Speedo worm wheel problems

[Lambr62]

Hi,
Wonder if anyone can help with this problem? I have recently changed the worm wheel at the cable end and the drive wheel that is located in the Hub for the second time. The hub drive wheel is now a metal one and the worm wheel at the cable end is plastic. I have been having problems with speedo waving at me regularly. After going out on it after putting it back together the speedo still doesnt work and i found when i took the worm wheel out it again it was damaged where the Hub wheel looks like it has just rubbed the worm wheel teeth away. Seems to me it is not meshing properly. I noticed that the original drive wheel was wider than the new one. When i put the new one on and it is set flush to hub face it does not sit against the shoulder on the hub by quite a few mm's. Should the drive wheel be pushed all the way upto the shoulder on the hub? I am confident that the speedo is okay as i have tested with a drill attached to speedo cable and the needle runs nice and smooth. Hope some one can help.

[IaninDorset]

From experience with metal Vespa ones, you probably want to check no bits of metal have gotten into any bearings as that was always the con with all metal speedo assys that if they broke up, it could mean anything from a twinkled bearing to a full seizure and over the handlebars experience

Perhaps utilise some engineers blue and mesh it together and see where the blue shows its meshing and adjust accordingly so you get the best direct engagement.

[HxPaul]

This might help viewtopic.php?f=10&t=1068

[terryj]

i have chewed a speedo up and the saw an article in scootering that showed me where i went wrong
i had been putting plenty of grease on to stop wear but what happens is the grease gets compacted into the grooves and causes the wear what you have to do is just put on a small smear of vaseline( this is for nylon speedo)

[Lambr62]

Hi,
I did some more checking earlier and found the speedo cable turns okay if i spin the wheel in the oposite direction to normal. When i spin it as if being ridden normally the cable starts to rotate briefly then stops. Very confusing.

[peejay]

Hi,
I did some more checking earlier and found the speedo cable turns okay if i spin the wheel in the oposite direction to normal. When i spin it as if being ridden normally the cable starts to rotate briefly then stops. Very confusing.

sounds to me like the two parts are not meshing correctly.

i would suggest NOT mixing plastic and metal cogs.

are you sure the axle cog is fitted correctly as suggested above?

[HxPaul]

I had a problem with a brand new inboard disc brake from ScootRS.The hub drive gear for the speedo was a sloppy fit on the hub,when I spun the wheel with the cable in it worked,but when built up and driven it didn't.This caused a lot of head scratching,changed the speedo,still no joy,changed the cable still nothing.Eventually found the problem and used loctite 270 thread and bearing lock on the drive gear,built it back up and its worked ever since.

[Rich Oswald]

I use the cheap metal drive wheel and worm off ebay, not the same quality as MB one's but last much longer than the plastic ones,

Rich'

[Lambr62]

Thanks for all the helpful info. Will be doing some more investigation over the weekend.

[kevinneil]

I know this might be a bit of a stupid question but hey ho. How do you get at the drive on the hub, I've removed the front wheel and can't see how I get to the speedo drive gear that turns the worm drive, can anyone help?

[HxPaul]

Unfasten the wheel spindle nuts and remove the brake plate,you will see the hub speedo gear once the brake plate is removed.

[kevinneil]

I did that but the brake plate didn't want to come off, should i just apply some more force?

[HxPaul]

The inner half nuts have to be unfastened from the wheel spindle.

[gaz_powell]

Best set up todate for me has been a metal drive (the part on hub) off ebay and a scootopia plastic worm. Got this set up on a scootRs hydraulic hub and SIL drum.
I've tried several set ups in scootRs hub including the expensive all metal MB one, which was set up off the bike and meshed with grinding paste etc etc.

I don't like the idea of metal on metal and think vespa got it right with the metal drive and plastic worm, as the worm is the sacrificial part that goes and is easy to replace.

That said my jet front hub (Spanish hub) has a unknown origin plastic drive and worm and has been spot on for years (in a TS1) and I just threw that together.

Setting them up seems to be part experience and luck with compatibility of the numerous different hubs/backplates/drives etc with a bit of trial and error. I don't think there's any formula.