jccaclimber

Hey, I was looking at pictures of old track bikes, and most things (including the no brakes thing) made sense. However there was one thing I don't get. What's the purpose of twisted spokes on track wheels? Oh, and the picture at the bottom of this was ripped from somewhere else on this site a while ago, my apologies for not knowing exactly where. Oh, and it's my first post so please let me know if I crossed any ettiquette lines.[IMG]mike_bike.jpg[/IMG] and since that html for a pic isn't working here's a link that should.https://www.bikeforums.net/attachment...id=30054&stc=1


A black hole is where God tried to divide by (near) zero.

Msngr

don't worry about it. twisted spokes don't really make sense. then again, neither does a triple triangle.

phidauex

I think its just for fun.

queerpunk

just speculating, but i think the twist might increase the tension on each spoke... maybe that makes for a stiffer or stronger wheel? but then again i'm also speculating that the point of the twist would be a weak part in the spoke... yeah, i want someone in the know to explain this to me.

jccaclimber

Ok, I figured that it was aero or something (random guess). As far as I know the triple cross is more of a side effect. In radial spoking the spoke is in line between the center of the axle and the rim nipple. If you look at the force a spoke can exert to stabilize (the torque it can create) you can change the spoke tension and the lever arm length. By making the hub come from the side of the hub at a perpendicular angle you change the lever arm length from nearly zero to the radius if the hub which I think would drastically increase the stiffness of the wheel. This of course mattters far more on the rear wheel where you are applying a rotaional torque to the hub via the drivetrain (which you want transfered to the rim as efficiently as possible) than on the front wheel where the only torque difference between the hub and rim is in braking. The rest of the time you are pulling strait down on it. The fact that the spokes overlap each other and happen to cross 3 times seems to be a side effect. Twisting the spokes shouldn't increase tension because you twist them BEFORE you tighten the nipples. If anything the fact that the spokes pull sideways at the rim might make it a tiny bit harder for the nipple threads to strip but I think the kink in the spoke and overlap would make the spoke harder to tension evenly making it structurally worse than a triple cross. From the aero standpoint it makes the overall spoke profile shaped far more like a four spoke carbon or aluminum wheel than the multispoked triple cross. I've seen people give up strength and weight (it will make the spokes a bit longer) in the name of aero before, perhaps this is just another example of that?

No english skills, over analyzing the problem...can you tell I'm and ME major? Oh, and if anyone wants a co-op or intern ME student over the summer get me at singdt@rose-hulman.edu. Resumee available upon request.

Oh, and as for the triple triangle frame, I never did get that as the rigidity added should be minimal.

WithNail

Do you know a kid that goes to rose hulman named Marcus Bohleman? he's german/argentinean and abroad studing in germany right now. . . I know it's a long shot but eh.

jccaclimber

Finding Marcus's picture I've seen the guy around sometime this academic year but don't know him. He has a really nice set of wheels (powered) on his web page https://www.rose-hulman.edu/~bohlemma/ but nothing more.
As a more related note I'm not sure how much twisted spokes would help as they shorten the spokes by different ammounts and therefore it seems you would need spokes of two different lengths to string a wheel. The spokes on the outside have farther to go to get to the center than the ones on the inside, and the same going out. The only way I could think of that helping is if they changed the spoke order such that holes say, 1,2,3,and 4 on the hub went to nipples 2,1,4,and 3 on the rim, but even that might not even things perfectly and it does wierd stuff to the tension levels.

cavernmech

Gerd Schraner mentions this in his book "The Art of Wheelbuilding" He says that twisted spoking is best for trials sport where wheels take a huge radial load suddenly. For most applications it is not worthwhile. And if ya break a spoke...its like breaking 2...crap.

andygates

I was thinking about building one of these (over here we call them "snowflake" wheels) but was advised by my guru that it's a poor torque transmitter - so pretty sucky on a fixie.

mob

I thought the twisted spoke thing was just for looks really. Triple cross I think is the strongest you can get, double cross a bit less and radial is also for looks and maybe saving weight since the spoke is very slightly shorter (yet still strong but not as strong as triple or double cross) Maybe I am wrong... but that is my thought.

Does anyone remember back in the day, someone came out with a 96 spoke wheel in the BMX arena... talk about bling bling. ha. ok bye.

bostontrevor

They say they make squishier wheels (thus the trials reference), but I believe that's never actually been tested. Still, it seems like it'd be the case as there's a lot of excess spoke length and bends to provide some spring action.

As such, they'll be terrible for a drive wheel if you want snap off the line, though perhaps not so bad as a front.

Oni

Twisted spokes don't actually have any advantage other than looking cool. In fact I'm pretty sure that they, as previously stated, reduce your wheels ability to handle torque without giving any benefit. As for cross patterns, the lower you go the less stiff and the less strong you get, so 4x is really stiff ride, but really strong, while radial is a really smooth "squishy" ride, but prone to spoke breakage due to poor load transference. I just rode my friends radial wheels and they're SUPER smooth and nice. I don't trust them though.

andygates

Crow's foot. You know it makes sense. Two-cross *and* radial in one. And a right SOB to true!

Martyr

i don't think that does make sense.
you dont twist spokes in a crow's foot: https://www.terminalvelocity.demon.co.uk/WheelBuild/