HOW TO FIT A MOUNTAIN BIKE TO YOUR BODY | Free Fit Kit 

Before you post a question. Please take a moment to look through the comments because there is a very good chance it has been answered. Keep shreddy!!!

“A hunk of meat hurtling to an uncertain fate” That, right there, is absolute GOLD! 🏅

Namastoke! May I recommend making an addendum video where you fix different setups? Stem rise/length/angle/stack, consequences of having grips behind or too near steering axis. Sometimes the solution isn't as simple as a stem change in my experience!

Both these R.A.D instructional videos made the most sense I've ever seen in measuring for a bike. Thank you, love your content

You guys are golden together. Your vids are so great. Can't wait to go home and check all 3 of my bikes. My mountain bike feels better than it ever has after I changed my bar and stem out after the last vid you did on bike fit. Keep making these awesome vids!

Definitely one of my favorite channels on RU-vid. I love the positive energy. I can't wait to check the fit of my bike. Thank you both for your time and positivity.

Loving your videos guys. I'm a beginner and this is really helping to inform my purchase choices for a sport with complex geometry. Cheers

JUST A HUGEEE CONGRATULATIONS MESSAGE THIS IS ONE OF THE BEST MTB CHANELS OUT HERE NO BS, ENTERTAINING, TECHNICAL, FUN, EYE OPENER... CHEERS FOR YOU BOTH GUYS!!

A UK series!! Yeah make it happen. Love this channel. Can’t put my finger on it but there’s something different and relatable about you guys. Always entertaining and informative.

After 7 years of riding and multiple bikes, I shortened the stem on my current bike to match the R.A.D. you suggested. All I can say is "WOW, what a difference!". The bike feels better than ever and I have noticeably more control. Even better is being able to take this to any bike. It 's a game changer. Much appreciation for sharing!

You guys! This one and your other video regarding bike fit about a month ago, have been watched by myself about six times each. This is so awesome, just dumb it down a bit for me, ha ha gonna reach out and get Lee’s book right away! Holding my breath waiting for your next post and pissed I can’t “like“ them more than once.

I have been The Reach Sizing Evangelist...and thanks for making these videos because you guys explain it so much better. I link to these videos several times a week!

After a clinic with Lee, I swear by this method. With hardly any bike inventory in Australia, knowing my RAD and the frame measurements accessed via Lee's book Dialed, I bought a bike sight unseen and it fits like magic

The four thumbs down have got to be people that are realizing they bought a bike way too big for themselves. 🤔

After watching the step stool video in the cold garage I was obsessed with having a set of stools to check my RAD! Having seen this video and realizing I can just lay on my back like you would to practice tuck no handers and bar spins was such a good moment! Time to find out if my bike is waay too big or not!

Mind blown. I just did this measurement and both my bikes with out me even taking that much thought i have set up the to my needed RAD. My hardtail is with a 50mm stem size medium and my full sus is with a 60mm stem size medium but with a head angle kit (making it slacker) intalled. 🤯 I set them up my self when i got them just by sitting in the bike and riding a few times made the changes and been happy first time now i have the proof. Another great video.

AWESOME VIDEO! After watching tons of MTB video over the last 2 years, I definitely think your channel is the best, and by far. THANK YOU!

I can't understand the thumbs down you got. Good info, it all makes sense. 👍Lee has his own thoughts about mountainbiking and isn't just copying what the majority is telling you about it.

I’m tired of being that hunk of meat waiting for impact. That’s why I subscribed. My new fav mtb channel

I just wanted to say thank you to you both. Once I was able to dial in my RAD, it was as if the clouds parted and light shined down. I had complete control of my bars with no weight in my hands and I was floating and flying with all my weight through my feet in the center of my bike. I controlled the bike and not the bike controlling me. It has opened up a whole new feeling to biking and it is spectacular.

I also checked my RAD for DJ, hardtail, and 20" BMX and ALL had within 1" of 32" RAD. I'm 5'9" with an inseam of 34" and realized a lot of our numbers were the same. Very cool stuff! Great to see things explained in a way in 38 years was never able to understand. You're channel is the PLUG homies 👀 🔥👀 🔥

So I had a buddy show me the last RAD video after riding a skills park one day. After stopping to think about how heavy handed I was on the down hills and how hard jumping along with other skills were for me I did the math. Turned out I’m an in between. Swapped from a XL to an L, and the large just fell right in place. Weather has kept me from riding, but I’m stoked to get it on the trail. P.S. I was already looking at new bikes! The video just saved me from buying another oversized bike.

Hey Alex and Lee - just saw this video - awesome! I've been off the bike for 6 months after breaking my hip (in a crash while commuting) but I thought I'd use your advice to check my beloved custom Ti hardtail. I had this built to my own design, based on my understanding of geometry and related it to bikes I knew I loved riding (including my own full sus bike, which is probably a mistake); ultimately, though, the final figures came out of a design that just *looked* right. On paper, it's probably a geometry you'd criticise - long, low and slack with a steep seat angle and a long (485mm) reach. I've loved this bike since the day I finished building it and took it for its shakedown run, though - and now that I've measured both my and my bikes RAD, I know exactly why - absolutely spot on (to within the measurement accuray)!

This is one of the best videos about bike ergonomics. Subscribed!

I stumbled across your channel when searching how to get a better bike fit for my wife. I'm addicted... thanks for sharing your wisdom with the world.

Absolutely fantastic! I am so glad I found your channel. This and the previous bike fit videos were very enlightening for me. And in my late forties, your channel , in general, really speaks to me. Thanks for the content!

This is a great follow up from the previous video. I went out and got Lee’s Dialed book and was able to order my new bike with confidence. I got the right size and I have the knowledge to get it to my perfect RAD. Lots of math and geometry but it makes sense if you take your time. The amazing part was after I understood the numbers I can within a few moments eliminate or verify any bike and move on. That really pared down the field to a manageable number.

Guys you can't imagine how much i could learn from these 2 videos. Thanks a lot.

Thanks for the video. Little changes can make a huge difference. I have shortened my stem by 15 mm which put it in my sweet spot and together with a 75 degree seat tube angle I still have the reach I need but with room to be comfortable on the flat and climbing parts of the trail. It is a shame that many believe that longer is the only way to go. I now avoid a few shops because they just can’t accept that there is another way. Keep on going guys!

A good tip for accuracy, double your crank length and make two marks on the floor at that measurement, (175mm crank = 350mm) when you position your feet, put the ball of your foot by each mark. Having your feet too far apart or close together can change your height. I also found its easier to hold a tape measure or string, or even a handlebar to get my hands at the exact width. I know none of this is exact science but it helps to get consistent measurements. Ive been wondering if I should really be on a bigger frame but Rad pretty much confirms that what Ive felt for years is correct. I'm 6'2" and I like a 475 reach, Large on most frames while a lot of "fit guides" put me on an XL. Nice job guys

Hey guys! Awesome video as usual. Hitting 42 in a few months and just back into MTB after taking a like... 20 year break. Yikes! Trying to learn some of those new tricks! Quick Tip for fitting. Make sure the rope or string you use doesn't stretch too much. If you're a climber think static line vs. dynamic. Twisted instead of woven is better. Paracord will probably work because of the core.

After watching the last sizing video I measured my fist to foot the same way. Then measured my bike bracket to bars. It is a very easy method. Turns out I'm riding a bit plus on my mid 90's Giant. But been looking to upgrade to a modern trail hardtail. This info will be very valuable for my next bike. Thank you! Love the vids!

Love everything about these precise, thoughtful guidelines, Alex and Lee. Thank you. Measured my wife's new bike and the reach is a bit long using the 2.5X method, but the RAD is right at RAD Minus so I feel great about the sizing. I then measured mine, and despite being 9" taller than her (6'3 vs. 5'6) our RAD is about the same because I have monkey arms (my wingspan is 6'6). Accordingly, I should be riding a medium instead of my XL. That's befuddling! On a separate note, Alex, I've been following your work since I first read about you in Fast Company many years ago, and was psyched to see you'd launched an MTB channel. Keep up the great work!

Long story short: started riding again after a 15+ yr hiatus, progressive geos are alien to me (they're great though!) and the size chart was wrong. After doing a lot of measuring and calculating I managed to get my RAD/spread down to a +10-15mm value (best I can do with this frame without affecting steering), and holy crap things are different. Jumps and pumps feel more natural, the bike feels a lot lighter, I'm not straining my back as much, riding playfully is a lot easier. I was expecting to lose a bit of high speed stability, but nope, quite the contrary. Your videos pointed me in the right direction, thanks!

A Big thank's from France because i'm deep in this problèmes of géométrie

This RAD helped me order and build a 1990 MTB full rigid and the bike feels amazing bombing for roads and around town. It seemed a little short at first but no it's feels like I have allot of power and mobility. Great Video!

Hi guys, Awesome video with fantastic information. I am a 55 year young guy watching you in New Zealand. You have finally explained why my bike does not feel comfortable. My RAB is 82cm and my bike that I’m trying to learn on is 87cm. Will see if I can change my handle bars and stem, but I think it’s too much been sold the wrong bike from the bike shop. Shame as I bought a Merida 160 800 for my first full suspension mountain bike. Guess I will have to buy another bike. Keep up the excellent work. Well done.

This R.A.D concept is interesting. I appreciate the intent of getting a bike that allows the rider to be as dynamic as possible, but I can't help but thinking that this concept is going to result in people optimizing for one ride characteristic/criteria at the expense of others, rather than striking a balance between the wide range of desirable characteristics. The R.A.D on my enduro bike measures about 40-50mm longer than the recommendation, while my dirt jump hardtail is exactly the recommended R.A.D length. Having ridden the DJ bike a lot recently, I can definitely feel how that size maximizes my ability to ride dynamically (move my hips, generate power when hopping, manual, etc.). Maximizing this trait makes a lot of sense on a dirt jump/pumptrack bike. However, if we accept that a longer bike is more stable at speed, it seems worthwhile to compromise some of that dynamism created by the short reach/R.A.D for more stability in an enduro or DH application, where you're riding faster and over rougher terrain, doesn't it? There is only so much length you can add to a bike while keeping the same R.A.D (slackening the head angle, lengthening the chainstay, etc), and each of the changes will also have an impact on the handling characteristics. My sense is that I gain more stability by adding length than I give up in that dynamic ride quality the R.A.D seems to maximize. It takes a bit more effort to manual or pop my enduro bike, but that seems like a worthwhile trade off for the additional stability brought by the longer reach/R.A.D - any thoughts on that? I also wonder if targeting R.A.D without considering other aspects of the bike's geometry and components will result in sub-optimal performance. For example, you talk about shortening the stem and adding backsweep to the handle bars. While this will shorten the R.A.D, it can also dramatically reduce the amount of weight the rider has on the front wheel, which can really reduce front end traction, which is essential for confident cornering. Similarly, for shorter/medium sized riders, sizing down to achieve on optimal R.A.D might result in them riding bikes with significantly longer chainstays than reaches, which can lead to some strange handling characteristics. Would these riders be better suited to a bike with a longer R.A.D, but a more balanced bike, rather than optimizing their R.A.D at the expense of some other handling traits?

"Chairs are cheaper than SB150's" 🤣🤣🤣

Thank you! Amazing info! I've been struggling against the mainstream fitment ideology. But your perspective 100% validates my real life experience with how my body feels when riding. I don't need to be all stretched out to "get maximum pedaling power".

Now I can B a Super Cool Old Sender with my very own Joy-of-Bike T-Shirt...I promise to wear it out on some jump lines👊. Nice to see you guys Flex’n...MAD GAME...sooo proud of you guys🥺🤙

This is great info, thanks, guys. And if I can get "a hunk of meat hurtling toward an uncertain fate" into a produced ad, I'll send Lee a royalty.

Measured my RAD number at 86cm and was very pleased to find out my Meta HT (size L) was 85cm. I remember I changed my order from Med to Large after I already paid, now I've got proof that was the right choice.

Cut handle bars, shortened stem to improve RAD, hinge saved my quads and hamis today during first family ride of the season. Thank you for the videos and lessons. I finally felt like I fit my bike!

Hey guys. Watched both videos about rad fitting. I m 170cms and I ve been riding a ‘19 medium Transition sentinel for some months. It came with a 40mm anvl stock stem and for some time i really didn’t like the bike, super fast but not very playful, and I bented my rear rim, wich is something that didn’t happened in a loooong time. So, I tried a oneup 35mm stem, decreased the stack height from 15 to one 5mm spacer and it felt a lot better, instantly!! Same handlebars btw, oneup 20mm rise. So, I liked your tip and last night i laid on the floor, and it is spot on behind the knuckles 🤘🏻👊🏻. I was really surprised and glad that it matched/ confirmed your rad theory. Thank you

Obviously too many comments here to read through, however, I’ll still add my story to bring even more credibility to this amazing video: I’m as average a 40yr old guy can be. 5’9. 190lbs. Went with the Rocky Mountain Instinct BC Edition Enduro as my first MTB... went into the Bike Shop and sales guy walked me through the different bikes and sizes. Then showing me the numbers explained that a M Yeti would be comparable with a L Rocky Mtn. The L Rocky still felt easier to handle then the M Yeti, and the M Rocky my knees were almost smacking the bars. So, I went with a large and I’m RAD neutral!! Yay! Despite the L of the Rocky, it’s fits my average dad bod perfectly. The RAD is everything where bike fit is concerned and I’m pretty sure that Rocky Mountain bike are bigger this year than last... regardless. So much goodness in these vids and I’m loving each one! Keep it up Alex, and thank you!

Yet another big thank you to you guys! I’ve just measured my RAD and set my bike up to suit. I dropped the bars and put a 40mm stem on. Turns out it was nearly 2-3inches too long. I always felt like I was falling off the back or could go over the bars at any minute. Always felt really awkward to pedal out the seat, it felt like I was riding a camel, just felt “too big!” But now the difference is incredible. Climbing out of the seat feels as natural as on my road bike!! I also feel way more balanced on my feet! I’m really shocked at the difference it’s made. Thanks again guys! So glad I found your channel! 😁👍🏻👍🏻👍🏻

The joy of RU-vid when you come across a gem like you guys!, great and professional work guys.

I can't wait I'm showing up to the bike shop tomorrow to make sure my new EB is the correct size. This video has made so much sense thanks so much for making it!

For the longest time I thought my bike is too small for me. This video tells me it's the right size😅😅😅👏🏽👏🏽👏🏽

I tried your method and my RAD is 873mm (I am 6'2" tall). I then measured my XXL RM Altitude Powerplay and the RAD is 873mm. Win :)

My favorite mtb info channel. Great work and funny comments. Learning a loot so keep them coming. From Denmark, Europe

Cant wait to check my RAD. I recently determined that the sweep I need is 16* and I went with a 30mm rise from SQ labs. Now I get to discover the rest of the story. Thanks for the insight

This works a lot better than the height based formula as it takes arm length into account. This also explains why my bike is so comfortable despite the published reach of 475mm being at RAD+ for me using the arm measurement forumla, with my bars and spacers I'm at 465, right in the middle of my RAD sweet spot, the height based reach would have me at 445

OK OK! Now, lemme play devil's advocate here: A RAD that matches you means you can generate maximum torque for bunny hops. That's it. It doesn't tell you whether you feel crammed while seated, your hands go numb, whether the bike inspires confidence on steep stuff etc. RAD makes perfect logical sense, but I doubt that it is the holy grail of bike fitting. What are the other possible benefits of going by RAD and what could be drawbacks? Objectively.

This is amazing. All my bikes have different geo.. reach, bb height, bar height, and I feel really comfortable on all of them but couldn't explain why.... Guess what, they all have identical RAD!!!! Great channel, great vibes, keep going

This video was awesome. I have been trying to dial in my setup for a year. This video helped me do it. Got 40 mm high bars, went from 50 to 35 mm stem and the bike feels great. However I would almost start with handle bar height (level with seat at full extension), the start measuring RAD.

Hmmm thats funny. I calculated reach by the 2.5 formula and got depressed, because i have 35mm to much reach. And with this method, bike fits perfectly, now im happy again 😁🤟 greetings from slovenia

Wow! I wish that I could DOUBLE SUBSCRIBE to this channel! That is some incredible info! Grabbing my tape measure, shoestring, sharpie, and heading to the garage! Thanks guys!

You two are golden together and in front of the camera! So entertaining and the shared knowledge is greatly appreciated. I hope you get to take the "Joy Ride" to the UK soon!

Thanks so much for this video guys. This and the previous Fit video have really helped me visualize and understand what I read in Dialed. I especially appreciate Lee’s discussion about seated reach as this has been really bugging me. My current bike is a L and fits perfect but it’s 8yo and the current iteration of the model I now fit a S by RAD and I was really concerned about that much shorter seated reach. “You’ll get used to it” was just what I needed.

I like the theory and approach Lee uses for bike sizing, since it's much better than just the height chart approach. Basic body dimensions are taken into account with this approach. Take note when measuring your rad: 1) wear your bike shoes 2) Feet correctly distance apart (34cm front to back, 28 cm side to side, for 170mm cranks, mid pedal location) 3) hands should be handlebar length apart (I use a string to mark it) For myself, I noted about 30mm difference between measurements without marking my feet and arm positions. Do note that you can further play with stem length, bar rise, bar roll to optimize your position depending if you ride old school or more modern body position. I prefer a higher rise for my riding style and goals 1) comfort 2) easier to try and lift front wheel 3) Not climbing super steeps fast anyway. If I can make it up, that's a win. So like all things, good to understand and apply. Thanks for bringing this approach up and showing how to do it.

These bike fit videos are great but they don’t tell the full story. You need to purchase the Dialed book written by Lee. Recently I have and I couldn’t be happier. Finally I have a formula which quantifies my ideal geometry numbers specific to the type of bike I want to buy. I’m 6 3 and my bikes have always felt too small even though they were XL’s and recommended by the manufacturer as my size. A friend of mine (who shreds btw) has always said on his current bike it feels perfect for him so for curiosity’s sake I measured him and his bike and all the numbers corresponded with the recommendations from Lee’s book! Mind blown! There’s more variables than just RAD which come into play which will help you find your fit and it is all explained in the book. This comment probably sounds like a paid review but rest assured it is not. I’m just so stoked to finally find a defined analysis of Mountainbike bike fit.

I like my RAD- 2019 medium Canyon Strive. Good vid and I’m glad I found your channel because this video confirmed a few things for me that I couldn’t really put into words. 👍🏻

Gorgeous! I love mountains! We are surrounded by mountains and hiking trails in Tucson, Arizona where I live, but I like watching other people’s videos and vlogs about their adventures in other places. Thanks for sharing! I’m following!

You guys are messing with my head! I love these videos.

"...more like a hunk of meat hurtling to an uncertain fate" Many others have already commented on the best line from this video. It's just too damn good not to repeat again. Instant classic!!

Mind Blown! So cool! It totally makes sense and I can’t believe I’m today years old when I learned about this!

Thank you for all those valuable information! All of which being super useful, making huge difference to how we ride.

I’ve found that you may not need to jump to get into the bike stance as shown in 4:30, you can use a tape measure to lower the body. You need to measure 1 crank you are comfortable pedalling on and times that by 2, lets say you have 170mm cranks that would be 340mm or 34cm. Using a tape measure rule it out so it shows 34cm then put the tape measure on the floor and stand over it with your left foot on one side of the tape measure and vice versa. The inner edge of the ball joints or widest part of the foot should be at the tip or end of the measured distance (depending if the foot is forward). When looking at bike geometry measurements online I calculate the hypotenuse of the reach and stack from the smallest size available and take a note of that number, the closer that number is to my RAD the more likely the bike will not fit me as it will be larger and you’d need to take into account the stem length, stack height for the headset, and the handlebar rise which is not shown on the geometry charts. In my head I assume that I would put the shortest (or longest depending on the type of bike) stem possible on it thats on the market, and put flat 0 rise bars on it. Stack height doesn’t really matter at this point because its a few millimetres off from the RAD or to RAD neutral and you can adjust that to get a more upright or lower position. An example of this methodology, using the Marin San Quentin 3 at size S and my RAD being 76cm, shows that its reach and stack (in mm) is 422 and 618 respectively. Using a hypotenuse calculator gives us 748.3mm. Immediately I’m thinking “Yeah this might be too big for me”. When I subtract my RAD of 76cm/760mm from that calculated number (760-748.3) it gives us 11.7mm. This is virtually impossible for me to reach my RAD as I know that adding a stem, slamming it, and adding 0 rise handlebars will put me way over RAD+ with no room to adjust. A case where this methodology puts my RAD in a safe spot would be to use the Kona Process 134 DL 27.5 at size XS. Its reach being 400 and stack being at 585. Its hypotenuse shows that its 708.7mm, now I’m thinking “hey this might give me some room to adjust my RAD”. So, 760-708.7 gives us 51.3mm. Depending on the situation, I could either get a 50mm stem length, slammed with 0 rise bars, OR a 30mm stem with 10mm riser bars with 10mm stack, OR a 30mm stem slammed with 20mm riser bars, OR a 30mm stem with 0 rise bars with 20mm stack height. The extra 1.3mm is pretty unnoticeable and it will only put me slightly into RAD-. So basically, size down tailor up is pretty much what I’m tryna say.

Would love to see something in saddle height, fore and aft.

I'm 5'10" with a RAD (standing up sharpie method) of 32"; riding a Medium Giant Stance (only modern bike I've ever ridden) and I was afraid it was too small based on current trends. Come to find out it's just right if not slightly RAD plus!!! Thanks guys for the video and confirming this is a good size for me. I really like the way the bike feels (especially after a bunch of upgrades LOL) but have no reference for different size bikes so this really helps. Thanks again and love your content!

Thanks Alex & Lee for the awesome vids. With these last two I am double checking my RAD before going for my first full suss! With my long torso this method works much better. Main problem now in the UK is finding a bike in stock to measure with my piece of string 😁 All sold out with long pre-orders Btw I tuned my current bike with Dialed - great book Lee!

Freakin A bros. I’m gonna use Alex’ RAD measuring method in every bike shop I visit 😂

That was rad guys🤣

First time that I agree with a way to measure a modern mountain bike. Thanks. Good job guys!

Love this vid! As a road bike fitter I always suggest going down a size for the same reasons you do. I’m amazed manufacturers recommend up sizing!

How to get RAD using geometry charts. You can get pretty close using a right triangle calculator. Pythagorean theorem, Insert stack and reach into the calculator. This will be short cause it does not take into account headset and bars on stack measurement. Guys what would be a good "average" measurement to add to stack?? Example Nukeproof Scout I added 9cm for headset and bars from website info, 73 squared (stack+9cm) + 45 squared (reach) = 85.75cm. My RAD barefoot is 85! so pretty good! I understand that if you add to the stack it will decrease the reach because the head tube is on an angle so you can knock off a couple cm if you want this should get you pretty close. Thanks for the info, subscribed!!

I would totally lie on my back to size a bike at a demo. That would be one of the least embarrassing things I've ever done in public. Thanks for this video though! It turns out I've been riding rad double minus (ridiculously small) on my hardtail down chunky black trails. For this reason I was convinced a Large Revel Rascal was going to be too big for me. Turns out it's not. Medium will be rad minus. Large could be rad plus OR rad neutral. BTW I'm only 179cm but that really does put me on a Medium or Large Rascal (still Medium on other brands though) I just M and Large yesterday and they both feel amazing. I really am right in the middle. Going to demo some again and will re-measure. My ideal would be rad neutral for this bike.

You guys are awesome. Thanks to you I'm already riding safer and better. I'm even back on jumping after some years afraid of. Now you just saved me of making a big mistake with my new bike. Thanks a lot. Cheers from Canary Islands :D

I haven't bought a new bike in 20 years, but will do so soon. There's a really good chance that this video has ensured that the next bike I get is going to fit me PERFECTLY and make me absolutely love the bike, no matter what I get. Thanks in advance.

Great videos, love watching them. Just a question about the bike/body position at the core of the RAD fit theory. When you measure, eg 4.48 and 9.12, the feet are flat but when actually riding and executing that move Alex ( and probably all riders) are up on the balls of their feet eg 7.37. For me that extends the measurement by 30mm. Is this relevant ?

I love this video. Couldn't say more about how much this has opened my eyes to bike fit issues and given me possible explanations for why my bike probably isn't for me (even though I pass the lay down test). However, I do think the fitting methodology here should be improved to account for rider proportions. I'm a tall rider at 6'5", and most of my height is in legs. Even with getting the rad right, I think most bikes' stack/reach ratio, is too small for my disproportionately long legs, so I end up with my torso more parallel to the ground, and my weight all over the place forward/aft. I either have tons of weight on my hands and my head in front of the bars, or my ass is above the rear axel. For reference, I have a Ripley V4 XL which is 500 reach, 631 stack, and a 1.26 stack/reach ratio. I haven't had a chance to ride anything else recently since there are no demos, but my hunch is that something with a ratio above 1.30, and a reach around 490 (which ironically is what Lee's height in cm * 2.50 = reach equation spits out for me) will be better. Need to do the actual rad measurement though, so this hunch is kind of uninformed at the moment. I just suspect that if you don't account for this, on the average bike (or my Ripley anyways) either your long arms make you stand too tall putting your weight too high, or your long legs put your butt in the air and make you too bent over unable to keep your weight between the axels (rad remaining equal in both cases). Really the question is "is there an optimal torso angle over the bike?" Then with arm, torso, and leg measurements you could REALLY dial in fit.

Keep up the great work boys, love this channel! Dining room chairs for the win!

This was really cool. I worked pretty hard to fit my bikes to me, swapping stems and bars. I know what feels good, but not how to measure it. Just checked my two bikes. I was right at my RAD. Super Stoked!

Great video. Step 1 - Aha! I'm 6' riding a 2020 Norco Sight size XL. Big must be too big. This is why I can't wheelie, manual, jump, bunnyhop, and a host of other skills. Step 2 - Run out to the garage. 6 measuring tapes before I can find one with metric measurements. Terrible excuse for a Canadian. Step 3 - Grab a marker and stand by my bright white overhead door, make a mark. It squiggled so tried to erase it. Doh. Permanent marker. Step 4 - Find a dry erase and make a different mark. Measure. Step 5 - Run the string between the handle bars as shown on the video. Measure... Short by 1 cm?? That can't be. Remeasure. Same thing. Step 6 - Realize I'm just a poor rider. :-( Can't blame equipment. Step 7 - Watch other Joy of Bike skills videos and actually practice

Hi, Lee! Thank you very much for the book ‘Dialed’, it is very helpful. I have a question though. Is RAD and RAAD measurements are performed with sagged bike or not? I’ve found this moment crucial for hardtails. Thank you!

These are great vids guys, easy to understand, keep um coming.

This is awesome. I'm actually at the opposite end of the spectrum. Bought a starter mtb in 2017 and after actually riding off-road I feel like it's difficult to be active on the bike. Come to find out I was fitted for a short, comfy seated reach. Did my RAD measurement today and the bikes RAD is 30mm too short! This all started when I rented a bike that felt a little stretched in the saddle but awesome on the trails. It's reach was 20+ mm longer than mine. Now I know why it felt better.

I was super relieved to find that using this measurement, my new bike is perfectly RAD, but I’m struggling with understanding how this applies to those with extreme ape index. If I have abnormally long arms, would not my RAD be much shorter than what my bike should be?

Glad you followed up with this after the last video. Going off of height is certainly inaccurate. For instance, I'm slightly over 6 foot 2 with my shoes on but I have long legs and average arms for my height. This lengthens my rad number. However, there are a few other variables here. Most people position their pedals towards the front third of their feet which causes them to leverage through the balls of their feet with their heels up which extends their rad number. Also, the position of your hands while leveraging is typically 2 or 3 inches in front of your thighs which also would increase your rad number. I would suggest measuring your rad with your heels slightly up and your hands two or 3 inches in front of your thighs.

Hi guys, thanks a lot for this and your other videos. I just found you as I was getting into mountain biking. I'm 69, have been riding road bikes since I was 15 or so, but have rarely ridden off road. I'm spending time in Crested Butte these days, and have a new mountain bike. Like many, I got the bike based on my overall size (I'm around 5'7" 145lbs, average leg/arm ratios). Fortunately, the medium I got is pretty close to what I need based on measuring my RAD (which is around 795-800mm). The new bike with the 60mm stem it came with has a RAD of around 810. Doing the lay on the ground hack, my hands seem to be at about the right spot, but I'm going to replace the 60mm stem with an identical 40mm stem so I can err on the side of RAD - (or at least for sure RAD neutral). I've also been watching your drops videos, which has been super helpful. I was practicing them all wrong based on some other videos, and there was an accident in my future!! Best regards, and thanks again for the super help. Mark

I'm 6' 1.5, my RAD based on my height is 836 mm. My wingspan is very long so I have a low knuckle height of 31.5 inches (same as you) which gives me a knuckle height RAD of 800 mm. Which RAD should I go by? How much RAD size is okay to add to your bike with stem length and handlebar height, or should you try to stick as close to stock stem lenght and handlebar rise as possible?

Any thoughts on how leg length vs torso length effect sizing? Short legs=shorter chain stays and longer top tube?

This was a super fun and useful experiment. Id bought a sized medium Commencal Meta HT this spring and stupidly sold it for a ridiculous reason, immediate seller’s remorse. A day later a nicer spec’d size large Meta HT came up for sale 10 minutes from my house for the same money! I bought it right away figuring I’d probably have to swap a frame out when they became available. For some reason I instantly bonded with it, just felt like a perfect fit. I’m 5’9.3”, which this frame is recommended for 5’10-6’2”. Either way I’ve just been in love with it, though it didn’t make sense on paper. I watched both of your fit tests and tried it out. I quadruple checked my Rad neutral and low and behold the bike and I are within 1/4” of each other! I’d love to see how a shorter stem changes it, but what a validating feeling! Awesome video guys!

I will try this definitely!!! Nice work guys 👍

hey can you guys do a video on that huck-to-flat technique? seems different then the technique you showed in your drop videos, those all ended with a down slope where there's an angle to make.

A discussion with Christ Porter (Mojo Rising) & Leo (Pole Bikes) would be very interesting since they seem to preach the opposite ;)

I recently got a larger bike, and then lengthened the stem on my smaller bike, because the larger bike just seemed to "fit" me better. I just now went out and measured the RAD after watching this video and both bikes measured the same! That's pretty cool!

I just grabbed my dirt jumper and my trail/enduro bike, laid on the floor to check the R.A.D. Both bikes are in my top 5 favorite bikes I've owned. They feel amazing, it sounds cliche, but they feel like an extension of my body. When I laid down they both fit exactly the same, about 10mm short. Now I gotta do math and make my own rope for when I buy my next bike. Thanks for this update video. You guys rock 🤙🏻