New Builds - Learners

Good Morning Tim,

You mentioned before about starting a topic on building for us learners so i that i would start it off so we arent posting over all other topics and keeping it in one place. What have you got so far, what do you need to get, what can you do yourself and what do bits do you need to outsource or get help on.


Eddie.

Hi Eddie,

Good job, I was about to start one anyway, but cheers! True, a thread for just learners like ourselves was a good idea, seeing we can not have all the "jargon" of other threads and other confusing terms.

What I have so far is pretty much half way there between a bike in bits, and a bike that hasn't been started in a few years, or a few decades!?

The engine I am using is a 1952/1953 D1 engine, I think it's a thin finned model (52MM studs?), and I have quite a lot of spares to get the bike working, but not necessarily tuned. Yesterday I had a packaged that came with most of the clutch parts I would need and also the main bearings and seals. I've also got a few bits being made up for me and they will be used in time. I doubt I will get it finished this year (I started this build January 2010!), but I know by the end of 2011 I will probably be able to have a mock up of what it will actually look like.

As for the tuning, I'm going for a 54X54 motor with these internals:

I'm going for the 125 engine seeing I will not have to fit a liner to it, which will also be a hand when I come to do port timings and all, and the decrease in machining time overall for the bike.

54 BORE X 54.5 STROKE.
TZ250E ROD, 45MM IN LENGTH SO FITS PERFECTLY.
RM125D PISTON OR YDS7/RD.
38MM LECTRON CARB, BUT I MIKE STICK WITH MY INITIAL IDEA OF USING MY AMAL.
BIG HOLE IN PISTON NEEDED TO IMPROVE HIGHER RPM AND ALSO PISTON SKIRTING.
96MM DIAMETER FLYWHEELS, 20MM THICK WITH A "BUILT IN" SHIM OF AROUND 0.5MM AROUND THE SHAFTS.
13MM WILL NEEDED TO BE CHOPPED OFF FROM THE CRANKCASE MOUTH.
EXHAUST PORT ABOUT 37MM IN DIAMETER, IF KEPT ROUND, AS CAN THE INLET PORT BE.
BY USING YOUR PROGRAMME YOU SHOULD ME WITH THE INFORMATION INPUT AND RPM/EXHAUST INFORMATION OUTPUT, THIS ENGINE WILL BE EFFECTIVE IN THE RANGES OF 8,575-11,200RPM, BUT NOT ANY FURTHER THAN 12,000.

I've got a few experimental cooling methods coming up in the mock up stage, and I'll update you on how this goes.

As for the frame I've got a D7 chassis, but I am unsure how to prepare it for racing and also the forks/headstock modifications? I don't think I will be able to do that in my facilities (one small garage with a Record vice and a load of carpentry/metalwork tools. No lathe, drilling machine etc like everyone else has...). I know what bodywork I am going for though; LATE 1970's-1980's racer lookalike; I prefer it seeing the seats are more higher and will allow my 6' 7" frame some room!


What I will need to finish the project:

Well, there are loads of things I will need to finish the project... But I'll give a shortlist;

A 54MM piston with a 16MM gudgeon pin hole to allow my RD250 to be used.
Motoplat Ingition/PVL (short on money to can't buy the best)
Rear sets need to be made
Forks
Racing frame needs to be made/bought off a previous racer
Wheels
Rims/front brake/front disc
Bodywork (tank, seat, fairing etc)
New carburetter (I only have an Amal Monobloc but apparently they're not too good for Bantams..?)
Rear shocks (if needed!)
And possibly a way of how to beef up a racing frame to take my 15 1/2 stone and 6'7" body (Still gaining weight and height due to rugby!)


I have a feeling this will all take a long time, and seeing most people I have met are extremely nice with helping, I am unsure about how many left over Bantams there are lying around in sheds or in racer's garages waiting to be used by learners like ourselves...

Hope this gives a rough idea of how much work that needs to be done... I don't think that's all of it, but the list will get longer...!

Have a good day,

Tim

P.s. heres my Photobucket if interested:

https://s968.photobucket.com/albums/ae168/timbantamracer/

Hi Tim,

Good to see you have worked out what you need, what you have and whats to be done. Have you been to any meetings and met the racers before as if the have time and arent busy im sure you would get some adviced on a few bits or atleast get down there and ask if its okay to take some photos to get some ideas to get a few other bits started.


Eddie

Hi Eddie,

Yes, I've been to only two. Being in the South of England near Southampton isn't good when everyone else lives "Up t' North aye". I've been to Lydden 2 years in a row, and met most of them. They're a really nice bunch of people I gotta say. Yes, I've got loads of photos, but most of them are on my Facebook rather than my Photobucket, which is a shame I guess. Should transfer really.

When did your Father start his project/have the intention to go for a Bantam?

T

Hi Tim,

Ive been to a few but usually Mallory Park,they are a nice bunch of gents and have had very good advice and tips and help from quite a few. Regardless of location people will see give help and advice when they can if they have time.

the build has been going for quite a few years, we had a good burst at it and then for a few reasons it got put on the back burner. The reason my dad went for the bantam was because it was the first bike he ever rode in 1962, i got the bug when it was one of the first bikes my dad ever bought when we were growing up plus when we used to go to mallory to help we would sneak off and look at the bantam racers.

my dad was just telling me the build all started off from buying some footpegs while at the manx gp.


Eddie

Hi Eddie,

Ahh sounds nice. I came to it as a bi-product of my defunct Aprilia Superteen challenge, which costs way to much!

I bought my engine January 2010 from a previous Bantam racer, David Brasier, with a few ported barrels, and pretty much went from there. Tonight I need to buy my RD250 con rod and then work out how to get the main bearings out, well, not today, but another day. I'm playing county rugby for Hampshire tomorrow so I will have no time to do it, plus coursework needs me as well so literally no time to do anything anymore. Shame really, started to make real progress with the bike and then Summer exams kick in. Eurgh!

Do you have any photos of your Dad's bike, can't find the link on here..

T

P.S. On the subject of rear sets, are they for the Bantam? I'm preparing a frame, and was just wondering about these "rear sets triangles" everyone goes on about, but limited resources and facilities and pretty much £0 in the bank I don't quite know what to do...

Hi Tim,

Well all racing does cost money, was it a complete engine you got? I am having the same problems as you with the foot rest hangers but have been looking at pictures, maybe worth asking. The link for the pictures should be on here for my dads bike but if it is gone i will do it again.




Eddie

Hi Eddie,

Yes, it was a complete engine, but some of the gearbox ratios were different from original D1 gearbox teeth, confusing much? I'll have a look around for the link right away.

What facilities does your Dad have? Seeing he's built his bike nearly I'm thinking sort of lathe, drilling machine type?



Here's the engine lying in the kitchen top circa. January 2010. Please note the ignition cable from the points is cut, which was annoying when finding that out.

T

Hi Tim,

With reference to your gears have you looked under the bantam site and looked at mike's page on gearboxes as it is very useful for working things out.

no we dont really have facilities but have been very fortunate with getting certain things done by some very helpful people.


nice picture, as your base have you stripped and cleaned and checked it yet?



Eddie

Hi Eddie,

Think I've looked them up once, but I'll try another day i.e. tomorrow and then post them on here.

I've managed to get it stripped down and the cases are separated. The last thing I did was rebuild the clutch with random Bantam clutch parts I found lying around the place and also had an order of parts come during the week, one of which included a clutch mushroom pushrod.







What ignition does your Dad use?

T

Hi Tim,

Well good that you are doing bits, you doing the clutch modification as shown on here or stciking to what came with it?

Interesting secong pic, carb manifolds for others? Dad has a pvl ignition with the modified shaft but the motoplat and contacts on others

Eddie.

Hi Eddie,

I might go for a 8 or 9 spring conversion, which only involves putting in a new plate and more springs. I received a gift from someone with some extra hard clutch springs so I thought they'd come in use.

Yes, they are carb manifolds. I made the one on the right, and that has a 35MM inlet I think by memory, and the one on the left was made by a friend and it was made for a friend's water cooled barrel, which I might model a soon-to-be experimental barrel on.

I'm using Motoplat ignition probably, seeing PVL is too expensive for me. What do you mean by "others"?

T

Hi Tim,

Always good to get gifts if it makes you pregress, good job on the manifolds as shows you are trying and experimenting.


I take it you mean the cost of a s/hand motoplat versus a new pvl ignition. Others as in a few bits i have been looking at.



Eddie

Hi Eddie,

Yes, a second hand Motoplat versus new PVL is what I mean. New PVL is £120+ and s/h Motoplat is £20-50. How much did you Dad buy it for? Or was it lying around somewhere?

I guess that, seeing the amount of unused racing bikes in sheds or garages, they should really be on tracks or be loaned/used by learners like ourselves. I had one bike I was going to buy, but a new phone and a lost number lost me £600 of a racing Bantam and probably 2 years of progress haha, but at least I am enjoying what I am doing and that I am learning that counts. I did model jet turbines/pulse jets before this as well....!

T

Hi Tim,

No thats about what dad paid for his pvl ignition, i cant remember who said it on here but its a bit like people looking for cr boxes, maybe a few have been sold to people who say they are going to start and for whatever reason dont and end up on on ebay or at auto jumbles for silly money so people have gone down the route of having their own made or the four speed conversion.


Eddie

Hi Eddie,

I agree with you there. It's annoying when people say they will do a project, buy the things and then tot up everything and find the time, money and effort we put into our projects is far too much for them, and thus end up selling everything for stupid amounts of money. Bit of a waste of effort I guess, and a tedious job for learners like ourselves.

Have you ever gone racing or owned a motorcycle before? You certainly sound like you have though..

T

Hi Tim,

Everyone has their own reasons. I have been racing but only with me and my dad spannering althought my dad goes to the manx to spanner or do some racing.

Yeah i have owned and ridden motorcyles but only road going and mostly jap stuff apart from a mobylette.


Eddie

Hi Eddie,

Ah, sounds nice. I've never been to The Island. Would always like to, heard a Bantam's been round it as well, something Harrison, but can't remember his first name.

My Bantam is the only bike I've ever owned, so far, but I did have a 50cc Italian scrambler from the 70's, and it had a Minarelli engine just like the ones used in the 50cc racing machines with stretched frames; it was slightly overpowered I gotta admit. I know some Honda employee put a supercharger on a 50cc Honda, haha, now that is overpowered!

Jap bikes are very nice, but I have a slight touch for the Italians. Before the Bantam I had a brief moment with a friend's 125 Motobi racing motorcycle which I absolutely loved, and probably had the same or less power than a Formula 1 Bantam, but it made a nice sound so that suppressed it's power. The Moto Guzzi V8 motorcycle of the 1950's-60's is what I prefer most, and that they were beating 350 twins with their 250 singles!

T

Hi Tim,


All good stuff. Right lets get back to keeping this to our bantam learning topic or we are never gonna get anything done or get any help from anyone



Eddie

True, I must agree. Haha! One thing I do want to know is the bodywork and frame modifications. I've seen around that they add extra bracing tubes for stability etc and the mounting brackets for fairings, tanks and all. Plus the undoubted fact of rear set "triangles". As I do not have a welder, but I think somewhere a couple of plumbing Butane torches I don't see why not I can't experiment on a blank piece of metal to make some rear sets.

Does your Dad have any tips? I guess you just make a rearset then thread the triangle through a pilot hole and then the footpegs/rear sets just screw in? Or is it a lot more complicated than that....?!

Where did your Father buy his bodywork from? Looks pretty nice in French blue, or blou as we like to say in Afrikaans.

T

Hi Tim

Im not too sure to be honest, might be worth asking the question and im sure somebody will say and have pictures.

Dad got the bodywork through the club.



Eddie

Hi Eddie,

I'll post a new thread about it to answer the question. What does your Dad have planned for the ongoing Bantam project? Anything new and exciting?

And for bodywork I'm going for an MT125/early TZ125 mix; hopefully move the seat far back to allow my 6' 7" body to lie flat haha!

T

Hi Tim,


See you got you topic going, lets hope you get some replies as it will be something we need to look at ourselves. Dads currently working on his exhaust design and his seat fixing.



What made you go for the bodywork type?



Eddie

Hi Eddie,

Is he using a formula for his exhaust I gather? One thing I'd like to know is how will he curve the cone-shaped exhaust patterns made out from 0.8-1MM thick sheet steel!

I went for that sort of design seeing that I have a large passion for the late 70's to 80's racing motorcycles such a the RG500 and alike, so having a minimalistic one of those would look the part. Still undecided about the paint job though, possibly go for my home country's colours of red, black, yellow, blue, green and white lol.... Take a guess at the country? Sounds nice I guess, slowly getting there, though my gearbox tooth numbers are slightly different from a standard D1's, possibly a semi-c/r box perhaps?

T

Hi Tim,

Yes he is using a formula that was done for the engine, i believe the cones you are talking about are also done on a roller. Well colours and designs are all down to a persons taste and what works for you.


I take it you read mike powells gearbox info to check them, if not put up a topic post and see if you get any help.


Eddie