three bearing in the gearbox ?

just can not understand why you guys run three bearing in the gearbox ?

1) why ?
2) The outrigger bearing, well the way its done, i can not see how it can line up properly, besides, is this why you guys always use to say about moving the clutch actuator outside of the case for better clutch action /clearence ? was this true or was it just to hide the fact it was in the way and had to be done to allow room for the outrigger bearing. ??

3) your adding additional friction by adding another bearing seals and friction is this why you remove one of the crank bearing, to even it up?

beside DKW never did this so why.?

derek

3 bearing outrigger bearing
- the jury is out on this one i feel, and for the work in doing it, its not worth it. When Rick and I bought the SMS Bantams off Tom and Ned the No1(i'll skip all the 00 bit coz you get confused) had an outrigger bearing the No2 didn't.

The bearing boss was brazed on to the gearbox sleeve gear(then re-machined) and the gearbox mainshaft was shortened by 3mm? This was a good way as the bearing boss was concentric with the 7/8 dia sleeve gear. Problem was then would drop off on occasions. Later ones had the left hand thread nut with an incorporated boss. Problem was the boss is only as good as the threads cut on the sleeve gear and most of them are way out.

My (friends) contacts with a large engineering firm led me to have numerous parts made which have in the past been supplied to Tom,Jimmy and sold on bikes. I think they are a good idea to stop the wear in the thin EE8 bearing or perhaps the logical idea is a bigger bearing to replace the EE8... Ian's prob testing one as we chat??

Mike

For a long time now I have used sealed EE8s they are 1/8" thicker. They are so good Rex Caunt is now selling C3 ones !
Knock off the inner seal and fit 1/8' thick outer plate.
Then you can easily use a 13T sprocket too (yeh, yeh, I know you can cut down the seal holder)
Stops a lot of loosening and misalignment of thinner bearing.

If the flimsy outer seal leaks, usually less than around standard shaft setup, you can bung on a seal plate in the paddock.
Or, better still, take off the outer bearing seal off and fit one of Peter Savages small seal covers and the whole lot is held flat and stops the bearing moving outwards.

So John are you saying the sealed EE8 is actually 3/8" in width? Or something else? A bigger more robust bearing would definately be a lot better. I've got a normal EE8C3 from Rex just recently as 001 is due a full bearing/big end change post Mallory race day...

Mike

No, it is 1/2" thick in order to accommodate seals.

Rex Caunt has both on e Bay store.
This is the one I use:
http://cgi.ebay.co.uk/BSA-BANTAM-TRIALS-SPECIAL-SEALED-EE8-GEARBOX-BEARING-/360143604759?pt=UK_Motorcycle_Parts&hash=item53da3b4c17#ht_1472wt_907

Standard C2s are easy to find, I have not found C3s anywhere else. I think he sourced them after me asking.




Shows bearing and plate (counter bored to accept needle roller LS bearing)

so can we all agree out rigger bearing / two bearing crank a complete over engineer, and not worth the efforst and time in doing it, better to spend an hr on the Dyno cheaper, get better results

Derek

This is the small seal cover with standard 3/8" EE8 and usual Bantam bearing cover plate on D10 3 speed cases.
It will just fit over my 1/8" plate.

I reckon 2 bearing crank is another way of doing things, might try it !

John I think the sealed 1/2" EE8 is a great way to go, and think of the weight saving of no out-rigger bearing. All good stuff coz i thought i knew everthing 'bantam wise' and low and behold i've learnt two great technical thinks this week! Thanks.....

Mike

Hi mike "now" I always thought you were the educated one! out of the two of us! - and as you Know im deslexic, you have won so may championships compare to others , and had your fair share of family issues, along the way, so I have an issue with spelling, and sometimes, other things, but rather than talking to or telling us about you, talk to us abiut the development of your new Engine, #

1) what was the main problem at pembrey ? ignition failure or porting?
2) inginition ?? I whatched you changing the ignition. ? so why was'nt it revinging ? ports ?, you modified the porting since ? in which case what have you done, and for the comming, ------ who is testing for you in 2011 for you " Iam not volunteering but would be happy to make an accurate parley on - just incase you wished for my opinion ? , hope these make sence !!".

kind regards Derek

Prembrey didn't really have much in the way of problems however:-

Saturday 001 practice fine went well, race one too slow in a straight line 2nd, race fell off trying to hard.
003 had a 38mm carb on - keep stuttering as if running out of fuel 3rd
Sunday 003 36mm carb ran well 1st x2
001 went out in 250 race to make sure it was straight.

Cadwell Bikes remained the same

This season both bikes have longer port durations Ex98(96) Tr67(65) In97(95) previous in brackets...

Will be on rolling road again with 001 next week...

Mike

wow ? - mikes increased his port open periods/timings - anyone notice anything else ???????????????????????????????????????????????????????????


Regards Derek

Intersting to see your port timings Mike.

My new tuner has left my sswc engine with E 98 T 66 I 170 (piston port) used 1.7mmBTDC ignition timing with old fixed Motoplat at Pukekohe (went like the proverbial sexually assaulted primate, well this is a family site!), might go back to 1.9 for short, squirty Taupo track in April.

Do you think there would be any benefit in increasing the Inlet timing ?

I will also be looking at getting Rex Caunt ignition system fixed or ...... did your Electrex system work well and can they make a custom curve ?

As a piston ported rider;

I often ponder the inlet timing question but if extending it is not beneficial why bother with a reed valve, isn't the point that a reed valve can, if the engine demands, give 360 degree inlet duration where as a piston ported engine will always be limited.

My experiments have shown little benefit in terms of peak power output but some other effects,

James

Derek not sure what your on about? Is there something in trevors post?
But this course of action i decided last October after first for 9 years RR session!

John had an Electrex world universal ignition on 003 last year until before Pembrey where I put an
Rs 125 ignition on but no different!? 003 will have Electrex world ignition back on this season.

Will start another post on Ignition.... in a bit....

Mike

Hi Mike no hidden agenda there, and yes you are all correct" Mike ignored my ignition questions/suggestions but very interesting about his port timings. dont you think and pleasse stop PM-ing me just say it on here, every one wants to hear what your saying,

but to be fair Looks like Mike going to discuss ingition / timming and systems as a topic, soon soulds like he has tried a few at Pembrey! "

James ask Alan about the inlet issue - my take is from 170 openening to 190/195 would make a massive difference on a piston ported engine on reed valve the question would be why is it only 170 ?

piston ported - would increase / power /revs /torque, but asuming others ports should be there or there abouts, tunning manual and you have an exhaust that is asking for it, down side will reduce torque out side the powerband ? but again dependant on other spec's.

James piston ported allows no restriction to incomming charge and the sonic waves can be tuned to work in harmony for you. Reed valve is easier to tune as it can be very forgiving when you get it wrong, a pistion ported engine will anilate your power band if you get it wrong.

thats why when Mike ! came up with the 175 formula, we both agreed no reed valves, as it makes sure you dont capitalise on your already bigger torque advantage. imagine a 175 with a reed valave would be uncatchable, by even the best current 125's my opinion this is.

I am quite limited in the area of inlet piston ported /over reed valve area, there are others posters who could give a far more indepth prognosis on this.