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/125756
o CONTEST th ese th ings. Next tim e I'm going to rid e th e club over did it a bit. But when you my trials bike!" Even Bob was decid e to put o n a very tough National Champ ionship Enduro , th e judgment con sistently running between 8 and 15 minutes late an d lost over 100 poin ts. requiremen ts get pretty heavy. Myself, I Bob said, " I would lik e to invite pr efer to see err or in the direction of everyone wh o h ad trouble on that " too tough" rather th an milk runs, but cou rse to come down and ride some lots of people don't agree and 'th ere was trials. Most rid ers get into one of those plenty of bad feeling th is Sunday. T echnically it seemed th at th e run can yons and th ey see onl y a pile of roc ks. I see several lines through the was quite well done. There were more roc ks." The winning margin. If y ou'd che cks an d more people at th e checks like to tak e Bob up on his invitation, than I've ever seen at an Enduro before. th ere's going to be a trials for enduro I felt th at the marking was more th an bikes d own at Escape Country th is adequa te , but there were some pe opl e weekend, an d Bob will b e there. Ask who got lost. This co ntr ibuted t o nice and he ju st might tea ch you a few Steffan's demise. things . (See page 25.) When the b est enduro riders like High point of th e day was a ca ny on Ste ffan and Howesman can 't fin ish and in the six mph sec tion th at was a real Expert trials riders like Nickelsen and deIigh t t o ride. I've got no id ea wh ere it Evans have to p lay racer and still can 't is, but I hope some oth er club uses it l ~tlllll. aigain. keep up the schedule, it's evide nt th a I I , MOIO IMPORTS CD. 172 Freedom Ave. Anahei m, Calif. 9 1106 I . - DRACO'S MOTORCYCLES lAW ASAII ONLY O ne of Orange County 's , Largest Stock of I W ..J U >- U ~ \ ~ ,~ MOTO RCYCLES & PARTS M oto rc ycle 1nsurance F inancing A vail ab le M ast er C harge - BanKamericard 543-9688 5imichrome Shines Suddenly r_ ':" " ~ , ~ ' }~ . ~ /1' lAW ASAII 1629 S Standard SA ~ w Z 51mi chr ome i s a hon.y "'CC l eans quick as a bunny OMPETI TION CHEMICALS T ube S1 Can $3.4 5 713 Estes Street Iowa Falls _ Iowa 50126 , 13 5 2 Ce n t lnela , W. L os Angeles ,,-, ",,"',, ~"".~.""-' '' .''''.' (21 826-7856 3) Adv e rti s vm t! 1I t DiffBrake Reduces Rear Wheel Hop brak es the an gl e of t he anti -lift line i s red uc ed by th e perc ent age of fron t brak es u se d. If the front an d rea r brak es a re app li ed equall y', then half of the b raking i s on the f ront and th e an ti -lift compon ent is sl ashe d in h al f. T hi s in tu m mean s that th e tendency to ho p i s also cut in half. Thi s c an be most important on bikes wit h a s ho rt s wing ann an d a high pi vot. Und er som e co ndi tion s th e fo rc e causing th e hop is actually gr eater t han th e braking fo rc e at t he rear "h e el. Hop in t hese case s can be qui te viol ent if you ne ed to st op fa st. by Ru ss Shre ve HUSQVARNA Oi str ibute d by Med-International 4790 Pal m Ave " La Mesa, Ca lif, 92103 . ~. ~, Mike Patrick's ~ YWHA of COlONA 1101 E, 6th St, - Corona - 10- (114) 13~1l21 .. .: CYCLE NEWS The Cycle News office will be closed from D EC E MBER 21 thru liniIDA Y Spons ori ng T im H art FULL MAl C 0 PARIS STOCK • _-"""I I "'H'V I M IK. On e of the first reac ti ons we o ft en get from Cif fBrak e us e rs i s, " I don 't k no v, why , but the rear en d doesn 't , ho p , aro un d anymore when I put, the brak e s on " . we kno w why. Be si de s stopping fast er. t hi s is just on e more bene fit of a uto ma ti c al ly apply ing th e f ront brak es in a propo rti o ned amo unt when yo u apply th e rear brakes. Th e key is a sus p en s ion Charact eri sti c c alled " anti- l if t " . Th e nam e i s derived from aut omoti ve pract ice wh e re a geome t ric force i s appli ed by the re ar s us p en si o n to redu c e th e rear en d "lift .. of the ca r under braki ng. Her e i s ho w it works. All we ne ed to kno w i s t he lo cati on of two points; th e ground co nt act patch of th e re ar ti re an d the pi vot poi nt of th e rear suspen sion. In th e u s ual moto rcycl e ar ra ng em ent this l att e r i s sim pl y the s wing arm pi vot. Thr o ugh the s e two point s we draw a li ne rUe ") cal l ed the " a nt i - li ft " lin e . Th e an gl e ( U a " ) bet ween thi s anti - lift line and t he groun d defines a per c ent a ge of ant i - lift. Th e easi e st thing to think about though, i s th e rel a ti ve l engths of th e anti -lift compo nent s . In th e draw ing , " B" repre s ent s any mag ni tud e o f rea r b rake terce t rying to stop t he bik e . and " A" repre s ent s the rel a ti ve for c e t ryin g to prev ent li ft of th e bik e. No" , this works fin e on a car wh e re the re ar a xl e Is-quite hea vy , but on a bik e it is ri di culo u s to ima gi n e tha t the mass of the rider and the re s t of the bik e is going to be held do wn by I tld I ~' ~m r J t't (~ l ~ ll) f ';.J I JI ' . th e rear whe el. I\hat really happ en s is t hat t h e re ar wheel is lifted off the g roun d by the re s t of th e bi ke . As soo n as re ar t ract ion and b raking i s lo s t , th e unti-e- Ii ft force i s los t at so and th e rea r ' '' he el fall s ba ck to the ground . As so o n as il touc he s the 'groun d, t he fo rce ret urn s and th e wheel i s driven up war d again. Thi s co nti nues at a frequ en cy dete rmi ne d by th e m as s of t he rear wh eel and th e rat e o f th e re a r sprin gs , in a conditi on we all recogni z e a s " whe el h op " . So , what does Diff Br ak e ha ve to do with al l (hi s ? Simpl e. Th e act u al amount o f anti- lift i s modifi ed by th e p erc entage of front to re a r b rak in g. I n effect , apply'ing th e front and rea r brak es s imult an eo u s ly reduc e s th e an gl e of th e actual anti -lift lin e. When th e braking is all on t he rear, t he anti -lift lin e i s as shown in the i llust ration . \\ith the use of fron t ~- --_. - _...... ---_... - ........_------------ To sum it all up- DiffB rak e appli es a proportio nat e amo unt of fron t bra kin g with each re ar br ake applicatio n. Rear whe e l hop i s redu ced by the p er cen t a ge of front t o rear brak i n g. F or a giv en amoun t o f stoppin g pow er, th e bike with DiffBrake will have l e s s hop. G et mor e s top wi th less ho p DiffErak e