by Graham Weeks

Skyway Frame Serial Numbers Identification
Skyway Frame Serial Numbers Lookup
Skyway Serial Numbers
Skyway Frame For Sale

Originally appeared in the UK Vintage Japanese Motorcycle Club Newslettervol. 19, no. 4 (Aug 1996).

Skyway Frame Serial Numbers Identification

There are three different identifaction marks on all Bridgestonemotorcycles. There are the usual engine and frame numbers, with anadditional Vehicle Serial Number on a separate plate riveted to the frame.

The Vehicle Serial Number follows the same format for all models,and uniquely identifies an individual machine as it leaves the factory. Atypical serial number (actually from my own 350 GTR) is shown below:

21 D 05121

The Model Code (first two digits) identifies the basic modelfrom which the machine is derived, and the code numbers used were asfollows:

12 ... BS 90 DeLuxe, Trail and Mountaineer
13 ... BS 50 Sport
14 ... BS 90 Sport
15 ... BS 60 Sport
16 ... BS 175 Dual Twin and Hurricane
17 ... BS 90 DeLuxe, Trail and Mountaineer (Oil Injection versions)
18 ... BS 90 Sport (Oil Injection)
19 ... unknown
20 ... BS 100 Sport
21 ... BS 350 GTR and GTO
22 ... BS 100 GP and TMX
23 ... BS 200 Mach 2 'RS' and 'SS'

The Month Code (third alpha character) identifies the monthof manufacture and repeats in a 2-year cycle, starting on an even year(1964, 1966, 1968, etc.). Thus, the codes refer to the months inthe table below:

Month	Even Years	Odd Years
`Jan`	`A`	`M`
`Feb`	`B`	`N`
`Mar`	`C`	`O`
`Apr`	`D`	`P`
`May`	`E`	`Q`
`Jun`	`F`	`R`
`Jul`	`G`	`S`
`Aug`	`H`	`T`
`Sep`	`I`	`U`
`Oct`	`J`	`V`
`Nov`	`K`	`W`
`Dec`	`L`	`Z`

The factory manufactured frames in 'runs'. 100 or 1,000 or even perhaps 5,000. As these runs were done, the frames were each given a serial number. The parts were also given an assembly number to keep all of the matching and hand fitted parts together during the assembly process. Even stocks that were fitted to the frame received a serial number. Skyway 26' T/A complete bike kits are now available at PlanetBMX! $799 for what you see here! And THAT'S A LOT OF BIKE! Features Skyway 26' T/A frame and fork with Skyway cruiser bars. Redline Flight cranks, Flight gear, and Flight seatpost clamp. Sealed bearing wheels with double-wall rims. The serial number on a Schwinn frame will tell you the date that frame was manufactured. It will not identify the model of the bike, only the year the frame itself was manufactured. Schwinn Bikes Serial Numbers. This site provides historical information about vintage Schwinn bicycles.

The Identification Number (last five digits) identifies the individualmotorcycle and simply increments for each successive machine built, startingfrom 00001.

The precise month of manufacture is obtained by combining the month code andthe Identification number. No official information is available on productionrecords for each model, but the factory Parts Lists do give specific dates andserial numbers when modifications were introduced on the production line. Itis quite easy to work back from these 'milestone' dates to date any individualmachine reasonably accurately. Relevant 'milestone' dates and serial numbersavailable for the models sold in the U.K. are as follows:

BS90 DeLuxe	12 N 036928	Feb 1965
	12 B 057034	Feb 1966
	12 R 065628	Jun 1967
BS90 Sport	14 S 002364	Jul 1965
	14 C 007418	Mar 1966
	14 G 011238	Jul 1966
BS90 DeLuxe (Jet-Lube)	17 F 009030	Jun 1966
BS90 DeLuxe (Jet-Lube)	17 B 021551	Feb 1968
BS175	16 A 03736	Jan 1966
	16 M 22448	Jan 1967
	16 O 27401	Mar 1967
	16 R 31816	Jun 1967
BS350	21 S 01022	Jul 1967
	21 E 05455	May 1968
	21 W 07415	Nov 1969

Frame and Engine Numbers

The frame and engine numbers follow different systems for each Bridgestone model.

Skyway Frame Serial Numbers Lookup

For the single cylinder models, the enigne number is stamped on the transmission case, and is of the same format as the Vehicle Serial Number previously described. The frame number is stamped either on the headstock (50cc and 60cc models) or on the right hand side of the frame behind the swinging arm pivot (90cc and 100cc models). This number is of the form 'KE 064287'. The prefix letters seem to refer to the Basic Model for which the frame was built, but I have insufficient information to confirm this. The final 6 digits of the frame number form an individual frame Identification Number, again simply incremented for each frame produced.

For the 175/200cc models, the frame number is stamped on the side of the headstock, and the engine number on the transmission case. Both of them are of the form 'TA1-30991'. Here, the last five numbers form the incremental identification number, and the prefix is the factory production code. The 'TA1' prefix was used for 175cc machines, and 'TA2' was uded for 200cc machines. Note, however, that the very early BS200's were built using up the last of the stock of 175cc frames (175 and 200 frames are identical), and these therefore would have had frame number prefixes of 'TA1'.

For the 350cc models, the frame number is once again stamped on the side of the headstock, but the engine number this time is on the upper crankcase, just forward of the rear engine mounting lug. This number is usually stamped quite lightly, and can be difficult to see under the usual layer of oil and road dirt. The format is similar to the 175/200cc but using the 350's own prefix code of 'NA-1'.

It may be of interest to note that the factory production codes can be cast into many components, from speedo drive gears to engine casings. 'NA1' will indicate a 350 part, 'TA1' as 175 part, 'EA1' or 'EA3' a 90 part, 'GB1' a 50 Sport part, and so on.

A final note: As the machines left the factory, the Identification Numbers with the Vehicle Serial, Frame and Engine numbers were unlikely to be the same on an indivudal bike, but were always within 200 or 300 of each other. Any machine with numbers further apart than this has probably had an engine or frame change during its lifetime (apart from the early 200cc machines mentioned previously built with the late 175 frame numbers).