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#Post#: 5554--------------------------------------------------
BSA 3 wheeler.
By: Jimr1999 Date: February 18, 2022, 5:24 am
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Hello all,
It started getting a bit much for the technical section so, as I
now intend to build, I thought I would move things into the
right catagory.... So continuing on from my thread on "BSA 3
wheeler ideas for springs" on the technical forum, here we go.
My inspiration, without stealing a phot too blatently is here...
HTML https://www.prewarcar.com/288973-bsa-three-wheeler
So far I have managed to CAD up rough a working front end with
not too many obvious clashes of mechanics.
HTML https://www.tinkercad.com/things/4Y7iKZgHcGn-fantabulous-krunk/edit?sharecode=y2tkrSQap2IaMf3w5WkV0dbn53ZLZsqAQxLggF6SLcM
And have just layed out the full size chassis, without detail on
the rear end...
Next is to buy some bits. The painful part.
#Post#: 5613--------------------------------------------------
Re: BSA 3 wheeler.
By: Jimr1999 Date: February 22, 2022, 1:19 am
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Been playing around with the front uprights to connect to the
springs. I know there can be issues with rose joints, but the
design is fail safe as it is encapsulated and can be adapted to
top hats if failure is an issue. It would allow a few degrees of
KPI adjustment...
Work in progress, your thoughts please.
#Post#: 5614--------------------------------------------------
Re: BSA 3 wheeler.
By: RhysN Date: February 22, 2022, 1:57 am
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Very nice. The lawnmower racing guys use a very similar system
with no issues, and are much more rough and tumble than us.
#Post#: 5633--------------------------------------------------
Re: BSA 3 wheeler.
By: Jimr1999 Date: February 25, 2022, 2:52 am
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Been buying this week. Wheels on the way, spindles and steering
arms from Gemini, a few bits of ironmongry and a lead on an
engine. Still got to locate a TAV. It seems like I am making a
lot of it up on the hoof at the moment and I have been looking
at the spring loadings on the front end...
Loadings at zero, 25kg and 50kg max deflection about 27mm
#Post#: 5648--------------------------------------------------
Re: BSA 3 wheeler.
By: Jimr1999 Date: February 27, 2022, 3:40 am
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I got the spindles and steering arms from Gemini yesterday and
they look very sturdy. Impressive. I have been messing around
with a monocoque timber chassis utilising a smaller rear pit
bike wheel (14" with a wider tyre) as this will be near
impossible to see when it is bodied. This will give me a little
more engine room to play with - which is my next set of
experiments. It should have the added bonus of a stiffer rear
wheel that does not need such a large gear attached to it.
Wheels arrive Monday :)
Your comments welcome.
#Post#: 5743--------------------------------------------------
Re: BSA 3 wheeler.
By: Jimr1999 Date: March 4, 2022, 5:11 am
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Wheel day. I have all 3 now and after reading a few build
journals and articles here I bought a 60 tooth sprocket for the
rear. A total dinner plate of a thing and it has the correct PCD
to mount to the 14" rear. With the tyre, the gearing would be
equivalent to a 71/72 tooth sprocket on a 17" + 2 1/2" tyre
wheel as my rear single wheel tyre will be a little fatter and
wider than the fronts.
I hope this gives me a reasonable ratio and, as always I welcome
your comments/ experiences.
#Post#: 5768--------------------------------------------------
Re: BSA 3 wheeler.
By: Jimr1999 Date: March 5, 2022, 11:06 am
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What a beautiful day! I get to see you fellows on Zoom and five
hours grinding metal in the sun. All in all a good one.
#Post#: 5788--------------------------------------------------
Re: BSA 3 wheeler.
By: Jimr1999 Date: March 6, 2022, 9:41 am
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Well, the expensive bit might be on the wane now. Ordered a
clone Honda Gx200 and a clone TAV. These might not be the
highest quality items available "on't tinternet" but it is a
start, and until proven, the whole concept should not be too
powerful. More gloriously sunny grinding and fitting today.
Job one.
Finish the front upright body ready for welding and make a
foolproof jig for my friend the welder.
Job two.
Make a chuck out of scrap wood to mount the big rear cog on my
wood lathe to put a keyway in to match the key on the wheel face
- An epic battle of high speed steel vs high carbon steel and
willpower. all I can say is it worked. It might not have met
health and safety requirements of a workplace, but I am not at
work! (the alternative was to remove the key from the wheel with
a grinder)
Job three.
Emery a few thousandths off the spacers on the Gemini
hub/spindles to make a polished sliding fit into the 16mm rose
joints (see CAD image earlier in this thread)
Job four.
Set out centres on carriers for drilling to accept rose joints
set to a 6 degree caster.
Drink a beer in sunshine and draw spacers for turning.
Another good day.
#Post#: 5792--------------------------------------------------
Re: BSA 3 wheeler.
By: David F-R Date: March 6, 2022, 12:18 pm
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Looking very neat Jim, and great progress for the day.
Remind me please - will it be front or rear engine?
#Post#: 5794--------------------------------------------------
Re: BSA 3 wheeler.
By: Jimr1999 Date: March 6, 2022, 12:30 pm
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[quote author=David F-R link=topic=756.msg5792#msg5792
date=1646590734]
Looking very neat Jim, and great progress for the day.
Remind me please - will it be front or rear engine?
[/quote]
Rear, I think for a first shot at a cyclekart, the drive needs
to be as simple as possible. I suppose it is actually mid
engined as I am trying to squeeze it in between the seat and
the smaller rear wheel. The motor and TAV should be here mid.
March and until then I can't finalise the chassis. Plenty to do
until then. 😁
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