1971 Suzuki A100 from United Kingdom


At 40k miles, I treated the bike to a full restoration, including new paint and full overhaul. Only one break down owing to a broken contact breaker point fibre heel.

General Comments:

The Suzuki A100 is a great bike. As I only weigh 78kg, the bike does a genuine 70mph. Handling is very stable and the drum brakes are safe and quite good for the ancient technology.

As commented in the other review, it's a far better bike than the 50cc sports mopeds. Performance is good enough for modern traffic and will even cope with the occasional motorway journey. The furthest I've travelled in one day is 300 miles. This took seven hours with three fuel stops.

An easy machine to work on, with good quality materials, it will do 20,000 miles on a set of piston rings, with the made in Japan piston being replaced at 43,000 along with its first cylinder rebore, costing less than £40 all in as I have access to engineering machinery in the form of a centre lathe and milling machine. The crankshaft is still the original part with the main bearing showing zero wear. I will probably fit a new rod set at around 80k miles.

In summary one of the best small bikes ever made, which will outlast myself and are now fetching silly prices on eBay. Buy one whilst you still can!

Would you buy another motorcycle from this manufacturer? Yes

Review Date: 13th June, 2023

1969 Suzuki A100 from United Kingdom


The most fun you can get from 100cc!


Only items expected with a 54 year old Japanese economy bike.

General Comments:

The Suzuki A100 is very similar to the Yamaha 100cc two-stroke disc valve singles from the era. It has an alloy cylinder with two transfer ports and twin boost ports to the rear of the cylinder. It is in a quite high state of tune for the era with similar performance to the 175cc BSA Bantam & 200cc Triumph Tiger Cub from the robust 9.5bhp motor.

Fuel economy is around 100mpg and the 4-speed gearbox is precise. The engine is very well engineered and will last forever, having large bearings and decent metallurgy. Parts are plentiful owing to the A100's immense popularity in Indonesia.

The last year of the chrome tank, it has great classic Japanese bike looks.

Although the later models look very different, the basic bike is identical from 1966 until the early eighties when sadly discontinued in the UK. The GP100/125 being the replacement, also a great, very tunable bike with one Indonesian racing bike being developed to make a genuine 30bhp.

With large amounts of money spent on betting on 125cc drag racing, in this country, some racers actually import their own 2-stroke engine experts from Europe!

Brakes are superb for the era and handling okay with modern tyres and new suspension.

The Suzuki A100 is very similar to the AP50 & A50 and modern owners will be far happier with the 100cc version which will touch 70mph, whereas the 50cc will struggle to do 50mph. The 50cc bikes go for twice the price of an A100, which is daft as they are basically the same bike...

In the sixties, Suzuki were 50cc world champions and even built a liquid-cooled GP racer with three cylinders and as many as eighteen gears making 13bhp @17,000 rpm. Honda made an 8-valve 4-troke twin revving to close to 20,000 rpm. Incredible times.

The disc-valve technology allows close to 200bhp/litre from what is basically a commuter bike. Compared to the 7bhp 150 Bantams the A100 must have been a revelation to bikers trying one out. Suzuki also made a 15bhp 125cc twin capable of close to 80mph, which was also a reliable bike capable of doing the ride to work, but will see off many 250cc British bikes like BSAs C15 four-stroke.

Honda's similar looking 90cc four-stroke singles, which capable of close to 210mpg when ridden around 30mph, it is difficult to favour one over the other. The Honda will also last forever when cared for and has a very over-engineered OHV or OHC engines. Performance is about 90% of the Suzuki, which is incredible considering rival 4-strokes from the sixties would be around 4bhp but Honda manages an unburstable 8.5bhp.

My A100 is close to as new condition and close to 100% original. Suzuki published details on how to convert the A100 into a motocross competition bike and sold a race kit. The head, cylinder, new rotary valve, special piston & rings and and a high-level expansion chamber exhaust raised power to a claimed 17bhp @10,200 rpm. Suzuki's impressive CCI Autolube was retained, supplemented with a 20:1 premix as the crankshaft bearing on one side needed this to be kept. A tiny oil tank replaced the large standard one and the bike won races in Japan and Australia.

All in all a great classic bike from Japan, but with prices now going up, with a really mint sixties example fetching £5,000 on eBay, buy one while you can. You will love it, make money if you buy well, and the performance will surprise you.

I have already made a kit of parts to convert mine to motocross spec and as I only weigh 75kg, it does a GPS tested 78mph on the flat with octane booster so I can run a more advanced ignition timing. I am currently machining a Rotax 125cc water-cooled kart cylinder & head to fit. It should - in my dreams - give a genuine 25bhp as the kart engines are making over 30bhp :-)

I am aiming for 85-90mph and hope the bottom end will hold. It will...

Would you buy another motorcycle from this manufacturer? Don't Know

Review Date: 18th May, 2023

11th Jan 2024, 23:35

Great write-up; looking forward to hear about your motocross-spec engine mods.