LWFF Ball Bearing Conversion
(No lathe at home? Contact me by email)

Based on Mauritz' idea I redesigned the conversion kit to be fitted into the Logi without serious manipulation at the wheel.

Feb 00: 
The kit is ready
Target was to leave the Logi unmodified, due to warranty and user-friendly assembly. Changing to bigger bearings, it worked. The only things I couldn't save were the wheel-stop (sawing) and a PVC-sleeve (cutting by knife). Installation manual can be found here. 

 The ball bearing conversion kit, ready for takeoff

The original bushings. The arrows point at the gaps, about 0,5mm play

The kit is in, left picture without outer bearing holder

The above wheel I got new in exchange for my old one.
There have been some changes in the past concerning the wheel:

• Former wheel were made in Taiwan (my old one), white box
• Change to China as manufacturer (my new one), still white box
• Changed to stiffer springs in the pedals and SCGT instead of F1RS, made in China, red box
  

There are some changes noticeable, but I cannot tell if they are coincidences or not:

• Taiwan wheel had quite warped pulley-wheels
• China wheel has incredible play in the bushings (against squeaking?)
• My new wheel had the motor-shaft bent significantly, suspect: hammer-assembly in China. For new buyers: If the wheel turns notchy when switched off, the motor-shaft is bent.

BTW: If you want to know, where your Logi is from, there is a sticker underneath the wheel unit.

My first impression of the fresh converted wheel:

• a bit noisy, coming from the motor. Needs a break-in period
• stiffer than my old one. dito

Sept. 00:
Jammy feeling when turning over the center 

I got some slight (but disturbing) jamming in my wheel recently. It always occurred once when steering to the opposite site after going through the wheel-center.
As suspected, play between pot-shaft and D-joint was the reason. Adjusting the D-joint to perfect fit then was not quite easy and I expect the same problems to come up again.
Solution: put some glue like epoxy (no superglue please) onto the pot-shaft before finally slotting this thingie in. Make sure you don't glue the shaft to the pot-casing, elsewhere jamming will even be increased ;-)

I'll try out another way using a flexible joint (like a rubber hose) between wheel-shaft and pot-shaft a.s.a.p.

Oct.  00:
Tips for maintaining the ball bearings:

In general: not needed.

If you still want to do it, here some hints:
I changed the lubrication from thin oil to normal engine oil. The bearings seem to have some play inside (too small to feel) as compensation for heat-expansion. Since you don't turn the wheel at suitable revs to achieve serious bearing heat (Greger Hutu is an exception of course), the balls can start vibrating (the ones in the bearings). You will never feel this during use, but it was noticeable when assembling the bearing-units. The thicker oil induces some damping, but doesn't increase resistance noticeably.

Lubrication:
I use a syringe for the job. One small drop in each quarter, then turning the bearing to spread the oil. Excess oil will drip out and mess up the inner of your wheel. Therefore the bearings have to get cleaned out before re-lubricating. I soak them in thinner, then blow them dry with compressed air. This also drives out dirt particles, if any inside.

You have no chance with less then an air-compressor, so please don't even think about it.  

For you it will be even more difficult than for me, since the bearing units are pre-assembled and the bearings difficult to access.

Some of the bearings are fixed with Loctite high strength, but this should be resistant against thinner.

My advice:
Don't fix it, if ain't broken.

Once you have the wheel apart, you should also check the insulation of the wire-pack (through steering shaft). The wire pack slides over the lower bearing holder during usage and the insulation could get thinned out. If you need the urge to beef up the insulation, use shrink wrap (the black stuff from the electronics shop), this stuff is quite solid.

Mar. 01:
Comments on MikeT's long-term test

MikeT, who has the BB-kit in his wheel for almost one year, wrote down some thoughts, observation and comments about the kit on his website at http://website.lineone.net/~mikebay/MTLWWFMods.htm (dead link, sorry)

Thanks for your effort, Mike!

Let's go through:

• the collapsed end of pulley2 is really not appreciated. I'm not sure whether I'm able to machine the upper holder with an inner *and* outer support, but I'll try. As workaround, beside Mike's solution, it could be helpful to flood the inner volume with hot glue to support the shell. Have to try this myself, then I will bring out some pictures in the manual
• when straightening the motor-shaft make sure that the cylinder is centered over it's whole length. What sounds perfectly clear, gave me a lot of trouble once. The shaft was seriously bent and due to some metallurgic reasons the shaft didn't bent back exactly at the right position. Result was a S-curve in the shaft, and the cylinder centered either at one end or in the middle, but never over the whole length. Those days I solved the problem by pressing on another (custom-made and oversized) cylinder and ground this one down to the original thickness by letting the motor do the spinning  
• the worn out signal cable insulation is a serious matter. I have no idea, what part of the electronics will smoke, if one of the cables gets contact to the shaft. Anybody, especially those who did cut the insulation really thin, should keep an eye on it and in case of wear should use some shrink-wrap to beef the insulation up. 

Jul. 01:
Update

I experimented with the upper pulley2 holder to machine a collar, which supports the upper pulley2-end better. The prototype is in my wheel now and will be introduced to the series a.s.a.p.
I also tried the hotglue-strategy with some good success

For sure this collar won't collapse in 100 years :-)
Unluckily it's quite a mess to get the glue out in case that you have to disassemble the wheel again :-(
I haven't tried it myself but some guys reported to utilize the D-shape of the original unit. Of course you have to cut the plastic thingie for that.

Be warned: This will void the warranty ;-)

Aug. 01:
Design change on upper pulley2 adapter

I followed MikeT's input and modified the a.m. adapter. Since the adapter supports the plastic collar from the in- and outside now, there is no more need to flood the hub with hot-glue.

Aug. 01:
Reducing slack between wheel hub and shaft

Yesterday I examined the a.m. play, which gives the wheel this lousy elastic feeling.
Taking off the wheel from the shaft, you find at the top end (where the nut is) zero slack, a quite perfect fit. Unluckily the lower end (towards the casing) has some serious play at about 0.5 mm :-(
I machined a cup which is plugged onto the lower end and has a tight fit to the wheel shaft. Never had such a sturdy wheel before :-)

This cup is included in the BB-kit from now on.