Cycle News - Archive Issues - 1990's

m er a nd n arro w er KTM m otorcy cl e between your legs . KTM didn' t ignore the motor, either. In sea rc h o f m ore lo w end , KTM d es ig ned a n a ll- new cyli nde r, w hich now features a "KTC" torqu e chamber. T he cha m ber, a bo xy-loo king device mounted abo ve the exhaust manifold on the cy linder, increases exhaust volume. Th e res u lt is essen tia lly th e sa m e as len gthen ing th e head pip e - more bot tom end . Th e pow er va lves w ere also tweaked to boost po wer off the bo ttom. Fuel is fe d into th e new cy linde r throug h a Keihin PWK 38mm "0" Slid e carbu retor. Brid ge stone M77 a nd M7 8 ti r es, instead of Met zelers o r Pirel lis, co me stock o n all the KTMs this year. W!:! we re q uit e a nxi ous to rid e th e new KTM 250SX wi th th e PDS su spension system, but we were forewarned by KTM that th e beefy WP s hoc k tak es a lon g tim e - perhaps up to 20 hours - to br eak in , a nd they w er e right. In the short time th at we 've had the SX in our possession, we have yet tu fully break in the shock and ge t a tru e feelin g of how th e POS su s pen sio n sys te m performs before having to m ak e o u r repo rt for this issue 's d eadline. We will have more thorough informa tio n w ith more ti me on the bike, especia lly after th e 250cc shoo tout, bu t for now, we can tell yo u that th e sy stem see ms to work awfu lly well, even if the shock does feel as rigid as a steel flagpole. We've ridd en the SX on two d istinctively different kinds of tracks thu s far, and o n our las t ou ting on th e bike th e shock started sho wing signs of breaking in and feeling a lot better. Th e back end still feels a little harsh over the smaller bumps an d w hoops but hand les th e ha rd hits just fine. We have no rea son to beli eve tha t, once fu lly broken in, th e KThfs rear sus pension will perform, at the very leas t, as good as any thing else ou t th ere, w hich is ex ac tly w ha t KTM wanted to accomplish . Recently, eNreturned from the Internationa l Six-Day End uro in Italy, where ma ny of the com peti tors rod e the new KTM - ma ny of w hich had absolutely no break-in time befo re the s tar t o f the event. Some of the rid ers we sp oke to who rod e th e new KTM sa id the shock felt broken in after just the first day, and the y liked the wa y the bike handled. We heard comp lain ts fro m no one, including Italian Giovanni Sala, who rode one of the new KTMs to victory . We di d , however, hear one fact orybacked KTM racer e xpre ss co n ce rn abo ut the shoc k, qu esti on ing its reliability a nd p ossibly hi gh m ainten an ce schedule. He felt that having to con trol both damping and speed sensitivity is a lot to ask for from a shock. "I coul d see havi ng to reb uild th e shoc k and replacing the oil a lot," he sa id . "Tha t's okay for me, bu t I don' t kn ow how that wi ll work for the average rid er: ' KT M claims th a t th e s hoc k w ill req uire no mo re maintenance than any o the r s hoc k. On ly tim e w ill tell. We ha ve noticed that the top shock-mo unt-ing bolt loosens itself quite readil y and needs to be chec ked after every ride. We have also heard of this happen ing wi th ot her '98 KTMs. Perhaps some Loc-Tite or other thread-locking agents wi ll cu rtail this. The WP fork, on the other hand, performs just fine right out of the crate. On e tes te r im media tely said . tha t th e new fork wor ks better than last yea r's , a nd a n o ther test er sa id the WP fork fee ls very good in all situa tio ns, from br eaking b umps to hard land in gs. We d id b um p up b o th com p ress io n a n d (Right) KTM basic ally bu m th e SX's chassis around the new PDS direct-link rea r-su spensi on system. Th e sho ck itse lf no w acco m pli shes what the linkages used to d o - co ntro l the ri si ng rate. (Left) Th e motor feat ures 8 new " KTC" torq ue chambe r on t he cylinder to enhance bottom end. There's als o a larger ai rbo x. (Below ) The rea r sho ck . which features tw o p ist ons Inside th e body . takes a lo ng t im e to break in. • rebound damping, as in stock cond ition the fork felt a tad on the so ft side: We w ere im p res sed wi th the SX's powerplanl. O ne of o u r tes ters spoke hig hly of the KTM's power on top , this Pro-level rider sayin g it felt stro ng fro m midra nge on up, and follo wed that up by saying it feels even more powerfu I th a n the Honda C R250. How ever , he was n' t impres sed with the KTM's bottom-end performance: "Not that there wasn't any (bottom end)," he sa id, "but (it) just d idn't feel real usa ble to me." However, we couldn' t get all of our testers to ag ree. Another Pro-level rid er sa id of the KTM's po wer: " It revs o kay , but doesn 't pull on to p . Otherw ise , it has good, controllable mid range and is eas y to ride." "Co ntrollable" is the key word here, as the KTM's engine is definitely easy to manage, though it could use a bit more punch off the bottom, e speci all y in power-robbing sa nd. Still, all of our testers ag reed tha t the bike has a competitive, usable engine. O n the downside, we had one particu la r rid e r w h o d islik ed th e way th e KTM shifted, complaining that he had to back off the throttle whil e clickin g up ano ther gea r w hile und er a heavy load . "Thi s is w ha t I disliked most abo u t the bike," he sa id, adding, "The clutch pull feels good , th o u g h the le ver is to o straigh t, but th e whole cl utch / shifting p a ck ruin s y o u r co nfid e n ce o n th e KTM. " Thes e problems cou ld be sym pto ms of a transm ission no t entirely broken in yet - again , time will tell. None of ou r other testers complained of the KTM's Shifting . Overall, th e KTM is a solid handler. It has good stability d own the straights and co rn e rs ex tremely wel l. You ca n ju m p it with co n fi d ence, too , as it doesn't do any thing weird or unexpected in th e a ir. Th e brakes have good fee l a nd are .::. -- st ro ng a t both ends, thou g h the 'fr;nt bra ke d evel oped a n an noying sq u ea l un der hard brakin g. One of our other big complain ts wi th the KTM is the overly hard seat. It's narrow, which makes moving arou nd easy , but it' s just too dam hard for our likin g. KTM info rm ed us, th o ugh, that la ter product ion ru ns w ill includ e softe r seats. O therwise, the SX is very comfort ab le, as far as the handlebar / seat / footpeg relation sh ip is conce rned. Ad mitted ly, we wou ld have liked to have put more time on the KTM for this rep or t, but deadlines a re dead lines . We have ma ny pl ans for the KTM, wh ich we w ill certainly inclu de in our ann ual 250cc shoo tout. But, for now, we can say wit h confidence that KTM has done its h ome w ork a nd h a s an o u ts tand i ng motorcycle on its hands, f~ While Cycle News believes the foregoing test reliable, it is the opinionof the reviewers only alld should not be relied upn" in determilling the perjormance or safety of the oehicle. The reader should make his or her ouon investigation. 1998 KTM 250SX Specifications Uat Price Displacement Engine type $5698 246.6cc Uquid·cooled, single-cylinder two-strok e w /e xhaust power valve and KTC (KTM Torque Cham ber) Bore x stroke 67.5 x 69.5mm C arburetion 38mm Keihin F'Vv'K Ig ni t io n Ko kuso n DigItal Tra nsmi s sio n s peed s Fuel capacity 5 1.9 gal. a tJ ~ , .57.3 in. ,26 .5 degrees/ N /A , 36.4 in. I'-. 0\ 0\ ,..... Front tire .. 80/1 00·21 Bridgestone M77 1'-. ' W heel ba se Ra k e /trail Seat height , R ear tire .. 110/90· 19 Bridqestone M78 Front suspension . . . . .W P adju stable SDmm Extre me conventional fork w / l1 .8 inches of wheel travel Rear s uspensi on WP adjustable PDS (Proqr essive Da mping Syste m) w/1 3.3 inches of wheel travel Front brake 26Om disc m 22Omm disc R ea r brake 216 .7 Ibs. C l a imed dry w eight ,.... .... Cl) ..0 E .... 0Cl) Cl) sr: 17

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