Bantam racing project

I am the curriculum manager for an engineering training provider and have a number of students who wish to undertake a project to build and race a 175 Bantam.

I would appreciate any advice to assist my students in undertaking this project.

They have done some research and are concerned about the gearbox situation are they difficult to obtain? Or has any one which we can copy?

Paul

Hi Paul, i'm one of the old school, 70's bantam racers and was very pleased to see your post. As an engineering exercise it is ideal and i wish you all the best with the project. If you take a look at the links on the site front page, you should find a whole host of info to help you get started. I'm sure some of the guys will be around to offer help soon enough, be patient with them . By the way, where is the project based? good luck.

Hi Paul!
Ex Bantam rider cum racer speaking, was also BRC chairman until a fantastic job offer came for Canada in `74.
Take a look at the formulae for the Bantam racers and you see the 175 is more like the real Bantam hence more simple to build yet more difficult to tune (than the 125) and hence much more of a challenge. The close-ratio gears might be the most difficult problem. Someone is getting sets made and needs enough customers to get things rolling -- so let us get asking together...
... WHO IS IT THAT WAS GOING TO GET CR GEARS MADE ON THE OLD FORUM in 2006 -- or 2005?
There are also some articles and books by one Roy Bacon who wrote 'Racing On The Cheap' and books on two-stroke tuning.
The frame also needs some work doing to make it a bit more robust for racing. There are places where gussets are normallyy welded in which may or may not be necessary yet give the real racer a feel of confidence if nothing else... On some early frames there was a footrest location which needed reinforcing ... And definitely a triangulated plate above the swinging arm lug on the D7 (D10 - also I think?). What I did on our D7 frame was to braze that plate (horizonztally) to the swinging arm lug and then weld it along the the upper edges along the saddle down-tube ALONG ITS NEUTRAL AXIS for about an inch at three to four inches above the swinging-arm lug.
What is important about welded- in gussets is that you do not weld them in on the inside or outside of a curve in the frame tube: that is what is meant 'welding along the neutral axis', you weld where there are NO bending stresses... Some earlier mistakes were made this way by the Japanese 'Experts' ...
So let us finish this by calling on the fellows that know:
-- COME ON YOU EXPERTS LIKE PT; AB; MP; AB AND MANY MORE --
get HELPING THE LAD!
All the best ----- JB.

Hi There!
Had an alert to a Private Message from Paul Brown...
Tried to open and came back here. Did it twice. It is a closed loop
-- I come back here both times.
Tried to send Private Message to Phil Betty -- appears to have NOT
gone...
Help! JayBee.

Are you looking in your Private message box John? it's situated at the top between Profile and Login/Logout.
i just sent you a test pm to make sure it works, seems ok.

Hi Paul I know were they are two c/r gearboxs for sale
so go a head and build a bike for the track
Robbie

Hi Mick!
Mine says what the title here says... just where you said. It is a closed loop. It sends me out and onto my e-Mail and that sends me back here.
I'm tearing out my hair! Come to think -- what hair?
Was in the sauna at The Village Hotel ... Nottingham - Eeyupp! why weren't you there? -- and said something on that theme. Said I hated The Beatles 'cos they had too much hair when mine was dropping out and I spent a fortune on liquids from Liverpool and it still fell out. I then included Paul Mac in my personal hate and one woman said she'd sleep with Paul for 9 million... Several women then said they would too.
Then a bloke on the top bench piped up that he would also. The place was rocking. Reminded of a BRC Dinn-&-Prance way back. Anyways up Mike Powell asked if Slick (son Anthony over from The Island) would present the Wobbleyman trophy and he refused so I had to... I went with an A-4 sized paper and the announcer almost went ape. I said this is Colin's eulogy which was inside the trophy when it left the Fatherland (and ain't there now...) so I'm giving it to Phil Betty to read later. Much like the good old BRC days I said a couple of words which I have totally forgotten. Any-road-up it was a fantastic do from which I am still recovering.
---- The Wobbleyman trophy was the best there. ----
Keep well and stay cool!
Aye --- JB.

PS. A week before the D&D, I phoned Slick asking his flight time Ronaldsway to Liverpool. He answered,
"How would I know? -- should I?" -- which comes from being in a Works Team where all such arrangements were always done for him. They still are! JB.

Paul Brown wrote:

I am the curriculum manager for an engineering training provider and have a number of students who wish to undertake a project to build and race a 175 Bantam.

I would appreciate any advice to assist my students in undertaking this project.

They have done some research and are concerned about the gearbox situation are they difficult to obtain? Or has any one which we can copy?

Paul

Hello Paul

Good luck with the project, I teach a couple of M/cycle maintenance classes in London. I ended up doing this as a consequence of building this racer in the college workshop.





You've seen the build a 175 racer artical on the main site? most of the info I collected from current bantam racers and tuners to give them a break from all the questions they get asked and put this little artical together to help others. there's lots of help out there best get yourself to a meeting and have a chat with some of the riders and bike builders.

There's gearboxes out there and there's ways of converting road gears if you are a decent engineer with good facilities.

Tony

ps Where abouts are you in the country?

Tony!
Neato! Wünderbar!
Did you ever see a picture of the Walsh Bantam?
Looked dreadful: had plunger back-end and megaphone pipe but apparently went very quick.
Gets me thinking I ought to make 'Icarus 3' ...
All the best!
Aye!

That rings a bell John and on the subject of bantam building, looking at that pretty bantam a la Tony, it kinda gets me thinking. My days of knee scraping are long gone but i'm itching to build something. If i get a contract that allows me some spare time, who know's?

Answering two of JayBee's questions:

I was one of the people who talked about getting some CR gears made on the old forum site. I got some 25/22T Snell CR 3rd gear sets made and some road 25T LS sliders modified from square to round dogs to work with CR LS 1st gears.

I have talked to a few senior Australians who raced Bantams alongside Walsh tuned machines. I have always been amazed such high speeds (100mph+)were obtained with early sixties technology. Apparently he ran methanol, big fin alloy muffs over early <1954 barrels, with very high compression ratio. Lots of specially made parts:forged pistons with a spring steel ring, forged conrods, magneto with small internal flywheel.

Hey JohnsBantam in Oz!
That is fantastic!
This seems to be expanding -- this enthusiasm in the background -- or is
Oz in the foreground!?
No matter. It is good to see its all happening. And at the VMCC dinn & prance (17th Feb...)I got to feeling I could take part again. Nothing to do with the booze, I was on shandys -- typical of MC D&Ds there were ladies sitting looking bored so I cheered them up by telling... I was 'Free & Available'. Was 5 kg lighter on the Sunday! At the rate of a D&D per week I could get down to racing weight again. Also must have spent hours telling of how I got my 'Druids Elbow' and 'Snetters Shoulder'...

Yeah! That Walsh Bantam was something else. Bill Lomas rode it and was greatly impressed. From the picture I saw it looked rough. Used one piston ring made from proprietary rings ground to 60 thou thick, frequently changed between practice and race -- and like you say on dope with a 15:1 CR...
During the VMCC D&D Slick & I got chatting with a sidecar crew who were on leave from Afghanistan to attend...Really amazing weekend.
If I do make 'Icarus 3' I'll need CR gears - it'd be great to sponsor some nutty kid ...
Stay cool* and keep well!
Aye! JayBee.

* saw on the idiot box the temp there was 32°c...

Hi JohnSbantam!
Sorry! Just seen you are not in Oz -- New Zealand.
If you have time, tell us about the difference.
All the best, JayBee.

Mick Jones wrote:

That rings a bell John and on the subject of bantam building, looking at that pretty bantam a la Tony, it kinda gets me thinking. My days of knee scraping are long gone but i'm itching to build something. If i get a contract that allows me some spare time, who know's?

Get building Mick, you can always sprint it 1/4s or twisty and then let someone else ride it in the Championship.


Bantam building,just as much pleasure as riding it

ps Hoping to be out on mine later on in the season, far from fit at the moment but will be at Mallory (spectating )

Twenty odd years ago Tony, I would have disagreed with the fun building thing but looking back i guess it was kinda fun. Those little experimental tweaks that actually worked were quite satisfying. Mind you most of my serious tweaking was on the proddy bikes where similar to bantams, every little helped. I need to completely refurbish my garage before i could even think about starting such a project but i was gonna do that anyway. I guess a 175 is definately the way to go, being less technical and time consuming. Time is the thing at the moment, being a contractor i have to bow to some hefty demands on that resource but i'm sure it will pan out. I hope to get to some meetings this season as i missed out last year, i'll be taking a bit more notice of the mechanics involved next time.

Hi Mick!
Sorry about this folks but the Tony build and things Mick has said - plus that VMCC D&D -- have really got to me. A couple of beers with Bill Lawrence in an East End pub in 1981 (I was over from Canada...) and I was agreeing to attend the '81 BRC parade at my jinx circuit Snetterton. Ned knows what happened then... I woke up in Norwich hospital!

After a couple of shandies at the VMCC D&D I was motoring through the bends with some sidecar lads leaning dangerously out of the bar-stools.
Great fun! I never got to riding a really quick one although the 250 would rev to 9 500 rpm and I really would like to do it all again!
In the meantime I'll try gee-ing up the rest of you... until I'm drummed out of this site, of course!

Oh! By the way, I tried to get a Private Message to Phil Betty but it obviously didn't go. My e-Mail address is on the Profile file -- Phil or Miki please get in contact, there's good lads!
Stay cool and keep well, JayBee...