| What, Another HT Ariel? by Jim Hunter |
| Ottawa Section CVMG |
Jim Hunter
It was all Lew Walwork’s fault. At the 1993 Ariel Owners MCC Annual Rally in Norwich, England, Lew offered my
son Doug and I a ride on his HT. Doug rode some of the sections in the trial with it, and I tried it in a few sections
with it after the trial was finished. We were hooked. We had both wanted an HT, for vintage trials for many
years; mainly because of our long involvement with Ariels. Doug currently rides a TL250 Honda in CVMG
Vintage Trials, and wanted to stay with a four stroke machine. An original HT was out of the question, as there
were only four imported into Canada and none were for sale. The only solution if we wanted one, was to build
one; as I have done with all of my Ariels except the Square Four. Years passed, until the summer of 1997 when a
friend advised of a late Ariel single (1956 it turned out) on a farm in Hemmingford Quebec that might be
available. Doug said he would fund the building of the HT, and we would use it jointly and share ownership, if I
built the bike. The project was a “go”.
We arrived at the owner’s farm, and were shown the Ariel, a pathetic looking mutilated, long silent machine with a
tractor headlight on it, stored in the back of a derelict van out behind the barn. It was a rusty mess, with no
engine or gearbox. They were in the basement of his brother’s house just up the road, we were told. I was
apprehensive. If it was in anything like of the condition of the bike, it would be a lost cause. We went to the
brother’s house, and were pleasantly surprised at the apparent condition of the engine and gearbox. It was
intact, still mounted in the mounting plates and complete with the magdyno, sitting on the basement floor. We
started negotiating at $250, which produced a pained look on the owner’s face. Did you ever notice how often
owners of “barn fresh” un-restored machines think they have their “pension fund” in a rusty old piece of junk?
We pointed out reality to him, and he finally agreed to an increased offer of $275. He produced other parts out of
the barn, a gas tank, a good looking speedo and a voltage regulator. We loaded it in the van and took it home.
Even if the machine was entirely junk, we could certainly get $275 worth of fun out of it.
Starting the disassembly was easy, as most of the bike went in the garbage. The frame was so butchered it was
unrepairable. We got a tool box, oil tank and fork clamps out of it. The engine was another matter. It looked to
be in good condition, no broken fins or casings. Then we opened the primary chaincase, which was quarter full
of sand. The clutch, sprockets and chain were toast. I thought the magdyno was the same, as it was full of
sand; but when cleaned up and lubricated, produced a healthy spark. Not so with the generator, it will be used for
parts. The gearbox came apart with great difficulty and was half full of what looked like gray washwater, (like the
laundry tubs had overflowed once upon a time, and the water had sat in the gearbox since) and badly corroded
inside. And did it stink! Some of the gears and shafts, surprisingly, were in good shape; some were corroded
beyond use. Disassembly of the engine revealed it to be in surprisingly good condition considering the rest of
the machine. It probably would have cleaned up a bit and could have been run -- no sand, no washwater, no
butchery. Our $275 investment was now secure in the engine alone.
With the unuseable bits heading off down the road in the garbage truck, restoration began. Doug ordered a new
manufacture frame an alloy cylinder and an aluminium bash plate from John Bartram, a fellow Ariel Club member
and specialist frame manufacturer in Southampton, England. Meanwhile the engine work got underway. All
bearings were replaced, and Ducati guru Guy Martin of Pointe-Claire QC changed out the big end roller bearings
and lightly honed the raceways. We decided to replace the big end rollers, the crankshaft was reassembled and
trued, and the crankcase reassembled. There were some anxious moments when we wondered if the Ducati
truing jig would handle the 8” diameter of the Ariel flywheels. It did – just! The new alloy cylinder and the “oil in
frame” frame arrived from John Bartram, and the cylinder was bored to accept a NOS +.020” 7.5 - 1 piston and
NOS Wellworthy rings that I have had for years. We chose this CR as we thought we would need the extra power
to handle the weight of a heavy rider. New valves and guides were installed in the head. The frame was
powdercoated black. A Lucas KNR1 Magneto was obtained in a swap for the magdyno and overhauled by
Warren Wheeler. The gearbox was rebuilt out of my parts stash, serviceable casings, gears and shafts. An
outer housing from a Matchless Burman gearbox was modified to fit. While this is an easy modification, I can see
no real reason for it, as there are no gains in decreased dimensions and weight over the Ariel box. Gearing,
internally; is as per the road models. Incidentally, the scrap washwater filled gearbox housing was to be given to
a friend who “thought he might be able to do something with it”, and delivery was arranged for the CVMG Annual
Rally at Paris in 2001. It was stolen from my campsite overnight before he could collect it. I think the thief will get
more than he bargained for when he opens it up. The smell alone will be enough to spoil his day.
The engine was installed in the frame, using John’s alloy front mounts and Lew’ Walwork’s alloy rear mounts, as
John wasn’t making them at the time. All fasteners are stainless steel with locknuts. We made some departures
from the “its what Sammy Miller does” theme. Instead of Norton forks, we used 35mm Ceriani forks from a
Greeves, and spoked new manufacture Volante rims (an Akront knockoff) with new stainless steel spokes, onto
Rickman conical polished aluminium hubs. Norton forks were not available at a reasonable price, (the old
pension fund thing again, I guess) and the Ceriani forks were generously given to us by a fellow CVMG member
and well known vintage roadracer Eric Pritchard. The forks required relocation of the brake plate anti-rotation
boss, and a couple of internal parts that were missing. Renthal aluminumium handlebars are used, as are Pirelli
“Garra” radial tires.
The primary drive line uses a 15 tooth Villiers 37A sprocket on the engine, with no compensating device. It uses
a 3 spring Norton clutch with a 42 tooth sprocket, running dry; with the chain lubed before every trial. (Norton
clutches, you may remember, have rubber damping snubbers in the hub). The gearbox sprocket is a 16 tooth
item from a wartime WNG Ariel. All this fits very nicely in one of Sammy Miller’s fibreglass primary chaincases,
with a flat .070” sheet aluminium inner chaincase. The rear chain and wheel installation required all my fitting
knowledge to get it right, because the clearances are so critical. First, the wheel has to run centre to the frame.
The chainline has to be straight, and everything else has to fit somewhere in between, yet not interfere with each
other. I think I spent more time getting this right than on any other part of the build. The footrest support
installation was tough as well, and that must be why almost every HT that I’ve seen has a different footrest
installation. (Different solutions by different builders.) The rear sprocket is aluminium, 48 teeth. After all, the bike
needs a lot of low down grunt to pull two rather large riders (one at a time of course) around trials sections. It
would be OK for a normal size rider with a 46 tooth, I think. The rear axle was made by Steve Busby from
stainless steel. This same “artist in metal”, also milled the rear brake lever and the rear brake pedal from .250”
6061 aluminium. Three thread forms are used on the bike, Metric on the forks and rear wheel, CEI on the
engine, and UNF on the frame. Not good engineering practice, but something we have to live with. One of Miller’
s fibreglass gas tanks was used. The first one leaked so badly it had to be replaced, and finally was at no
charge; courtesy of Miller. One of his fiberglass based seats was used, but had to be modified before it would fit.
The exhaust system also from Miller, on the other hand, fits very well; and with the aluminium muffler, has a
distinctive and authoritative bark to the exhaust note. (You know it’s not Japanese!)
Another Ariel has now been resurrected. The first "test flight" after the 4 year long HT project was held dodging
snowflakes up and down the road in front of the house on 2 April 2002. Luckily, I could get a couple of litres of
fuel in the defective fuel tank for test purposes without it leaking; so I was able to at least ride it down the road
and check it out. The engine ran very well, and so it should as everything is new in the engine, mains, big end,
piston, valves etc. It pulls like a steam engine. The only adjustments I've had to make so far was a small ignition
timing adjustment, and the usual fiddly ones to the carb, a 376 Amal Monobloc. I had to make an adjustment to
the rocker feed, and install a 1/8” I.D. restrictor in the oil return line to restrict the return to the tank (oil in frame)
and force the oil return supply to back up, and feed into the rocker shaft. For this reason, we used clear plastic
oil lines to keep an eye on the oil flow.
It has been a very interesting project, perhaps the most ambitious restoration I have ever undertaken. Fitting all
these parts that were never designed to work together, and to make them work together was indeed a challenge
but a great satisfaction to me when it all came together as well as it did. There were some real “headscratcher”
problems, though; but of course that was not totally unexpected. New Volante alloy rims and stainless spokes
from Central Wheel Company that I had to wait a year for, despite their "largest stock in Britain" advertising.
There have been a lot of modifications and fabrications accomplished. We've bought parts from suppliers that
are supposed to be for the HT, but are for all intents and purposes unusable. The good news is that our efforts
paid off, when we found the weight of the HT on completion to be 230 pounds dry, 243 wet. This bike won’t be
“just another pretty face” either; but an operational, purpose built trials bike. We had to change out the rear
Betor Gas Shocks originally installed, as they were not strong enough for heavy riders. Walridge Motors
supplied us with a set of custom made NJB 14 ½” Gas Shocks that do the job quite nicely.
The moment of truth came on Sept 29th 2002 at its first outing in a CVMG Ottawa Trial at Dave Makin’s farm.
Doug tells me the bike steers lighter than the TL-250, and the power and torque are impressive. The 25 hp of the
Ariel coupled with the torque from the two massive flywheels really do a fine job in a trials section. It was really
impressive to see (and hear) him coming through a section, and attacking a rock climb about 10 feet tall. During
the climb, the torque was evident when Doug exited the climb with the front wheel in the air. Memorable! As
‘Rick’ said to ‘Inspector Renaud’ in the ending footage of the classic movie ‘Casablanca’, “this could be the start
of a beautiful friendship” .
It was all Lew Walwork’s fault. At the 1993 Ariel Owners MCC Annual Rally in Norwich, England, Lew offered my
son Doug and I a ride on his HT. Doug rode some of the sections in the trial with it, and I tried it in a few sections
with it after the trial was finished. We were hooked. We had both wanted an HT, for vintage trials for many
years; mainly because of our long involvement with Ariels. Doug currently rides a TL250 Honda in CVMG
Vintage Trials, and wanted to stay with a four stroke machine. An original HT was out of the question, as there
were only four imported into Canada and none were for sale. The only solution if we wanted one, was to build
one; as I have done with all of my Ariels except the Square Four. Years passed, until the summer of 1997 when a
friend advised of a late Ariel single (1956 it turned out) on a farm in Hemmingford Quebec that might be
available. Doug said he would fund the building of the HT, and we would use it jointly and share ownership, if I
built the bike. The project was a “go”.
We arrived at the owner’s farm, and were shown the Ariel, a pathetic looking mutilated, long silent machine with a
tractor headlight on it, stored in the back of a derelict van out behind the barn. It was a rusty mess, with no
engine or gearbox. They were in the basement of his brother’s house just up the road, we were told. I was
apprehensive. If it was in anything like of the condition of the bike, it would be a lost cause. We went to the
brother’s house, and were pleasantly surprised at the apparent condition of the engine and gearbox. It was
intact, still mounted in the mounting plates and complete with the magdyno, sitting on the basement floor. We
started negotiating at $250, which produced a pained look on the owner’s face. Did you ever notice how often
owners of “barn fresh” un-restored machines think they have their “pension fund” in a rusty old piece of junk?
We pointed out reality to him, and he finally agreed to an increased offer of $275. He produced other parts out of
the barn, a gas tank, a good looking speedo and a voltage regulator. We loaded it in the van and took it home.
Even if the machine was entirely junk, we could certainly get $275 worth of fun out of it.
Starting the disassembly was easy, as most of the bike went in the garbage. The frame was so butchered it was
unrepairable. We got a tool box, oil tank and fork clamps out of it. The engine was another matter. It looked to
be in good condition, no broken fins or casings. Then we opened the primary chaincase, which was quarter full
of sand. The clutch, sprockets and chain were toast. I thought the magdyno was the same, as it was full of
sand; but when cleaned up and lubricated, produced a healthy spark. Not so with the generator, it will be used for
parts. The gearbox came apart with great difficulty and was half full of what looked like gray washwater, (like the
laundry tubs had overflowed once upon a time, and the water had sat in the gearbox since) and badly corroded
inside. And did it stink! Some of the gears and shafts, surprisingly, were in good shape; some were corroded
beyond use. Disassembly of the engine revealed it to be in surprisingly good condition considering the rest of
the machine. It probably would have cleaned up a bit and could have been run -- no sand, no washwater, no
butchery. Our $275 investment was now secure in the engine alone.
With the unuseable bits heading off down the road in the garbage truck, restoration began. Doug ordered a new
manufacture frame an alloy cylinder and an aluminium bash plate from John Bartram, a fellow Ariel Club member
and specialist frame manufacturer in Southampton, England. Meanwhile the engine work got underway. All
bearings were replaced, and Ducati guru Guy Martin of Pointe-Claire QC changed out the big end roller bearings
and lightly honed the raceways. We decided to replace the big end rollers, the crankshaft was reassembled and
trued, and the crankcase reassembled. There were some anxious moments when we wondered if the Ducati
truing jig would handle the 8” diameter of the Ariel flywheels. It did – just! The new alloy cylinder and the “oil in
frame” frame arrived from John Bartram, and the cylinder was bored to accept a NOS +.020” 7.5 - 1 piston and
NOS Wellworthy rings that I have had for years. We chose this CR as we thought we would need the extra power
to handle the weight of a heavy rider. New valves and guides were installed in the head. The frame was
powdercoated black. A Lucas KNR1 Magneto was obtained in a swap for the magdyno and overhauled by
Warren Wheeler. The gearbox was rebuilt out of my parts stash, serviceable casings, gears and shafts. An
outer housing from a Matchless Burman gearbox was modified to fit. While this is an easy modification, I can see
no real reason for it, as there are no gains in decreased dimensions and weight over the Ariel box. Gearing,
internally; is as per the road models. Incidentally, the scrap washwater filled gearbox housing was to be given to
a friend who “thought he might be able to do something with it”, and delivery was arranged for the CVMG Annual
Rally at Paris in 2001. It was stolen from my campsite overnight before he could collect it. I think the thief will get
more than he bargained for when he opens it up. The smell alone will be enough to spoil his day.
The engine was installed in the frame, using John’s alloy front mounts and Lew’ Walwork’s alloy rear mounts, as
John wasn’t making them at the time. All fasteners are stainless steel with locknuts. We made some departures
from the “its what Sammy Miller does” theme. Instead of Norton forks, we used 35mm Ceriani forks from a
Greeves, and spoked new manufacture Volante rims (an Akront knockoff) with new stainless steel spokes, onto
Rickman conical polished aluminium hubs. Norton forks were not available at a reasonable price, (the old
pension fund thing again, I guess) and the Ceriani forks were generously given to us by a fellow CVMG member
and well known vintage roadracer Eric Pritchard. The forks required relocation of the brake plate anti-rotation
boss, and a couple of internal parts that were missing. Renthal aluminumium handlebars are used, as are Pirelli
“Garra” radial tires.
The primary drive line uses a 15 tooth Villiers 37A sprocket on the engine, with no compensating device. It uses
a 3 spring Norton clutch with a 42 tooth sprocket, running dry; with the chain lubed before every trial. (Norton
clutches, you may remember, have rubber damping snubbers in the hub). The gearbox sprocket is a 16 tooth
item from a wartime WNG Ariel. All this fits very nicely in one of Sammy Miller’s fibreglass primary chaincases,
with a flat .070” sheet aluminium inner chaincase. The rear chain and wheel installation required all my fitting
knowledge to get it right, because the clearances are so critical. First, the wheel has to run centre to the frame.
The chainline has to be straight, and everything else has to fit somewhere in between, yet not interfere with each
other. I think I spent more time getting this right than on any other part of the build. The footrest support
installation was tough as well, and that must be why almost every HT that I’ve seen has a different footrest
installation. (Different solutions by different builders.) The rear sprocket is aluminium, 48 teeth. After all, the bike
needs a lot of low down grunt to pull two rather large riders (one at a time of course) around trials sections. It
would be OK for a normal size rider with a 46 tooth, I think. The rear axle was made by Steve Busby from
stainless steel. This same “artist in metal”, also milled the rear brake lever and the rear brake pedal from .250”
6061 aluminium. Three thread forms are used on the bike, Metric on the forks and rear wheel, CEI on the
engine, and UNF on the frame. Not good engineering practice, but something we have to live with. One of Miller’
s fibreglass gas tanks was used. The first one leaked so badly it had to be replaced, and finally was at no
charge; courtesy of Miller. One of his fiberglass based seats was used, but had to be modified before it would fit.
The exhaust system also from Miller, on the other hand, fits very well; and with the aluminium muffler, has a
distinctive and authoritative bark to the exhaust note. (You know it’s not Japanese!)
Another Ariel has now been resurrected. The first "test flight" after the 4 year long HT project was held dodging
snowflakes up and down the road in front of the house on 2 April 2002. Luckily, I could get a couple of litres of
fuel in the defective fuel tank for test purposes without it leaking; so I was able to at least ride it down the road
and check it out. The engine ran very well, and so it should as everything is new in the engine, mains, big end,
piston, valves etc. It pulls like a steam engine. The only adjustments I've had to make so far was a small ignition
timing adjustment, and the usual fiddly ones to the carb, a 376 Amal Monobloc. I had to make an adjustment to
the rocker feed, and install a 1/8” I.D. restrictor in the oil return line to restrict the return to the tank (oil in frame)
and force the oil return supply to back up, and feed into the rocker shaft. For this reason, we used clear plastic
oil lines to keep an eye on the oil flow.
It has been a very interesting project, perhaps the most ambitious restoration I have ever undertaken. Fitting all
these parts that were never designed to work together, and to make them work together was indeed a challenge
but a great satisfaction to me when it all came together as well as it did. There were some real “headscratcher”
problems, though; but of course that was not totally unexpected. New Volante alloy rims and stainless spokes
from Central Wheel Company that I had to wait a year for, despite their "largest stock in Britain" advertising.
There have been a lot of modifications and fabrications accomplished. We've bought parts from suppliers that
are supposed to be for the HT, but are for all intents and purposes unusable. The good news is that our efforts
paid off, when we found the weight of the HT on completion to be 230 pounds dry, 243 wet. This bike won’t be
“just another pretty face” either; but an operational, purpose built trials bike. We had to change out the rear
Betor Gas Shocks originally installed, as they were not strong enough for heavy riders. Walridge Motors
supplied us with a set of custom made NJB 14 ½” Gas Shocks that do the job quite nicely.
The moment of truth came on Sept 29th 2002 at its first outing in a CVMG Ottawa Trial at Dave Makin’s farm.
Doug tells me the bike steers lighter than the TL-250, and the power and torque are impressive. The 25 hp of the
Ariel coupled with the torque from the two massive flywheels really do a fine job in a trials section. It was really
impressive to see (and hear) him coming through a section, and attacking a rock climb about 10 feet tall. During
the climb, the torque was evident when Doug exited the climb with the front wheel in the air. Memorable! As
‘Rick’ said to ‘Inspector Renaud’ in the ending footage of the classic movie ‘Casablanca’, “this could be the start
of a beautiful friendship” .