said:
Apparently there was a cross flow head version built (100 mph) but was not put into production.

I had read part of the problem with the bronze worm wheel was the wrong oil recommended by the factory , you can adapt a Ural centre to the final drive but the Ural wheel hub would need to be used (The wheels on the S7D are interchangeable)


Sunbeam 500 twin- 70 mm x 63.5 mm
Late Triumph 500 unit 69 mm x 65.5 mm
Norton Commando 750 73 mm x 89 mm
Triumph pre unit 650 71 mm x 82 mm

Surprisingly the Sunbeam does not have the 'worst rod ratio.

View attachment 111179
Click to expand...
Sunbeam certainly seems to have the best big end diameter to BHP ratio !
 
Fast Eddie said:
Sunbeam certainly seems to have the best big end diameter to BHP ratio !
Click to expand...

The engine is almost car like so the crank and diameters are similar.
Not my pic.

Ball bearing at the front (roller bearing being an upgrade) and bush at the rear. The rear being the right in the pic and external flywheel on the taper.

TW wrecks a perfectly good Commando etc.
 
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