Meet bikelab.cc: my professional vibrations measuring lab

My name is Krzysztof Wierzbicki and I have nearly two years of experience in testing and reviewing everything that can improve comfort on the bike (suspension seatposts, suspension stems, tires, wheels, handlebars, saddles, etc). I have created gravelbikes.cc site to finding the most comfortable bike parts. Now, I want to continue my mission but on a much more professional level. Based on my experience and knowledge I have created a professional bikelab that not only will professionally measure the efficacy of comfort improving bike parts but also allow the creation of objective ranking of those parts so you can really know what is best and what to buy if comfort is what you are after.

The story

I started my testing using a vibration measuring app on my phone. I have carefully selected two test routes (one in the forest with big bumps where I rode at 15 km/h and one on a gravel road with high-frequency chatter thanks to a speed of 35 km/h). In each case, I have been using a phone mounted either at the level of my wrist (measuring front end vibrations) or at my lower back (measuring rear end vibrations). This approach worked quite well but it had two main drawbacks that I really wanted to address. The first was that measuring in the real-world meant that I can’t create a proper ranking of tested bike parts (because of the changes in weather, humidity, temperature, and the road itself I could only draw conclusions based on comparison tests made on the same day). The second thing was that I was measuring vibrations on my body and this meant that, especially at the rear, I registered fewer vibrations than I should because of the dampening effect of my body itself (of course in the winter it was also the case of added layers of clothes).

The approach

To address both of those issues I needed an indoor lab. But It was not an easy thing to do mainly because I really wanted to maintain as much as possible of the real-world experience and thus, make this lab mimic those conditions as good as possible. This meant a lot of riding and experimenting with different approaches. I started with recording the vibration on my test routes to see how exactly they look like on the graphs. After considering and testing various different approaches I settled with a professional Woodway treadmill that has 60 separated belts made from aluminum (with rubber on top). This allowed me to mount different obstacles on each belt.

So I begin testing different variants of obstacles to mimic as much as possible real-world scenarios. Having those vibrations graphs I knew what I was after but getting there was no easy task. First I find out that riding even on a good quality tarmac generates constant vibrations at a certain level. So to achieve this I had to install on most of those belts a 5 mm high and 30 mm wide wooden planks. Then, I needed something to stimulate roots and potholes. To achieve that I used wooden and aluminum bars with 10 mm and 18 mm in height. I arranged them in a certain way to mimic various scenarios: a single hit on a 10 mm obstacle, a single hit on an 18 mm obstacle (both wooden and aluminum), and series of obstacles that come one after another (again with different scenarios using 10 mm and 18 mm bars placed in various distances). Then I needed to set up a proper speed. My treadmill offers speeds from 0.1 to 15 miles per hour (0.1-mile steps) so I had plenty of options but after hours of experimenting I settled with 5 miles, 7,5 miles, and 10 miles. The first speed is the closest I could get to my 15 km/h ride in the wood (in terms of vibrations graphs), the last is as close as possible to a 35 km/h ride on a gravel road, and the one in the middle is somehow an average performance.

Riding on a treadmill

Yes, I use a flat treadmill to be sure that wheel is behaving in the same way as in the real-world but of course riding on a treadmill with both wheels on it is simply too dangerous so I had to find the next best thing. Again, after many experiments, I settled with the Cycleops Tempo Fluid trainer and two wooden pallets. Depending on what I want to test (front or rear) I put the front or rear wheel into the trainer which is mounted on wooden pallets. This construction gives me a secure hold in terms of forward / backward movement but at the same time, the almost free movement side to side and totally free movement up and down (which is the movement I want to measure). To be sure that measurements are always comparable I always set up the exact same position on the bike (the distance between the saddle and the hoods, and between the saddle and the bottom bracket).

The measuring itself

In my lab, I am still using a phone with a mobile app (it really offers enough accuracy and measurement consistency). But this time I use an app that allows me to perfectly measure the vibrations in a certain time frame and gives me RMS results (an average vibrations) separately on each (X, Y, Z) axis. The app I use measures vibrations at the rate of 100 refreshes per second so I am sure that I can properly track changes in vibrations in real-time. I also get a very informative graph showing the vibrations in time. To be sure, that this time my body is not interfering with the results, I mount the phone directly onto the bike. At front, to the handlebar near the hoods (so I can measure the handlebar movement as close as possible to real-life riding on hoods) and at the back, with the phone mounted directly to the saddle (so I can measure vibrations at the level of my butt). In each case, the phone is tightly secured so there is no additional movement whatsoever. Like in my real-world testing, I do at least 3 measurements (each lasting 30 seconds) and then I calculate the average result (and if for some reason one measurement seems off, I discard it and rerun the test one more time).

I know that one picture can be worth thousands of words so to give you more visual testing representation I will also record everything in slow motion (240 frames per second) and publish the video so you can really see how tested products performed not only on the graphs but in real life.

Why I want to do all of this?

Yes, you may still wonder why all of the hassle? The answer is very simple. I really want to create a proper ranking of all comfort improving parts and tell you objectively what is working and how well it is working. So you can make an informed purchase decision and enjoy riding on your bike comfortably.