Weird Braking Phenomenon

Brake pads aren't angled? All worn out? That might be the case if you've never changed them in the past several years.

heehee, look what I found. Since you mentioned it was cold and the discharge was as you release the brake (slowly I presumed to ensure a smooth descent) I figured maybe it was a static discharge. Apparently i wasn't the first to see the resemblence to a toroid but a Wilmhurst Generator?

http://www.halfbakery.com/idea/Bicycle_20wheel_20Wimshurst_20Generator#1079110800

A bicycle wheel is a variation on a hollow cylinder. There is a fixed axle, bearings in a hub and a means of connecting the rim and tyre with the hub. Traditionally, wire spokes connect the hub to the rim, but solid disks may replace these. The disks could be metal or plastic, or a combination of these materials. Other parts may also be either insulating or conducting and constructed of metals or ceramics. It is also possible to construct a disk or disks fixed to the axle within the wheel which would effectively be surrounded by rotating disks.

The whole wheel could be constructed as a sealed Wimshurst machine with the static electrical poles being the axle and the rim, and charge could be collected and stored in capacitors within the hollow frame of the bicycle. Fluorescent and xenon discharge lamps could present a variety of ways to brightly illuminate the moving bicycle, with a very minimal drag on the moving parts of the generator compared to magnetoelectric devices. It should be possible to effectively weatherproof all high tension connections with silicone and teflon coatings.

Stored charge could also be used as a theft deterrent. it may therefore be necessary to wear an antistatic grounding device when using the bicycle to dissipate charge safely.

TomBombardil, Mar 12 2004

Glowingrod said:

heehee, look what I found. Since you mentioned it was cold and the discharge was as you release the brake (slowly I presumed to ensure a smooth descent) I figured maybe it was a static discharge. Apparently i wasn't the first to see the resemblence to a toroid but a Wilmhurst Generator?

Electrician? Physics teacher? Anyway, Faraday is smiling on this post

Interesting I never saw that. Must have been kind of freaky. The brake pads are gripping on metal so anything is possible. It must of worn it down and flicked up some of the scrapings. It gets hot there so the combination must of made a spark.