The name Colin Seeley is known and respected by everyone in motorcycle circles. He's been involved with every branch of the business, from racing to retail. In the Sixties, he won the British Championship and six Isle of Man TT silver replicas.
Starting with the legendary Seeley Mk I and Mk II chassis for now classic British single racers like Norton, Velocette or Matchless, he developed and built frames for the works teams of Ducati, Husquavarna, Barry Sheene's 1973 Suzuki and the famous Yamsel, Seeley's chassis for Yamaha's TZ 250 / 350 racer.
Before "retiring" into vintage racing, Colin Seeley made a series of frames for the Honda CB 750 SOHC/4. Unlike his UK competitors (Dresda, Spondon, Rickman and Harris), the Seeley Honda frame was designed to fit not only the Honda 750 engine, but also most of the components to facilitate conversion as much as possible. Unless the owner had special orders (and most had), the stock Honda CB 750 would donate engine, carbs, air box, front fork, wheels, brakes, oil tank, battery box, fenders, head/taillight, turn signals, brake pedal, footpegs, side covers. Three (actually four) different versions of frames were available, to accommodate K and later F models. There were two different models of F frames for the earlier F1 and the later F2/F3 models. And Colid made a few chassis especially for racing, with custom oil tanks and some other weight saving modifications. During the period from May to September 1975, six prototypes were built. The later fabrication by Arch Motor consisted of 302 Seeley Hondas in total, from frame No. 501 in October 1975 to 803 in late 1978.
Frame design is duplex cradle made from Reynolds 531 Chrome Molybdenum tubes, bronze welded. Finish is usually polished and nickel plated (some frames were just painted). Caster angle is 62 deg (stock K model 63), static wheelbase is 56.5" (stock K model 57.3"). Steering head has tapered roller bearings.
Chassis for the German market had some modifications because of German regulations. They also have a GER in the frame number.
Due to weight savings - the Seeley frame, complete with rear swingarm only weighs 26.45 lb (12 kg), softer fork springs were recommended. (My own Seeley, as in the first two pictures, weighs 474 lb / 215 kg road ready) Swingarm has Seeley's racing chain adjustment which was also adopted by Ducati. Swingarm has bronze bearings. Shocks were usually Girlings or Konis. The frame came with with either a 4.5 gal aluminum tank and a dual seat or a 5.5 gal tank and a single seat.
Upon request, Seeley also offered several options, like a 38mm Marzocchi front fork that fitted stock Honda dual disk brakes, Seeley's own fork, Magwheels, rearset footpegs, 4-1 exhausts, the works. (My bike bike pictured above has a Honda K2 fork with a custom damping system, softer springs and a fork stabilizer, rearsets, Tommaselli clip-ons, K2 engine with 915cc Wiseco kit, K7 head, Megacycle 125-25 cam, custom 4-1, pointless Kroeber ignition, Kroeber tach, Ronal Magwheels 1.85x19 / 2.15/18, dual disk Honda brakes front, Grimeca disk brake in the rear)
Besides better stability and easier cornering, there is one more advantage of the Seeley frame to to stock chassis: You can take off the cylinder head and block without removing the engine.
Wheelbase: 56.5" / 1435mm
Trail: 3.7" / 95mm
Chain length (530): 98 links
Roger Titchmarsh is manufacturing Seeley replica chassis with the approval of Colin Seeley himself:
Roger Titchmarsh Racing
PO Box 8
Harrogate HG3 4XQ
Tel./Fax +44 (1423) 781772
Own a Seeley Honda?
I also run the Seeley Honda Register. If you own a Seeley Honda which isn't listed yet, please don't hesitate to register.