Continuing our New Zealand based special edition, our journey onward from Pongakawa resumes around the eastern peninsula of the North Island and following down the eastern coast, to where the Art Deco town of Napier softly nestles into the gentle caress of Hawkes Bay - but the early morning tranquil peace of New Year's Day: January 1st 2012, is shattered by the screaming wail of new Samurai cyclemotors howling along the sea front cycle track.

Over Christmas, on the far side of the world, it just seems that nothing is impossible, and right now we're in town to test the two-stroke Mitsubishi TLE43 & four-stroke Robin Subaru EH035 cyclemotors.

Mitsubishi was initially established as a shipping firm in 1870, from which it diversified into related activities.  Coal mining to fuel its steam ships, then shipbuilding, an iron mill to supply the shipyard, marine insurance ... and later into aircraft, then automotive, etc. Today, the company is best described as a broadly based conglomerate.

Mitsubishi TLE43 is probably among one of the meanest, nastiest, roller drive clip-on units that you're likely to come across today.  It's based on a 43cc industrial/commercial brush cutter motor, which is just about the biggest capacity and most powerful unit that you'll generally find for this portable power application, much above which weight becomes impractical for commercial use.  This fiery two-stroke engine with forced-air fan cooling, is a crankcase induction reed-valve producing 2.2bhp, and it revs like mad!

Now, anyone familiar with cyclemotor units is probably going to appreciate this really doesn't sound quite like the most ideal combination of qualities for a roller drive clip-on ... and you're absolutely right - it's not!

The proprietary Mitsubishi engine is adapted to this application by Stanton Inc in the USA a cyclemotor assembler who offered various arrangements for a number of different motor types.

Since the owner of this machine is quite a tall gentleman, the clip-on is mounted on a lofty Iron Horse 19½-inch rigid-frame mountain bike with telescopic forks.  While modern cycles such as this probably hold little interest for our general readership and will have little more involvement in the rest of the article, it may be of some amusement to appreciate that the saddle set was rather on the high side for our test rider, who required the aid of a kerb to mount.

Undeterred by such minor technical difficulties...

The Mitsubishi motor is mounted on the left-hand side of a composite U-section channel that bridges the rear wheel.  The channel is appropriately bored through to clear the crank journal, to which may be screwed a range of coarse diamond pattern knurled and hardened steel drive rollers, variously sized to suit a selection of drive ratio ranges, rider loading, and application required.  A smaller diameter drive roller may be selected to suit a heavier rider in hilly terrain, while a larger diameter roller may be preferred for greater speed in flatter country with a lighter rider.

Roller ranges go in 1/8 inch diameter increments from an inch to an inch and a half.  The rang of diametric sizes is pretty much dictated by the practical drive ratio ranges that the motor needs for suitable gearing operation, and there are certain engineering limitations to the practical depth of a diamond pattern knurl.  Well, let's say, it's not quite like having a toothed roller, or a grit roller, or a rubber coated roller ... though it's hardened, and is durable.  But anyone familiar with cyclemotor drive rollers will probably be cringing at this point, appreciating that these are quite small driving diameters and, with this furious 2.2bhp motor, it's sure going to give the tyre absolute hell!

The drive roller extends across the width of the mounting channel to locate into a sealed bearing on the opposite side, so the driving assembly is suitably supported.  Drive roller pressure is adjustable into engagement with the tyre, and it's certainly going to need plenty of that!

There's an off/on kill-switch on the left-hand engine mounting bracket, so click this into 'run' position.

There's no petrol tap since the fuel tank is under the motor with a diaphragm pump to draw fuel up to the carburetter, but the engine does want to be rich for starting.  There's a dial on the side of the carburetter to turn for choke, and one pump on the ball primer is the generally recommended practice.

The Mitsu engine is recoil start and, because of the location of the motor, you'll only be able to get it going from off the bike.  A few spins on the recoil soon have the motor running, then just leave it ticking over a few minutes to work up some temperature before easing the choke dial to 'run' position.

The throttle operates by a trigger on the right-hand bar and drive enables through an automatic centrifugal clutch with metal-shoes.  Blipping the throttle to 'clear' the engine without the rider aboard isn't a great idea, since the clutch readily bites and you'll find the bike will be quite keen to leave without you.

Mounting the tall frame with the assistance of a kerb, it's then best to pedal up to primary speed to avoid spinning the drive roller on the tyre, then feed in the throttle to take up the pace.  The metal faced clutch shoes jangle and clatter harshly until the drive is engaged, at which transmission noise abates and the engine assumes the role.

It's generally better to maintain consistent running above 12mph, otherwise the clutch is constantly acting, and resultant mechanical noise becomes quite unpleasant.

The 2.2bhp output means a fair amount of useful power if you need it, and the reed valve will deliver very effective torque from low revs, but you can't generally snap open the throttle or it'll induce instant roller slip.  To be honest, mere 'slip' is quite an understatement, the roller spins wildly under full drive pressure and instantly converts the tyre into smoke!

So far, there sounds a lot of downside to the Mitsubishi, but its better qualities don't start coming through much until you get above 20mph - and out of the roller slip zone!  Now you can begin to use the power, pin back the throttle trigger, and in the manner of any classic Italian sports 50, Mitsu delivers a dramatic burst of acceleration to surge straight through the 30mph barrier.

The accompanying noise is pretty furious too, since there's nothing subtle about giving Mitsu the gun - pedestrians are going to notice!  Just think how angry any petrol driven line trimmer sounds, and this is a big nasty one, on the back of your bicycle!

There's no trouble maintaining traffic pace at 50kph urban limits through Napier town, but our Mitsu powered bike makes much harder work of weaving around other cyclists, pedestrians, kids and dogs along the sea front cycle track.  The slower pace means the metal clutch is jangling in and out, while you consciously try to suppress noisy bursts of throttle.  Mountain bike steering gives front-end heavy handling, feeling rather clumsy at low speed, but we try to avoid actually stopping since the over tall saddle presents other difficulties.

Consequently, we end up cycling slower sections with the engine on tick-over then, once the path clears, blasting up to speed to catch our pace rider ahead.  It's a very difficult machine to ride smoothly and slowly, you can't really - the bike's just a hooligan!

Finally we get to test what our Mitsubishi does best, flat out speed.  On the level, clocked by radar gun, tucked in a crouch, along the smooth carriageway tarmac of Napier Esplanade - 60kph / 36mph.

Mitsu was absolutely revving out at this speed, but it needs to be appreciated that this was accomplished on just a 1-1/8 inch diameter drive roller.

Rollers are available in 1, 1-1/8, 1¼, 1-3/8, and 1½ inch diameters.

Re-fitting with the largest 1½ inch diameter roller would increase the drive ratio by 27% so, presuming the motor could pull the same revs, the maths suggests that up to 46mph might be possible ... that may be something for the suicidal to contemplate.  This would almost surely be at further cost to even greater roller slip issues and low speed usability, so probably only a trade-off against practicality.  Any water pickup on the tyre and the roller will constantly slip - you simply can't use the Mitsu in wet conditions at all.  The 'useful' power produced by the motor is probably not going to be much use on hills, since the drive roller will almost certainly break away under the increased load of climbing.

The Mitsubishi is a frantic and angry motor, the vibrations can quickly become tiring and it would probably benefit the rider if there were some isolastic mounting arrangement (rubber bushes).  Somehow, petrol strimmer engines seem to produce one of the most offensive and irritating sounds known to man and, once the novelty has worn off, it's possible the noise created by this motor could wear the rider down until they hated using it.

Typically Top Gear, the TLE43 is a delinquent toy, but doesn't really make any practical cyclemotor.

Not all petrol strimmer motors are created equal.

Not all petrol strimmer motors are screaming two-strokes.

There is another way ... Robin Subaru EH035.

Subaru is the automotive manufacturing division of Fuji Heavy Industries, which was established in 1953.  Subaru is the Japanese name for the Pleiades stellar cluster, which is reflected by the company's six star logo, also representing the six original companies that were merged to form today's Fuji Heavy Industrial Group.

Fuji's roots started in 1915 as the Aircraft Research Laboratory, and in 1932 was re-organised as the Nakajima Aircraft Co.

Subaru Industrial Power Products are marketed with Wisconsin Robin branding in North America, and as the motor assembly hails from the United States, that explains the Robin Subaru decals.

It's pretty easy to imagine that a 35cc four-stoke OHC engine is going to grab the interest of a lot of traditional cyclemotor enthusiasts.  The forced-air fan cooled, wet sump motor produces 1.6bhp from its 35cc four-stoke OHC motor, and you can almost hear the ghost of Ducati Cucciolo knocking at the door.

The motor is non-specifically described for 'various and general industrial applications', which obviously includes use as a cyclemotor.  The engine is adapted to this purpose by Golden Eagle (www.bikeengines.com) another USA cyclemotor assembler who offers various arrangements for a number of different motor types.

Since the owner is quite a tall gentleman, the clip-on is mounted on a gargantuan Giant Boulder 25-inch rigid-frame mountain bike with telescopic forks.  While modern cycles such as this probably hold little interest for our general readership and will have little more involvement in the rest of the article, it may be of some amusement to appreciate that the saddle height was probably still 6 inches taller than the inside leg measurement of our test rider, even when standing on tiptoe!

The motor is mounted above the rear wheel from the right hand side, with a toothed pinion on the driving shaft and synchronous belt drive to a large pressure die cast pulley that is clipped to the rear wheel - so there's not going to be any nonsense with slipping drive rollers thank you very much!  Our test machine is fitted with a ten-tooth driving pinion, but other gearing options are available to suit rider weights and type of terrain.

There's an off/on kill switch on the engine cowling, so click this into 'run' position.

There's no petrol tap since the petrol tank is under the motor, with a diaphragm pump drawing fuel up to the carburetter.  On the back of the air filter housing is a dainty little red plastic choke lever that you'll need to switch to enrich, but handle ever so delicately since we told it's prone to snap like a matchstick.

The Suby engine is recoil start and, because of the location of the motor, you'll only be able to get it going from off the bike.  A single spin of the recoil fires the motor up right away, and within 20 seconds or so, you'll need to start easing off the choke.

The throttle operates by a trigger on the right hand bar and drive enables through an automatic centrifugal clutch with lined shoes so that operation is smooth and quiet.  Blipping the throttle to 'clear' the engine without the rider aboard isn't a great idea, since the clutch readily engages and you'll find the bike quite eager to leave without you.

The Subaru runs and sounds very much like a small modern generator engine, puttering quietly and soullessly away in the background, trying its best not to attract any attention - pretty much a complete opposite of the insane Mitsubishi!

Since there's no issue in taking up the drive from a standstill, you can trigger in full motor power right off the mark; but appreciating this is a single-speed drive, it's being a little kinder to the clutch and skinny toothed belt to give a little pedal assistance in the take-off phase.

The clutch phases in quietly and smoothly, then build up of speed continues steadily to the 50kph pace of urban traffic.  There's none of the excited boost like the Mitsubishi, Subaru progressively accumulates its pace in an unhurried and measured manner, the muffled exhaust tone blending and disguising the pitch so you're barely aware of much change in the revs until we run flat out speed.  On the level, clocked by radar gun, tucked in a crouch, along the same smooth tarmac carriageway of Napier Esplanade - 61kph / 37mph!  The Subaru required a much longer run to build up its speed, and particularly the last few mph were quite gradual, a real indication the motor was cresting its capability.

We were really surprised to find the Suby built up to a fractionally quicker top speed than the fiery Mitsubishi.  Certainly the Mitsu accelerated much more rapidly, and always felt as if it would be the faster bike, but not so it seems!

Like the Mitsubishi, we feel it only fair to take into account the final drive ratio on our Subaru.

The Golden Eagle is offered with optional 12, 13 and 14-tooth belt pinions, and our test machine was fitted with the smallest: 12-tooth, which means it could be geared-up by a further 16.7%, and theoretically suggests that 43mph could be achievable, though it would seem unlikely the motor would develop the power to effectively pull such a high ratio.

There are no water related drive slip issues to consider with toothed belt transmission, so the Subaru should be thoroughly functional for use in the rain, and the Golden Eagle mounting and drive arrangement was by far the more practical of the two comparable methods.

The Mitsu does everything with excitement, drama and aggression, but is pretty impractical - and if anyone is looking for a new Ducati Cucciolo, the Suby spec sounds great on paper: 4-stroke OHC ... but has all the dull character of an irrigation pump!

Following our Mitsu/Suby test session, we rounded off the day by pulling out a pair of old Cyclaids for an end-to-end ride of the Napier sea front cycle track.  Having been popularly exported to New Zealand, there are still quite a few working Cyclaids in the former colony and these are keenly maintained in service by a number of vintage vehicle enthusiasts across the country.

Our first test ride Cyclaid is mounted on a Gents 22-inch Humber frame with Beeston forks and 28-inch wheels.  Still mounting the original engine, this machine was sold new and complete by Onward Cycles of Hastings, New Zealand in 1955.  The engine is a very early example Cyclaid mounted with an original fitment Bosch magneto set, before British Salmson went over to the Wipac Bantamag.

Our second Cyclaid is installed on a period 1950s 21-inch BSA Streamlight crossbar frame with 26-inch wheels.

Both cycles are equipped with Sturmey Archer 3-speed epicyclic rear hubs.

British Salmson Aero Engines Ltd. of Raynes Park was established in 1930 to build air-cooled radial engines of French Salmson design.  This, however, failed to generate sufficient orders and, by 1934, the company was angling round for additional business.  Salvation materialised in the form of various subcontracted engineering works and construction of 1½ - 2½ litre coach-built sports cars with bodywork by Ranalagh or Newns, of which some 350 were built up to 1939.  While the factory was bought by Napier Aero in 1947, the former directors went on to register the new British Salmson Cyclaid Company from an office at 76 Victoria Street, London SW1.

The all aluminium, Cyclaid 2-stroke motor was actually a licence-built derivation of German Rex design, and assembled at Larkhall industrial site near Glasgow.  Its 35mm bore × 32mm stroke gives 31cc for ¾bhp @ 3,500rpm, and the clip-on attachment kit was offered from 1950.

The motor featured the characteristic Rex extended crankcase cavity system to house the primary reduction gearing, and lubricate these parts and all bearings by means of the induction gases.  Except for the very earliest 200 production kits, which mounted a Bosch magneto set, sparks came from a Wipac Bantamag ignition unit, with a lovely pressed brass cover that would polish up beautifully, once you'd got the awful silver paint off it.

Horizontally mounted over the rear wheel, the motor unit proved very consistent in operation, while the belt drive down on the left-hand side effectively smoothed out the unpleasant transmission snatch that affected many competitors' direct roller-drive designs.  Tyre consumption was not at all the issue that afflicted roller driven cycles, while the aft mounted engine offered better stability than installations over the front wheel.  The Cyclaid displayed all the features of a more practically thought out machine, and is justly credited with a reputation as one of the 'nicest' clip-on units.

The Cyclaid unit does not have a ready drive release, so non-running movement of the cycle is negotiated with the decompresser on, characterised by a blup, blup, blup through compression venting as the engine turns over.

Fuel turns on with a pull tap hidden under the back of the tank, full strangle on the carburetter shutter, then gently pedal away and release the decompresser.  The humble 5.6:1 compression ratio offers little resistance, and to commence firing most easily, a light take-up on the throttle lever produces the best response.  Continue pedalling assistance in this manner for a few moments to warm the motor, then reach behind you to open up the strangler (that's if you can find it behind your back, under the fuel tank, on an unfamiliar machine).  Alternatively, stop, dismount, open out the choke shutter, and restart again.

While waiting for our accompanying rider on the Humber, we complete a few slow circling turns in the road on our BSA Streamlight to get the feel of the balance and manners, which prove the little 31cc motor to be docile and tractable.  A fixed drive, no clutch, yet it still runs dead smooth performing tight cycle turns at an absolute trickle!  It's hard to imagine any clutch/geared machine or even an automatic moped that would ride so slowly and controllably.

Having shown its skill in the slow riding competition, our Cyclaid is joined by the second machine and we burble on down to Napier Bay.  Tweaking back the lever throttle the Rex engine pulls gently and cleanly, but can break into four-stroke phasing as it tops out off load, typically around 20mph.

Our Streamlight with 26-inch wheels is running 'standard ratio' drive, but the Humber on 28-inch wheels will be driving an 8% higher ratio, so should prove slightly faster on top speed - maybe 22 given a fair wind!

Out and out speed though, isn't what a Cyclaid is about. If you want something faster, then get something different.

Napier's sea front cycle track/walkway is where the Cyclaids come into their environment, threading between the bicycles, round the pedestrians, easing carefully round the kids, the dog walker hazards, the joggers ... the Cyclaid exhausts produce little more than a light phuttering on throttle and intermittent muffled pulses on the overrun.

All the classic old two-stroke character, but ever so very gently.

The Cyclaids are so mild in character that no-one along the way is disturbed by our motorised presence - just the converse as it happens, amused by the eccentricity of our antique machines, they smile and wave as we glide on by.  The fiery Mitsubishi certainly wouldn't get the same reaction!

Light pedal assistance helps build up momentum from low speed rather than pointlessly labouring the tiny motor, but the Cyclaids prove the most ideal machine for riding in these conditions.  We stop for a while at the Fishbike Hire seafront cycle workshop on Marine Parade (www.fishbike.co.nz) to chat with owner Brian Fisher, before resuming our ride.  Even when thoroughly hot, Cyclaid restarts are always easy since the magneto set barely seems affected by heat transference to the electrical set, so there's never any concern if you need to pull up on the decomp.  Who needs a clutch?

There's no lighting coil included with the Bantamag ignition set, so any requirement for illumination means resorting to cycle systems

Probably the mounted Cyclaid's greatest weakness was its vulnerability to falling over when parked, as the resultant high centre of gravity from an all-up motor of some 19 pounds perched above the rear wheel would always be courting disaster from gusts of wind or pedestrian contact.  Conventional cycle prop stands or leaning against a wall, are both methods of tempting fate, and the best available precaution would probably be a Shuresta centre stand.

The Salmson kit came in right at the fore of the cyclemotor boom, and its cheap DIY appeal with up to 300mpg economy claims, managed enough business to keep the unit on sale up to 1956, before "manufacture discontinued" was reported in market listings for 1957.

Surviving factory paperwork indicates the initial order of 6,000 component sets, so comprises the accepted figure of total units produced.  A second batch entry of costings to produce a further 6,000 units was a manufacturing option under consideration, but not taken up.  Sales of the Cyclaid kits had slowed right down in its later years - the heydays of the cyclemotor were already clearly passed and it was time to move onto something else.

British Salmson did continue beyond the Cyclaid at the Larkhall works, finding new direction in the manufacture of printing presses, while the old Raynes Park factory subsequently turned over to jam making!

Due to its amiable reputation, the Cyclaid now falls amongst the most sought after and prized of attachment units for those who enjoy the gentle pace of cycling, but without the effort of pedalling.

Sadly, modern and featureless strimmer-like motors hiding inside plastic fan cowlings, with integral blow moulded fuel tanks, seem to have such little visual appeal or character.  Similarly, though undoubtedly a fantastic evolution of cycling technology, sticker branded modern mountain bikes rather lack the historical mystique and soul of classically badged traditional makes.  The result of this combination to create an all-modern cyclemotor produces a very different interpretation of an old fashioned theme.

The modern engines will be probably prove faster, cleaner, and more reliable than their historical counterparts, the modern cycle frames probably more robust and versatile than their forebears, but will they ever achieve the desirable heritage of the original '50s generation?  Only time may tell.

A great cyclemotor isn't made just by the fastest performance, or the greatest practicality.  The Mitsubishi and Subaru may claim one of these latter qualities each, but maybe only the sixty year old Cyclaid may claim the former.

Next - There could be three article options bubbling under for the next edition, and depending how their respective situations develop, might see any one of them making it through to the finishing post first, so we're keeping our options open:

You may not have noticed them much, but they're out there, fighting the battle for urban survival as daily commuter transport - the "Moped Army"! Probably a strong military favourite.

It almost sounds as if this might concern some office filing equipment accessories, but "Folders" is certainly a firm contender.  An interesting two-piece feature held together with staples!

Starting as an outsider due to carrying a weight penalty in heavy metal, but coming up fast on the outside is "Iron Horse".  Last year there was just one iron horse, this year there are two, and maybe soon there could be three - perhaps it's a herding instinct drawing them together?

This article appeared in the July 2012 Iceni CAM Magazine.
[Text and photos © 2012 M Daniels.]