Spitfire Mk4 Rear Spring Rebuild

[Douglas]

Hi

I'm rebuilding my Spitfire Mk4 rear spring but I'm not certain I have the correct pads/buttons.  When I stripped it I'm pretty sure I removed 8 pads but I've been given 4 new ones and that seems to tie with the parts manual.  The new pads are cylindrical and about 7/8^th inch diameter and 1/8^th inch high.  (See picture).  Do I have the correct pads?  Do I need 8?  Any other tips for reassembly?

Thanks

Doug

[PhilDav]

On Facebook, there is group "Triumph Spitfire Owners" 

The moderator on this is Rob P Turner" 

I think he had a stack of these buttons made, for a nominal charge. 

[Auldman]

On 05/03/2024 at 20:51, Douglas said:

Hi

I'm rebuilding my Spitfire Mk4 rear spring but I'm not certain I have the correct pads/buttons.  When I stripped it I'm pretty sure I removed 8 pads but I've been given 4 new ones and that seems to tie with the parts manual.  The new pads are cylindrical and about 7/8^th inch diameter and 1/8^th inch high.  (See picture).  Do I have the correct pads?  Do I need 8?  Any other tips for reassembly?

Thanks

Doug

 

Firstly, I think you  may have made a wise  move by restoring your old spring rather than going for a new one, as a surprising number of people ( including me ) have found new some springs  to be very disappointing .I sent one back to a well-known supplier, (who readily refunded me, to be fair)

For a Mk 1V,  Ie with swing spring, there would have been eight of these.

There seems to have been two different diameters.

Originals were made of rubber.

Other more  suitable materials have been used which are longer -lasting

- including Teflon, polyurethane,Acetal.The most wear resistant  is probably UHWPE* - ultra high weight polyethylene.

Different thicknesses of these ‘ buttons’ or ‘insulators’ can influence ride- height  significantly ( though this can be usefully exploited if the spring has sagged to some extent)

* I made some from this material, turning them from 41. mm bar stock  on a lathe.

It is quite a cheap material but because  of its extraordinary ‘ tough / slipperiness’, I found it really frustratingly difficult to work with  -producing a growing pile of failures to get eight good ones!

( btw Acetal , perhaps second best to UHWPE   but superior to Teflon,  is  very easy to turn )

 

[Douglas]

On 06/03/2024 at 17:08, PhilDav said:

On Facebook, there is group "Triumph Spitfire Owners" 

The moderator on this is Rob P Turner" 

I think he had a stack of these buttons made, for a nominal charge. 

Thanks both!  Looks like I do need more isolators and of a different shape - more as you've shown Auldman - rather than the cylindrical ones I have.  Hopefully that will be all I need!  

Cheers

Doug