Cycle News is a weekly magazine that covers all aspects of motorcycling including Supercross, Motocross and MotoGP as well as new motorcycles
Issue link: https://magazine.cyclenews.com/i/126008
KTM 250 KALIBRATIONS Olassis and suspension Wheelbase 56 in. ±. Y. in. Seat height (w/150 lb. rider) 34% in. Ground clearance (w/150 lb. rider) 9Y. in. --- - Front suspension: Ceriani w/travel ... .. 7Y. in. Rear suspension: Marzocchi No.2 Gas-fluid dampers w/travel ' 6Y. in. at rear axle Swingarm: 6·position lower mount . .. . 19Y. in. w/cantitever standard for MX model ; on needle bearings Engine/transmission Displacement Bore & stro ke Carburetion Air filtration 245.4cc 71mm x 62mm ~ 36mm Bing Twin Air oiled foam in still air box Gearbox 6·speed constant mesh 1·N·2·3·4·5·6 with multi -plate wet clutch Maximum horsepower (claimed) .... . 32, with more available Running gear Wheels/tires Akront ridgeless alloy rims, Metzeler 3.00x21 and 4 .50x18 . "Six Days" knobbies Magura throttle and power levers Alloy fuel tank w/capacity .. 1.85 U.S. gallons Dry weight 229 Ibs. West Coast retail price (rec.) U.S. $1725 VARIATIONS ON A THEME - Gary Hymes' bike (206) and Jeff Wright's (opp. page) are bare months apart, yet significandy different in detail. Air holes in Gary's airbox (below left) help reworked cylinder/pipe breathe. Below right. John Penton kneels beside "Eastern" version. The porting on the latest model KTM (Wright's bike imported through the Western distributorship) is apparently done according to the factory motocross specs - or a close version of them . There is less low end than with the' previous stock cylinder, though it is still impressive by the standards of current "30 HP" 250 racers, and there is a more even transition into the mid-range and top end of the powerband than the all-out go-faster Cranke cylinder. Those points are fairly subtle, actually. Carl was just about spot on for the full horsepower requirement. The power available from the latest KTM has been spread more evenly through the numbers and helps make the 250 version one of the most serious motocross bikes you, or anybody else , can buy. Remember, when they won the Championship in '74, nothing on the GP circuit could touch them in terms of speed. It is one of two 250s that riders from novice to pro agreed had enough acceleration for them to be competitive. That acceleration goes a long way, though you still must shift through the lower gears in a spritely manner. It soon becomes natural to do so. You're never at a loss for a gear (out of the six) to keep it moving quickly. On any given course, however, only four or five speeds (1 to 4 , 2 to 6, etc.] will be used, according to the terrain. The power is explosive but it combines with the chassis and suspension to make you feel magi c rather than scared. You can over-gas it, ge t sideways and have the' chance to think you must look like a Russian GP rider, and then be under control by the time you have to do something else, like corner. There is a totally 'decep tive lightness to the feel and the front end of the KTM. Yet the 250 weighs over 230 pounds ready to race, most of it due to the massive KTM engine. There is little you could reasonably do to shed weight. Most of what should be plastic and alloy already is, so that even if you really tried it would be a struggle to get Jour or five pounds off. Then you would have a 250 KTM that weighed slightly Under 230 ready to race instead of slightly over 230. So what 's the point? As far as anybody riding it can tell , the weight either doesn't hurt at all or is a slight advantage in terms of directional stability. Part of the increasingly apparent swellness of the 250 KTM is the current suspension that is hanging on the frame as it comes out of the crate. Gary 's model had eight inch Cerianis that bound on the downstroke and same make gas shocks that collapsed. Gary did some work to improve the performance of the front Cerianis and " sm all body" Bilstein gas shocks went on the rear. It was a noted improvement, However, the current stock suspension is even an improvement over that mod and, to our taste, the best of the three combinations. The importer had a choice of any European-built gas shock for the rear end of the KTMs and he chose the Marzo cchi. The ride is plush, control is good .. . like we said the best stock dampers we 've experienced on a motocrosser. Still, in all honesty to folks who don't get to test every major gas-charged damper on the market before they buy , some experts said they would prefer to try a set of, Bilsteins.,;Ih1' final, choice would probably, be decided by any consistent difference in lap times. Most everybody agreed that the performance differences between the Bilstein-Marzocchi combos was very slight and would probably boil down to the old personal preference ; ie, one looked neater than the other, or it matched the color of the frame. Most of the currently available crop of gas-charged suspensions are "beyond our poor power to equal," as Abe Lincoln said. Most of us aren't good enough - but we can sure enjoy it, The latest model Ceriani fork keeps up with the rear boingers, but they'd all better get their R&D designs into production so rear suspension doesn't run away from the front, again . That covers the major improvements in the latest version of the KTM 250. You'd be safe in calling it the 1976 model. There are other subtle changes; however. The wheels (finally) have the latest version of the ridgeless Akront rims and the excellent Metzeler motocross knobbies, The front hub is slightly larger than before and contains a truly impressive brake. Combined with the leverage advantage built into the standard Magura "dog-leg" levers, the feel and stopping power become first class. Jeff Wright noticed and all riders confirmed a fine trait of the new KTM. You can wait beyond your previously established braking points on a particular course, then get on both binders hard. There is no jerk or hop. The entire machine settles evenly on its front and rear suspension much like a Formula One car does when braking for a corner. If you can time your acceleration with the throttle to coincide with the suspension rebound, the burst from the comer is awe-inspiring. Both to the rider and those who are now behind you. In direct comparision (which usually gets people upset but is the final test on the race course), the Montesa and CZ have comparable brakes but the stock rear suspensions on those marques compromise that smooth settling down feeling that's part of the KTM. You can wait late to brake and love it, The firm seat goes unnoticed, so it must be right. The seat-pegs-grips configuration is right for a wide range of potential pilots. They combine to inspire confidence for the handling and high speeds attainable. The stock grips are the stingy Magura types for which we have no use and, while the peg location is good, the footpegs themselves are ' of mediocre design. There is still a characteristic drool of oil from the kicks tarter seal. It is a continuing mystery why European neoprenerubber is inferior to the U.S. stuff. One fork leg of the newest KTM also drooled slightly. Everything else about the 250 KTM is ready to go . Plastic fenders and sidepanels, good wheels (in which the spokes require some attention between motos), a magnesium-cased engine with power enough for any class, and a superlative suspension holding up a rigid chassis and swingarm all result in a competitive 250 that, in application, is more than t e sum: of its parts. There is a very good reason for the growth of that underground of KTM freaks. The machine . works. Now, that underground can become part of the mainstream of U.S. racing. At a recommended retail price of 1725 U.S. dollars, the KTM 250 looks like more C)l7 .of a bargain every day . It is hard hot to like the motorcycle ' ,' , a 10L . ". . .. • .. ill