marshace

Thanks for detailed explanation. Much appreciated.

Very interesting, thanks Johan

Got some 20 " presta tubes from Solomons in Woodmead JHB, prevoiusly got some from Kroft cycles in Paarl. Nobody in SA ssems to have those with removeable cores anymore. Continental use to have them but no stock is the common answer I get. Shwable (SV7 model) make some and you can get from sites like Chain reaction and Evans in the UK. Removable cores work better as you can clean it when it gets jammed up and it helps to pop on non UST or old tyres as you can force more air in. Have done the conversions both ways but having the rubber inner lasts longer. Have fun, my first few attempts were acomanied by a few choice words.

Took my rear mech (XT Shadow 12 month old) to pieces and cleaned it up. Found the bottom wheel had a nice little sealed bearing in it that runs beutifully, the top one has a ceramic bush in it, and no matter how well I cleaned and lubed it, it simply does not run as smoothly as the bearing one. Now the question: Is this correct ? Can I replace with both having bearings ? (Might help to go faster, less friction) The KCNC ones that you pimp you bike with, do they both have bearings ? Does XTR have both with bearings ? I suppose many ar gigling at the thought of this minor amount of added friction, but I was just wandering.