SUSPENSION TUNING FOR THE AVERAGE JOE
WITH DIALLED TELEMETRY
Words by Robert Johnston | Action photos by Adam Lievesley
CONTENTS
Introduction | Interview | Set-up Day | Test Results |Last Word
If you follow the Downhill World Cups, you’ll likely spot some lucky riders with extra wires and sensors strapped on to their bikes through practice. These are usually collecting data on their suspension and helping them to find the setup that gives them the best chance of putting down a fast time come race day. This equipment doesn’t come cheap, but more importantly it doesn’t tell you exactly how to make your mountain or motocross bike fast – it simply shows you the data it collects, leaving it down to you to analyze it. So for your average Joe, there is a lot of time and effort required to experiment and learn what this data means; and with countless possible setup options for a top tier fork and shock, it’s easy to make things worse rather than better when you turn the dials. Given that most riders will rely on a sag setting from an o-ring, or at best the recommended settings from a suspension calculator, it’s safe to say that many people are likely running bikes that aren’t optimized to their morphology or riding style, but thankfully there are some options out there to change this.
I was very lucky to be given the opportunity to spend the day with Dave at UK-based suspension tuning company Dialled Telemetry. After struggling to find a setup on a Radon Swoop 10.0 test bike that offered the level of sensitivity and support that I desired, this opportunity came at the best time and I was excited to find out the improvements a day spent with Dave could yield. Given that I am far from a professional level racer, I was most interested to deduce what a proper mountain bike suspension setup could mean for a typical rider, as opposed to the pros who would usually receive the service.
Due to the personal nature of the service, I was very keen to find out some more about Dave’s background and the motives behind starting up his own telemetry based tuning company, so let’s start off with a quick interview before we dive into the results from the day spent with him. If you’ve ever wondered how you can get a better mountain bike suspension setup, you may find some useful info below.
WHAT IS YOUR BACKGROUND?
My own background is actually in industrial chemistry. I studied chemistry to degree level and then took further qualifications in a variety of areas. I spent many years in the cement industry where amongst other things I specialized in X-ray fluorescence, X-Ray diffraction and in particular, laser diffraction particle size analysis. I led some pretty interesting projects and I always loved trying to figure how to make use of new technology. So, lots of data, charts, and graphs!
When I had children, I wanted more time off and less time travelling so I actually became a teacher and have spent the last few years teaching the sciences up to A-level. I love teaching the scientific processes but if I am honest, it is not the dream. Budget limitations make it a very frustrating job. Rewarding though, at times.
Mountain bike-wise, I live near Llandegla in Wales. When the trail center opened 15 years or so ago it really did start a scene in the area. It was also a sport that I could more easily fit around my family. I have had a go at just about everything from XC marathons to enduro and downhill racing. I have even racked a fair few road cycling event too. I will not even try to make out that I am a good enough rider to race at the highest levels though – I am more of a social rider. I have run a club for local youth riders and through that got funding to take bike mechanic qualifications.
In 2017 I started working at Revolution Bike Park and worked there up until the covid pandemic earlier this year. I just drove the uplift, but I loved being part of it and getting some cheap uplift days was certainly a bonus!
HOW DID DIALLED TELEMETRY COME TO BE?
I am a huge World Cup fan, and I was aware that top riders are using telemetry to get their bike set-up specifically to the rider, track, and conditions. I had just lost my job at Revs and taken a demotion in work, so I had a bit of time available. I listened to Podcast with Rob from Motion Instruments and it seemed a no brainer to use this to get my personal bike set-up. I looked into it and there was really no one offering the service, so I began looking into systems and had a chat with Rob about doing it myself.
At the same I also did some calculations using my own DH bike as an example and I think I found that there were over 67 million possible combinations of ‘clicks’ without even starting with volume spacers and air pressure. I had spent a lot on the bike but never really felt like I had got it set up very well. With this number of possible combinations, it seemed impossible without some extra guidance.
Anyone can collect data, but doing it well requires experience. I spent a lot of time running trials on my own bikes and then started on friends. When I was confident, I was starting to get a good grasp I called on some contacts from my time as an uplift driver. The first takers were Stacey Fisher and a young local rider called Alex Storr (he should have raced his first EWS season this year). They were both blown away with the results – Alex thought I had swapped his fork out! It just started growing from there.
WHAT DO YOU OFFER, AND FOR WHO?
The idea of the service I offer is that any rider can book me and get the kind of detailed and person-specific bike set-up that a pro racer gets. Just because you are not racing World Cups or EWS does not mean that you are not passionate about riding. We spend a lot of money on bikes these days and to me it is a no brainer to have it running the best it possibly can. Getting the bike set up well will make it climb better, descend better and generally handle better. Put simply, you are going to enjoy your bike even more when it is set up right!
For most people I offer a set-up day. We will take the bike from your settings/factory setting and through the process until we get to a point where the bike uses the full range of travel and has balanced compression and rebound speeds when comparing front and rear. When the bike is all balanced it really comes to life.
This is best done at a bike park because long runs are good for generating data and plenty of runs gives us plenty of opportunity to make adjustments. In my opinion you really need a minimum of 10 runs to get it pretty good.
For pro/semi pro riders I may do this over 2 days to get a detailed tune. I offer a service where we can fine tune a bike to a specific track, too.
I also offer the opportunity to run whatever experiments you like. At the moment I am looking to devise a series of experiments to look at the pros and cons of the mullet bike vs a full 29er with a World Cup team. We can break the data down and see how the bikes perform on specific parts of the track. You can use it to look at the advantage of running inserts, tire pressure changes on much more.
WHAT DIFFERENTIATES YOUR SERVICE FROM THE LIKES OF SHOCKWIZ, OR AN ONLINE SUSPENSION CALCULATOR?
Both Shockwiz and online calculators are only really intended to get you into the correct ballpark. You will not see Greg Minnaar using either of them, that is for sure. I will explain a little more:
Shockwiz has inherent problems in that it does not directly measure fork/shock position. It can also obviously only be used on an air spring. Shockwiz also attempts to tell you how you should have your bike set-up. The Motion Instruments kit will never do that, nor will I. Suspension setup is such a personal thing, and a rider’s preference for how the bike reacts to the terrain should always be taken into account.
The system directly measures shock and fork position at a rate of 200 times per second (it’s actually capable of 1,000 times per second!). From that we can get a very accurate account of where the axle spends its time. We can get a dynamic sag and see exactly how the axle position is distributed around that point. We can look at the maximum position too, but rather than having an O-ring on the fork that only tells us that it has bottomed out, we can look deeper into the data and see exactly how many times that happened during a run, and even see how long it was at the bottom for (so how hard the bottom out was). If it is a single event in a five-minute run, it is not a problem, if it is happening frequently on mellow terrain then it is. The system also outputs compression and rebound speeds. The Motion IQ software uses these speeds to quantify the balance of the bike in terms of suspension movements. We can take this into different levels of detail depending on the rider’s bike. We can for example break the data down into high and low speed compression velocities. In my opinion you just cannot tune that without a way of measuring.
To compare to an online calculator, I will give you a worked example. Let us say you and I are the same weight and ride the same bike on similar trails. If we use an online calculator then we will be given the same settings. Now consider the forces through your suspension. Weight and speed are key, it is essentially Newton’s second law. So, if you ride faster, you will put more force through the bike and your compression speeds will be higher. So, if you ride faster than me with the same settings, then you will blow the bike through more travel. That will lead to a higher average axle position; potentially more bottom outs; and higher compression speeds. That would likely lead to us adding air (or changing a spring), adding volume spacers, and adding compression damping. The additional air and reduced volume leads to faster rebound which you may want to dampen. So, two riders on the same bike at the same weight on the same trails will end up with different set-ups simply because of the speed they ride. The reality is that as you advance as a rider you also start to ride more technical terrain and hit bigger trail features. So, a faster rider requires a much stiffer set-up. That does not make it beneficial to everyone though. If I were to hop on Greg Minnaar’s bike and ride at my pace it would feel horrendous and vice-versa.
Weight is also critical and perhaps one of the reasons female riders are benefitting from my service. Their bikes have often been set-up by men hopping on them, bouncing around a bit, and saying ‘Yeah, that’s good’. Becci Skelton is sub 60kg, fully kitted up so her bike will feel relatively soft if a 90kg guy throws a leg over it.
And then there is riding style. My boy Alex Storr loves the bike to be really poppy so we run a ridiculously fast rebound that most people would hate. By contrast, Becci will straight line it through rock gardens and so the rebound damping is critical. The set up takes into account the rider’s style, with other factors like weight distribution and body position also taken into account when a bike is set up based on data.
WHAT ARE YOUR PLANS MOVING FORWARD WITH THE COMPANY?
It is a totally new industry, so I learn something from every bike and rider I work with. I plan to keep as busy as I can so that my bank of knowledge and therefore service is unrivaled. I love working with each customer anyway and often get a few laps in with them. So, that is cool – the more the better.
My passion really is with the racers though. I cannot reveal too much at this stage, but I have riders lined up over the next couple of months from a wide range of disciplines and levels. I will have riders representing at Welsh, UK National and EWS level enduro events. I also have DH racers from local level through to the World Cups. I would like to hook up with a serious XC racer if there is one out there reading this and maybe even look into 4X. In the long run I would like to set up a development team to help bridge the gap between the privateer and the factory teams – maybe a Welsh team? I am already in touch with some Universities in terms of supporting this concept. Who knows though?
In terms of testing there is a lot of attention around braking data. If I were designing frames or offering a coaching service it would be a no brainer, but I am not sure the equipment is there yet though in terms of commercial viability. This is why I opted for what I think is the best system for purely setting suspension up. We will see where that goes though – if the demand is there then I will do my best to cater to it.
THE TUNING DAY
My day with Dialled Telemetry took place at the incredible Revolution Bike Park in Wales, which was selected for its efficient uplift and all-weather friendly trails. We were glad for both merits when the day came, as Wales delivered a truly miserable show with the weather. I was so glad to see Dave’s awning being erected as I pulled up, knowing that the time in between runs would be rewarded with a brief escape from the relentless rain pounding down.
We quickly got to work with rigging up the Radon Swoop with Dave’s Motion Instruments data acquisition kit. Dave chuckled to himself as he pointed out that Motion Instruments recommends against the use of the kit in the rain and mud, as we looked down at the river of silt filled water rushing through the car park. The fork tracer is a decently chunky and purposeful piece of kit, however the MIPS sensor for the rear shock is quite the opposite and had me seriously concerned that it would not survive the day. Nevertheless, after some clever use of black tack to protect the Radon’s glossy paint, and a few zip ties here and there to strap everything in place, the bike was ready to roll, and boy did I feel special. Few things make you look and feel more “pro” than sensors hanging off your bike! After some fiddling to wake the equipment up and sync it with the data logger – an old iPhone – we made our way up to the uplift to commence the testing.
On our way up the hill, Dave gave me the low-down on the setup process, walking me through the order of modifications we would be making to efficiently hone in on the optimum settings. He explained we would begin by independently modifying the air chambers, followed by rebound and finally the compression settings. Keeping the modifications to one category at a time would allow for the easiest comparisons between runs and ensure that a particular modification had produced the desired outcome. I wondered how important it would be to repeat a single track over and over to produce comparable results, however as it turns out this is not a necessity since the data does not discriminate from track to track. Nevertheless, I was still keen to feel the difference in how the bike reacted on the same tracks with differing setups, so we began with the highly repeatable “Freeride” line to collect the data on the baseline setup. My previous ride on the Radon had ended with a somewhat experimental setup in the rear shock, trying a very softly sprung, highly damped approach to feel the effects and try to find some beginning stroke sensitivity, but this had not performed as desired. So, Dave had his work cut out!
With a warmup lap in the bag, it was time to have a look at the baseline setup and figure out what needed to be improved. As it turns out, this was essentially everything – experiments are often exercises of failure, after all. Dave ran me through the collection of graphs that the Motion IQ app had produced from the first run, and quickly suggested several things that were in need of improvement.
A glitch in the software led to the times at rest being included in the data, hence the big peaks at 0mm travel in the histograms which should be ignored. Straight away, a look at the histograms for the axle positions at both ends of the bike suggested that both were under sprung and sitting far too deep into their travel, shown by the peak at roughly the 35% and 38% points for the front and rear, respectively. The flat-top on the fork graph also suggested that there was some packing down occurring as the fork struggled to recover from the previous impact, leading to a buildup in harshness through extended sections of braking bumps or a root cluster. Looking at the G-force vs axle position diagram supports this, with the fork remaining down at 80-90mm travel throughout a rough section and only recovering once the terrain became smoother. The rear end looked somewhat better in this respect; however, the deep axle histogram showed a number of episodes of the rear end travelling to 140mm or deeper into the travel, which for a relatively relaxed warm up run on a highly progressive frame and shock pairing indicates that there’s a significant lack of support. Dave was keen to limit the amount of detail he shared, but it was clear that both ends had begun the day significantly under sprung.
Comparing both axle positions on the same graph with the G-Force (taken from the sensor attached to the front triangle of the frame), it is clear that not only are both ends sitting deep in their travel, but also that the rear end sits even deeper than the front, leading to the front end “sitting up” and detracting from the front-end grip. If the bike was to be climbed in this configuration, then there would be a compounding effect of the seat tube slackening due to the rear travel sitting deep. Clearly this experimental setup was not a success.
Comparing axle positions is something that is obviously important, providing the basic control of the reaction of the bike to rider and terrain input. However, I would suggest that riders will generally be more perceptive of this, and it is not necessarily where the biggest gains are to be found with the telemetry system. The element of the telemetry that goes over and above what you would typically be able to understand from general feel is the speed of shaft travel in both compression and rebound. The relatively fast 200Hz sample rate of the Motion Instruments system allows these speeds to be monitored, and for adjustments to be made to both find a sweet spot and find a balance between both ends of the bike. A balanced bike should theoretically produce the highest level of predictability and control, with an equal reaction and recovery of both wheels to the same impact on trail.
The first run indicated that compression speeds were within an acceptably balanced ballpark, however the rebound was significantly slower in the back with a huge -48.5% imbalance. With the average axle position already indicating that there was too little pressure in the shock, this slow rebound could be attributed to this lack of pressure and would be somewhat fixed upon the stiffening of the rear end.
The following runs were conducted with that rough procedure in mind of hitting the sweet spot with air pressures and volumes, followed by rebound then compression settings. Of course, every setting has some form of impact on the other tuning elements, so it is very much an iterative process during which certain targets are sought after. Pressures were increased on both ends, with the fork seeing 5psi extra (6% increase) and the rear a whopping 80psi extra (30% increase) over the significantly under sprung experimental settings that formed the baseline. An extra token was added to the fork to increase progression, allowing for a relatively soft initial portion of travel that would allow for a slight dive when cornering to increase front wheel weighting and steepen things up – this is my preference to manage tighter sections of track, with limited need to bolster the stability of the Radon’s front end. Compression damping was backed off both ends, settling on 11 from open for the rear shock, and 4 HSC/6LSC on the fork – the increased pressures resulted in less reliance on the compression damping to prevent the wheels from using their travel too readily. Rebound damping was reduced on both ends gradually, settling on a couple of clicks faster for the fork and three faster in the shock to accompany the further increase in return speeds produced by the higher pressures. During the rebound-focused portion of the day, the rebound on the rear end was sped up even faster by a couple of clicks, which led to a serious “bucking bronco” feeling to the bike as I struggled to maintain control of the extra-lively rear end. It was very interesting to feel the significance of these two clicks of rebound pushing the setup from a happy level to quickly becoming so profoundly difficult to ride. The resulting rebound speeds come the days end were faster than I would usually run, with an extra level of traction being offered thanks to the wheels being so inclined to stick to the ground, but I was surprised by how manageable these speeds were once on trail. The final setup of rebound speeds left the rear end a touch slower than the front, which as it turns out is quite a common preference – perhaps due to the lower sensitivity or reactivity in the movements made by the feet and legs on the bike.
TEST RESULTS
Analyzing the data from the last run of the day, the resulting improvements were quite profound. The overall trend from both ends is a bike that is sitting a little higher in its travel, with more favorable distributions that indicate both fork and shock are no longer packing down. The important thing to remember with this service is it does not rely on programming within the app to tell you how to set the bike up, but instead allows for a fully personal setup which can account for any particular requests by the rider or any ideas the tuner may have. My request to try to find some improvement in suppleness of that Radon rear end led Dave to working towards a setup that was softer in its initial travel. The final histogram for the rear end shows this progressive nature quite clearly, with its drawn-out shape. The stiffness increase led to an average axle position at 26% into the travel, which sounds too stiff to my lesser educated ears, but was more favorable in Dave’s expert eyes. The most notable improvement can be seen in the balance charts, with closely matched velocities in compression and a better match in travel usage between the two ends. Rebound speeds still differ slightly between the two ends, but this was a product of the optimization of performance meeting the point at which I simply could not control the behavior of the bike. Still certainly an improvement over the beginning of the day.
Looking at the data showing G-forces, the overall peaks have reduced, likely due to the suspension generally absorbing the impacts more effectively – these G-forces are the same as the rider will feel and so a reduction in the peak forces is a huge deal, leading to reduced fatigue and potentially even injury prevention on the biggest hits. The two ends are now moving in unison, producing very similar reactions to the same impacts in both compression and rebound. And a final cherry on the cake is the dynamic sag appears to be nearly identical on each end, with the smoother terrain seeing both ends at roughly the same point in their stroke.
That is it for the data produced by the Motion Instruments IQ app, but how did it feel? There was certainly a stark contrast in feel between the beginning and end of day – the stiffer and faster setup felt a lot more agile and “racey”, with an increase in appetite to go fast. With Covid-19 restricting the number of days I have spent getting serious laps in a bike park, I was concerned that this stiffer setup was going to exceed my ability to hold on, but in reality, the bike was easier to ride once up to speed. The balance between the two wheels was nothing short of incredible, and it led to a serious reduction in the amount of pitching required between my feet and bars, instead keeping things much more levelled and effectively skipping over the rough terrain that was previously unsettling the bike. I felt the need to attack hard, particularly in the slightly rougher corners, with the bike rewarding me with increased grip and a much more settled nature when hitting the highest level of G’s at the apex. I was concerned about the potential reaction of the bike when landing some of the bigger jumps, worrying that the reduced rebound damping would potentially produce a squirrely sensation, however the balance between the two ends and the predictability that accompanied led to a more composed nature, even when tagging the knuckle on some bigger natural gaps.
Back on the slower speed, more natural trails that I frequent in my local area, most of these notions remained, with a serious improvement in the composure of the bike and its predictability across many trail scenarios. The stiffer rear end led to a more favorable seated climbing position, however the quicker rebound occasionally made things a little harder to control in dynamic climbing scenarios, with any bob being intensified and the wheel breaking traction a little easier. Something like Cane Creeks CS system with an accompanying increase in low speed rebound damping when the climb switch is activated may prove to be very beneficial in this case.
What the resulting setup did not really achieve, try as we might, was the suppleness that I had really expected from that Radon. It transpires that was likely due to that model year Fox Float X2 shock, which has been recognized by some to feel a little harsh, and it goes to show that even the best setup process cannot fix the unfixable.
I would be somewhat inclined to say that this kind of balanced, predictable setup is almost more important for your average to expert level rider. My experiences have suggested that whilst the professionals will often have their strong ideas, they are usually the kind of people who can react to any reasonable setup and make it work. That is not to say that your average rider cannot adjust their riding, only that it may lead to more significant improvements if the bike is naturally balanced and predictable. Speculation it may be, but I believe it has a level of substance.
THE WOLF’S LAST WORD
The day spent with Dialled Telemetry has opened my eyes to the world of telemetry and has made me reconsider my values in a suspension setup. Taking “right ballpark” out of the equation and replacing it with actual data to analyze and optimize the setup can prove invaluable to both casual riders and racers alike, looking to get the ultimate performance out of their bikes. Adding in the valuable knowledge of an experienced individual benefits the process greatly, as the data generated can be so easy to get lost in if you do not fully understand the relationships at play. A professional can utilize this data to guide you to a balanced and effective setup that produces real gains when out on the trails. I now have serious equipment envy and will be looking to add telemetry to my repertoire as soon as I can.
Website: Dialled-Telemetry.com