Track Wear

**LTLFTC** · 03-07-2007, 02:48

A question for the how and why Gurus. I seem to get about 5 months out of a rotor before it comes loose on the shaft. But the other thing that is happening is that I get a lot of track wear Pic 1. around the inside rim of the ball and corresponding grooves on the rotor support ring Pic 2. There is nothing wrong with the rotor pictured just the track and support band. I tried the emery paper thing. I did it before my hour spin then pulled the ball apart again and it was same again. I took some impressions of this and a new ball and the gap between the tracks is 1mm wider. Does any one else get this should I be getting new rotor bands more often? The down side is that it creates a lot of friction on the ball and slows it down a good 800 rpm or so without being particularly rattly???

Another question can I use a support band with a magnet for a neon on a pro rotor

**Dariuz69** · 03-07-2007, 08:59

I got the same trackwear as you got. Even after using fine sandpaper and a proper clean, it's all there again after the session. Using a rotor and supportband which are less than a month old.

Speeds are dropped dramatically aswell. As it was easy to get atleast a few 13k runs in a session, now I max at 12.7k-12.8k. (could also be a cold mode though).

I don't know if there are other cleaning methods to get the sphere halfs as smooth as new again besides using very fine sandpaper.

**LTLFTC** · 03-07-2007, 09:24

I just measured the track width as well and it is about .6 to .8 of a mm wider which makes sense as it wears down the sphere becomes narrower. Should I grind some off the width to stop the rotor banging on it so much?

**LTLFTC** · 04-07-2007, 07:08

OK well I took it upon myself to try below are the before and after shots. If you have ever pulled apart a new ball you will notice the edge of the track has a chamfer on it. I put a chamfer back on it at. First impression is its as smooth as a babys bum. I can't notice an difference in speed compared to a newer ball. Before it was raspy and rough and noticeably slower.

I will wait for a hot mode and compare speed then

Disclaimer: This was an old ball that I had condemned to the past it basket. I use it for long endurance runs not for records. If you only have one ball I wouldn't recommend it. I also used a dental handpiece with a special acrylic bur which I'm a bit of a dab hand at. The closest domestic thing I guess is a dremmel. Also I would like the repair guys opinion of it before you rush out and do it. But if you have an old rattler like me that you basically don't use( or let other people use

) and don't mind if you screw it up completely it could be worth a go. You may get a good ball back out of it.

before

after

**One-Eye** · 04-07-2007, 09:22

Nice looking job, Rob.

Going to dental school has paid off at last.

Interested to hear how it performs now.

**Sayex** · 04-07-2007, 22:14

Anyone know¬¥s if the blue rings from the Metal powerball have those chamfers?

Hey LTLFTC, you made that chamfer with a dremmel?

**LTLFTC** · 05-07-2007, 08:21

Originally Posted by Sayex

Anyone know¬¥s if the blue rings from the Metal powerball have those chamfers?

Hey LTLFTC, you made that chamfer with a dremmel?

No I was sying the closest thing I can think of to what I used would be a dremmel. I used a slow speed dentist drill with an acrylic cutting bur.

Don't know about the blue ring on the metal I haven't looked at a new one closely enough. I can tell you my old worn out one does now and I'll let you know how that goes. It was doing the same thing.

**LTLFTC** · 06-07-2007, 03:37

Well I had a go with the blue band on the metal with a chamfer put back on. Before I did the chamfer I noticed that the rotor ring was very tight within the blue band and a kind of sharp bit had been burnished on to the side of the blue band and this was cutting into the rotor support band after removing it the ball is a lot more smoother. It is harder to start and control initially but no more so than when I clean it out anyway. I was swapping back and forth with the untouched band and the altered one and couldn't tell the difference in speed. I would be tempted to say you don't need to chamfer the edge but removing that little sharp edge cuts back a whole heap of friction. And it could easily be done with sand paper or emery board.

Still no word on the 250 chamfer and speed effects. I'm going to have a crack tonight though so I will let you know.

PS I just checked out my untouched blue ring and noticed it had the sharp edge as well so I removed that and yes all the benifits of the chamfer without so much initial loss of control. Much smoother