2020 update : JC Verdier La Platine

thank you @ledoux1238  - i also hope i never have to install that little thing,  it would well and truly test my soldering skills.  my linen diversion was prompted by me losing the silk thread.  but also because silk doesn't last long.  as it shreds one gets all sorts of speed issues.  i feel like a fool when i have enjoyed a record and then find i was running 0.5% slow.  i am glad you are having some luck with the rubber belt.  i might try one with the new motor but i cant get the la platine to spin slow enough when i use one it turns out.  i want to try "tape" next.  

how fascinating @pindac - i think i read about the famous hobbyist led LDA SC shootout.

yes Nick from long dog audio was very kind to reply to my email and I have very high hopes indeed.

the pulley is on the way (40 mm) and i am hoping for a moment as profound as the one i had when i first used it on the garrard.  "Tidiness" is a good word to describe it  although to me it sounded grander than that humble word might suggest.  i look forward to re-trying my garrard 401 soon now that i've had the la platine for a few months.  

 but also because silk doesn't last long.  as it shreds one gets all sorts of speed issues. 

This flabbergasts me.

I have been using surgical suture silk thread for 40 years on my TT - it's pulling a 26kg platter. I've only ever had one failure, when I went overseas for 2 months and accidentally left the TT running. Came back and the silk belt had broken.

My silk belts go for years without needing replacement.

I also ran surgical suture silk on my Verdier - no shredding or breakages on that either. Pretty sure that the silk belt on my Verdier ran for about 3 years until I sold it.

@dover suture silk is alot tougher than the silk thread i've been using. also i used floss as a belt once and it left wax all round the platter.  i then used a very sharp chisel to try and remove this wax and i roughened the surface of the metal.  so i think this makes my table uniquely thread shredding!

but speaking of which i found my silk thread spool last night and used it to make a fresh double loop.  i recant on suitability of linen.  the silk thread for me is the difference between a good table and something quite sublime.  it must be the noise.  late last night, when the good quiet power was running, i listened to kate bush (the red shoes) and princess chelsea and it was amazing.  profound even.

@mr_gray 

 i then used a very sharp chisel to try and remove this wax and i roughened the surface of the metal

This is pretty bad. The Verdier is designed for the platter to dominate the motor, not the other way round. You really should fix the platter.

If you use 2000 grit wet and dry sandpaper you can gently sand the platter rim  - what you do is smear some light oil over the rim to reduce the aggression of the sandpaper , and then gently spin the platter hold the 2000 grit wet and dry sand paper ( wetted ). This should take off any roughness while removing minimal metal. That Process is more gentle than most metal polishes.

With regard to Linen vs silk - after reading earlier posts I did some research on the merits. I was surprised to find the linen has less elasticity than silk, but linen is woven flax which is more course than silk which is softer. This might explain you preference for the silk. Note here that Verdier suggest very low tension with the Linen, silk you can run higher tension with less noise issues. The designer of my TT suggested chalked silk, which may be he intended a low level of tension, similar to the Verdier, hence the chalk to add a little grip.

Linen thread has wax in it and I'm pretty sure the Verdier linen thread is a low wax linen. Ideally you would want no wax.

Cleaning the platter -

I use heavy duty degreaser CRC Electroclean to degrease the rim, using a microfibres cloth, and then use electrical contact cleaner CRC CO to remove any residue from the degreaser. This works extremely well, and I have found that the platter stays cleaner and shiny much longer than with polishes.

I found the surgical silk leaves no residue.

I really appreciate the detailed pointers here. I will do this. Thank you.