Cable lengths - Quick action throttle

Status
Not open for further replies.
Joined
Mar 11, 2006
Messages
98
Anyone know what the front throttle inner/outer cable length difference should be for a Norton quick action throttle?

Just in the process of fitting one and the so called 'correct cable' I've just bought for a quick action throttle seems to be to short - Its got 60mm of inner cable protruding with the cable adjuster screwed fully in. This is not long enough and won't let the carb slides seat when its fitted.

At a rough guess I think the inner cable should be about 80 to 90mm longer than the outer for a quick action throttle. Can anyone confirm this before I return the cable for an exchange?
 
Joined
May 19, 2006
Messages
1,612
Country flag
What twistgrip are you using Mike ? I have a twinpull Tommaselli Daytona 2C and made up cables for it. I'm not sure that it's quite as quick-action as some of the motocross styles with a huge drum. It needs just over 1/4 turn from closed to full throttle.

Off the bike, my cables have 112 mm free length with the in-line adjuster screwed in. Are you measuring with the slides connected ?

Does this help at all ?
 
Joined
Mar 11, 2006
Messages
98
Its the proper Norton one - part 064600 which is a single pull quick action throttle, with the front throttle cable I've bought - part 064601 to suit. The problem is it doesn't :(

I'm not certain what length the standard Norton front cable is as I'm changing from an Amal twistgrip (which is a different length cable to a standard Norton twistgrip) but I have a sneaky feeling the front throttle cable I have been sold is for the standard Norton twistgrip and not a quick action one.

The length quoted is with the cable off the bike and the adjuster screwed fully in. Also its about a quarter turn travel on the Norton quick action throttle, can't wait to try it - should be a vast improvement over a handfull and a half :!:
 
Joined
Jan 10, 2005
Messages
1,043
Country flag
Mike
Had the same issue and had to shorten cable for a new AMAL twistgrip from Surrey cycles recently. The old Wassell quick action (1/4 T) from Norvil (my spare) has 82mm inner including nipple with inline adjuster screwed down.
Depends if you have an insert/ferrule at the t/g end. the Wassell used one, the AMAL doesn't and that increases the inner length needed by appx 6mm. Hope that helps.
 
Joined
Mar 11, 2006
Messages
98
Keith1069 said:
The old Wassell quick action (1/4 T) from Norvil (my spare) has 82mm inner including nipple with inline adjuster screwed down.
Depends if you have an insert/ferrule at the t/g end. the Wassell used one, the AMAL doesn't and that increases the inner length needed by appx 6mm. Hope that helps.

Thanks for that one Keith - the lengths you quoted make complete sense.

I went to Norvil and we checked all the cables in stock and none suited the quick action throttle. The Norton part number for a quick action throttle cable turned out to be for the Amal grip I'd just taken off. (Thats Andover Norton stock for you - why do they use a Norton part number for something different instead of giving it a new original number???)

Eventually I bought the nearest cable Norvil had and modified the length so that 85mm of inner was available. Fitted it with insert sleeve and all now works fine.
 
Status
Not open for further replies.
Top