speedo drive gearbox
-
- Posts: 20
- Joined: Sat Dec 03, 2016 8:09 pm
- Location: Derbyshire UK
speedo drive gearbox
hi all,i read somewhere about the speedo gear box turning on the spindle and locking up the wheel with the cable.what do i look out for to avoid this when refitting my rear wheel,cheers dave
D G SIMS
- dave16mct
- Member
- Posts: 3245
- Joined: Mon Jan 01, 1990 12:00 am
- Location: LANCASHIRE UK
Re: speedo drive gearbox
It usually only happens on the heavyweight models with full width hubs when incorrectly assembled. I've never heard of it happening on a lightweight (yet!)
Dave.
Dave.
-
- Posts: 20
- Joined: Sat Dec 03, 2016 8:09 pm
- Location: Derbyshire UK
- Rob Harknett
- Member
- Posts: 11211
- Joined: Mon Jan 01, 1990 12:00 am
- Location: ESSEX UK
Re: speedo drive gearbox
Speedo drive turning and winding up the cable on heavyweights, causing the wheel to lock, is due to the nut that tightens it is loose.
The nut in question can only be fully tightened after the wheel has been fitted and spindle nut fully tightened. In reverse. If you need to remove the speedo drive, you need to slacken off the speedo drive retaining nut first. I've never had a light weight drive off, I guess lightweight wheels have a different assembly.
The nut in question can only be fully tightened after the wheel has been fitted and spindle nut fully tightened. In reverse. If you need to remove the speedo drive, you need to slacken off the speedo drive retaining nut first. I've never had a light weight drive off, I guess lightweight wheels have a different assembly.
- clive
- Member
- Posts: 5669
- Joined: Mon Jan 01, 1990 12:00 am
- Location: LONDON UK
Re: speedo drive gearbox
Not sure that it only happens when incorrectly assembled. If the worm drive is worn then it and the ring in the Speedo drive box can cross thread and seize. This will then tend to turn the drive box with the wheel and rip the cable from the head.dave16mct wrote:It usually only happens on the heavyweight models with full width hubs when incorrectly assembled. I've never heard of it happening on a lightweight (yet!)
Dave.
clive
if it ain't broke don't fix
if it ain't broke don't fix
- Janet
- Member
- Posts: 4131
- Joined: Mon Jan 01, 1996 12:00 am
- Location: EAST YORKSHIRE UK
Re: speedo drive gearbox
Why wouldn't/couldn't it happen on a lightweight? I'm aware that lightweights and heavyweights have different types of spacers, nuts etc, but isn't the basic method of holding it all together the same? It's a serious question. Unlike some other people, I do have intimate and, sadly, frequent knowledge of what's fitted on my lightweight rear wheel spindle, but I don't know what's on a heavyweight.dave16mct wrote:It usually only happens on the heavyweight models with full width hubs when incorrectly assembled. I've never heard of it happening on a lightweight (yet!)
Dave.
-
- Posts: 20
- Joined: Sat Dec 03, 2016 8:09 pm
- Location: Derbyshire UK
- dave16mct
- Member
- Posts: 3245
- Joined: Mon Jan 01, 1990 12:00 am
- Location: LANCASHIRE UK
Re: speedo drive gearbox
On the heavyweight full width rear hub, the speedo drive fits on the bearing adjuster. If assembled incorrectly this can unscrew causing all kinds of damage. The lightweights have non adjustable bearings, so the speedo drive fits directly onto the hub. Obviously make sure it's located propery on the slots of the hub and is in good condition. Same applies to pre full width hub models. Not sure about '63 inerim and '64 on Norton wheels.
Cheers Dave.
Cheers Dave.
- Janet
- Member
- Posts: 4131
- Joined: Mon Jan 01, 1996 12:00 am
- Location: EAST YORKSHIRE UK
Re: speedo drive gearbox
Ta everso.
Every day's a school day.
Every day's a school day.