É muito simples e barato! Cada roldana ficou-me por 1,5€, e já vêm com rolamentos selados.
A roldana de cima encaixa num parafuso normal para travões (daqueles que ficam agarrados á suspensão ou ao quadro quando tiras os V-Brake). A rosca é a mesma medida para o eixo da escora. De resto, são parafusos e anilhas normais

Tenho que por aqui as fotos do kit, a explicar.

  HAHAHA, realmente, já temos fama! Como dizem lá fora "to pull a MacGyver"!

Agora funciona ainda melhor, porque "escavei" mais um pouco o interior das roldanas, por isso agora a corrente encaixa mesmo bem. Assim pude retirar a cobertura em aluminio que tinha antes, e a parte superior do guia da corrente antigo, que estava a apoiar essa cobertura.

 It still need's some improvement...
I'll keep you all up to date

 Obrigado

 Hutchinson Octopus 2.8 (71-559) in the front
Kenda Nevegal John Tomac signature series 2.7 (67-559) in the rear. This one is the biggest that can be fitted on. When it's a little bit more inflated, it starts to eat the rear shock (as you can see here www.pinkbike.com/photo/7947982, near the red rebound adjuster)
Also, on when the bike flats out after a big drop, This tire paints in black the back of the frame, right on the "hand made in USA" sticker. I've to post some more pics on this

 well its one bad ass lokking bike for sure

 thanks!

 Can it withstand the 1000 km?

 I mean chaingiude.

 The great thing about this setup is that I can quickly and easily remove the chain from the upper chainguide. For example, when I'm pedaling uphill, I don't need the chain passing the chain guide. However, for the hardcore rides, the chain goes through the chain guide, as the pic shows.

Meanwhile, I'm already making another chainguide setup, that is going to fit directly on top of the rear arm. This will make a "propedal" effect (less shock pumping when pedaling), since the chain stress will push down the rear arm.

More to come! Stay tuned!

 Many thanks! You know, my chain guide is dead and I'm looking for a good solution

 In my case, since I'm planing to put a smaller dish, I'll need a new pass for the chain. That's why I'm doing all these experiences.

 Since you have the inner and outer bash, isn't that enough? Pirat's Magnum works well like just with that, right?
Or did you broke the lower chainguide?

Anyway, these rollers I'm using are quite cheap (1,5€), and easily replaceable, so I still think it remains an affordable solution.
www.pinkbike.com/photo/8099748
www.pinkbike.com/photo/8099747
The upper roller might wear faster than the lower one, since it supports all the chain torque when pedaling.

 Ok, thanks, useful for the future Meanwhile, have done such a thing: www.pinkbike.com/photo/8385659 It works perfectly, 0 resistance, weight 90 grams