Starter gear spring / leaf spring ?

[DewCatTea-Bob]

" it is a close ratio box for racing so first gear is even higher "

____ Very impressive Eldert! _ Thanks for the pictures.
Is that 6-speed set only for just the wide-case models?
If that 6-speed set is available to others, then you really ought to post a new/separate thread-topic, just for it! _ As it really deserves to be out-front where it will be more easily noticed!
__ Could you please tell us all 6 ratios (or gear-pair tooth-counts), so that I can then play with comparing the ratios (to the standard 5-speed trans)?
Regardless, thanks Eldert!

DUKE-Cheers,
-Bob

[Desmoto-M.3]

Eldert, it's a good looking tranny you have posted and i'll bet it works good for racing but, what i understand from Bob's post about all the gear ratios, etc, I don't think that i would really want that type of close ratio 6speed tranny for my kind of riding.
I would never want to race my Mark 3 or do anything else that might possibly put it in any kind of danger! I love my Mark 3 too much to take any chances with it!

Bob, I never made any contact with any DIOC tech adviser myself, but the one told my Dad more stuff about Ducatis than he asked for, so i would not be surprized if you are the same person.
If I deside to lower the gearing on my Mark 3, what would you recomend i change the sprockets to?
Another thing, I have always had some trouble shifting gears on the Ducatis i've riden, mostly from 1st to 2nd gear i get caught in between gears, not the real neutral setting though.
I do not think it's my fault because i don't have this happen with Yamahas or most other motorcycles very much.
Do you know what could be the cause of this teeth gritting trouble for me?

Thanks for any advice!
Ken

[Eldert]

Hi Bob



ratio s are :

1st 29 - 13 = 2.23
2nd 27 - 15 = 1.8
3rd 25 - 17 = 1.47
4th 26 - 21 = 1.24
5th 22 - 20 = 1.1
6th 23 - 23 = 1

gears are for widecase only
gears are wider then original and a bigger ( stronger module is used ) where possible gears run on needle bearings
to minimise friction losses . i had these boxes made for real long tracks with tall gearing like the IOM
the steps between the gears get to big then
1st is allmost the same as the Nova 5 sp close ratio box ( = 1 - 2.25 ) and 6th is the same as the 5th in the Nova box
one off are very expensive so i had one prototype made and run that for 2 years and found everything to be OK
then another 5 gearboxes where made . so far i sold 3 of them . 2 are running on the Isle of Man
the gearbox comes with a reworked selectorbox for the new selectordrum and a positive stop was added
so no more missed or in between gearshifts

Eldert

[Eldert]

the gearbox from the 500 CC is another thing
as i was finding more Hp the boxes that where available kept on breaking gears . 4th was allways first to go because
the gears where not lined up properly and if you did line the gears up the dogs where not engaging very well
so i had new 4th gears made in a bigger module and the inputgear a lot wider so it allways lined up with the output gear



after some more tuning 3rd gear broke to so i had the other gears made as wel
where there was room we made the gears wider and again a bigger module was used
wherever possible the design was inproved : on 2nd the gear was changed to Z = 16
so we could make 4 dogs on the whole tooth






my 500 has about 50 horse and no more gearbox problems

i am working on a new head and hope to find 2 or 3 more ponys

Eldert

[DewCatTea-Bob]

Eldert,
__ While it seems that you don't really care to boast about your 6-speed trans, ya gotta still realize just how fantastically great this transmission of yours is! (Even with the fact that it's a 6-speeder aside!)
Everything you've posted about it is quite worthy of being posted in it's very own thread-topic! _ (Rather than lost within this thread primarily concerning old narrow-case kick-starter springs.)
You really ought to consider moving all your related posts here (concerning your 6-speed trans), to a newly created main thread-topic! (On the main-topic page.)
Cuz if any topic is worth having it's very own thread, THIS particular subject is!!

____ Here follows a comparison of Ducati's wide-case 5-speed trans with Eldert's fabulous close-ratio 6-speeder.

Ducati wide-case: ____________________ Eldert's 6-speed:

_______________________________________ 1st = 2.23
1st = 37/15 = 2.467 ___________________ only* 19.3% rpm drop to 2nd-gear
__ 30% rpm drop to 2nd-gear ______________ 2nd = 1.80
2nd = 38/22 = 1.727 _______________________ 18.3% rpm drop to 3rd-gear
__ 22% rpm drop to 3rd-gear ______________ 3rd = 1.47
3rd = 35/26 = 1.346 ________________________15.6% rpm drop to 4th-gear
__ 18% rpm drop to 4th-gear ______________ 4th = 1.24
4th = 32/29 = 1.103 ______ _________________ 11.3% rpm drop to 5th-gear
__ 12% rpm drop to 5th-gear ______________ 5th = 1.10
5th = 30/31 = 0.968 ________________________ 9.1% rpm drop to 6th-gear
______________________________________ 6th = 1.00


__ *I myself would've liked to have made 1st-gear closer to the stock (5-speed) raito,, but then, I don't race anymore either.
It's my opinion that Eldert's 6-speed trans has been very well thought-out, in every way!! (To say the least!)


6 SuperCheers!
-Bob

[DewCatTea-Bob]

By Desmoto-M.3 ...
" If I deside to lower the gearing on my Mark 3, what would you recomend i change the sprockets to? "

____ Well Ken, I know how very nice it is to be just smooth-cruzen -(low rpm cruising) in a high top-gear like your 250-Mark-3 has! _ So I wouldn't suggest lowering that gearing too much!
I'm thinking that either you have to travel through much in-town city-traffic before you can get out into the country-side to enjoy a nice country-road ride, or, you're somewhat on the heavy-side for such a small motorcycle.
In any case, I suggest that you either replace the stock 18-tooth countershaft-sprocket with a 17t,, OR, replace the stock 40t rear-wheel sprocket with one that has 43 to 45t. _ This will lower 1st-gear to 14.88 - 15.81:1, and provide a fair compromise with Ducati's rather narrow spread of internal-ratios.


By Ken ...
" Another thing, I have always had some trouble shifting gears on the Ducatis i've riden, mostly from 1st to 2nd gear i get caught in between gears, not the real neutral setting though.
Do you know what could be the cause of this teeth gritting trouble for me? "

____ Please don't take any offense Ken, but I'm quite familiar with that rider's-error !! - (Bad Luck!) ...
Many people who are used to riding Jap-bikes, experience those false-neutrals regularly found between the gears on Ducati models! _ Here's why.....
__ Most-all riders learn to shift gears by the following method.....
1st.) - PULL-IN the CLUTCH-LEVER (as far as it will go);
2nd.) - PRESS the TOE/SHIFT-LEVER DOWN (until it has gone-down as far as it will [then happen to] go);
3rd.) - RELEASE PRESSURE FROM TOE/SHIFT-LEVER -(lift toe off shift-lever);
4th.) - RELEASE CLUTCH-LEVER -(let go of hand-lever) ...
At this point, the rider who uses this method, expects to have shifted into the next gear, but, if he has done so successfully, then it's only because LUCK was on his side that time! _ (As he could have just as well 'missed' the shift!)
__ You see, when the shift-lever is worked, it causes one pair of gears to disengage while also ATTEMPTing to engage another pair. _ However, the gears have 'cogs' -(slots) & 'dogs' -(finger-like stubs) which must engage/mesh with each other in order to complete a successful gear-shift! _ But what can often happen, is that instead of meshing within each other, the dogs may just happen to land on-top of each-other instead,, thus-then bringing the shift-lever to a (premature) stop, leading the rider to (incorrectly) assume that the shifting of the gear procedure has completed & should next be ready for use.
It's always a matter of luck, if at the particular moment when ya choose to work the shift-lever, that the dog-sets on the two engaging gears miss colliding with each other & successfully engage (fully) !
Most Jap-bikes increase the odds of a successful shift, by making the dogs thinner (and the cog-slots wider), but that comes with a cost! ... While that does indeed make it easier for the average-rider to successfully complete full-shifts, the downside is that there is then more drive-train slop -(that annoying lag -[like bad U-joints on a car], experienced during adjustments of the throttle).
__ There's a very simple way to assure that every single shift done on your Ducati (or most any motorcycle), is ALWAYS done fully & successfully !! ... Just adapt yourself to use the following shifting method.....
1st.) - PULL-IN the CLUTCH-LEVER (as normally);
2nd.) - PRESS the TOE/SHIFT-LEVER DOWN & HOLD IT DOWN -(not yet relaxing your downward-pressure!);
3rd.) - RELEASE the CLUTCH-LEVER ;
4th.) - RELEASE all TOE-PRESSURE from the SHIFT-LEVER .
This method will always assure a complete shift, EVERY time !
__ There will be times when you will feel your toe drop a little further downward as you release the clutch-lever... THAT lets you realize that that shift would have been one of those times when the gear-shift would've been missed, (using the normal/standard shifting-method which most everyone normally uses) !
That extra added drop you feel as the toe/shift-lever gives a tad more (downward), is the dogs falling off tops of each other & engaging (finally)!
____ It's not at all difficult to learn this new/unfamiliar shifting-method ! _ I've done it for decades, every since I discovered & taught myself to shift that way, back in the late-60s,, and without any consequence !
Be sure to try & learn it! _ Everybody! _ Especially those of you who seem to be natural 'TOE-JABBERS' ! - ('Toe-jabbers' most often don't realize who they are until they try to learn my suggested shifting-method.)


DUCATIly,
-Bob

[captpaul]

Dew-Cat-Ty Bob

My question for you, I am cosmically restoring a 64 125 Bronco. I own a dozen or so 250-350 singles with adjustable shift adjusters near the pedal. This Bronco jumps out of first a lot unless I hold the lever down a while, till first gear stays in gear,
then it's ok. My question is there an adjustment in the shift mechanism to better align the shift pattern?

[Eldert]

Hi Paul
looks like your a long time Ducati single owner to . just the other day i was going thru the old D.I.O.C. rags and who
introduces himself in issue nr 10 Paul M and if i am not mistaken that is you

by holding down the shiftlever you will blue and damage the selectorfork
dissasemble the engine and have the dogs undercut

Eldert

[DewCatTea-Bob]

" This Bronco jumps out of first a lot unless I hold the lever down a while, till first gear stays in gear,
then it's ok. My question is there an adjustment in the shift mechanism to better align the shift pattern? "

____ Well captpaul, I'm sorry I can't give you an answer near as detailed as I could if you were asking about one of the OHC-singles. _ As I never had any interest in those push-rod models!
That model always struck me as being so completely different, that they may as well had been made by just another of all the many non-descript Italian cycle-manufacturers which existed back in those days! _ Nothing really special about it! _ (Sorry, that's just how I feel about them.)
I did own a couple of Broncos for some time though, but only cuz both came into my hands along with a couple of trade-deals (which I only agreed to for the benefit of the other parties).
__ During all the years when I worked on DUCATI motorcycles, I worked on only about a hand-full of those Bronco models, however, no later than 1981! _ So any issues concerning them, is a relatively dim-memory for me!
I suspect that the issue you're asking about may be a common one, cuz I do recall that the number-1 area which required attention on those models, had to do with their shifting set-up!
I just can't recall exactly what, but what you have mentioned does not exactly ring-a-bell for me. _ But it's likely still related.
Most times, I think only an adjustment of some mechanism in there, was needed. _ But I also recall having to replace a worn part a couple of times, relating to the shifter-mechanism.
If only I could look-over what you have in there, I'm sure it would all come back to me again. _ I just can't see a 3D-picture in my mind of everything that makes a Bronco go, (like I'm able to with the OHC-models!).
I'm fairly sure that there's some adjustment which you can make in there that will allow full engagement into 1st-gear. _ As I recall however, it's something that ya have to be careful not to adjust & reset too far so -(more than necessary), or a new problem at the other extreme may result.
____ Have you taken anything apart and looked things over near the shift-lever area? _ If not, you should go-ahead and do so. (Be careful with the removal of the plastic gear-indicator.)
If it's not real clear to you what needs to be done, then how about posting a good picture or two, so I can then see & be reminded of what's all in there, and better recall what can be done to address your issue.

DUCATIly,
-Bob

[captpaul]

Eldert;

I bought a new Ducati 200, that looked just like a Monza in 1962, On a cold day it would bump 72-75 mph.
After Vietnam A 1965 Sebring Then a dozen 250s and a 350w/case 1978 900GTS my last is a 1965 bronco.
I have to paint and cosmetically restore a 2556 mi (lo millage ) bronco. The parts shop manual has an exploded view of the shifter that might be adjustable.A low millage bike shouldn't need dogs machined, would they? I've got a 63' blue Diana, a 63' blue scr, and a 1966 black scr to restore this winter.
Yes I joined DIOC way back. The editor of it used to come to Daytona bike week on an old 750 GT that was ratty to say the least, and sling the bull. A few years later I joined the Canadian Ducati Owners Club. A bunch of good guys. Only met a few of them at Daytona, I guess it's too long a ride for them. I own a push rod,a piece of a 2 stroke, and bevel twin, 10 or so singles.
No desmos,or bubber belt late models I belong to 4 other Ducati web sites, but honestly I like this one the best so far. Capt Paul