Building high-end 'tables cheap at Home Despot II

Jean; Thanks for the tip on how to further improve The Mighty Lenco. As you know, I am already extremely pleased with the Lenco you rebuilt for me and my particular Lenco is just a 75 pounder (i.e. presumably no where near the performance of the massive Lenco Reference). I really did not think you could make further improvements to this design but I was clearly wrong. Well done!
As tempting as it is to jump right in and do the TJN Mod myself, I think I will wait for your kit. It seems to me that $60 is very reasonable (in this hobby, this is a laughably small amount) and the kit will take the hard part (getting the weight right) out of the equation.
Once again: Thanks and well done.

I certainly would not want to argue the question of whether this new mod actually improves sound quality, which it may well do, but on the level of theory, I have a question: Why would one expect the string not to transmit vibration, as compared to a spring? Sources of vibration could be (i) the bearing of the idler wheel, (ii) irregularities in the shape of the motor drive shaft, or (iii) dirt or other on the underside of the platter that might cause the idler wheel to bounce a bit. The force applied by a spring to maintain contact between motor shaft/idler wheel/platter will vary according to Hook's Law, which says that F is a linear function of the amount of stretch of the spring. The force applied by the string to do the same would be equal to gravity less any frictional losses where the string touches anything. I don't get why (theoretically) the string would obviously be a better way to do the little bit of work (small force X a very small distance) that is required. I guess you are saying that the spring itself is a source of noise/vibration that mucks things up; yes?

Fourth and probably most obvious source of vibration of the idler wheel: Deviation of the idler wheel from perfect round-ness and roughness at its contact surface. The spring or string may or may not be the major player in maintaining contact among drive shaft/idler wheel/platter, as idler wheel bumps along. A knowledgeable friend of mine thinks that the idler wheel is held in place primarily by the platter/drive-shaft "squeezing" effect, as both of those rotate, i.e., the spring or string is pretty much out of the picture once power is applied to the motor. Dunno about that. Still don't see how the spring can do much that is bad, once the platter is turning.

This is not to say that the whole idler wheel, idler arm, and spring set-up could not be improved upon, but I think it would require a radically different approach. Win Tinnon has done that in his Saskia, but he won't say how, and I don't blame him a bit for that.

WARNING....Actual Ear Witness Account!
I have heard the TJN Mod at Jean's place and knew it was a hit...I also have had enough experience with Lencos of all shapes and sizes to know I have had issues with that spring. I have often tested torque by placing my hand at the edge of the platter - and then clipped the spring as a quick fix.
So Jean stopped by today with his drill, template and mod kit to de-spring my Reference Lenco. I will post some photos of the latest system and also of the mod kit in my systems page (I haven't updated that page in quite awhile!) I have been running a Reference Lenco for about 2 months and have been smitten, Fidelity Research FR64S tonearm with a 90th Anniversary SPU. I'm using a Dact Kit Phono Stage with the dual Dact Power Supplies thru an Audible Illusions 3A (with the John Curl Gold Phono board ...although that is not being used at the moment) with Fisher Model 200 Mono Amps (1962...Interstage Transformer...El34s are the Treasure Tubes) and all this plays music out of the Electro-Voice Patrician 800 Speakers - I had been very impressed with the bass from the 30" woofers since the Reference Lenco was installed... and was curious and maybe even a touch skeptical that the Mod would make THAT any better... I was in for a surprise, there wasn't a single sonic area that wasn't improved....detail, imaging, depth, highs, bass...did I miss anything??
We listened to 2 tracks, both tracks we know well and have used a million times. First was Larry Carlton's Alone/But never alone LP, its one of those guilty pleasure LPs but it sounds great and is Fun .. Next up was the 45RPM on Clarity Vinyl of Holly Cole's Temptation (we actually cheated and played the 2nd and 3 rd tracks on side A)
The Reference Sounded amazing..as it has sounded since the day it was installed!
Jean did the Mod on my living room floor in about 20 minutes, using the template to mark the hole, drilling the hole and then removing the motor to allow room for a hand to secure the string tube/lock nut and washer.
Then I fired up the Lenco and the first thing I did was test the torque, Holy Shit! I could tell immediately that the torque was a lot stronger, hard to slow the turning platter, I knew this was going to be good!
The Larry Carlton sounded great from the opening notes, I could tell immediately that my 30" woofers were a lot more controlled, those lowest HZs were a lot more tuneful, bass lines were easier to follow and up thru the midrange... the slam, oh the slam, Its the slam that I love from these Lencos (most Idler wheels!) and that power in the midrange was amazing..It was pretty damn good already but it was now clear that this little string had improved everything! Bass...Midrange but it was the highs I was most impressed with, the Larry Lp has a lot of ear candy, and it was hung out there perfectly..man this is what a Turntable is Supposed to do! OK now onto Holly Cole, this LP can sound pretty darned good, it has some astounding low bass and the Lenco controlled it and resolved it to even greater perfection. I have been struck by the fine details as never before, This whole idea
of being able to hear the subtlest breathing..smacking of lips... like someone is in the room with you, and its almost spooky...

I spent the day playing one LP after the other. Never a single disappointment.

Now, if you are building or owning a Lenco out there, TRY THIS! Its not a hard tweak to Implement (and its free) and I have been reading over on Lenco Heaven some reports from people that have actually tried it and noticed the improved TORQUE!!I think this added speed stability is really audible to these ear PLUS all the Sonic improvements that come with the Torque, try it on your ears.

Clarification please, Johnwdt. You say the tweak is FREE. How can that be?