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/126248
Up pipes versus down pipes INSDE CZ t hat works 6 Backyard special is a GP replica Parker 400 . . . . ...•.. . . .. 8 Bikes destroy buggies. with some help from Larry Roeseler and Uncle Rolf 10 Desert Return of the Moose Run M ike Curoso . •. .. . .. . .. 11 T alks of juggling withJesus in England 12 W inter-AMA MX Glover , Hannah and Sugar Bear tops in th e tropics 14 Bikepacking Happy trails around Mammoth Lakes 16 Western Hotline Roadracing, motocross & scram bles 28 · North Tales of Puyallup and points south 32 New Products Training wheels for roadrashers? Central. 36 Ice -racing Results Cat .. : 38 ' 39 ON THE FRONT PAGE: Pridmore slicing through traffic at OMS, Mike Purdy in the Parker 400 desert, and mass confusion at CMC , Carlsbad, Photos by Ulrich. Brown, and Trotter. Carlos Serrano not smoked 'Serra no is no match, h uh? The EI 'Paso Coliseum MX race was a good event, but people reading your report were given the impression that Mr. Wise smoked Mr. Serrano . Not true. I read the Feb. 9th issue of Cycle N ews and was a little baffled at the B.S, that was printed. First off, the comment made about Carlos being no match for Mr. Wise was a rather stupid remark beca';lse Mr: Wise was riding his heart out JUSt trYlOg to keep up with Carlos in the 125 class , Had tl not been for a mechanical fa ilure in the second moto , Carlos would have wound up first overall. The article also stated that Mr. Wise was unfamiliar with his 400 . Well, nobody mentions that it was only the second time Carlos had . ridden an Open bike himself. MIKE RAMSEY Tucson. AZ Charles C. Cla yeon. President Bobi Scon, Assl. to th e President Sharon Clay eon, Pub lishe r Edna Mewtcn. Secretary to the Publisher Advertising Robert L. Nor Velie. National Adverti"ing Sales Manager Debbie Wilk.ins, Western Regional Advertising Sales Manager Ch ris Kelber. Advertising Assistant Editorial John n. Ulrich . Editor. Lan e Campbe ll. Edit or . l'lah- Brown . All. sistant Editor . Graphics and Production Production: Bonn ie Strunn. Judy Klinger . Typography: Muion Hatashi~a . CarolY!1 Branham . Laboratory Productlon: Dennis Cox. Circulation Accounting , Green and ' Ca ylm~ l..aionz. Manager. Mik~ Klin~r . Aut . Mgr . Jrann,=, Hammond. Accts . R~~vablr . Pamna Dick,=,noD . Asst. Accts . Receivable. Ca thy Srcdgel. Credit Depr . Rhonda Van Dorm . Col lectio n Dep t. Services and Support Mich ael Cclikas. Omnis Watts . Brenda Zodda . Recep tionist. - West nOI Cherry A",=,. • Long Beach. CA P.O , Box 498, Long Beach . CA 9OBOI. L,A . Line 6~6 -88+4 . (1 15 )4 27 .74 ~~ ; East P.O . Box 80S. Tu cker . CA 30084 . (404 ) 9!4 · 7850 , Subscription OnC' year . K'COnd class mail S15; 2 years . second cla M ' ma il. S27; .5 years. second class mail. S57.50 . CLASS I L1M:2 MEMII£ t11 4 What happened to Bobbi Hunter. a girl racer, who rode with the guys and showed the m the way at Corona Raceway. Did she quit racing? J. 0, DAVID " Rh ebe Smith. Manager. Pam Juanita Blanton, Assistan ts. Bobbi Hunter Copyright Cyc le N~W1. Inc . 1977. Trade -:nark regierered U.S. Parent Offi ce . All rights reserved. Published weekly excq>t rhe first and last week of rhe calendar year by Cycle N("Ws. Inc .. P.O. Box 498. Long Beach . California. Second clay posta~ paid at Long Brach. CA 90801. Edit orial stories . cart oons. photos. etc. are welcome. Addressed . sta mped envelope a$Sum return of unpu rchesed editorial m~u.er. Reprinting in wOOIC' or part only by pt'nnwlon of the pub lishers. Advertising rates and circulation information will be sent upon rrqunt. S« S.R .D .S. San Bernardino, CA No, she took up speedway racing, and has been seen , her right umst in a cast, both at a Mike Bast Speedway School, and at Elsinore practicing , . . Ed. lap, (at which point Ro n Evans ~ad just taken the lea d away from Brian Burch), the race was red flagged for a res ta rt after one rider complai ned about the start. After the restart race , when the reason for t he restart became known, many riders complained very loud and long but didn't get any action or satisfaction to their protests. Written protests we re made after the race results were received . As of this date no word has been received on these protests. BRIAN BURCH Hemet , CA Quicksilver not thrown out We enjoyed the article on the Quicksilver Enduro , but writer Mike Kinsella was in error when he said the entire enduro was thrown out . Checks one and two were thrown out, but the enduro was scored from the remaining three checks and the winners will receive trophies. GERALD DENT Secretary. Salinas Ra mblers M. C. . Salinas, CA Starting road racing I'm getting started in road racing and need some in form ation . W ho is in cha rge of the races in California? I need a calendar of sched uled races in the Southwest. Where do I get' this information, and what do I have to join? . RA N DY FULLER San Luis Obispo. CA Jackrabbit starts and rest arts Maureen Le'e's art icle in the February 9, 1977 issue of Cycle N ews gave readers an insight into the troubles between riders and Jackrabbit M.C . starters at the District -S? TT Scrambles held January 23 . 1977 at Elsinore Raceway. Almost every race that day was redflagged for a restart , but the 125 Novice Main restart was unbelievable. After waiting about five minutes for a start and then after going into the fifth We recommend Amen'can Federation , of Motorcyclists (A FM) and the Cont in ental Moto-sport Club (CMC) road races. For information, contact AFM, 4996 Argyle Dr. , Bu ena Park, CA 90620 , (714) 523 ·3892; or CMC , Manning Racing, 3407 West Olive, Burbank, CA 91505 , (2 13) 842-7433. AFM and CMC have long histories of success ul, fair race promoting in f California, and have a policy of cooperatinf.{ with each ot he r . . . Ed . I ta ke pra ctica l exce ption t9 your " . . . one -half to one horsepower more." statement co ncerning d own pipes vs. up pipes in Cycle News issue Number 5. page 12 . With the identical pipe mounted as a down pipe. as compared with the same piece of hardware mounted in a n u p po siti on, you may have some slight theoreti.cal increase in 'output due to the reducuon in pumping head , as the exit of the chamber would be higher in the " u p" position. rather than in the "down. " The difference in potential energy of a slug of hot exhaust gas , due to the difference in exit elevation , has to be rather small. Particularly since the mass of the unit volume of a 1700 F(avg.) gas is pretty small, maybe . 15 Ib .lft.'. the weight of the gases is .005 pounds. With an elevation difference of two feet, the work (force-distance) involved is .0 10 foot pounds. Now . a horsepower is -5 50 fo ot· pounds/second , You would have to eleva te this slug two feet (.01 ft .ll b.) in .0000 182 seconds in order to expend one horsepower , This is comparable to over three m illion r pm (rpm /60 ,= 1/.0000182 sec.). My contention is' that there are so many ot her things which ca n make one horsepower difference in pipes. that eve'} the mention of "up vs. down" places ..a magical air about a subject already overloaded with folklore . I will admit that the manufacture of an u p. or snake. pipe might entail more bends and irregularities wh ich may reduce the flow regime and efficiency to a degree as mentioned. But don't place any significance to the up vs. down with respect to inherently useful horsepower. I'll bet the CZ peo p le went to a down -pipe due to manufacturing ease and the fact that their previous " u p" pipe was a liza rd : poorly tucked in (if at a ll), In fact, note that the photo of the AW ·250 has the pipe exit pretty close to the location that the exit would be on a comparable u p p ipe. A NTHONY T EL LIER Phoenix. AZ Trippin' to Scotland The America n Trials Associ a tion has voted to send Marlan d W h al ey a nd Bernie Sch reiber to the Scottish Six Day event held in May 1977 ne ar Ed inburgh , Scotl and . T his is made possible by the proceeds from EI Trial de Espana, 1976. We would like to thank everyone wh o helped support this event. Anyone who would like a 1977 calendar of ATA events, please write .A rnerica n Trials Assoc .. P . O . Box 2498. O range, CA 92669. If you 're interested in going to Scotland for the Six Day Trial, there will be groups going for abou t $430 round trip. Write the above address for further info. EI LEEN SMIT H ATA Secretary O ra nge , CA