El_Kinematico
Profile picture for user El_Kinematico
About Me

My name is Luis Arraiz, I am a frame design engineer and specialize in bicycle vehicle dynamics, kinematics and geometry design. I was the founder of K9 Industries Ltd in 2005 in the UK. I worked at CSG (now Pon) from 2015-2013 where I was responsible for the geometry, kinematics and packaging for all the full suspension bikes both analogue and e-bikes for both Cannondale and GT bikes and also several GT hardtails. I introduced the concept of size specific geometry and kinematics for Cannondale dubbed “Proportional Response”. I am now back to the UK, where I am a senior Lecturer in Vehicle Dynamics at Oxford Brookes University. I am also a consultant in bicycle, kinematics & components design and analysis as well as provide data logging services.

Member Summary
Followers: 5
Following: 1
Forum topics started: 1
Forum replies: 15
Lives in:

GB

Member Since:
1/16/2024
Recent Activity

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hobbsh Liked a reply to forum topic Case Study: Jekyll DH Data Logging Setup

4/22/2025 4:21am
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very interesting!! thanks!!
This forum topic has 48 replies.

El_Kinematico Added a reply to Case Study: Jekyll DH Data Logging Setup

4/22/2025 4:21am
Hi Rob, I am glad you enjoyed this case study. As you know i have always been a big fan of the Motion instrument data logger from the day I tried the beta version. I was truly looking forward to getting my hands on the System2 but what happened was a sad day for MTB. I know how much work...
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robprzy Liked a reply to forum topic Case Study: Jekyll DH Data Logging Setup

4/22/2025 4:09am
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Amazing work Luis! I was always super stoked to work with you at Motion Instruments. Happy to see you have a system still giving you the data you need. Too bad System2 never saw daylight. After all of the R&D we put into it, getting it through to manufacturing and ready to ship, to have the rug pulled at the finish line was disappointing to many customers. Keep up the great work. This was an incredible story to read.
This forum topic has 48 replies.

El_Kinematico Added a reply to Case Study: Jekyll DH Data Logging Setup

4/22/2025 4:09am
Hi Astrizzle, I ma glad you enjoyed the article and I hope you enjoy your Jekyll, The Jekyll is one of my favorite bikes. unfortunately I do not have too many pictures of this bike as it belongs to my friend. However, if you would like to convert your bike into a DH or park sled, you should follow a...
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tam Liked a reply to forum topic Case Study: Jekyll DH Data Logging Setup

4/22/2025 4:05am
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Remember these are 95th centile speeds, not absolute maximum
This forum topic has 48 replies.

AndehM Liked a reply to forum topic Case Study: Jekyll DH Data Logging Setup

4/22/2025 4:03am
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Very interesting, and makes me annoyed all over again that Motion Instruments got shut down and System 2 canceled. I set up a couple of my bikes with a friend's System 1, but that was very difficult to mount on certain frames (i.e. Santa Cruz with shock tunnels). Still, I learned a lot from those tuning processes, and taught myself to use a similar diagnostic path as you outlined (just without data now): get the sag/pressure/spring rates right first, then sort out rebounds & balance them, then use compression to further balance.
This forum topic has 48 replies.

El_Kinematico Added a reply to Case Study: Jekyll DH Data Logging Setup

4/22/2025 4:03am
hi Nico, Thanks for sharing your feedback. The maximum velocities for rebound were around 2700 for the fork and about 1900 for the rear. However, as stated earlier I do not care too much for them when setting up a bike. Sag, is a different story which i will go into a lot more in-depth on a later case study...
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carlinojoevideo Liked a reply to forum topic Case Study: Jekyll DH Data Logging Setup

4/22/2025 3:53am
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What data system do you use? What comp, reb and dynamic sag is your target range?
This forum topic has 48 replies.

El_Kinematico Added a reply to Case Study: Jekyll DH Data Logging Setup

4/22/2025 3:51am
Ni Nico, the speeds are based on the 95th percentile not maximum velocities. The reason I prefer to use 95th percentile is that maximum velocities can vary greatly depending on bike speed, rider inputs, slightly different line choices. Different suspension displacements will also have an effect on the maximum suspension velocities as well as the tracks or trails. Each bike...
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carlinojoevideo Liked a reply to forum topic Case Study: Jekyll DH Data Logging Setup

4/22/2025 3:45am
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Awesome in depth work right there!
This forum topic has 48 replies.

El_Kinematico Added a reply to Case Study: Jekyll DH Data Logging Setup

4/22/2025 3:44am
Thanks Ryan, I miss working with you and trying to chase you sown the hill. I needed all the help I could get with the set up just to keep you on my sight, lol. you are right, and most often than not it is very common to be on the wrong wheel rate and with the rebound wound too...
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El_Kinematico Started a new thread Case Study: Jekyll DH Data Logging Setup

4/21/2025 5:34am
My name is Luis Arraiz, I am a frame design engineer and specialize in bicycle vehicle dynamics, kinematics and geometry design. I was the founder of K9 Industries Ltd in 2005 in the UK. I worked at CSG (now Pon) from 2015-2023 where I was responsible for the geometry, kinematics and packaging for all the full suspension bikes both analogue...
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This forum thread has 48 replies.

Ryan Burney Liked a reply to forum topic Case Study: Jekyll DH Data Logging Setup

4/21/2025 5:20am
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Really cool stuff, Luis! Love that you’re dialing things in based on wheel rates, makes total sense. It's fun to think how much more people can get out of a bike with setup and not changing out a single part. The number of times we’ve found out someone’s just on the wrong shock tune or turns their compression knob the wrong way is an eye opener for some easy wins as well😅 For some background, Luis and I worked very closely together on a lot of projects. He has a ton of experience and is a kinematics guru. Some great...
This forum topic has 48 replies.

El_Kinematico Added a reply to Suspension Data Acquisition

1/16/2024 8:25am
Hi all, I wanted to jump in here and let everyone know that i am offering data acquisition services for MTB and Motos using the Motions Instruments system. I have over 15 years of experience data logging bicycles. I used both Aims and Cosworth motorsports system and they are great. they can allow to record and analyse all kinds of...
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