Friday, 13 December 2019

Berd spoked wheels. Why your mother or grandmother would do it faster?

If you think you're a good wheel builder and you build your wheels fast and efficiently then I recommend you to try the Berd spokes. Those spokes will change your wheel building life and for the first time you'll regret that there is no mom and grandmom next to you to help you with lacing (!)

The Berd concept.
First things first, the Berd spokes. What are they? Well, most probably the lightest spokes on the planet. The weight is only 2.5g per spoke. That's crazy light but that's not all. Those are made from a polymer which is basically a hyper strong string. It's so strong that when spokes are tensioned and you squeeze them with your bare hands they will cut your hands like steel spokes. The polymer also adds something special here - the vibration reduction, which basically means better ride comfort without losing stiffness.
Putting all puzzles together: lightweight+stiffness+comfort you get something special, unique wheels which I had a pleasure to build recently.

My job was to build strong and light wheels for a very experienced rider. Gravel set based on wide carbon rims, 22mm inner and 29outer width, Chris King hubs and 32/32 Berd spokes. All that below 1500g on the scale.
Making the same set with standard spokes I'd end up with about 1720g, so the difference is significant, especially that the spokes are part of rotation mass. 

The build.
It is different in many aspects so let me walk you through how I did it.

First, the hub preparation. What you need to do is to work out the hub's holes by using the Berd starter kit.
The instruction is very simple. They ask you to mount a special tool on your electric screwdriver and drill the hub (!)


That sounds easy unless you do it first time with very expensive hubs :-)


At the end, it's not that bad. Very quickly you get the concept and thanks to flexible endcap you can work out the holes under angle which is super important for the flanges close to disc rotor mount.


What I used on top of the basic tool is two additional dremel tools - one for outer and the other for inner diameter to make a very smooth and sharp edges free holes.


The precision here is very important so the spoke doesn't get cut by sharp edges during the ride.

The next step is to prepare the spoke threads. On the Berd youtube tutorials, you will find the recommendation to treat spoke threads with blue loctite. I found that very confusing as they also say that spokes need to be retentioned after 48h and that would mean breaking the loctite bond. Instead of loctite I used wheelfanatyk fix which is just perfect for that type of job.  


While the fix was curing I did the fresh calibration of my tension meters as I never used Berd spokes before.

I find that step one of the most important during the whole build. Without that, I wouldn't know how much should I tension the spokes, especially that I didn't know how those spokes behave.


First tensioning was pretty scary but soon all fear was gone. I tensioned the spoke up to 130kgf without any problem.


As you can see on the above pictures I'm still using my first prototype of spoke tension meter jig. Tomasz from fetish.bike strongly forbade me to use this version as we already have ver. 3 of this tool but I'm the type of guy who just likes to use the tools that work. I'm ridding 18years old car and I do not see any problem with that, so until I have this jig in my workshop I'll still be using it :)

The calibration was pretty simple. I tensioned the Berd spoke to 50,60,70,90,95,100,105,110,115 and 120kgf, read values with my both tension meters and wrote them on a piece of paper. 
Having that I was ready to lace the wheel and I knew that the tension will be right on the sweet spot like I want it. Not too tight and not too loose.


Lacing was pretty simple but it's damn time consuming... 30min later I had that:


and I really wished I could have my mom with me


Every spoke pulled through the hole had to be hooked by a small little fellow like this:


Thanks to that, spokes could be tensioned and the wheel could be built.

The wheels.
After lacing and initial tensioning where spokes were pretty stretched I saw this:


If that would happen with steel spokes (threads not engaged into the nipple) I'd leave those wheels and go for a beer but here I had a little hope, Berd guys said that the spokes will stretch a lot so...


I continued and the result was great. After several rounds of stretching and tensioning the spokes lengths were right on the spot and wheels came out beautifully.



Spokes were aligned on the hub flange and the small stoppers aligned to not touch the strings.


Every spoke has a small flat metal section which is used to hold the spoke during tensioning. That prevents spoke from twisting which is very crucial in the whole process.

One observation which might be useful for other wheel builders - those spokes are not entirely round. In the middle section, they are like aero spokes. Edge to edge has around 2.2mm and the flat (blade) section has 1.7mm.


That is important during tension check. Without knowing that, your tension readings will be not entirely true and you will end up fighting to equalize spoke tension and keep your wheel true which will be simply impossible. 


Another observation I made is that when the spokes are fully stretched, they pull the rim very strongly. Only 1/4 of the nipple turn will make significant changes to the whole wheel. I could compare that to the thick steel spokes like 2.0mm ones. That means that the spokes are really strong and stiff. I also felt that during stress removal. Putting all my weight (75kg) I could not bend the wheel.



The wheels themselves came out really beautifully. Very strong, light (1499g) and good looking. Wide rims give stability and comfort.


Gold decals will match well to the bike


@kazafaza enjoy your new hoops!

If you're wondering about the price - one spoke costs 9USD/CHF. It's not cheap but it's worth it. Totally different bike feeling and ride quality. Life is too short to not try it, so if you're interested to have a new set with Berd spokes or rebuild your existing wheels with those spoke then simply contact me. I will be more than happy to make such work for you.

Thanks for reading, 
Cheers

Tomasz

blog-wheelbuilding

No comments:

Post a comment