Project "Go-Slow" BSA Bantam honda powered!

whippet

New Member
I have recently found and joined this forum, i would like to share my project a 1950? Bsa Bantam bobber
The project started with a pile of bits left over from a mates resto consisting of 2 frames one cut off and missing the head stem, 1 x fuel tank in bad shape but rust free, 1 x rear guard missing the last 4- 6" at the back, bars, a set of rear plungers, seat frame, exhaust inc fishtail muffler and a few brake and engine bits which i gave to my brother for his bantam resto project,
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fuel tank had been smashed pretty well!

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rear guard pre bobbed!
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i was going to drop in 1984 Honda Xr 250 motor that my brother had in his shed, and started repairing the cracked head, a another work mate seen what i was doing and offered me a "old bike" the farmer had left in his shed when he had bought his farm 12 years ago!
turns out it was this little gem
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with some fresh fuel in the tank she fired up second kick!, we rode it our around our paddock for a while my 3 year ld daughter loves it and would not let me go a single day without taking her for a few laps!, and was horrifed that dad wanted to pull it apart!, luck has it a flat rear tyre was enough to convince her it was broken!
 
i firstly attacked the tank the damage was so bad i decided to split it open to repair it
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i decide the bottom area was to rooted and cut it out and made a new replacement section
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i then tacked it together after beating the rest of the dings out
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i didn't weld the tank back together at this stage as i had suspected it may need modifing to fit the motor in.
i also streched the rear of the frame outwards to be able to fit the hondas 18" rear wheel making sure to keep the sprocket alignment to suit where the motor would mount,
40 minutes had the 1978 honda xl 125 releived of it important donor bits, using the honda front engine mount the motor was fixed into the frame.
Bendigo swapmeet i came across a set of front forks that looked like the would do the job, 1969-71 cb350 forks with external springs with the triple clamps for $40 so i purchused these and will utilise them, as it turns out the larger offset on the clamps works well and i don't need to move the fuetank back to clear the steering gear! i purchused a set of tapered roller bearing for the head stem and have machine new bearing bosses which will be welded to the bantam head stem, this makes up the the longer cb head stem length!
spent an arvo working on it needing to recess the bottom of the fuel tank to clear the head, pretty happy with the concept so far!
so i mocked it up and this is what it looks like ( sorry about the crappy phone pics )
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Love it!

The Bantam will never have gone so fast. Novel intake manifold - not easy to fit a carby otherwise.

Crazy
 
Bloody brilliant. Bantam frames are the dogs bollocks for cryogenically cool hybrids.
I'm holding out for a hard tail one. Twin shock ones can be had for peanuts here in the uk.
 
the honda rear wheel fitment required stretching the rear frame out about 70mm, because the plungers shafts are round the plungers self align with the rear axle!
i origanally stretched it 90mm but found i didn't need that much ,70mm allows the std honda axle bolt to be used!
The std bantam had the rear wheel offset to the centre of the frame to align the sprockets, i bolted the motor central in the frame and worked out how much each way needed bending , (more to the left frame) to get the rear sprocket to line up, them gently heated with the oxy and bent it out near the frame to suit.
 
Thanks for that, yep was wondering about the asymetrical bantam rear end.
I've thought about hard tailing a plunger frame but the rear forks would have to be quite long to get a decent wheel base.
 
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