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.

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Followers: 5

Following: 1

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Forum replies: 15

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1/16/2024

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

4/29/2025 11:32pm

Hi Astrizzle, First, the bike was configured like that by the owner and rider. The mx link with a 27.5 rear wheel preserves the original geometry. However, the increased in fork length due to the 190 boxxer changed the geometry significantly in head angle, reach and front center. These changes completely changed the ability to load up the front wheel...

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

4/28/2025 10:35am

Hey Joe, I will be covering this topic in more detail on a later case study. I don't to give anything more at this time, haha! Talk to you soon buddy. Luis

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

4/28/2025 10:33am

Definitely interested in Luis opinion on the matter! But consider the V4 might have had a bad suspension set up that could be causing the issues. But I have owned a V4, V5 and Session. The mid pivots don't pitch as much for sure. The V4 has a very high anti-rise that squats the rear then as you let off the brake it lifts. So this could be what you are feeling. But setting up the suspension to combat these issues is what Luis is the master at.

This forum topic has 48 replies.

f.i.t.nj Liked a reply to forum topic Case Study: Jekyll DH Data Logging Setup

4/28/2025 10:31am

Disclaimer - I'm no where near the setup Guru that the OP is - I have had a V4 Supreme (29/27) for 4 seasons. I has to be setup up differently than anything else to be able to maximize it's strengths and minimize its weaknesses. It's about as extreme of the high/growing rear center pivot as any mass produced bike in recent history. it's not something you can just jump on and feel at home with unless you're coming from a Forbidden or similar. For me, that involved progressively running less and less rear sag and overall setting the bike...

This forum topic has 48 replies.

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

4/28/2025 10:31am

Hi AvgMTBEnjoyer , i have not done much testing on the Commencal V4, but it is mainly an observation based on its kinematic profile and applying some vehicle dynamics principles. No the Mid Pivot bikes are less affected by the changes in dynamic weight distribution as it goes thru the travel.

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

4/28/2025 10:28am

Did you ever find any weird handling characteristics when you first tried the supreme v4? I managed to try one for a run or two and I felt like I was going to high side it when going around every berm, I could feel my weight being jolted forward faster than I was able to react. If so, does a mid-pivot have that same weight transfer or is it more akin to a normal pivot setup?

This forum topic has 48 replies.

enricorodella22 Liked a reply to forum topic Suspension Data Acquisition

4/28/2025 10:25am

The BYB Telemetry V3 version is designed as a more basic and easy-to-use solution, including only essential features. In general, V3 users are focused on quick insights rather than exporting or working with raw data. The Pro version, on the other hand, includes all advanced features, such as raw data export in CSV format, to meet the needs of users who want to dive deeper, code custom analyses, or integrate the data into their own workflows. Given the company's track record, I think we can approach these concerns confidently and without worrying too much. We're always available to help and...

This forum topic has 431 replies.

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

4/27/2025 11:55pm

Hi Slonschtor, I am hesitant to recommend Shockwiz as it does not take into consideration leverage ratios j no or the velocities at the wheel. It only looks at what happens at the shock. Also, I am not sure about the scoring and recommendations, I rather use the data. however, some data is better than none. So ShockWiz maybe helpful...

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

4/27/2025 11:49pm

Hi Luis, Super interesting post, thanks so much for sharing your knowledge. I wonder what’s your opinion on ShockWiz device. Would it be beneficial for an experienced rider who doesn’t understand a thing in kinematics, have lots of enthusiasm, and not much budget? Asking for a friend :D

This forum topic has 48 replies.

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

4/24/2025 3:07am

Very good point made, from my experience i have found that the data from the MI system is fairly repeatable. However, i normally go for a balance that makes sense from the data and that the rider is happy with.

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

4/24/2025 3:04am

Yeah I kind of see the data systems as I do pressure gauges or shock pump, I have mine for tire and suspension. I use those because if they are right or wrong, I go off those numbers. Totally agree on the sensor movement and stuff also, there's definitely variability!

This forum topic has 48 replies.

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

4/24/2025 3:03am

TheSuspensionLabNZ very well said, its not just about obtaining the magical setup by using the data system, its the whole process and also depends what the outcome or goals are. two riders of similar weight and different abilities may end up with somewhat different setups based on other external factors. I also agree with you that the system2 from MI...

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

4/24/2025 2:57am

Nice work! It's awesome to see the whole process laid out like this - its not always (or ever) as simple as bolting sensors on and getting a result straight away so its great for people to see whats involved @robprzy it was such a bummer to see the rug pulled on that one - I really thought you guys were close to the perfect consumer system and I hope something similar will see the light of day eventually!

This forum topic has 48 replies.

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

4/23/2025 12:59pm

Yes It’s the same for the rebound. It will end up a bit faster too. It will vary based on the bike too.

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

4/23/2025 12:58pm

Hey Luis, does the same thing go for rebound on high pivot? Less damping is needed for HSR?

This forum topic has 48 replies.

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

4/23/2025 1:22am

Hi DServy, Yes that is a very good observation. High Pivots bikes do tend to have lower vertical velocities as a result of the rearward axle path. That can be quite significant with very rearward axle paths such on the Commencal Supreme V4. The Jekyll is more of what could be called a "High Mid Pivot" design. it does have...

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

4/23/2025 1:15am

So one thing to note about HP bikes (from Steve at Vorsprung when I chatted with him) is that the nature of HP bikes with their reward axle path means that axle velocities tend to be slower. I know a lot of people with HP bikes run fairly light compression tunes because of it (though, ironically, the Telum runs a bit stiffer HSC with a smaller LSC range so that you can actually get damping from the HSC circuit). Speculative thoughts ahead from my own opinion, do not take as fact: The LSC adjustor tends to have a much more...

This forum topic has 48 replies.

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

4/22/2025 4:22am

When you guys mention dynamic sag, is that the average or mean travel value over a run?

This forum topic has 48 replies.

f.i.t.nj Liked a reply to forum topic Case Study: Jekyll DH Data Logging Setup

4/22/2025 4:22am

This is amazing! Please keep them coming. I really like the set-up heuristic's. It's a great framework to approach a new bike setup from.

This forum topic has 48 replies.

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

4/22/2025 4:22am

Dynamic sag is the average sag during the run. Thats depending on steepness of trail and grip in the dirt, this can change a lot. It's one of the most helpful metrics on the data to get a balanced bike.

This forum topic has 48 replies.

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