Advantage in drilled cam gears ET157/1 ?

[Vincent Brake]

What I do, to lighten the lot, is get the gears, (nowadays made from hardend and high temp annealed like 4015, then Nitreded) is have the big idler fitted with a new bush as good centered as possible (i use pins on the gear, to centralise in soft jaws) then run them in with diamond paste on a lathe against the respecive cam (with the gear on). each takes an 2-4 H to do, side from left to right, until my eyes blurr. at that time its mostly yust about OK and i measure about 0,01-0,02 difference, now one can set the whole in the casing, virtually without any play, (its getting when hot), and NOT having a heavey point.

its far better lightening this way than yust machine some off, but as read before in this thread, now and then super sneakers might get attention by the girls

HA the sun is out and i am ging for a spin....
bye

 

[Big Sid]

An important point . The hard case on followers extends down only 30 / 35 thou. deep . Sid .

 

[highbury731]

So, what you are doing is to grind the gears into each other so that they run more smoothly. How do you judge when this is done sufficiently?

 

[redbloke1956]

So, what you are doing is to grind the gears into each other so that they run more smoothly. How do you judge when this is done sufficiently?

If one rotates and the other does not, then you have gone too far

 

[Vincent Brake]

I do it on a precision lathe, and one can notice if it is running smooth all the way round, when togelling with the cross slide. (more or less gear play) I use 1,4 Ym diamond paste and later clean with a ultra vibration bath (one does not like the paste in the oil)
Vincent-Brake.

the spin still dit put some salt on the bike need to clean it...

 

[bmetcalf]

At least a few years ago, Dave Matson's bike had thinned and drilled cam wheels.

 

[riptragle1953]

Because whoever made that decision had a sense of humor?

 

[riptragle1953]

There's enough beef on those gears to do about anything you want. The advantage to neatly radiused and polished gears is they are really pretty.... and that's something worth while!

 

[riptragle1953]

Sid is right... and they are quieter and more efficient. You are done when thy are smooth.

 

[Big Sid]

Another very rare but very desirable piece is the big idler support . Originally a two piece , the base of alloy with its steel shaft an interferance fit . These rarely stay tight but red Loctite does a good job of restoring the fit if properly done .
The racing piece was a forged one piece steel component developed for the Picador drone motor , trouble free and lasts forever . My drag bike and street bike used these . Sid .