1964 BSA Cyclone 500 - 4-Page Vintage Motorcycle Road Test Article

Description: Yes we combine shipping for multiple purchases.Add multiple items to your cart and the combined shipping total will automatically be calculated. 1964 BSA Cyclone 500 - 4-Page Vintage Motorcycle Road Test Article Original, Vintage Magazine articlePage Size: Approx. 8" x 11" (21 cm x 28 cm) each pageCondition: Good Those who have raced bsa’s 500cc Gold Star single(known affectionately around these offices as the“BSA Roto Rooter”) will offer the opinion that any re-placement would have to be awfully good. Well gang,BSA has a replacement and it is awfully good. They havethe Cyclone 500 twin for you scrambles racers, and ithas all the sturdiness and thunderous power that madethe old single a winner. The diehards will say that thereis no substitute for the single, and they may be right; butin the long run the twin will have the last word.The reasons for this are manifold, but basically thetwin has the advantage because it will turn faster, andhigher engine speed inevitably means more power. Thismaxim is particularly true when the twin in question is agood one, as the BSA certainly is. In overall layout, theBSA twin is very modern, with nearly equal bore andstroke (65.5mm x 74mm; really should be the otherway around) and a unit crank/transmission case. Thecrank runs in two mainbearings — one plain; the otherball — and plain inserts at the rod journals. The plainbearing is used at the timing end of the crankshaft pri-marily because that arrangement offers a simple meansof feeding oil to the passage that carries lubricant out tothe rods. A double-gear pump inside the timing coversupplies pressure to the bearings and scavenges the sump,returning oil to the reservoir tank located under the seat.Unlike another popular British twin, which has apair of camshafts, the BSA has a single cam, mountedhigh in the crankcase behind the cylinders. The cam fol-lowers are carried in bores machined into the cast ironcylinder block, which is rather a neat way of doing things,and the pushrods pass up through a chest cast into theblock and cylinder head. Incidentally, in these late BSAtwins, the flange at the base of the cylinder block, wherethe block is bolted to the crankcase, has been strengthenedand that stiffens both the block and the crankcase.Removing a single cover exposes all of the uppervalve gear in the BSA engine, and there is enough roomunder the fuel tank to permit removal of this cover andadjustment of the valves. Take a peek in there and youwill see that the rocker shafts are carried in posts castintegral with the head. This provides a good, solid mount-ing for the rockers and eliminates flexing — which canhave a surprisingly upsetting effect on valve timing athigh speeds.Like other BSA twins we have tested, the Cyclone500 was very smooth and easy to start. The twin carbu-retors appear to affect low speed tractabiiity not at all,but it is impossible to state this as an absolute fact. Theengine has a cam that gives rather racey valve timing, andit has to be up “on the cam" before it begins to run cleanand develop any power. Once it does begin to chum atthe proper rate, which is at a relatively low engine speed,there is a lot of power on tap and it does not trail awaymuch until the engine gets right up to the threshold ofvalve float. At any point between burble (about 2000rpm) and valve float (about 7500 rpm) it runs strongand clean. In accord with their long standing policy, themakers give no figures on power output, but on the basisof the machine’s performance we would judge the output... 11596-6410-08

Price: 11.59 USD

Location: Kingsport, Tennessee

End Time: 2024-12-15T02:24:56.000Z

Shipping Cost: 5.95 USD