FOX Mini Bike Information and Chronological Guide.
I buy and collect Fox minibikes. 9/1/18. Email: cfh@provide.net

Overall Fox History and Info.

    There isn't much history on the Fox Corporation (Janesville WI), so details are a bit thin. But I'll try and fill in what I know, and hopefully add more info to this page in the future.

    Fox Corporation started just after WWII in 1946, selling motorized vehicles. Mostly stuff like farm carts and golf carts and later snowmobiles. But in 1958 Fox got into the go-kart market selling their "Go Kart" brand of fun carts. This fad seemed to fade a bit and by 1965 Fox was making minibikes too. Their first bike seemed to be the 1965 Fox Little Gen and it's 2.5 or 3hp motor (probably Lauson.)

    In 1966 Fox started to get more serious about minibikes and introduced their "Sport Bike" (2.5hp Lauson) and "300" models (3 or 4hp Briggs) mini bikes. The 300 model had 6v lights, full suspension, jackshaft, fancy fenders and gas tank covers, centrifugal clutch. This can be seen in their Fox minibike catalog #6, along with their go karts.

1967 Fox Campus Mini Bike from catalog #7.

    By 1967 Fox really got serious about mini bikes. Their Fox mini bike catalog #7 showed their "Campus Bike", which was basically an upgraded model 300 from the prior year. It was available in a variety of formats from a no motor version, to a 5hp Briggs model with lights. The Campus mini bike had 6" solid wheels and full suspension (front and rear), and the top model had a funky gas tank plastic cover, giving it a sleeky 1960s look. Fox also sold lower minibike models like the Sprite, the Trail Bug, and the Doodle Bug (no relation to the China-made Doodle Bug DB30 of the 2000s). The Sprite had 4" wheels, and the Doodle Bug used 6" wheels. Most mini bike models used a jackshaft. Note that in 1968 and 1969, as seen in the Fox minibike catalog #8 and Fox minibike catalog#9 (looking for a full Fox catalog 1969, or a good scan of it), the models didn't change.

1970 Fox Street Scamp mini bikes from catalog #10.

    With 1970 Fox completely changed their mini bike models, as seen in their Fox minibike catalog #10. This probably came about because Rupp changed their models significantly, and Fox wanted to compete. The big change was spoked 10" wheels on all models (except for the Doodle Bug, which still used 6" solid wheels.) These 10" spoked wheels were not available from any U.S. manufacturer, so they were imported from Italy (originally used for Italian scooters), which was what Rupp was doing too. Also all minibike models had chrome gas tanks and fancy exhausts (except the Doodle bug's was painted, but it used the new gas tank design too). Also new to Fox was Kelsey-Hayes rear disc brake used on the rear sprocket for all mini bike models (even the Doodle bug minibike). Some Fox mini bikes had disc front brakes too.

    A first for Fox (and something many others followed) was the 20 degree slant motor mounts and a jackshaft (but no jackshaft on the Doodle bug, but it too had the slant motor mount). This 20 degree motor mount was known as the "tilt power plant" and was a first on the Foxs' in late 1969. Tecumseh was the motor of choice too, as Briggs was trying to get away from mini bikes. To get around the float bowl issue on the carb/slant motor issue, they used a diaphram carb. Single speed bikes used centrifugal clutches and dual speed minibikes used a 2-speed automatic clutch system, which utilized two centrifugal clutches (one on the motor and the other on the jackshaft.) This set up used a centrifugal clutch with two chains going to the jackshaft.

    In 1971 Fox again changed their mini bike models, probably again to follow Rupp's changes. A Fairbank Morse torque converter was the norm for most models (the 2-speed automatic centrifugal clutch set ups were gone). This dramatically increased the power of the bikes, as the Fairbank Morse converters were a very good design. Suspensions were bulked up too, again probably to compete more with Rupp. The Tecumseh diaphram carb was no longer used (a change Rupp made too). Instead a slant intake manifold was utilized to keep the float bowl carb level (because the 20 degree motor mount.)

    The 1971-1975 Fox mini bike catalog(s) have escaped me (does anyone have a copy they call sell me or at least scan???), so the 1971 to 1975 Fox models are a bit of a mystery to me. But below are some pictures of these bikes I personally own, restored, or have seen. Fox was definitely moving to more mini-cycles than mini-bikes with many of their models, increasing the wheel size to as large as 14" diameter. Again this followed what Rupp and Speedway were doing at the time. Their Thunderbolt and Desert minibike/minicycle models were the new flagships of the mini bike model lines. Note most models had "TC" and "4HP" round stickers on the original torque converter covers, signifying their proudness for the 4hp Tecumseh motors and Fairbank Morse torque converter. But by 1975 Fox had moved to Comet brand torque converts (probably price dictated that move.)


The 1971 Fox AM Scrambler mini bike model. This is a great minibike with 10" wheels,
rear disc brake, Fairbank Morse torque converter, 4hp HS40 Tecumseh motor
(non-original carb). Note the torque converter cover is not original on this bike
(a commonly damaged part.)


The 1973 Fox Thunderbolt 170 mini bike model. Awesome minibike with 12" rear wheel,
14" front wheel, drum brakes, Fairbank Morse torque converter, 5hp HS50 Tecumseh
motor (non-original carb). Note the torque converter cover is not original on this
bike (a commonly damaged part.)


The 1974 Fox Thunderbolt mini bike model. This is really more of a mini cycle with
front "earls" leading link suspension, 14" wheels, drum brakes, Comet torque converter.
The original motor should be a 5hp HS50 Tecumseh, but this model has been changed to a
more modern OHV honda style engine. Note the torque converter cover is not original
on this bike (a commonly damaged part.)


The 1975 Desert Fox mini bike model. Another minicycle more than a minibike.
Again front "earls" leading link suspension, 14" wheel rear wheel, 16" front wheel,
drum brakes, Comet (or Fairbank Morse?) torque converter, and a two-stroke AH817MB
80cc Tecumseh motor and diaphram carb. Preston Petty Products "mini mudder" front
and rear plastic fenders.