Bates Classic Chopper Springer Forks
- Springer fork »Classic Chopper« by Bates
- fits 4-speed Big Twins 1937-1986
- internal thread neck post: 3/4”-14 UNS, external thread neck post: 1”-24 UNS
- steel, chrome-plated, chromed springs
- length over/under stock: +12"
Distinctive look of the classic Springer fork for custom projects with a choice of standard length to radical Swedish style. With forged stanchions and connecting pieces.
Length is measured from axle center line to seat of lower steering head bearing.
- Unlike the original replacement versions, there is no mudguard mount on the lower bridge.
- Due to the trail geometry, versions with an extra length of 8 inches or more have an adjusted positive rake offset of +3°.
- To ensure that the 16“ and 20” forks retain their spring action, they are supplied with special, slightly extended rockers. These are also drilled for 19 mm axles for use with custom wheels and brakes.
- Fork stem with two Ø1” bearing seats for the use of 1949-up tapered roller bearings without any modifications
Although these Custom forks are intended for 1936-1957 rigid frame Big Twins they can be mounted with later frames, too, provided you have/install matching frame head beariings. The builder has to consider rake, trail, overall chassis geometry, brake function, etc.
Internal Threads on the Upper End of the Legs
For custom riser installation the fork legs have M20x1.5 internal threads at the upper end and accept riser adapter studs or plugs which are available separately; an extra added by the manufacturer which saves you a lot of work and axle grease.
Inline vs. Offset
Classic Springer Forks are produced for different frame rakes.
- In the beginning, both the main tubes and the steering stem were in the same plane. This is called "inline". The rake is 0°. Of this type were all 45” Springer forks 1936-1957 and all Big Twin forks 1936-1945.
- From 1946 onwards the Big Twins had the neck angle increased to 30°. To maintain fork inclination and ground clearance, the steering stem was tilted to the rear by 3°. We call these forks Offset -3°, they were stock on 1946-1948 Big Twins.
- When building a bike with ≥+8” extra long forks you don’t want the steering neck so high and inclined that the bike is difficult to steer. Therefore such forks are manufactured with a positive rake, i.e. the steering stem is inclined to the front by 3°. We call these forks Offset +3°.
The sketch shows the placement of the lateral tubes and steering stem seen from the drivers place. Now it is clear, too, why there have to be three different types of top trees or handlebars for Classich Springer forks.
1.) The pivot point of the brake shackle on the backing plate or caliper bracket must not be positioned vertically above or in front of the wheel axle (driving direction). In this case the moving forces in your fork parallelogram will be reversed and the fork will rebound instead of being compressed when you apply the brake. This will generate very high forces to impact on your rigid fork leg with possible damage.
2.) Caliper bracket or drum brake backing plate must float on the wheel axle. If not, the fork will rebound as well when applying the brake. Result: see above.
Have any questions?
Our service team will be glad to help out: Mondays - Thursdays 08:00-17:00 CET, Fridays 08:00-16:00 CET, Phone: +49 / 931 250 61 16, eMail: service@wwag.com