29 replies to this topic

[Monty_Jon]

Very Nice

[Old trials fanatic]

Monty_Jon, on 19 November 2011 - 10:56 PM, said:

Very Nice

well done

[Andy M]

Old trials fanatic, on 19 November 2011 - 11:12 PM, said:

well done

Forgot to say, it's not my workmanship, had it done.....

[Monty_Jon]

Has the head stock angle been altered or is it standard bantam?

[Andy M]

Monty_Jon, on 20 November 2011 - 10:30 PM, said:

Has the head stock angle been altered or is it standard bantam?

The re positioning of the rear s/frame mount turns the cradle forward which slightly steepens the angle, apparently a lot of Bantams end up too short if done wrong. I am going to use leading axle forks which helps also.

[charlie prescott]

Hi Guy's.
Hi Bo.
What forks ? Bultaco perhaps?

Regards Charlie.

[Old trials fanatic]

charlie prescott, on 21 November 2011 - 11:18 PM, said:

Hi Guy's.
Hi Bo.
What forks ? Bultaco perhaps?

Regards Charlie.

here we go ??

[sensi]

When Considering Engine mods you might consider looking at RCR Villers on the net. I have used electronic ignitions,185cc conversions & clutch lightening items to very good effect on a D14B Bantam. Where did you get the swingarm & rearloop subframe very nice.

[Andy M]

sensi, on 22 November 2011 - 02:00 PM, said:

Where did you get the swingarm & rearloop subframe very nice.

Had it made by a frame builder who makes new frames, but I had my main frame loop modified as well.

Charlie and OTF Re forks..... Don't ask...

[1bantamcloser2divorce]

broony, on 19 December 2010 - 07:55 AM, said:

Been doing a wee bit work on the Bantam and found out the following.Some of it is old information but it might help-starting with the frame:-the top tube can be lowered and the subframe mounting repositioned and the subframe narrowed/shortened.the swing arm can be extended by 1 inch(2 ways to do that extend at the slotted end(put in a fillet) or extend the tubes,if using an early (narrow) swingarm the right hand tube needs to be reshaped where the tyre/wheel runs for clearance.Front forks either standard heavyweight or fiddler type,rear shocks about 13" what you can afford(using road ones at the moment but even on there softest setting are a bit hard),Rims-front 21"xWM1 and rear 18"xWM2.Engine:- plenty can be done but its all down to the coin,with any two stroke a crank rebuid,big bore"don't laugh" the most common way to go is a Suzuki TS185 piston(standard =187cc,+2mm=198cc),the only prob is the small end is a different size(needs a bit of work),noticed that Rex Caunt does oversize pistons(big Bore).Todd head or later center plug head.Gearbox:- swapping second and third gears around makes the box close ratio,fitting a 12 tooth primary crank sprocket.Gearing 13 tooth front and 68 rear.Amal concentric with carb spacer/manifold and K and N style filter.Exhaust ,its recommended that the silencer has a volume of about 2litres and that it is close to the engine also that the exit is half the area off the inlet.Then you have various ignitions to choose from.Hope this is a help to fellow Bantam owners.
cheers the noo Brian

Brian,

Do you, or enyone else reading, have any info on making the Bantam small end work with the Suuki piston. I am about to face that problem and I see the gudgeon pins are quite different in size. I am thinking along the lines of having the Suzuki pin cut down into two short pieces that would fit over the Bantam pin, and butt up to either side of the con rod. These would be held in place on the outside with the Suzuki circlips and attached to the Bantam pin with loctite to prevent the Bantam pin from wandering into the bore.

Any advice appreciated!

Thanks,

Andy

[broony]

Andy if you go on the Bantam Racing website I think you might
get the information you are looking for.I think that one of
the gearbox bushes is the right diameter for the wee end ???.
cheers the noo Brian

[martin 305/7]

1bantamcloser2divorce, on 09 January 2012 - 04:51 AM, said:

Brian,

Do you, or enyone else reading, have any info on making the Bantam small end work with the Suuki piston. I am about to face that problem and I see the gudgeon pins are quite different in size. I am thinking along the lines of having the Suzuki pin cut down into two short pieces that would fit over the Bantam pin, and butt up to either side of the con rod. These would be held in place on the outside with the Suzuki circlips and attached to the Bantam pin with loctite to prevent the Bantam pin from wandering into the bore.

Any advice appreciated!

Thanks,
Hi Andy what about Rex Caunt he does a piston that fits the roller bearing small end for a bantam , a copy of the suzuki one i think about £40.00 usually on Ebay .Hope that helps Martin
Andy

[smelling123]

I run a Suzuki piston and just made my own bronze bush (phosphor bronze - NOT BRASS). This has been in for a few years and seems fine - I run about 1mm squish clearance with a Todd head at 11:1 and all is fine.

I agree that the Rex Caunt pistons are a better solution and good price.

[Andy M]

Apparently ts genuine pistons are thin on the ground now, pattern are about, Wiseco etc (pricey) the Rex C piston has the ring pegs in the same position as the BSA piston as well as correct small end size. On the box it says "modified TS piston" Just bought one and had bore done 186cc.

[Pat]

Hi all,

Everything is possible today, thanks to first class inspired engineers..

ideas..
http://bsabantamraci...ll-s-125-engine

Edited by Pat, 13 January 2012 - 10:51 PM.