Berd Spokes

Yesterday I came across the Berd Spokes and thought that they seem really cool and I immediately though that they would be really cool to use on a unicycle. the basic Idea of them is that they are much lighter than any other spokes which would reduce the rotational weight of the wheel so it would help with acceleration and deceleration. They are really expensive though so I wont be trying them anytime soon like $8usd per spoke but I thought I would share them here incase anyone is interested.
The website
A youtube video explaining and reviewing them

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I ordered mine 2 days ago!!! Will post picture when the test is over. The main issue is about they tend to overextend. I’m interested in the dampening action, but the wheelbuilder already told me the main issue will be with the spokes when hopping… we will test if it will be better with different tensions

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Sadly like basically all spokes out there, they don’t make them large enough for a 36" wheel :cry:

If they work well, I wonder whether they would do by request. A 32h hub, some Berd spokes and a Braus carbon rim…

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Their web site doesn’t say anything about how stretchy they are vs. standard spokes, but I bet they stretch a lot, which would mean a really flexible wheel. I’m sure you can tension them up, but it’s not tension that makes for a stiff wheel; it’s how much or little the spoke stretches as the tension changes.

Despite how they look like regular string, once you’ve started to tension them up they won’t move much as
UHMWPE is not at all a stretchy material.

UHMWPE typically has creep issues that would mean pretty regular maintenance, but I presume they must have mostly resolved that one. I think you can anneal it to make the creep performance better.

I dunno, my casual googling is finding Young’s modulus for UHMWPE less than 1 GPa; stainless steel is ~200 GPa. Is there a huge range of properties for UHMWPE?

I see 70-100 GPa for kevlar, and kevlar spokes have been around forever.

Now you’ve got me googling.

I’ve found figures putting Dyneema fibres at >100GPa.

Perhaps it’s down to fibre vs non-fibre?

This is getting well past my materials knowledge anyway!

One interesting note on the UHMWPE Wikipedia article that I thought was interesting:

I wonder what Berd have done to solve that problem.

I also own a carbon 36"… they wrote me about they could make one special order for 1000 spokes at least. But 1000 is too much. However we could insist for 500 spokes about 13 wheels

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The wheelbuilder told me that if I’m willing to waste money I’ll be happy to help me test it. He underlined that they can stretch a lot (3 or 4 different retensioning for a bike wheel), and the main issue will be the spokes at 90° and 270° vs cranks that will stretcht due to jumps or drops, so we will test a normal wheel and maybe a slightly ovalized one ready to stretch and became circular

Perhaps a group buy? You could see if there are 25 other people interested enough to put their money down. I might be interested at $100 for a set but definitely not at $8/spoke.

I thought about making my own a few years ago but had trouble finding suitable cord. I’ve kind of fallen out of tinkering but I might have another career shift soon that may give me time for half baked ideas again :slight_smile:

They are not really clear about the material the spokes are made of they say UHMWPE but they are really made of UHMWPE fiber. UHMWPE fibers, commercialized in the late 1970s by the Dutch chemical company DSM, are widely used in ballistic protection, defense applications, and increasingly in medical devices.

Normal UHMWPE is a soft plastic.

My idea for a 36" will be about using 2 small spokes together to reach 1 long one. That way you’ll have a long spoke, a big issue about the right lenght for a specific tension and a cost of 16$ per spoke

I’m glad someone is doing it! I was going to order a set this winter for my muni, but my rim has too much damage to rebuild it and the cost of spokes + a new carbon rim is out of budget. I’ve been following them for over a year and totally like the concept!

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Someone on IG has already built a uni with Berd spokes: https://www.instagram.com/p/CKeb23FA_gL/

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Honestly for how many people have purchased new 32h hubs (/brakefast adapters) and carbon rims I’d be surprised if there isn’t the market for 1000 spokes.

Perhaps UDC could help here if people do show enough interest. (I would be interested, but I don’t currently have the money for the rim, let alone fancy spokes to go with it).

If anyone’s DIY inclined, someone did also have success making their own here:
https://www.mtbr.com/threads/make-your-own-polymer-uhmwpe-spokes.1091276

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If it’s for a good cause I’m willing to count for two. :innocent:
I have two 36" carbon rims, one with a 32h hub and the other with a schlumpf and the BF. The only problem is that it’s not the same spoke length.

I’m in too, but mine is a Qaxle 32h disc… too much different hubs?

I have to admit it kind of skipped my mind that hubs are all different sizes :laughing:

Maybe they’d accept an order of >1000 spokes, but 500 or so of a few different sizes.

It’s cool that it works with standard hubs. but from a technical point of view, Pi Rope seems to be the better solution and aber lighter (but not compatible to standard hubs)

It almost seems like you could lace one continuous piece of fiber through the entire wheel. You’d just need some sort of tensioning mechanism. Maybe use several fibers that each affect 4 or 6 spokes.