Cycle News - Archive Issues - 1960's

Modifying The 450 Honda For Speed Or Sport --Part I By Dick Kil/:roe In order to best evaluate which of the many avallable performance accessories for the 450 Honda would best suit your needs, let's first consider the relative likes and dislikes most frequently alred by the discriminating rider . The first, and most universal complaint one usually hears, is that 450' s are just too heavy . Frankly, this is one problem that one just learns to live with, for even a correctly set up Grand Prix 450 road racer weighs in at about 350 to 375 pounds. The first 75 pounds you get off a 450 are by far the easiest, as bolton fiberglass accessories and a different exhaust system playa major part of this first stage. One thing worth remembering is that the frame on the 450, which weighs about 38 pounds, is extremely rugged, and withstands crashes that would easily bend many lighter frames (a Manx frame weighs 30 pounds). If you are interested in building a bona fide road racer, a Rickman or Sonic Weld type frame might well be worth the investment - unless you plan on racing in A.M.A. National Events, in which case A.M.A. rules state you have to run the stock forks, brakes and rame. Anyone silly enough to think that a Super Hawk front brake and a 160 size rear brake will stop a 450 at racing speed better just forget it. 10 order to have legal A.M.A. brakes that stand any chance of stopping, you need the 4-shoe brakes off the C.R. 72-77 Series Honda factory racers, which are about as easy to obtain as gnats teeth (also quite expensive). A last minute development which could be of some help to Daytona bound Hondas who already have the Cutlass disc brake was brought about by an arrangement between Cutla s s and Airheart to take over the manufacture (and hence the liability) for the three-year-old proven design'S reliability. This resulted in an immediate decision by American Honda to submit the model already used by Norm Reeves and Precision Machining fcor A,M.A. approval. "These units sell for $200.00 in ready to install kit form , and are the only known remedy for adequate racing braking for 450' s, Plans are afoot to come out with an improved version by Laconia time, as Airheart is just too overloaded with prior work to guarantee any deliveries for at least 60 days. The present model brake can be ordered through Cutlass on a prepaid 20-day delivery basis from Cutlass Disc Brakes, 5333 Canhuenga, North Hollywood; phone (213) 763-4138. The combination that won two A.M.A. Nationals this year was not the highly touted factory prepared team Hansen Hondas, but rather a super-tuned overweight "legal" A.M.A. type built by Precision Machining of San Bruno, who also gr ind the best all out racing cams in the business for Hondas and Triumphs. It should be noted that Precision Machining specializes in race- winning product development primarily, while most other manufacturers of similar products seem to slant their products more towards the street/drag market. We have seen rather good showings by some Weber equipped 450's, and of course everyone knows of Harman-Collins record with Triumphs. We hope to be as falr as possible in our comparisons of the different products avallable for the 450. We will therefore attempt to show the more specific advantages of each product mentioned herein. Bear in mind that our racing product preferences are based on 'what we've seen win races . Nothing else, except maybe direct ynamometer comparisons , really gives the buyer anything concrete to consider if you want to win races. FRAME: There have been some successful ~ttempts made towards modifying the stock frame to reduce twisting and flexing under load, which seems incredible to consider until you try to lift a 450 engine unaided. The team Hansen and Precision Machining Honda had exira braces fabricated onto the fork, triple cla mps and Manx type braces added to the rear of the frame, which allows removal of the center-middle frame member. We feel that the forks probably cause more problems than frame flexing, but then we also run 19" wheels, which seem to help the handling of every bike we've run 19's on. For .... one thing, although you get at least adequate ground clearance of a 450 with 19's, it becomes necessary to dress off parts of the engine mount bolt-ends and nuts, as these will ground out even before the exhaust pipes. We also found it necessary to relocate the battery box 3/8" closer to the left carburetor to give the Hosman velocity stacks enough clearance to avoid gouging the battery. We have successfully used both the Webco 1-3/4" exhaust pipes, and specially fabricated by an muffler shop type 2" exhaust pipes which definitely show the better results, although you have to fabrIcate megaphones that are approximately 6" longer and 1" wider at the bIg ends than Super Hawk megs, We r eally wish somebody would produce megs to these approximate specs, as you need all the pIpe sIze and length you can get when you attack the exhaust ports. We finally opened ours up all the way, but that's another story which we'll cover later.

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