Set of 3 racing type 'square section' clutch springs - these being of 1.620" length, this being a length commonly used on the Norton scolloped racing clutch (which used 4 plain plates, rather than the roadgoing clutch which used 5 plain plates) - read listing below for more detail. Price is for a Pack of 3
This listing is for a set of 3 clutch springs of 1.645" overall length of 'square section' coil, which were of the design commonly fitted to DOHC Manx Nortons in the 1950's/60's. The square section type spring has a bigger surface area across its X-section than round springs, for a given coil diameter, and are therefore stronger in comparision to the same length round springs fitted to standard models.
The racing clutch used one less clutch plate than the roadgoing clutch (4 plain plates rather than 5). This spring length should be suitable for this type of clutch - but if you are replacing existing springs, we suggest you check the length first - as there were various lengths of spring cups and spring bolts. Later racing clutch's i.e. post war also employed shouldered clutch spring bolts, identifiable in that they normally had a female 'square' head to tighten them up.
This length of spring should be suitable for this type of bolt - but you may find some racing clutch's have longer bolts or deeper cups - if this is the case, then we also offer a square section spring (Item 0386) with a length similar to the the standard road clutch - with a length of 1.845". I cannot be definitive, but this longer length of spring may have been fitted to some early racing clutch's.
It is also worth noting that there were various lengths of cups and clutch bolts (both male and female) - again, another reason to check the length.
Manufactured in the UK by a top quality specialist spring manufacturer to our specification. This square section spring type is now very diffcult to obtain, so this is an item we are very pleased to offer.
Update Feb 2020: We are currently in process of manufacturing the distinctive square head shouldered bolt for the Norton racing clutch of the 1940's/50's. This should be available in the next 3 months - email on firstname.lastname@example.org if you wish to reserve a set