Just wondering, are we doing any real unneccessary damage to the wheels of our unicycles by always dropping on the same spot? I’m talking particularly about rims and spokes although I was also wondering, would any damage be done to the flanges of the hub? The issue of having to rotate the tyre to avoid wear has been discussed a fair bit, but what about the other bits? I guess I’m only talking about those people who rotate the tyre and not the cranks. Is the damage done to the dropping spot negligible or should I be paying more attension to the health of my muni?
a) your wheel is underbuilt so that spokes are fretting (I bet 90% of wheels are), or
b) your tire is underinflated so that you are hitting the rim, or
c) your wheel is underspec’d, so that it just isn’t made for the drops you are doing, or
d) you are dropping with poor technique, so that you are overstressing the axle because you are not absorbing momentum with your body,
I don’t think that there is any problem. The entire wheel supports your drop, not any one spot on the wheel.
In a properly built wheel the spokes are always in elastic mode, so that they are just doing their thing, whether you are rolling, hopping, or dropping.
Crank grabs on concrete are devastating to spokes and hubs.
My spokes tend to lossen up from time to time especially when I’m doing Trials. So I would say dropping in the same place can effect your wheel.
I deffenatlly destroyed a Monty rim by dropping on it when I didnt realize I had a loose spoke. Now I check their tension more frequentlly.
A) Can you please explain ‘fretting’? I laced my wheel so I’d like to know if I’ve done something wrong.
C) Of course not…this is my custom muni we’re talking about. (actually I am talking about all wheels but specifically mine)
D) Well I’m always trying to roll out when I can and do soft drops but I can’t say I’ve got great technique at all.
Wheels are fascinating things aren’t they.
I have to check my tension, trueness, etc. frequently so the wheel doesn’t rub against my clearance-lacking frame.
Fretting happens when spokes are tensioned too low or don’t match the hub well. The spokes move slightly during riding and abrade on the surface. Eventually an overstress that the spoke should handle easily breaks the spoke at that spot. Almost all spoke breakage is due to fretting and occurs at the spoke head. Stock Cokers with cheap rim and spokes that cannot be tensioned properly break spokes often due to this reason. 0- or 1-cross wheels also fret spokes easily because of the angle of the spokes to the hub.
For these reasons, a wheel with higher tension and 3- or 4-cross pattern will hardly ever break spokes due to fretting – the spokes don’t move. This is also why I put washers on Suzue hubs - to improve the stability of the spoke-hub interface.
It is almost impossible to break a spoke, during almost any kind of riding, except at the spoke head. The wheel will taco first or the hub will break or something else will happen. Spokes only break if they have abraded at the spoke head first.
Yup Andrew – wheels are really cool things.
Okay, that makes sence…thanks a lot.
Dave, could you explain where you put washers on Suzue hubs & how it helps please?
Hey Mike. I put them between the spoke head and hub. Gerd Schraner talks about them in his book that I mentioned to you and explains how to install them. They provide better support for the spoke head, thus helping reduce spoke movement within the hole. They also look really cool.
Here’s what they look like in practice:
That’s a beautiful picture. I don’t know about everything you’re talking about (although I do believe you), but that is an excellent shot of a wheel. You should make that into a poster!
The last spoke I had break was on putting pressure to roll backwards when mounting… Twang! Off flew the head.
The second to last spoke was when fiddling with the spokes; I was tightening it up and Twang! Off flew the head.
Am I doing them too tight, or not tight enough? I think I’m going to admit defeat and take it to the bike shop…