Perfect onboard MoBo Mini-bike: BSA Bantam 175cc 2str?

rustybarge

rustybarge

Well-Known Member
Joined
9 Aug 2012
Messages
3,665
Visit site
Hi all,
I've been looking for a super lightweight scooter/mini-motorbike to bring on a Motorboat. Must be able to cruise at 50-55mph to keep up with traffic.Has to be light enough to sling on board with a davit, or gangplank.('Passerelle' to all you yuppies.)

On a previous thread I looked at:
Gasgas 125cc trial bike: too expensive£3000, too slow 40-45mph. Weight 80kg
Honda 90 (110cc clone): too slow 40-45 max. Weight 80 kg

Came across the BSA Bantam 175cc 2str., 55-60mph cruise, 80mpg, 80kg........about £1k or less.(1966)

Is it any good, and does it actually start?

View attachment 32973View attachment 32974

Very early version:

View attachment 32975
 
Last edited:
doug748 said:
They put on a bit of weight over the years, expect nearer 100kg for a late one.

It will start and run, but short on street cred in Cannes.
Click to expand...

No problem: I'm a workboat, gangplank, ex-farmer type of person!

I've had problems starting old british bikes before, Matchless 250? I think, and a Triton featherbed with 350ta triumph engine, Permanently Parked on hill.....guess why? And those were 4 str. Bikes.

......the big question: Given the bad reputation of old English bikes, Do old British 2 str. Bikes from the 60's actually go?
 
Last edited:
Yes they go, went out of fashion when the Honda lightweights appeared, then also went the British Iron of all sizes not long after. Of course you have to "kick" them into life, but at least they can be fixed without the need of Masters in science or a boffin with a computer.
 
but at least they can be fixed without the need of Masters in science or a boffin with a computer.
Click to expand...

My son knows all about that, he's got a BMW 650gs single with electronic fuel injection and Cpu.........don't ask! :mad:
 
Last edited:
planteater said:
Blimey! That's a blast from the past. I fell off one those and broke my arm over 40 years ago!
Click to expand...

I think the GPO used them to deliver post......

View attachment 32978

It's a blast from the past for me as well, my late brother-in- law had an early 125cc version without the back springs. I can remember riding it in a field when I was a teenager.

Trials version:
View attachment 32979

Do you think the 175cc version would go well on B Roads?
 
Last edited:
Must admit I am a fan of old two strokes and own a 76. Suzuki gt750. 3 cylinder water cooled two stroke. But if I were you I would look for a Honda cg125. A little bit heavier but will always start you will be able to see at night and it will stop ang prob 70-80 mpg
 
itspaul said:
Must admit I am a fan of old two strokes and own a 76. Suzuki gt750. 3 cylinder water cooled two stroke. But if I were you I would look for a Honda cg125. A little bit heavier but will always start you will be able to see at night and it will stop ang prob 70-80 mpg
Click to expand...

Looks nice, and has a 65 mph max., but it weighs 115kg........that's 45kg more than the Bsa bantam.
View attachment 32982
 
The only Bantam that weighs in at 80kg is a D1(ish) machine. You might get 50 mph if you could fly a spinnaker in a stiff following breeze. Lacking rear suspension it would feel like 150. A more realistic cruising speed would be 40mph

A much better plan would be a Honda step thru. A C90 would meet all your requirements.

Ere you go, this sort of thing:

http://pembrokeshireclassics.com/sh...=1689&osCsid=20f9ff8d0af6f373c02efe1b50c3c785
 
Last edited:
There was an Australian guy called I think "Walsh" who used to get 105mph out of them. Thinking about old bikes a Le Velocette water cooled engine would make a fabulous generator engine.
 
itspaul said:
The earlier cg125 was a little lighter and the later bantam d14/4. The only one you could really call civilised lol is heavier. See here. http://bantam.150m.com/d14/gd/gd.pdf
Click to expand...


Found this quote re: the later models:

1968
BSA was far from finished with altering the Bantam, and introduced the D14 range. Production began late in 1967, and early engine prefixes were listed as D13, though this was never a model. BSA dropped the Silver leaving the other three models to attract the market. The Supreme was now also fitted with the 4-speed box, ending the Bantam's relationship with 3 speeds. The old exhaust pipe bore was found too restrictive for the new tune up, so a larger one was fitted. On the ever diminishing market for British motorcycles, BSA sought to make the Bantam yet more powerful. They increased the compression ratio to 10:1, resulting in a power increase to 13 h.p. The bike would now shift along at the best part of 70 m.p.h, the market had changed from wanting the fuel-efficient three speed D1, to the speedy D14/4. Asides from the diminished fuel efficiency, the high compression ratio made the bike notorious for difficult starting, as is normal with high performance engines. The Supreme and Sports models changed the style of air filter, but the Bushman kept the pretty D10 pancake type. The D14 was another one year only model, the D13 prefixed engines and frames are therefore probably rarer than the D5s.
Click to expand...
 
doug748 said:
The only Bantam that weighs in at 80kg is a D1(ish) machine. You might get 50 mph if you could fly a spinnaker in a stiff following breeze. Lacking rear suspension it would feel like 150. A more realistic cruising speed would be 40mph

A much better plan would be a Honda step thru. A C90 would meet all your requirements.

Ere you go, this sort of thing:

http://pembrokeshireclassics.com/sh...=1689&osCsid=20f9ff8d0af6f373c02efe1b50c3c785
Click to expand...

Problem with the Honda C70-90 and even the clone chinese Honda 110cc, is that the max speed is about 40-45mph......holds all the traffic up.
http://www.supermotorcompany.com/?nav=49
Click to expand...

The 1966 model D10 seems to be the best model, slightly up-rated engine, and 4 speed gearbox:

1966
Then came the second re-think, the D10
The capacity of the engine had got as big as it would go, so the only way to increase power was to increase the compression ratio. It was increased from 7.4 to 8.65, and the addition of a larger concentric carburetter increased power to 10 h.p. A new Wico-Pacy alternator, the 1G.1768, replaced the old series 55, after 16 years of service. This change of generator caused the points to be evicted to the other side of the engine. The 3 speed Supreme (De Luxe) and Silver models remained, but were complemented by two further models, the 4-Speed Bushman and Sports models. Apart from the obvious internal changes to the crankcase to accomodate the new gearbox assembly, it is almost impossible to tell a 4-speed engine without looking at the engine number. Both the latter models had high-level exhaust pipes, and other quite major changes to the cycle parts. Only the Bushman retained the direct lighting, with all other models utilising a coil driven battery lighting system.
Click to expand...


There was an Australian guy called I think "Walsh" who used to get 105mph out of them. Thinking about old bikes a Le Velocette water cooled engine would make a fabulous generator engine.
Click to expand...

Is it a diesel?:p
 
Last edited:
itspaul said:
Must admit I am a fan of old two strokes and own a 76. Suzuki gt750. 3 cylinder water cooled two stroke........
Click to expand...

Ah! The old 'water-bottle'. A couple of my mates (one has two of them) own and ride these bikes regularly. We do try to keep in front of them though because of the oily smoke ;) which is not that easy, they still move well!
 
You must log in or register to reply here.

Share this page

Top