Cycle News - Archive Issues - 1970's

The fever built bullet . . at what seems a ridiculous angle, but still the cy linde r doesn 't scrape.. Accelerating W FO out of the co m er, drifting out toward the sh oulder, speedometer needle quickly quivering past 110 in third. The straight en ds 'j u st ahe ad, rushing in against my direction. I grab a giant bunch of brake , then look down at the speedometer, exp ecting to see abo u t 40 mph in dica te d. It reads 70, not bec ause the brakes aren 't good - th ey are - but because the motorcycle was going so fast to start with. Panic. Too deep, too fast. Braking past the apex, the bike trying to stand up, trying to head fo r the straigh t line leading into the dirt. But it doesn't. It just st op s, turns, and continues on its way , un flustered. . Ferodo gre en linings make the brakes as good as the y are . Each BMW disc puck is a complex, sloped three-part assembly on a single backing. It looks almost like three thin wedges of gre en cheese on a porcelain platter, ea ch sloping in the same direction, each the same size, each evenly sp aced. What that means is that replacing the stock puck material with something better for ra cing ( Ferod o pads provide more friction, do no t tend to fade when hot, but wear o u t faste r ) is a laborious job. It too k Johnny 15 hours of exacting wo rk to m a tch and install p ieces of Fer o do lining to the stock pu c k car riers. He did it per fectl y, bondin g and riveting th e new mat erial to the p uc k back ing plate s, u sing stock pads as templ ate s. It was worth it. In spite of a st iff feel at the lever , th e twin rotor fron t di sc br ake is strong. Sta ndard shoe s in the rear brake squeal terribl y when ho t , an d fade. The co mer p asses. ·A straight bec ko ns . Th ird gear is go od un til almost 120 mph, then fourth star ts pulling, 120 .. . 122 .. . 12 5. It starts as a gen tle shake around 120 mph, worsening as the revs climb and spe ed increases. As lon g as th e gas is held on, the wobble gets worse. First ju st irri tating. Then annoying. Alarming. Terrifying. Religion -insp iring, Bar tips seem to blur from th e intensity and frequency of the wobbling hom dance. My face bu m s, my heart be ats harder, my arms be come tense. Pierce can rid e this thing topped out in fifth, and I'm not even' in fourth . 1 Can doit, I will no t be afraid. I'm gonna hold on 'til 8,500 rpm, th en hit fifth . No way ! At 130 in fourth, 8,000 rpm, the situation is desperate. I think of my st ree t clothes - jeans and n ylon j acke t, of the ca t tle blazmg by in blurs, of the ro cks and trees lining the roadway. No way am 1 gonna crash someone else's very expensive, very fast , very unsafe racer on th e street. I back o ff. Back in Bakersfield after 109 fast miles, I ask Ron if the BMW would have spit me off if I had kept on the gas and shifted in to fifth. "Yes ," he says, ''It probably would have. T he re's something wrong with it. Maybe the damping isn't equal ' in the fork legs. Normally .it wouldn't wobble th at bad, but like it is, it probably would have crashed you ." Johnny thinks that the fluid is low in on e fork leg. "1 didn't bother to touch the bike sinc e the last race because Ron told me y ou wouldn 't get it ov er 100 mph," he says. But Johnny must really think that th e problem is deeper-rooted than that, because he talks about other things he wants to do to the bike, modifications that point to a problem. . "1'11 reinforce the swingarm and run a bracket from frame to engine to eliminate the torque from the shaft. Then we can use road racing tires." Ko kinos speaks in burSts, like a machine gun . He goes on to talk ab ou t his racing background and this fever -built bullet. "We went into the production class after building GP bikes because people want to see the bike the;y c an bu y .. We had a few problems learning to set one up because we had never set up a BMW before. But it's been very successful, and what little work we had to do we could do over again easier - it's simple to do this if you know what you're doing. It 's a quick bike, and it's dependable. We've pulled it down and looked at th e rods, and they look ju st like n ew, everything beautiful. You can 't hurt it." It is a quick bike. But whether or not building such a machine is easy depends on what yo u consider difficult. The modifications are many, and a re not the homeworkshop variety . As for reliability , it was a long time co ming. - "We ran into a few problems at first trying to make this dependable and fast, " says J ohnny, as Red looks on. "The push rods would flex under severe rpm and fracture the rocker arms. Finally we got some chrome moly push rods. That .solved the problem, and now it's dependable at h igh rpm. You can run it forever, just like a stock BMW." He's telling the truth. Pierce regularly hits 9,500 rpm and runs the ne edle right o ff the optimistic 140 mph sp eedom eter face when racin g. Making the b ig BMW into a racer started with a .520 lift Sig Erson camshaft and special outer valve springs. 44mm intake valves were installed, and all the valves were countersunk so th at they would not touch when opened by the h igh lift cam . Countersinking the valves lowered the compression ratio, so the heads were milled. A stock BMW cy linder head cav ity displaces 55cc. On this bike, the cylinder heads displace only 4I cc each . Johnny "flowed" and ported the cylinder he ads us ing cigar smoke as a flow indi cator. "Worked great," he: reports. "That's wh at gave us more top end. " To help solve the classic BMW scraping rocker box problem , the barrels were milled 8mm, and special Venolia pistons with ' relocated wrist pins were used. With these special pistons, the bore and stroke remain stock, but the ov erall cylinder length is reduced. Drilling and cutting down the flywhe el took off two and one-half pounds, quickening response and improving shifting. The carbs are stOCk, but th e intake manifolds connecting the carb ureto rs and th e cylinder heads are tapered from an inside diameter of 38mm at each end to 32mm in the middle, creating increased ch arge velocity. Velocity stacks replace th e aircl eaner tubes on the 38mm Dellorto accelerator-pump carbure to rs. An oil cooler off a Triumph Trident isn't used to coo l the oil so much as to co n dense it back down into liquid after it is churned into foam by oil pump cavitation at 9,000 rpm . A deep oil pan in creases oil capacity one quart. A smaller battery replaces th e sto ck on e, making room for the behind-the-engine mounting of the oil cooler. Rearset footpegs are accommodated by a handmade brak e lever with a reversed shift lever. The BMW shifts one up and four down. An ugly, cobby outside fro nt fe n de r brace rep laces the inside-fen der stocker. That's because the front tire swells at high sp eed, and used to rub on the inside of the fender. The giant brace also strengthens the fork against twisting forces. Boge heavy duty shocks - the BMW factory replacement for use with sidecars - improve rear wheel con tr ol and handling. St iffer springs, AT F, and four _ in ch es of extra spring placed inside the sliders control nose dive under hard braking. A 19" wheel increases ground clearance. Un der 1976 AMA rules, production bikes Can run with gutted mufflers and enlarged engines up to I ,OOOcc. Pierce, with sponsorships on GP machines, is hesitant about riding a production bike in a class of street bikes he thinks are being pushed beyond their handling limits. Johnny isn't sure about the future of his racing effort. This year he's b een trying to break in a new rider (David Em de) on the local race circuit. "It gives us a little prestige," says Johnny Kokinos talking about his BMW. "It shows that a little shop like this can ge out and do it as well as the factory, maybe better. Th ey didn't give us any he lp in money or parts, because they didn't want us to beat them. They said we'd never beat them, but we did." (Pierce blew off the "factory" bikes at Laguna in '75.) Johnny Kokinos has the fever. And the fever -built bullet. • 'It shows a little slwp can go out and do it...' 25

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