Are these repo speedo gear boxes any good?

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This is the upgrade a forum member does for the speedo drive.It makes the drive unit bulletproof.
 

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Are these repo speedo gear boxes any good?
 

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YING said:
This is the upgrade a forum member does for the speedo drive.It makes the drive unit bulletproof.
Click to expand...
So it seems to replace the area prone to squishing from axle torque, which leads to pot metal casing extrusion out of plane, into contact with hub cover, leading to machine against cover and Black Star of Death scenario.

Where is this service offered and how much $ ?
 
Tornado said:
So it seems to replace the area prone to squishing from axle torque, which leads to pot metal casing extrusion out of plane, into contact with hub cover, leading to machine against cover and Black Star of Death scenario.

Where is this service offered and how much $ ?
Click to expand...
He has a bunch of the adapters made up. I will talk to him today and see what he wants to do.These are well thought out and work beautifully.
Mike
 
YING said:
He has a bunch of the adapters made up. I will talk to him today and see what he wants to do.These are well thought out and work beautifully.
Mike
Click to expand...

Ask how he deals with the different bore sizes that originals came with. The top hat spacer was one way to adapt a particular bore to a particular spindle (axel).

I would be interested in one if price is reasonable.

Slick
 
texasSlick said:
Ask how he deals with the different bore sizes that originals came with. The top hat spacer was one way to adapt a particular bore to a particular spindle (axel).

I would be interested in one if price is reasonable.

Slick
Click to expand...
AFAIK, all mainstream British Bike manufacturers other than Norton had the drives made to fit their axles. Norton used a BSA drive with Norton's little "top hat" spacer to make it fit their smaller axel. Also, AFAIK, all Nortons with magnetic instruments had the same issue and there was only one drive. I've never seen the problem with bowed housing on properly assembled Triumph or BSA and if tightened too much, all Commandos (at least) will have the problem. The workshop manual just says "tighten fully". From my Commando Torque page, i say:

Rear wheel spindle (one bolt) 80 ft-lb. Norton simply says: “tighten fully”. Andover Norton and Old Britts say 80 ft-lb. I say that is more than needed and will damage the speedometer drive. I make it tight with a standard ratchet – maybe 40-45 ft-lb

More and you can watch the housing deform! Judicious hammer use can correct the bow and make the drive usable again.
 
@ gregmarsh.
While I fully agree with you, I never tightened my axle nut to more than snug, probably less than 40 ft lbs. Never the less, I suffered housing bow and gouging of the hub cover plate. I removed the bow by squeezing with a vise and a judiciously sized socket. But the fix was only temporary as the ring gear was hopelessly worn. I obtained a NOS drive but the bore was oversized. That was rectified by TimeWarp who turned up a spacer to fill the gap, at no charge, and he bore the cost of shipping!
 
texasSlick said:
@ gregmarsh.
While I fully agree with you, I never tightened my axle nut to more than snug, probably less than 40 ft lbs. Never the less, I suffered housing bow and gouging of the hub cover plate. I removed the bow by squeezing with a vise and a judiciously sized socket. But the fix was only temporary as the ring gear was hopelessly worn. I obtained a NOS drive but the bore was oversized. That was rectified by TimeWarp who turned up a spacer to fill the gap, at no charge, and he bore the cost of shipping!
Click to expand...
Ya, if the "top hat" doesn't fit the drive and axel properly or the internal spacer or outer spacer is not right it can still warp. The drives are designed to have a simple, correctly dimensioned spacer inside and outside. the "Top Hat" is the thing that must fit everything exactly and usually doesn't because it is too soft and not exactly sized. Having a properly sized drive would be perfect but it's too late for that. Having proper new inside and outside spacers where the inside or outside fixed the drive hole side and slipped into the other so that had to be perfectly aligned would be the complete fix. I haven't had my hands on any of the fixes and I don't have a lathe, or this would have been resolved long ago at least for me.
 
I'm the one that modified Mike Yingling's speedometer drive.

Basically the modification consists of a machined spacer that takes the place of 3 spacers: One being the spacer between the wheel bearing and the speedometer drive; the speedometer drive itself and the top hat spacer.

This custom spacer was designed to work with LF Harris speedometer drives. I chose LF Harris speedometer drives because apparently they use hardened gears, while other manufacturers don't necessarily do that. I really don't know if any other brand of speedometer drive would work with my modified spacers. What I do with a new speedometer drive is remove the 4 rivets that hold the gear retaining ring and discard the ring, chuck the speedometer drive in a lathe and bore the center hole to a 1 inch diameter. The rivet holes are then drilled and countersunk for four 4 - 40 flat head machine screws.

The modified speedometer drive is then mounted to the spacer's flange using the four screws. The flange also doubles as the gear retainer.

As far as the hole size in the speedometer drive is concerned, it doesn't matter because the hole is bored out to 1 inch. A gear ratio of 15/12 is also the same as a 1 1/4:1. I also put a little bit of silicone seal between the speedometer and the flange so it seals out water.

To remove the inner spacer you need to remove the inner lock ring with the appropriate spanner. The felt seal for the wheel bearing can no longer be used so I would recommend getting a sealed wheel bearing.

Finally I would get a new wheel hub cap because the speedometer drive will never dig into it again.

If you are interested in something like this, pm me.

Peter Firkins
 
texasSlick said:
I use a pump syringe grease cartridge meant to lube the bar of a chain saw. You can find them where chain saws are sold.
It also works well to lube the shoe actuating cams on my front brake plate. Most cams can be easily modified if not so provided.

Slick
Click to expand...
Like Slick said. Made in Germany of all things!

 
PeterJoe said:
I'm the one that modified Mike Yingling's speedometer drive.

Basically the modification consists of a machined spacer that takes the place of 3 spacers: One being the spacer between the wheel bearing and the speedometer drive; the speedometer drive itself and the top hat spacer.

This custom spacer was designed to work with LF Harris speedometer drives. I chose LF Harris speedometer drives because apparently they use hardened gears, while other manufacturers don't necessarily do that. I really don't know if any other brand of speedometer drive would work with my modified spacers. What I do with a new speedometer drive is remove the 4 rivets that hold the gear retaining ring and discard the ring, chuck the speedometer drive in a lathe and bore the center hole to a 1 inch diameter. The rivet holes are then drilled and countersunk for four 4 - 40 flat head machine screws.

The modified speedometer drive is then mounted to the spacer's flange using the four screws. The flange also doubles as the gear retainer.

As far as the hole size in the speedometer drive is concerned, it doesn't matter because the hole is bored out to 1 inch. A gear ratio of 15/12 is also the same as a 1 1/4:1. I also put a little bit of silicone seal between the speedometer and the flange so it seals out water.

To remove the inner spacer you need to remove the inner lock ring with the appropriate spanner. The felt seal for the wheel bearing can no longer be used so I would recommend getting a sealed wheel bearing.

Finally I would get a new wheel hub cap because the speedometer drive will never dig into it again.

If you are interested in something like this, pm me.

Peter Firkins
Click to expand...
In your original post back in 2015, you mentioned maybe getting a cnc shop to make a production run of these. Any further steps? Member Madass140 makes a bunch of custom Norton specific parts for the members here from his base in the Philippines. Perhaps you should approach him to work something out?
 
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