After the last war, Ariel joined the other British bike manufacturers in producing parallel twins. Ariel brought out a 500cc twin (Model KH) with two camshafts as per Triumph, but driven by a duplex chain. The cylinder barrels were retained by a peculiar system of captive bolts which could only be undone a sixteenth of a turn at a time making removal bloody frustrating. I acquired one of these twins in 1965 for £25 from an ad in Exchange & Mart.
The performance was totally underwhelming - 80mph given calm conditions - I felt a complete berk with Honda 125s able to keep up with me. In actual fact, my Ariel Arrow, despite a nominally less powerful engine, was just as fast due to its lower mass. So reliable as the KH was it was plain that drastic measures would have to be taken to wipe the sniggers off the Honda mounted piss-takers.
There were several alternatives available but not easily put into practice due to lack of readies. I could part exchange the bike for a new Jap, but I’d tried a CB77 which if was a good bike was by no means exceptional. I could part exchange for a bigger Brit - I looked at a Velo 500 but really wanted a twin and tested a Royal Enfield 700. A bike that had the guts to wipe the floor with any of the opposition, after a decent run you’d have to spend quite a bit of time wiping up after it. Sure, all British bikes leaked, but not as bad as this.
Anyway, a solution was found - I was given a 650cc Huntmaster engine in reasonable shape. As all Ariels used the same frame and gearbox, this bolted straight in. Before the conversion I didn’t think there was much difference in the engines - was I ever wrong? Where the 500 had been straining to attain 75mph, the 650 was only just beginning to stretch its legs. After I became used to it, I cruised for long distances with eighty on the clock with the odd blast up to the ton. Needless to say, those Honda Benly owners were blown into the weeds. After a bit, one of them bought a Tiger 100, another a Dommie SS.
The Huntmaster was very reliable, although the oil required regular changing and every 3000 miles I use to take the engine down to check the big-ends and plain main bearings. I think that the roller bearing conversion that is available on these engines is quite a worthwhile investment when you consider the number of times the plain timing side bearing needs to be replaced.
Mention of the Dominator always reminds me of my mate Malcolm, who used to take the head off his Dommie every other week to grind the valves in. I told him it wasn’t necessary but nevertheless he insisted it had to be done to maintain performance - what did become necessary after about three months was a new head because the valve seats had sunk right into the ports. This apart, the Dominator was possibly the best British twin, it certainly outhandled the Triumphs with their quaint bolted up rear end and the Ariel with its inferior suspension.
After a few months on my re-engined Ariel I began to lust for a bit more poke, especially since I had discovered that the Ariel 650 engine was merely a badge engineered BSA Gold Flash. The next time I stripped down the engine I had Rocket Goldstar camshaft, pistons, barrels and head plus swept back pipes and silencers ready to fit. When I had rebuilt the bike in this form, I tried her out on a straight stretch we use to race along, and was astonished to find that I could get the speedo somewhere between 110 and 120mph.
This was quite a laugh, as it turned out, because idiots on A7 Shooting Stars and Tiger 100s would challenge the to a burn up thinking I was riding a bog-standard Huntmaster, which everybody knew was only fit for pulling a chair. One berk with a Tiger 90, for God’s sake, actually challenged me to a race to a village about ten miles away. I accepted, provided the race was there and back - I blew the wally away in the first 400 yards, drove like a maniac all the way there and passed this pillock going the other way when I was about halfway back. If the guy had had any sense at all he wouldn’t have come back, claiming a breakdown. As it was, he turned up half an hour later and had the piss taken unmercifully for ages afterwards (youth can be so cruel).
Back then, biking had its compensations. This was before most young people had cars. If a bird was daft enough to ride with you, a quick blast across the country would reduce her to putty in your hands (well, you know what I mean). As I now possessed a machine with the performance of a Rocket Goldstar, albeit in street sleeper form, I felt reasonably pleased. After all, the conversion had only cost me about £15, although that was about £3 more than a weeks wages at that time. I think the only new parts I ever bought were piston rings and big-end shells. With the RGS bits fitted it started knocking out big-ends and mains a lot quicker - it’s this that inhibits me from changing my current Huntmaster, that will stay with standard 6.5:1 pistons and soft camshaft - parts aren’t as cheap or as readily available as they used to be.
Apart from the inconvenience of frequent strip downs to keep on top of things, my machine was totally reliable. It handled very nicely, never did less than 60mpg and used a pint of oil about every 500 miles. The only thing that was annoying was that when it was hot it would sometimes prove impossible to start, which on a hot summers day was bloody infuriating. This baffled me until a new magneto was installed and the problem disappeared.
Talking of magnetos, it used to have another endearing habit, stripping the teeth on the drive gear. This never happened to me, thankfully, but I know several people who were stranded by this trick. The dodge to get round this was to revert to manual advance/retard on the mag, remove the poxy fibre automatic (spring loaded bobweights) A/R cog and fit a plain steel mag pinion. If you have one nowadays you mostly have to do this anyway as the fibre wheels are usually well shagged and totally useless. At an autojumble, out of curiosity, I asked a guy selling knackered fibre pinions how much they were - fifteen quid he replied. What an asshole, he’d be better off selling fridges to Eskimos. There are bargains to be had but there’s also one hell of a lot of junk; don’t buy in haste and regret at leisure.
Anyway, there you have it, my present day Huntmaster is nearing completion, although if someone offers me much more than he first suggested I may well sell it to try out one of these Japanese things.
Len Seeley