Suzuki Snapshots

Peter Jones - Part 2

A100

 I believe I only raced an A100 once and that was at a club meeting at Winton where the photo was taken. I exchanged bikes with Graeme Laing on the day, Graeme rode the TR250 and I rode the A100. This A100 started off life as a standard A100-2, a 4 speed, 50mm X 50mm aircooled single cylinder road bike with a rotary valve, but fitted with a Suzuki race kit.

Exactly in which year the photo was taken I am not sure, it seems from the correspondence I have that it would have to have been late 1968, or early 1969.

From Graeme’s memory the A100 race kit consisted of a cylinder, cylinder head, carburettor, piston, internal rotor ignition, gearbox drive shaft to achieve a close ratio gearbox, expansion chamber and a small oil tank and I presume also a new rotary valve. According to the US Suzuki Bulletin No2, dated August 1st 1969, fitting of the kit resulted in17hp, up from the 9.5 of the standard A100. Late in 1967 Graeme asked Suzuki if it was possible to increase the capacity of the A100 to 125cc, to which they replied; ”it is not designed for conversion to 125cc racer from the beginning”.

Early in 1969 Graeme asked Suzuki their thoughts of over boring the A100 to 54mm (to fit a T20 Wiseco piston) and so achieve 114cc and also if they had any advice regarding any improvements that could be made to the A100 to improve handling. Their reply regarding the increase in capacity was; “ we have already tested several times. However, decrease of the thickness of the cylinder sleeve from 4mm to 2mm caused the thermal deformation on the cylinder sleeve, resulting in serious piston seizure trouble”. However they added; ”To overcome this problem we have made the special cylinder the sleeve of which is 3mm in thickness. We can supply you two sets of these if you want.

But, Wiseco piston and rings cannot be fitted on the above mentioned cylinder because of unsuitable position of the knock pins for the piston ring.  It seems to be difficult to alter the position of the knock pins of Wiseco piston, so we would suggest you to employ the standard piston for T20 and change the position of the knock pins as illustrated below to prevent the piston rings from being damaged on the transfer and third transfer ports. In this case, of course, you have to use the piston rings and piston pin for T20. And it is also necessary to cut the skirt of the piston by 4mm to prevent the piston from touching the crankshaft”

Suzuki also had some suggestions regarding improvements to the handling which was to replace the standard rubber bushes in the rear swinging arm with metal bushings and to that effect they supplied part numbers for the required parts. In addition they supplied diagrams suggesting the location of gussets on the frame and the rear swinging arm to increase rigidity and they also added: “ Our sole distributor in Venezuela have succeeded in improving handling and stability with the employment of Ceriani front forks and Girling rear shocks.”

Graeme immediately ordered the cylinders and asked for information regarding what cylinder head modifications were necessary due to the increase in capacity. The cylinders were supplied, as was an explanation as to the required cylinder head modifications. Graeme did in fact change the location of the ring pegs in a Wiseco piston and the 114cc A100-2 was a very successful 125cc class racer. The engine was finally transplanted into an F50 scooter and became the “Superscooter” which continued racing in the 125cc class successfully for some time. I think it is still around somewhere.

 

The photo shows a few items which maybe of interest.

Firstly the helmet is a Cromwell “Jet” and I am wearing the very fashionable white handkerchief across my mouth.

Although the goggles cannot be clearly seen they were of Italian manufacture, very popular in Europe at the time and bought back by a friend of mine, Malcolm Stanton, who raced in the Isle of Man and on the continent for a few seasons in the mid 60’s. They had a number of features that made them superior to the usual goggles, such as laminated glass lenses, a form of “breather” which reduced the chance of “fogging” inside the lenses and the band had 3 long springs covered in nylon which kept its tension when wet. This certainly was not the case with the majority of goggle bands at the time.

The jumper I am wearing over my leathers was a reasonably tight fitting jumper that I used when it was cold. The boots were made to measure by “Medal Shoes” in Fitzroy (who are still in the phone book) and were one of the very first pairs of made to measure racing boots that they made. Do not look too closely; they appear to have pointed toes!  Black leathers, but I cannot remember the manufacturer, certainly made to measure locally.

Gloves?

The running gear on the bike is I think standard A100-2, but I am not sure, certainly the fuel tank is not the alloy one that was made by Graeme and fitted subsequently. The seat is certainly non-standard! I seem to remember that Graeme moulded it himself! The only other thing of interest is the tacho drive visible on the LH crankcase cover. This was also certainly made up by Graeme, as one was not supplied in the kit.

 

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