Posts
506
Joined
7/15/2015
Location
North Las Vegas, NV
US
Fantasy
1865th
Edited Date/Time
5/1/2018 1:35am
Couple of questions:
1. A Google search on whether the load seen at axle/Hub hangs more from the top spokes or stands more on top of the bottom spokes returned mixed results with some technical analysis seeming to support each argument. I realize the wheel assembly distributes the load with spokes at front and rear also helping to keep the wheel round but generally speaking does the load on a rolling spoked wheel like those found on a motorcycle not like a spoked wagon wheel moving along an even and smooth surface more so hang or stand etc.?
2. JA's broken spokes had me wondering if any teams have tested wheels to see how many spokes could be lost before the compromised wheel becomes too unsafe to not change it immediatly. Obviously rider safety is paramount and losing even a single spoke places more load on the remaining spokes not to mention if the missing spokes are random or sequential and if the wheel/spokes were properly tensioned to begin with and if the rim had any bends or dings but is there any accepted understanding with the teams that if the wheel has only lost X number of sequential spokes....although compromised they expect the wheel should last long enough to finish a moto?
1. A Google search on whether the load seen at axle/Hub hangs more from the top spokes or stands more on top of the bottom spokes returned mixed results with some technical analysis seeming to support each argument. I realize the wheel assembly distributes the load with spokes at front and rear also helping to keep the wheel round but generally speaking does the load on a rolling spoked wheel like those found on a motorcycle not like a spoked wagon wheel moving along an even and smooth surface more so hang or stand etc.?
2. JA's broken spokes had me wondering if any teams have tested wheels to see how many spokes could be lost before the compromised wheel becomes too unsafe to not change it immediatly. Obviously rider safety is paramount and losing even a single spoke places more load on the remaining spokes not to mention if the missing spokes are random or sequential and if the wheel/spokes were properly tensioned to begin with and if the rim had any bends or dings but is there any accepted understanding with the teams that if the wheel has only lost X number of sequential spokes....although compromised they expect the wheel should last long enough to finish a moto?
The Shop
Under tension has always been my understanding as well but there's some differing opinions that make legitimate points.
Be right back
Even if they lost all tension, the lower spokes couldn't support a compressive load as the nipple would just be pushed into the rim. And even if they lost all tension and the nipple somehow didn't press into the rim, they still couldn't support a compressive load as they are very long and thin and will buckle under a very small compressive force.
Regardless, broken spokes rattling about can cause all sorts of havoc and be unsafe. Changing the wheel was the right move for that alone, but the wheel would have also had serious structural issues missing that many spokes.
Pit Row
The bottom spokes probably do lose more tension because the rim is also flexing upwards under load. But the top ones continue to do the work. As do the side ones. It is a system.
For JA 3 spokes broken, a perfectly round rim, and the remaining spokes tight - could it have made it? I wouldnt be suprised if it did.
AJ Cantazaro lost 8 or 9 on his rear wheel....he believes it started out with only a few broken then progressed until it locked up.
By the way my question regarding if a rider can or should continue was with the understanding that any broken spokes would be cut and removed first. I didn't make that clear.
Tough call by Jason A, but I believe he made the right choice. Footpegs and spokes don’t mix that well!
Post a reply to: RE: the mechanics of a spoked wheel and reliability testing