Scooterotica

got an advisory on a non self closing throttle, this years mot is looming and despite friction free cables and a healthy throttle slide spring in my phbl it refuses to self close, so i was thinking of putting a return spring on the throttle rod, can anyone suggest a source of suitable springs, i imagine the circular type with one tang in the rod and another in a stop on the bar

Its not an MOT requirement, so let him 'advise' away.

You should only have a self closing throttle if you have indicators. If you have to use hand signals, you have to have an interference fit throttle otherwise, when signalling a right turn, your throttle would snap shut and, possibly, lead to you losing control if you were going fast.

dave wheeler wrote:got an advisory on a non self closing throttle, this years mot is looming and despite friction free cables and a healthy throttle slide spring in my phbl it refuses to self close, so i was thinking of putting a return spring on the throttle rod, can anyone suggest a source of suitable springs, i imagine the circular type with one tang in the rod and another in a stop on the bar

Scooter Restorations have a supply of Spanish throttle return springs. They were fitted as standard to certain Serveta models.

(I presume you are referring to a Lambretta? If it's Vespa, most decent parts dealers will stock throttle return springs that come as standard with PX's).

Completely agree with Storkfoot, if you ain't got indicators fitted, forget all about throttle return springs.

I used an elastic band inside the headset to close the throttle on my old race bike. I recall one end was hooked around the cable nipple.

Knowledge wrote:I used an elastic band to close the throttle on my old race bike.

Cheaper than a Pound Shop genuine cock ring that is you Pikey!

"Scooter Restorations have a supply of Spanish throttle return springs. They were fitted as standard to certain Serveta models.", 100% right

I've bought a number of these from Scooter Restorations and they fit and work a treat, giving a really good action and snapping the throttle shut. I started to fit these to bikes that I was sprinting in the classic bike comps, for which a self-closing throttle is required. They take a little bit of work to fit but then provide a really positive action.

This has been covered on here or LCGB, with detail and photos. If you Google the subject you will probably find the photos of the assembly.

Adam

My "home brew" version

additionally you dont say anything about whether or not you have plenty of grease on the rod and the throttle handlebar grip to ensure that's smooth?

I got the same advisory but as I had fitted indicators all I could say was I would have a look. In my case the bar end indicators have a Mylar tube through the bar end bush to help protect the wire from rubbing. I may have to rethink that one with some silicon wire as it makes your wrist ache on a long ride. Just a thought if you preload it with a spring.