New Builds - Learners

Hi Ed merry xmas to you too

And No I did'nt Burn the turkey, mind you I came close this year, I have a process I follow and been perfecting over many years, seems to work, I put an apple and sliced orange crushed galic and olive oil marinate for 24 hrs, then fill it full of chopped onions, never burnt it yet, and did not today "but thanks" -

see you wednesday, are you going to the Mallory Plum Pudding. !!

regards Derek

Sounds like the bantam fraternity are all sorted for food on a two day meet with chef betts about!!

Normally we would try to go to the pudding club meet but we have a family meal gathering by worcester to go to


Eddie

Good Evening All,


I am using my son's login.

I have been discussing tyres with a tyre technician who tells me that the Dunlop KR825 is not recommended by Dunlop to be used with a WM1 rim as the tyre is too wide for the rim. He did say that that was the recommendation but racers may nevertheless use them. My dilemma is:

1 Is the Dunlop KR825 18" 2.75/3.75 safe to use on a WM1 front rim? Do current Bantamites use it and what is their view?
2 Is there an alternative (pair) of tyres that can be used?
3 Should I make use of the WM2 rim I already have for the front and fit the KR825 i.e. have a WM2 rim on both the front and rear of the bike? What is the effect on handling?

Any views welcome


Regards



Malcolm Pickering

My advise is don't speak to a Dunlop Technician!!

Your dilemma:-
1 In my opinion Yes I have run KR825's since 1987(not the same actual tyre's you understand) on WM1 rims front and rear.
When they first came out they were for 125 race bikes.
There was a narrow front tyre (no longer made) and the 2.75/3.75 rear. However 125's went 17" tyres (90's?) and the KR825 seemed to become a Classic bike front tyre?!

2 Nick had some narrow tyres on the 'Colin Hall' bike ... over to Nick....

3 Seems like a good idea.. Handling don't think I will tell the difference...

NB I'd rather be on KR825(WM1,2,) than skinny tyres!!

Regards Mike

Good Morning All,

Does anybody have any advice on chain length and sprocket sizes for this seasons circuits.


Regards


Eddie

There is a good gearing chart in the old Bantam tuning manual. its on the site too.

But it does vary bike to bike. also its much different between gears, seems some unusualy combinations on top ratio's has come out in the last 12 months never heared of these before see below.

top gear ratio only with std 22x25 slider gears ? I assume 22 x 25 middle slider gears,

for top gear seems snell @ 22x25 not as popular as one would expect ? not sur why much better combernation for top or a low reving bantam / normal CR BSA is 23x24 but spotted recently a 23x25! combination also suggested could not work but obviously it does.

anyway for the 175cc you also have a snell 22 x 25 and the 21x 26 if you use the trials sliders (forgive me for not suggesting these will PM you) for a some 175 and for three speed only.

unsure what the ratios are for 175 4 speed but you can swap the middle layshaft ratios using the gears from two boxes to make a better/ closer ratio 4 speed box - by having 2 & 3 on 22 x 25 on both shafts and main shaft, but the other way round, this can be done with std gears, so within the rules. but I have never done this, only seen it done and rode a bike with such gear box top in my opinion just like a close ratio box but added advantage of having very low 1st gear. Rex gaunt has done this but had the middle gear strengthened slightly the ratios are the same so this too i would think is well within the rules. you may wish to talk to Rex on this.

hope his helps.

My gearing now is completely different to what it was with the same engine a few years back, when I was a little more competertive than I am currently.

What I have run recently
place recently back in the year
Cadwell - 14x50 cadwell / 15 x 52 in 89 long

Snetterton - dont know / 16 x 54 in 89 old circuit

pembrey - 15 x 56 / 15 x 50 in 89 onwards

three sisters - dont know / 12 x 70 90 onwards

Lydden - dont know / 14 x 54 89 onwards

croft - dont know / 16 x 52 2002 (once only classic club meet)

our 175 is running much taller gears on the front (17) !

Derek

Hi Ed bike look as if it will be out at Mallory, What tyres are you using? I like the look of them them are they Michelins? We used Pilots with race compounds a few years back I liked them MP thought Dunlop’s better.

Tyres are Avon Road Riders AM26 hopefully in race not road compound!
Pete Tibbits had some on his bantam in 2010 and there's one on the front of the G50 i race.

Regards Mike

Hi Ed

slowly but surely is always the best way, !

looking good ED - "looking good"

picked up the cases from dads re the welding we spoke about, went out in the garage last night and managed to block the oil holes with araldite from the gear box timing side and drive side, and then re-tapped all the holes in the gearbox output 3/16" bsw - mind you it was a nightmare to drill, the welding is much harder than the cases must be full of silicon or somthing, anyway done now.

keep me posted - when do you think you will be ready, I recon we still have a few weks - till we are ready.

are you and your dad intending to be racing this year, will you be ready for the practice day.

Derek

Interesting exhaust pipe!?

Diffuser direct into nozzle both long -- i.e. shallow angles --- not

being critical, I am just wondering about the difference from the pipes

I made long ago where there was a "belly"(Kaaden called it that!) -- the

fat parallel portion between diffuser & nozzle....

I take it you didn´t get my e-Mail Ed with pic of Bill Lomas aboard the

Walsh Bantam ... or should I try again?

Cheers!

JayBee.

Hi Ted, Mike and Derek,

Yes we are hoping to have dad out for Mallory, mike is correct on the tyre type but they are a race compound. Slowly is the way we are going rather than trying to do too many things at once, few bits to still get and trying an exhaust fit while i badly still try to make one.

Will keep you posted and im sure i will ask a few more silly questions, saying that where is a good place to get rear sprockets?


Kind Regards


Eddie

Hi John,

the exhaust is a tester as it was kindly given to us, have a few random ones which maybe a bit small and currently trying to build a new exhaust from data.

Yes i did get your email john but it came through as a word document not a jpeg, dont know if you have it as one or i can try and convert it.


Kind Regards


Eddie

Thanks Ed!

Not sure what a jpeg is but I´ll look for it...

Cheers!

JayBee.

Good Afternoon All,

Dad is currently checking the timing and wanted to test for a spark, it is a pvl ignition and we have hooked up the wires and added an extra earth bond but no spark?

Any comments or ideas would be greatly appreciated.


Regards


Eddie

Hi Edward and Malcolm,
The PVL spark is very weak at hand cranking speeds and it is very difficult to see, try rotating the engine faster, or assume the spark is there and fire up the engine anyway! this is a typical PVL problem! If the engine doesn't even pop within a few pushes then you could have the wires the wrong way round and the firing becomes 180 degrees adrift so will never start!! just swap the wires round and try again!
Hope this helps
Alan

Hi Alan,

Span the engine up with a drill and got a spark, thanks very much for the advice. Thats another beer we owe you!


Kind Regards


Eddie & Malcolm

Good Morning All,

Is the ignition coil okay where we have placed it or would it be better underneath the tank?

Opinions and comments appreciated.


Eddie

Hi Eddie I would be concerned that water and stones could be thrown at the unit in that position.

Hi Eddie & Malcom,
Looking good guys, i think your be ok to start with, my ex teddy bike had the same coil position on the
front frame tube all be it on a welded bracket. My concern would be in the wet, what i did was to cable tie a
polythene bag over it when it was p.....g down.
All the best Nick

Hi Ned & Nick,


Thanks for your comments, primarily we put it there just to check cabling and spark but thought it good to ask on here as you guys have done all of this and know what hapens.

Just checking fairing for bracket and modifying.





Eddie

hi ed will Pm my observations, and details on the other things, what does Mike P think of its position on the bike,I recon it needs to go up slightly looking how it sits on his Bike, but it looks great.

I see malc got those rolls to work then, and the cones look great, I thought the reverse cone would be difficult but it looks the business, they just need welding together now.

ask Malc to let me know how he get round the stop issue, I was struggling with, I would like to know.

cheers Derek

Hi Derek,

Thanks for the comments, it does need to go back and up but this was just to try a test fit to see what needed doing. Mike spoke to me in the car park while waiting to get into the meeting about opening up the front of it also with being a 175, he also had a look at the barrel that we had a problem with.

As for the exhaust, it isnt great and bar the centre section that i rolled the rest dad did by hand. All a work in progress and will try the rollers again.


Eddie

Hi Ed
Sorry I never replied to this, Im sure I asked this before, but where did your bike go, I know its back !!




its looking good though,

cheers Derek