Special Dirt Feature

Dirt Bike Accessory Buyers Guide

December 1 1975 Barry Watkins

Dirt Bike Accessory Buyers Guide BARRY WATKINS December 1 1975

Special Dirt Feature

December 1 1975 Barry Watkins

DIRT BIKE ACCESSORY BUYERS GUIDE

A WHO, WHAT AND WHERE OF AFTER-MARKET ITEMS

BARRY WATKINS

Editors Note: There are thousands of worthwhile accessories on the market for dirt bikes, and this guide makes no attempt to include them all. Rather, it's an accumulation of trick and unusual parts that will either make you go faster or eliminate repeated breakage of stock components. For convenience, the guide is divided into the following categories: Suspension, Engine/Transmission, Frame and Body, Miscellaneous, and Things to Come.

SUSPENSION

BILSTEIN SHOCKS

The Bilstein is one of the only gas-filled true monotube shocks on the market. The units shown have the trick 36mm-diameter body (an important feature to check) and Heim joints to prevent shaft flex. Available lengths are 12 and 13 in. This is one of the most rugged, dependable and best working shocks available. Price for a pair of dampers is $87.50, and $18 more for a pair of lightweight Ken Ross springs.

BOGE/MULHOLLAND FORKS AND ACCESSORIES

Muiholland is acutely aware that the main areas of concern in fork engineering are durability and performance.

Problems such as bending, over-flexing and the need for cumbersome braces are eliminated with Mulholland fork legs of seamless, induction-hardened and hard-chromed chrome moly construction. Consistent hydraulic performance is insured with a pair of quality steel-case, double-lip oil seals for each leg. Triple clamps of avionic 50-grade, cold-forged aluminum with Allen-bolt fittings give a positive fit. Air-vented caps eliminate fork-locking due to air buildup. Consistency is assured by preset chrome silicone-hardened springs. Travel is 8.0 in.; weight is 18 lb.

This fork system is unusual in that it is available in component parts (fork legs, triple clamps, axles in various sizes, and springs in several rates). That way you buy what's right for your bike and replace only what you break.

Mulholland also makes rear shocks for both street and motocross.

C&J KAWASAKI LAY DOWN KIT

Kawasaki owners will be happy to know they can get their shocks laid down for $45 with C&J Precision Products KX 125, 250 and 450 Lay Down Shock Kit. The kit includes a pair of replacement frame sections to move the shock forward, and gussets to strengthen the rear frame section. There are also illustrated instructions on how to install it. You will need to modify your airbox, but that's easy. All pieces are made from chrome moly and are heliarc welded. For $85 plus shipping, C&J will install the kit on your frame.

FAIRWAY RACING PRODUCTS YAMAHA MX LTR KIT

We saw one of these LTR kits installed on a bike and thought it came that way from Japan. This kit increases rear wheel travel to 6 in. and works with your stock shocks, although not as well as with a pair of Konis or Bilsteins. The bike we tested with Thermal Flows felt pretty good and it had heavier springs and oil in the shocks. The

kits are available through Fairway Racing Products for $21.95. Installation time is about three hours, including welding, and no alteration is required for your number plates or pipe. You'll need a hacksaw, hammer, file, arc welder and a can of black spray paint. For another $30 plus shipping you can get the kit installed on your frame. These kits fit all '74-'75 Yamaha 125 MXers, 175 MXers and '74 125 YZs.

FAIRWAY RACING PRODUCTS YAMAHA ENDURO LTR KIT

This is the econo high-performance LTR kit for '72, '73 and '74 250-360 MXers and '75 250-360 Yamaha Enduros. Rear wheel travel is increased to 6-1/4 in. No alterations are required to the upper frame. Simply weld the pair of gussets to your swinging arm and you're off. You can use your Thermal Flows, but they work much better with Bilsteins or Konis. Price is only $15.95 through Fairway Racing Products.

HACIENDA HONDA 125 AND 250 LTR KITS

One of the best performing LTR kits for the 125 Elsinore (see photos) takes only about two hours to> install. Hacienda Honda’s kit includes complete instructions that make installation simple. Rear wheel travel is increased to 6-1/2 in. with a pair of 12-in. Koni or Bilstein shocks (your stock shocks are not adequate for a long-travel suspension). Price is $29.95 for the complete kit, which includes all brackets, shock stud bolts, self-locking nuts, washers, etc. You’ll need access to a hacksaw, center punch, hammer, file, drill and arc welder. The top shock mounts are relocated forward about 2 in. to retain the proper shock angle.

At $15.95, the Hacienda Honda 250 LTR Kit increases rear wheel travel to 6-1/2 in. on ’74 and earlier 250 Elsinores, and provides a tremendous improvement in handling through the rough. The kit (similar to the 125 kit pictured), includes fully illustrated instructions and tips on setting up your shocks and selecting the correct spring rate. Installation requires access to a hacksaw, body grinder and a heliarc welder. The kit requires a good pair of 13-in. shocks. The important feature of this kit is that it not only works, but tells you how to modify your existing airbox and fender for the proper fit, and how to remount your number plates for a sanitary appearance. Available from Hacienda Honda.

KEN ROSS SPRINGS

These springs are the newest high quality items from Ken Ross. They are made from preset and shot-p00.......eened chrome vanadium wire. The quality of the material allows the windings to be spaced farther apart for less weight and more travel before coil bind occurs. Available in your favorite color, so long as it is yellow. Ken Ross springs won’t break and are unconditionally guaranteed. Price is $17.95 per pair. They're available in straight weights of 50 lb. through 150 lb. in 10-lb. increments and progressive windings of 60/90 and 90/120. Obtainable through your local dealer.

FOX SHOX

Fox Shox are the newest gas shocks from the Moto-X Fox. Lengths of 12 in. (3.8 in. travel), 12-1/2 in. (4.1 in. travel), 13 in. (4.3 in. travel), 13-1/2 in. (4.6 in. travel) and 14-1/4 in. (5 in. travel) are available. They must be mounted upside-down for proper operation, which also reduces unsprung weight. Damping is adjustable by means of a replaceable jet at the end of the shaft. They are completely rebuildable and are solely manufactured in the USA. Fox Shox are $99 per set, less springs.

FOX FORX KIT

This is a brand-new kit just released by Geoff Fox. It is designed and manufactured by Steve Simons and is the same kit they say Brad Lackey has been so successful campaigning in Europe. The unit shown is for late model Huskys (those with the black, ridged lower fork legs); however, other models will be available soon. The Fox Forx increase travel to 9 in. Installation is of the simple bolt-on variety. The damper rods are trick in that at both ends they are tapered to match the progressive action of the gas. Kit also includes new valved and sealed fork caps so that gas pressure is adjustable. Each pair can be individually tuned to your needs by varying gas pressure and oil viscosity and/or amount. You can use air from the gas station, but nitrogen is preferred. Price of the Fox Forx is $50.

FOX AIR SHOX

“Air Spring” suspension is what these new shocks provide. In practice, you get a smooth progressive action of compressed air for a supersoft controlled ride that won’t bottom out. Damping is instantly adjustable externally to suit track conditions and rider preference. “Spring” rate can be adjusted by merely increasing or decreasing internal air pressure. That means no spring sag, since. . .no springs! There is practically no damping fade and very minimal heat buildup. The weight of one Fox Airshock is only 3 lb. 7 oz. They are designed for inverted use to reduce unsprung weight.

The shaft is hard-chrome plated 4130 chrome moly with shaft seals and wipers of polyurethane, which is a special compound with more than five times the wear resistance of conventional nitrile rubber. There are no castings and all parts are machined from solid billet. Each and every pair is dyno tested before shipment. This may be the finest shock on the market, but the price of $219.50 per pair means that the serious racers are the most likely to use them. Available from the Moto-X Fox.

NUMBER ONE PRODUCTS FORK AND SHOCK KITS

Number One Products has probably sold more honest-to-goodness fork improvement kits in the last year than anybody. In addition to its fork improver kit number 133 for small Yamahas, Suzukis and Kawasakis, and its big fork improver kit number 233 for big Yamahas, Suzukis and Kawasakis, Number One has recently introduced fork extender kits that increase fork travel 1-1/4-in. These new travel extension kits are designed to work in conjunction with the fork improver kit mentioned above. Retail price is $89.95.

Another kit, number 144, is now available for the Kawasaki KX and KS125. It improves damping, increases fork travel 1 in. and includes new fork springs. Two more items of interest are Number One’s $14.95 pair of caps and seals for Koni shocks and the H101 kit for Honda forks at $29.95. Number One Products are available at dealers everywhere.

TERRY INDUSTRIES FORK KIT

This is today’s most popular desert fork kit. Referred to as the “Cream Puff” front end, it absorbs bumps you wouldn’t believe. Rider fatigue will be substantially lessened, especially in hands, arms and shoulders. Kits are available for big Yamahas (YZs and MXs); big-bore Suzukis; CZs; 125, 250 and 450 Kawasakis; and for Betor forks. Prices for the kits range between $30 and $50.

Front-end travel is increased to about 8 in. on most models. The “Cream Puff” raises the front end 1 in., up to 1-1/2 in., so may not be desired for precise cornering unless you raise your fork tubes in the fork crowns. However, this is the hot set-up for bumpy riding. Terry Industries also makes excellent teflon clutch, brake and throttle cables.

WEBCO ALUMINUM BODY KONIS

Koni apparently got tired of everybody else making aluminum housings for its shocks, so made its own large-diameter aluminum barrels complete with nine fins for maximum cooling. These are the famous Koni internals that are six-way adjustable to suit your suspension and riding conditions. Design is such that they accept standard diameter springs of all popular lengths and ratings. Top and bottom eyes have push-out bushings to accommodate various stud-mount bolts. Known as the G.P. shock, available lengths are 12 in., 12.9 in. and 13.5 in. Retail price is $130 a pair without springs, which makes them the most expensive of all the popular non-gas shocks. Koni G.P. shocks are distributed by Malcolm Smith and Webco, so see your local dealer.

WHEELSMITH ENGINEERING

This 8-3/4-in. travel fork kit is the latest trick from Wheelsmith Engineering. It is one of the few kits that add the travel below the axle so that the front end is not jacked up to disturb steering geometry. Price is $65 installed, which includes heliarcing aluminum extenders to your forks, as well as a pair of super springs that prolong coil bind for that extra travel. This kit works as well as anything on the market I’ve tried. Similar kits are also available for 125 Honda Elsinores.

ENGINE/TRANSMISSION

DG PERFORMANCE SPECIALTIES/125 HONDA

DG Performance Specialties is the headquarters for Honda motocrossers. The new 125 Elsinore air-box uses a Penton-type element and is constructed of fiberglass. Price is $39.95 including element. It is waterproof. The radial head is a preproduction prototype for the 125 Elsinore; heat strip tests indicate it lowers the cylinder head temperature an unbelievable 150 degrees over the stock head. Now that is a cool head!

The competition pipe is DG’s CR125 “Torquer” unit, which is designed to widen the powerband at all revs. Top end is increased, as is acceleration out of corners. These pipes are made of 20-gauge steel and retail for $48.95.

DG PERFORMANCE SPECIALTIES/100 HONDA CONVERSION

This is DG’s very popular l00cc conversion kit. This kit was on the bike that won the l00cc class in the Mini Nationals. Price is $250, and you must send your barrel. DG will install the liner into your cylinder and port it, as well as send you a 26mm Mikuni carb, radial head, piston, pins, circlips, rings and gaskets.

FLYING MACHINE FACTORY/MARTY SMITH REPLICA ENGINE KIT

Originally designed for Marty Smith’s bike, now available for 1973-’75 CR125 Hondas, this engine kit widens the powerband and produces up to 30 percent more usable horsepower throughout the entire rev range. Proven reliable in tough motocross competition.

Send only your stock ’73 or ’74 cylinder and piston to FMF. Your

cylinder will be ported and a special boost port added for increased torque. Your piston will be precision machined to match the new boost port. FMF completes the kit with a special Porcupine head with a high-com pression combustion chamber, a 32mm Mikuni carb and manifold, and competition downpipe tuned to match the cylinder porting.

Kit bolts on easily and requires no special tools.

FLYING MACHINE FACTORY/l00cc SLEEVE DOWN KIT FOR 125cc RM, CR, YZC

All the advantages of a smooth-handling 125cc chassis can now be used in the 100 class. Kit reduces engine displacement from 125cc to l00cc and comes complete with aluminum piston, special rings, cast iron cylinder sleeve and FMF high-compression Porcupine head with gasket.

Can be ordered in do-it-yourself kit or complete from FMF. FMF recommends sleeve installation be done in its facility so cylinder may be brought up to FMF performance porting specifications by its experts.

Send only your stock 125cc cylinder to FMF for sleeve installation. Honda CR cylinder may be boost-ported for additional performance. Specify boost porting or standard porting when ordering Honda cylinder. Available for: Honda CR125 standard or boost port, Yamaha YZC125 and Suzuki RM125.

FLYING MACHINE FACTORY/PORCUPINE CYLINDER HEAD

Unique design provides 18 percent more heat radiating surface area than stock cylinder head, but with less weight. FMF Porcupine head keeps power loss from heat buildup to a minimum. High-compression FMF combustion chamber increases engine performance. Available for: Honda CR 100 and 125, Yamaha YZC125, LT3/MX100, Suzuki TM125, (RM125 model available in mid-September).

FLYING MACHINE FACTORY/YZC MOTOCROSS HI-PIPE

Works style expansion chamber bolts on and provides clearance for stock or FMF Porcupine cylinder head. Widens powerband and smooths the “peaky” tendency of this engine.

(approved for AMA Amateur and Professional competition).

JONES MOTOCROSS PRODUCTS/250 HONDA

Of all engine builders around today, Don Jones of Jones Motocross Products seems to make twostrokes go as fast as anybody. In our opinion, his quickest and fastest engine modification (which you and I can buy) is the six-pedal reed-valve 250 Honda Elsinore. If you've got 200 big ones, you're just about guaranteed to be first into the first corner. The modification includes a very sophisticated Roto-Rooter job to your cylinder, including raising and lowering the intake ports, widening and re-angling the transfers and adding two booster ports above the intake. The package also includes a YZ six-pedal reed-valve, rubber carburetor mount and a finned magnesium intake manifold. The kit works best with a Keihin 37 mm carburetor (P/N 16100-133-014), which you get from your Honda dealer. You won’t beat this high-performance package anywhere.

YZC Hi-pipe comes with a special exhaust collar mounting flange and a rebuildable glass-pack silencer

RAINES ENGINEERING CLUTCH HUB

This racing clutch hub fits 1974-’75 Yamaha 125s, 175 MXes and 125 YZs. It will eliminate your “broken clutch blues” since it is guaranteed unbreakable and the factory one isn’t. This hub is completely hand-machined from a solid billet of T7075 aluminum and is then hard anodized. Price is $89.95 installed on your gear. Machine work is to aircraft standards. Truly a trick piece. Available from Raines Engineering.

FRAME AND BODY

DG YZ80 TRIPLE CLAMPS

Does your YZ80 go any direction it wants? Do you notice a lot of front-end flex? All of that is not necessary any more with DG’s aluminum triple clamp assembly for YZ80s. Super strong and light. Order yours for only $87.50 from DG Performance Specialties.

C&J FRAMES

C&J Precision Products is a fabricator and frame builder par excellence. Its latest trick is aircraft-quality 4130 chrome moly mono-shock frames for such engines as those of the Honda 250 Elsinore and Enduro, Suzuki 250 and 400, and Yamaha 250, 360 and 400. C&J will custom-build practically any frame for any application, including motocross, desert, enduro, flat track, short track, road racing, trials and even hill climbing. All frames come with footpegs, brake pedal, Timken head bearings and mounting hardware. You can even order an optional adjustable steering head on all models.

The monoshock frame is the current vogue and utilizes a Yamaha Monoshock unit and airbox. Price of the complete frame is $525 less shock and airbox.

HANNEMANN FIBERGLASS REPLICA TANKS

Hannemann Fiberglass makes hand-laid-glass works replica tanks for the TM 125, 250 and 400 Suzukis for only $49.95. Weight is only 3-1/4 lb., and your stock petcock fits right on. Available in yellow. Also featured is the Yamaha Monoshock 3-1/2-gal. desert tank for 1975 250 and 360 YZs and the 400 MX. Hannemann also has tanks for the ’73-’74 125 and 250 YZs in 3-gal. capacity. Price is $65 including cap.

The tank on the right is the famous Bultaco works replica tank of 1.8-gal. capacity. It really looks trick. Price is also $65, including cap.

MISCELLANEOUS

JONES MOTOCROSS PRODUCTS

Styrofoam fork protectors help absorb the shock of rocks and dirt. Available in black or red. The red ones are like those used by the Honda works “fire engine” team. Kit includes six nylon mounting straps. Available from Jones Motocross Products. Price is $3.45 a pair.

K&N ENGINEERING

An air filter is an item practically everybody has to buy, mainly because most OEM elements are of poor quality. K&N air filters use the principle of suspended oil. The oil acts like a magnet by attracting and catching minute dust and dirt particles. The corregated design allows for maximum surface area of incoming air. The list of available filters is almost endless. K&N aerosol filter oil works and makes oiling of filters much more convenient.

THINGS TO COME

JONES MOTOCROSS PRODUCTS/MAKING THE COOPER COMPETITIVE

Jones Motocross Products recently acquired the exclusive distribution rights to the Cooper motorcycle for the United States and Canada. It’s my own personal prediction that in no more than two years, the revised Cooper (or whatever its name may be then), will be one of the most competitive and durable machines available. Look for the progression to be in two phases. In the spring of 1976 will appear a basically revamped machine with good suspension and a very torquey, tractable engine. Chrome moly frame, still airbox, good tires and lots of clever small details will be present.

Phase two should be the 1977 version with the possibility of magnesium engine cases, Maico-type forks and triple clamps, but with the Betor name on them, a clutchtransmission assembly with 32 percent less weight and friction and gobs of strength. Included will be wide, lightweight wheels with straight spokes (for considerably greater strength) mounted to the sprocket on the rear wheel. There will probably be three bearings in the rear wheel, two in the hub and one in the sprocket. Fuel tank will be plastic and have a nice paint job. The main fuel tank will be about where the airbox is. You may also see a water-cooled engine for more constant cylinder temperature and increased horsepower. Would you believe a flexible cable drive instead of a chain. You might see it.

This cobby-looking prototype is one of the finest handling machines and best sliders around. Powerband seems slow because its smooth, but all the power gets to the road, so it sure scoots.

I was sworn to secrecy on all of the above, so don’t tell nobody nothin!

S&W 16 INCH SHOCKS/ THEY WORKED FOR CAN-AM, SOON THEY’LL WORK FOR YOU

These shocks are the closest thing on a motorcycle to the length of a pogo stick. This S&W prototype is an unbelievable 16 in. long, with about 6 in. of travel in the shock itself. Designing the shock with that much travel makes it possible to mount the bottom of the shock at the axle for good geometry. Swinging arms don’t need all the heavy gusseting, so they will be lighter and frames can be manufactured more easily too. Price of manufacturing is relatively inexpensive, resulting in a reasonable retail price. The word is that S&W has a winner that should be available soon. Webco is the distributor.