Author Topic: Custom Transmission Gears  (Read 3642 times)

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Offline grcamna2

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Re: Custom Transmission Gears
« Reply #25 on: August 27, 2021, 11:20:11 AM »
Its a new concept to me, goes against all the tgeory we were taught.
 So i can see changing the big one a tooth or two,  but changing the smaller  even 1 tooth would really affect clearance a lot.
 Must be increased wear ir noise when doing this ?

It is quite commonly done. These are stock Honda starter gear parts.
Old man Weissman, RIP, of Weissman Transmissions got his big start by changing ratios with only one of the gears for racers.
Most gear calculation software has the option to allow shifted profiles.

Cannot answer your last questionl

I'm just learning on this.Do the factory gears have enough clearance in their tooth engagement engineered into them to allow a one-tooth change on a single transmission gear in the cluster ?   thanks,Bill
75' CB400F/'bunch o' parts' & 81' CB125S modded to a 'CB200S'
  I love the small ones too !
Do your BEST...nobody can take that away from you.

Offline kmb69

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Re: Custom Transmission Gears
« Reply #26 on: August 27, 2021, 05:13:59 PM »
Its a new concept to me, goes against all the tgeory we were taught.
 So i can see changing the big one a tooth or two,  but changing the smaller  even 1 tooth would really affect clearance a lot.
 Must be increased wear ir noise when doing this ?

It is quite commonly done. These are stock Honda starter gear parts.
Old man Weissman, RIP, of Weissman Transmissions got his big start by changing ratios with only one of the gears for racers.
Most gear calculation software has the option to allow shifted profiles.

Cannot answer your last questionl

I'm just learning on this.Do the factory gears have enough clearance in their tooth engagement engineered into them to allow a one-tooth change on a single transmission gear in the cluster ?   thanks,Bill

Clearance in tooth engagement is called backlash. It is usually approximately 0.005", more or less, depending on the size and pitch of the gears.
That in itself will not allow the ratio to be changed. The "pitch" of the altered gear cannot be changed but the pitch diameter, tooth profile, and number of teeth can be.
Typically, I think this involves reducing the tooth count on one of the gears and "fattening" the tooth form. a profile shift, to take up the "slack".
Going the other direction, thinning a tooth form, would probably weaken the gear's tooth form too much.

I just updated my Takisawa to precisely synchronize the main spindle with the milling spindle and bought a WTO gear hobbing unit to make some gears for myself.
This is being done to accommodate my CB750 billet crankshaft gear drive project. Already have the crankshafts. Attempting to machine the mating parts.

I am not an expert on this - just learning actually. I consider gear making to be "Black Magic" at this point, but it is quite interesting to me.

Offline gschuld

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Re: Custom Transmission Gears
« Reply #27 on: August 27, 2021, 06:17:48 PM »
Keith, you are a brave and talented guy.  I may question your sanity at times, but never your skills or determination.

I do look fwd to seeing that geared primary sohc in action.

George

Offline grcamna2

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Re: Custom Transmission Gears
« Reply #28 on: August 27, 2021, 06:46:34 PM »
Keith, you are a brave and talented guy.  I may question your sanity at times, but never your skills or determination.

I do look fwd to seeing that geared primary sohc in action.

George

I think Gear Primary is a great idea for our vintage sohcs  ;)

I like what Keith said about changing the tooth profile:got it.
« Last Edit: August 27, 2021, 09:36:18 PM by grcamna2 »
75' CB400F/'bunch o' parts' & 81' CB125S modded to a 'CB200S'
  I love the small ones too !
Do your BEST...nobody can take that away from you.

Offline gschuld

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Re: Custom Transmission Gears
« Reply #29 on: August 27, 2021, 07:15:48 PM »
Honda race department thought so too.  And they then dominated endurance racing with their RCB 1000 racers that started off with a modified sohc bottom end(with custom greared primary drive in custom cast cases) and a DOHC 4v head grafted on.

Not justifiable for street engines, but for really high end sohc race engines, that’s impressive equipment.  It takes dedicated talented masochists like Keith to actually make it happen.

George

Offline simon#42

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Re: Custom Transmission Gears
« Reply #30 on: August 28, 2021, 03:47:57 AM »
The quote for a pair of gears is 400 euros. I thought the price was reasonable. We will see if they deliver quality parts in a timely manner.

that is a good price i am interested to see how you get on . i have a couple of restoration projects that need gears that are no longer available .

Offline johno

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Re: Custom Transmission Gears
« Reply #31 on: August 28, 2021, 07:06:58 PM »
Speaking of surprises and gears, I see Honda have a contracting company in Italy that manufactures their transmissions and clutch hubs etc
They must be good. ;D

They do work for other companies as well but not at a price for the average enthusiasts. The set up costs where it hurts, Developing the CAD blueprints for their CNC machines takes $
GRASSHOPPER SOHC HONDAS ARE THE MEANING OF LIFE.

Offline turboguzzi

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Re: Custom Transmission Gears
« Reply #32 on: August 30, 2021, 03:40:17 PM »
Speaking of surprises and gears, I see Honda have a contracting company in Italy that manufactures their transmissions and clutch hubs etc
They must be good. ;D

They do work for other companies as well but not at a price for the average enthusiasts. The set up costs where it hurts, Developing the CAD blueprints for their CNC machines takes $
company in italy? im all ears....

Offline MRieck

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Re: Custom Transmission Gears
« Reply #33 on: August 30, 2021, 07:20:44 PM »
One of my customers had special CBX cam gears made so we could change cam timing. I'm not going to get into the CBX cam thing with the gears but this fella made the gears. Not cheap but he made them from blank. I'll dig up his name tomorrow. Maybe he could help you.....gears are his thing.
Owner of the "Million Dollar CB"

Offline johno

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Re: Custom Transmission Gears
« Reply #34 on: August 31, 2021, 05:03:16 AM »
The gear manufacturer company is based in Bologna.
Costruzione Italiana Apparecchi - S.p.a

Web site "via-spa.com"

Ph: 0542 487 411

I used them once to makes some spare gears for Velo wine filters I used to sell, after Velo ( near Montebeluna ) went bankrupt . I didn't know at the time they were making transmissions and oil pumps for Honda bike division.
GRASSHOPPER SOHC HONDAS ARE THE MEANING OF LIFE.

Offline johno

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Re: Custom Transmission Gears
« Reply #35 on: August 31, 2021, 05:06:05 AM »
oops ciapspa.com  :o
GRASSHOPPER SOHC HONDAS ARE THE MEANING OF LIFE.