Bike Spokes, Made Of Rope

We know this one is a few years old, but unless you’re deep into the cycling scene, there’s a good chance this is the first time you’ve heard of [Ali Clarkson’s] foray into home made rope spokes. 

The journey to home-made rope spoke begun all the way back in 2018, shortly after the company Berd introduced their very expensive rope spokes. Berd’s spokes are made of a hollow weaved ultrahigh molecular weight polyethylene (UHMWPE) rope with very low creep. They claim wheels stronger than steel spoke equivalents at a fraction of the weight. Naturally forum users asked themselves, “well why can’t we make our own?” As it turns out, there are a handful of problems with trying this at home.

There are a number of ways to skin this proverbial cat, but they all center around some very special nautical ropes, namely, Robline DM20. This rope has excellent wear and creep characteristics, in a hollow weave much like what Berd developed. The hubs also require the addition of a bevel around the spoke holes to prevent wear. Beyond those two similarities, there are quite a number of ways to lace the spokes between the hub and wheels.

As detailed by [Ali Clarkson], one method involves creating loops out of bike spokes, with a custom jig and some brazing. Then a length of rope is passed through the hub and a special hitch is used to keep it in place. Two loops are made in the ends of this length of rope and passed through the spoke ends made earlier. Finally everything is brought up to tension and trued much like a normal wheelset. The front wheel ended up weighing around 700g, a rather impressive feat for a 24 inch downhill wheel.

However, a number of other methods have been tried on the forum threads. Namely, a number of users have attempted to varying degrees of success putting a length of spoke inside the hollow rope weave and “Chinese finger trapping” it together. The key issue here is sourcing a glue strong enough to hold the spoke piece on at lower tensions, but flexible enough to not crack with the cyclical loading on a rim.

Ultimately, this is a great look at the properties of some extremely special rope. This also isn’t the first time we have seen strange bicycle wheels made with UHMWPE.