I’ve got a 48 hole 24" BX-38 rim on my QU-AX. I want to drill it because it can save some weight and drilled rims look pretty cool, in my opinion.
Now, how much weight would I really save? And how much strength would I lose? I do a lot of trials riding on this uni, including sets and drops(Up to a meter, but I’ll probably go bigger later on). Do you think it’s worth the trouble?
Ok, there are several problems with just drilling your rim.
Because you have a 48h rim, the holes you drill will have to be really small, making weight savings minimal.
Unless you have access to a skilled machinist who has done work on bike and uni rims before you will lose considerable strength. I’m no expert on the subject, but I can tell you that by just taking a drill to your rim you will lose lots of strength (the double walls will be messed up by your drill, making the rim weak).
You will have to take apart your wheel (unlace it) and then re-lace it afterwards.
Because weight savings will be so small, and strength will be compromised, I do not suggest doing this.
Someone with a little more metal knowledge will pitch in with some more technical reasons not to drill the rim, but there you go.
I am sure that the 07 KH rims are not just drilled. Rather, they were pre made heavy, with the intent to be drilled. There was a lot of thought put into this.
Uniskaters rim appears elegantly done, and makes sense as a racers mod. It is still not what it could be, strengthwise , had this drilling been preplanned by the rim designer.
If you like the look, get a 07 KH rim, rather than drilling one yourself. For general use, drilling a rim will be a lot of work, and it will weaken the rim a lot.
For best results on weight saving, get a single wall rim, drill large holes equidistant between the spokes, and then parallel lines of smaller holes each side. If you have no brakes on the uni, more weight can be saved by drilling the sidewalls too. Then use a tubeless tyre. I also like to file down my nipples, but that’s not really relevant in a unicycling forum.
If you know a dentist, (s)he may also be able to drill the spokes, although that can be fiddly. For maximum weight saving, a single longitudinal hole, effectively making the spoke hollow, is best. However, several transverse holes may be easier unless your dentist has a steady hand.
Bike trials riders drill thier rims by themselfs all the time. Though yes thought into design might help strength, its not going to matter that much. Just keep in mind the more metal you take away the weaker it will get. I suggest marking the holes first so they dont come out off center. It doesnt have to be unlaced either to drill it.
Yeah I thought of getting a drilled rim for the uni I am building, but then decided for that minimal amount of weight I will save vs. strength I’ll just shit before I ride to get the same affect probably better.
Drill bits and labor aren’t free. Pete’s drilled rim makes sense because he has taken the best quality rim available and then made it a bit lighter, because he was willing to put lot’s of work into trading strength he didn’t need for lightness he wanted.
In general use, it would be much better IMHO to buy a very high quality stock wheel, and only drill as a last resort.
Let’s say you are a lighter then most super rider trying to set a new level of greatness with a super more spins crank flip. Buying a KH and drilling it extensively would be the ticket. Ti spokes, drilled cranks and rim. Or maybe custom light cranks (carbon ?), certainly the lightest pedals, then drill them to.
It would seem that unicycling crankflips and funny car dragsters have little in common. In both cases light isn’t just right, it is the only way. To strong is to heavy. Just right is light.