Dot Demon Scrambler
DOT DEMON SCRAMBLER
CYCLE WORLD ROAD TEST
BRITISH MOTORCYCLES can be credited with making the 250cc class in scrambles racing the hot-bed of activity it is. True, the terribly fast Spanish two-strokes are becoming a force to reckon with, but it was the Villiers-powered English machines that first demonstrated that a really light lightweight could beat everything with wheels — and they are still among the best scramblers the world has to offer.
Among these English scramblers, all of which seem to have a long-term lease on the winner's circle, one of the best is the Dot (Devoid of Trouble), which is much like the others, but manages to have a fairly distinctive flavor of its own anyway. Like its cousins, the Dot is powered by a reworked Villiers engine, in this case the 36A, with a special cylinder and cylinderhead. The cylinder is of aluminum, and has big, long-opening ports — which is roughly the same as having big ports and full-race camshaft in a four-stroke engine. The cylinder head has a completely machined combustion chamber, with a large "squish" area to give controlled combustion at the high compression ratio of 12.0:1. Both cylinder and head are heavily finned, and the fins are widely spaced so that they will not clog with mud or dirt and thus cause overheating.
Rather than cast an iron liner into this barrel, the makers have elected to simply lay a hard chromium plate in the aluminum bore. This type boie has given problems in the past, with the chrome flaking off near the ports, etc., but a new process is now being employed in applying the chrome. Also, the cylinder wall's resistance to wear and scuffing has been improved by a new finishing process, in which the cylinder is diamond-lap honed out to the final dimension. This leaves a cross-hatch pattern of fine scratches in the bore, and these scratches tend to hold oil and that vastly improves lubrication. The cross-hatch lapping has of course been regular procedure in iron-liner engines for many years.
From all that we could see by an external inspection of the Dot's engine, it did not differ materially from similar gussied-up Villiers, but it certainly had a lot of power. No power output figures are released by the makers, however, we understand that it has about 26 bhp, at some unspecified rate of revolution. Actually, the peaking speed does not seem all that important; the engine felt as though it had power right from idle all the way to 7500 rpm, where it hit its limit quite abruptly. It was rather ragged at low speeds on part throttle (and very few two-strokes are not), but otherwise had power, power and more power all the way through the engine speed range. Only two adverse comments come to mind regarding the engine: first, its stubby megaphone gives off an absolutely ear-drum shattering noise, but this seems to be part and parcel of running a hot two-stroke (and there are always ear-plugs) ; second, we had a very devil of a time getting it started. Almost every time we had to start the engine, it was necessary to kick, tickle and cajole the engine for a wearisome length of time before it would come to life. In all truth, we never did learn the proper combination. But, when we returned it to its owner, complaining of this reluctance to start, he looked us over (rather scornfully, too) and asked us please would we stand aside while he demonstrated. Sure enough, just the right amount of throttle and a familiar foot on the kick lever did the trick. While we stood there feeling foolish, the Dot started again, and again with only one or two kicks. It would appear that the trick is all in being quite familiar with the beast, as it will balk at strangers and perk right up for someone who knows it. Obviously, the man who buys a Dot would soon have the starting procedure mastered.
When looking over the Dot, there was one item that told us the factory understands conditions here in America: the elaborate air-filtration system. The carburetor intake horn is connected (by means of a rubber coupling) to a large U-shaped chamber, which has a big, round aircleaner on each side. " This provides a far greater filter capacity than is necessary in England, where the air is wet but relatively free of dust, but in this country such filtration is absolutely essential if ultra-rapid bore and bearing wear is to be avoided.
As any scrambles enthusiast will recognize, the Dot's forks are like its immediate competitors' in basic geometry, but very different in layout and construction. These forks are of the leading link type, but instead of having legs that run down and forward toward the axle, the fork legs are almost vertical, going straight down to the link pivots. The suspension units are mounted ahead of the fork legs, and extend right down to the links to a point just behind the axle. With everything hanging out in the open, it has been possible to provide a tremendous amount of wheel travel, and that is an asset. Another asset is the general behavior of these forks, which for reasons that are not entirely clear seems to be a bit better than that of similar leading-link forks. The Dot maintains really remarkable stability at high speeds over rough terrain. On the other hand, there was a tendency for the front wheel to slip away suddenly when the bike was leaned far over and sliding, and this resulted in our scrambles "expert" on the staff coming down in a big cloud of dust on one occasion. Again, however, with experience one soon learns how to avoid such misadventures; and for the well-trained Dot rider the machine would have no peculiar handling traits at all.
In the area of fit and finish, it is almost impossible to say any but the very nicest things about the Dot. The various parts of its square-tube frame are all very neatly bronze-welded together, and enameled in a bright red. Unfortunately, the paint was not as neatly applied as it could have been, and that is the only bad spot on the entire machine. We especially liked the brightly-polished aluminum alloy fuel tank, which has a squarish shape that is positively fetching, and a quick-release fuel filler cap right straight from the Grand Prix circuits. A fiberglass tank may have been just as good, from a completely practical point of view, but the aluminum certainly looks marvelous. Of course, Dot is not the only motorcycle to have an aluminum tank; we just thought it would be appropriate to toss in a good word for aluminum tanks in general.
The Dot is blessed with one of the more comfortable saddles we have had the pleasure to perch upon, it is wide and soft, with a hard rear edge that tends to hold one's hindside firmly in place when blasting up a hill. And, the footpegs and handlebars are located at just about a perfect distance from this seat. The bars are a trifle too straight for most riders, however, and the distributors inform us that they correct this by simply bending the ends of the bars back slightly.
When riding a scrambler, it seems as though there is never enough time to do anything properly except hang on, and sometimes not even that. For this reason, we were pleased to find that once underway, you can ignore the Dot's clutch entirely; just stab the gear lever and ease back on the throttle a bit. Many, many shifts were made in this fashion, and all were as neat and clank-free as if we had employed the clutch. The word is that Dot riders hardly ever touch the clutch while racing, and we can understand the reason.
Apart from the good finish, the Dot has two outstanding features: The first of these is sheer power: the bike is thunderously fast, even with the rather tall gearing it is pulling, and when it is moving along flat-out in top gear, it will either pass a lot of other motorcycles, or fling its rider headlong into the nearest bush, depending on the terrain. The second major feature, which compliments the first, is the ability to soak up large bumps without being bounced high into the air in the process. The long-travel suspension is certainly instrumental in this, but it also indicates that springs and dampers have been correctly selected.
For the expert, or would-be scrambles rider, the Dot Demon has a good deal to offer, as we have indicated. Individual preference might lead some of us to choose one of the other, similar scramblers,, but that would be a simple case of one man's meat, etc., etc., and not because the Dot is in any way lacking. It is, in fact, a really excellent scrambler; one that drew good comments from every staff member that rode it.
DOT
DEMON SCRAMBLER
List Price $795, FOB LA
