MyVeloFit - my thoughts….

[bikerboy337]

So I have been riding bikes for 20 years now, but never had a professional fit in my life. I’ve had my seat height the same for at least 10 years now, fit on my bikes has been pretty identical for as long as I can remember… little more stack on my gravel bike but otherwise stack, reach, seat height, etc all carry over pretty well. Also never had any use injuries from cycling…

Decided to try out Myvelofit and pay for a fit on a new bike I’m dialing in and to my surprise my seat height was lowered by about 15mm from what I’ve been riding for years… and it feels great….this was a huge surprise to me… all my other measurements/fit were about dialed in, recommended a slight longer (5mm) reach and bar height (5mm) on the bike I’m dialing in, but lowering my seat was a big surprise for me…

I’ve only got a few rides on the new fit so far, but so far it just feels better than my past position… less strain on arms and bottom…

Anyways, just wanted to put out some good thoughts on the service… for $35 to realize my saddle has been about 15mm too high all these years… and looking forward to really seeing how it impacts my feel longer term once I get a bunch more hours on the fit…

[Zackus]

I think you've convinced me to give it a shot. especially for $35.

[RoosterCogset]

Interesting premise. So for you, with the 15mm saddle drop and 5mm bar lift, netting out with a 20mm less saddle/bar drop? I'm curious how the software can determine measurements -- do you start by providing your current bike's geometry details, as well as your own physical measurements (eg. leg, torso, arm lengths etc)?

[bikerboy337]

Quick summary, I used my iPad to record short 60 second videos on the trainer… the software reviews angles for hip, knee, back etc and recommends a proper range for each based on how aggressive you want to be, flexibility, etc…and then recommends adjustments to seat height, saddle core/aft, handlebar height and reach… I saw very small adjustments to all except seat height… it wouldn’t give me fire/aft adjustments until my saddle height was in the recommended range…

I found that it’s best to warm up for 15 minutes then record a snippet, get nice and settled into my riding position. Hands on the hoods… they explain it all really well.

As someone with no previous riding issues I felt this was well worth it.. if I had nagging injuries a professional would definitely be the way to go, but from the reviews I read before I tried it, the fit worked out very similar to what professional fitters gave… again, no knee or back issues for me and a standard build for my body…

[RoosterCogset]

Originally Posted by bikerboy337

Quick summary, I used my iPad to record short 60 second videos on the trainer… the software reviews angles for hip, knee, back etc and recommends a proper range for each based on how aggressive you want to be, flexibility, etc…and then recommends adjustments to seat height, saddle core/aft, handlebar height and reach… I saw very small adjustments to all except seat height… it wouldn’t give me fire/aft adjustments until my saddle height was in the recommended range…

I found that it’s best to warm up for 15 minutes then record a snippet, get nice and settled into my riding position. Hands on the hoods… they explain it all really well.

As someone with no previous riding issues I felt this was well worth it.. if I had nagging injuries a professional would definitely be the way to go, but from the reviews I read before I tried it, the fit worked out very similar to what professional fitters gave… again, no knee or back issues for me and a standard build for my body…

Thanks, but I guess I'm wondering how the software determines any scale in the scene it's evaluating, unless you provide it some sort of measurements. Ie. how does it tell if it's looking at someone 5'3" or 6'4", on a 50cm vs 60cm bike, where the adjustment amounts might be different?

[lorenbike]

Originally Posted by RoosterCogset

Thanks, but I guess I'm wondering how the software determines any scale in the scene it's evaluating, unless you provide it some sort of measurements. Ie. how does it tell if it's looking at someone 5'3" or 6'4", on a 50cm vs 60cm bike, where the adjustment amounts might be different?

Do you need to calibrate the video, ie like a yardstick or measuring tape in the frame?

Cool concept for $35 that's tempting to test, but I don't have a bike trainer.

[RoosterCogset]

Originally Posted by lorenbike

Do you need to calibrate the video, ie like a yardstick or measuring tape in the frame?

Cool concept for $35 that's tempting to test, but I don't have a bike trainer.

maybe by assuming you're on 700c wheels?

[benb]

The crazy thing is with modern machine learning if you fed in enough data on a population of riders it will get it right without actually being aware of anything. You’d just have to give it videos and data on whether the video represents a good fit for that rider.

It would sure require a lot of data though! More than a little company selling $35 apps would be able to get! Bike fit has a lot of variables and one camera angle wouldn’t be enough for everyone.

[bikerboy337]

So there no calibration, it’s a side on video with you on a trainer. They are looking at all the angles of your body for fit… hip angle, knee extension, back angle, shoulder angle, arm angle etc…

There are normal ranges for each of those angles and the results are generated on getting those angles into the normal range… you have a choice to go for comfort, performance or comfort and performance fit, the type of bike your riding, and do a flexibility/mobility assessment…

Again I don’t have tons of miles yet after the changes, but the fit feels great so far, few minor tweaks, and the 15mm saddle lowering were something I never would have done on my own, but they’re feeling great so far on the bike… I really thought my saddle height for the last 10 years was set perfect, but I notice a much more comfortable feel with the slight lowering…

For my new ride I anticipated running my 110 stem at -7, but it pushed me based on the recommendations to move to -12 with a 112.5 reach (enve aero stem) and it’s spot on for feel now… again, never would have gone that route and lengthened my reach on my own…

[jadmt]

I have been using it and I like it. I will say I get different recommendations depending on if video is from left side or right side. strangely enough I broke my right elbow so my arm does not straighten completely out and it always catches that. seems to me being it is using angles etc it does not need to know height etc. it does have you submit videos of different flexes to see how flexible you are.
https://portal.myvelofit.com/shared/...d-ce0dc14bffa3

[AngryScientist]

Your stem's too short.

[catchourbreath]

The newer Retul programs are like 90% computer based with the "fitter" just providing info from prompts, they use cameras for capturing. There is a range for everything with "red" or "green" indicators. This kinda sounds like they're doing a similar thing just eliminating the "fitter" and making you do the prompts.

[kppolich]

I've done something similar with a free app, basically. you measure the point between the front hub and rear hub and plot 2 dots on the screen so the App knows that distance and then it bases the changes off of that known distance.

Nice little app for sure, especially for the price!
Current going rate for a computer based Retul fit here is $250.00 + Tax

^^ That's for 1 fit on one bike where I assume the App fit is one time $35 cost for the app and then unlimited fits on unlimited bikes which is another super nice to have.

[jklooner]

Thanks, but I guess I'm wondering how the software determines any scale in the scene it's evaluating, unless you provide it some sort of measurements. Ie. how does it tell if it's looking at someone 5'3" or 6'4", on a 50cm vs 60cm bike, where the adjustment amounts might be different?

Originally Posted by benb

The crazy thing is with modern machine learning if you fed in enough data on a population of riders it will get it right without actually being aware of anything. You’d just have to give it videos and data on whether the video represents a good fit for that rider.

It would sure require a lot of data though! More than a little company selling $35 apps would be able to get! Bike fit has a lot of variables and one camera angle wouldn’t be enough for everyone.

To provide a little context to these questions, the value-added of the app is the automatic body measurements. For this part, they are not training their own data, instead they use a toolkit provided to app developers (I believe it's directly from Apple) that is used for fitness apps to detect people's skeletons in video scenes. This toolkit uses ML models trained on tens of thousands of people at least. When you do the initial measurement, you give them your height and put QR codes on your calves and chest to assess proportionality. It then measures torso length, femur length, ankle location, forearm length, shoulder width etc...

From that point on my guess is that it is rule-based. Perhaps they use the measured parameters and feed it to a linear classifier that says this is a good fit and suggests changing certain things, which they certainly have enough examples for. Maybe it or Retul uses a more sophisticated reinforcement learning model or something, but the model needs to be able to explain how to change parameters to affect overall fit. But my guess is that it is rule-based, which is probably how most run-of-the-mill fitters probably work. Really experienced fitters are probably more like sophisticated ML classifiers that can eyeball the outcome, but can then work backwards.

-My 2c.

[fourflys]

so I did the pre-purchase sizing part of the app yesterday to see what they might suggest.. for best results you print out a couple symbols and tape on to your chest and one to your calf, start the app recording and, as prompted, turn around twice. Once it analyzes the video, it will confirm your height and overlay the "bones and joints" on your picture.. this was really accurate for me, the joints were right where they were supposed to be and the bones seemed to accurate.

The app lets you decide between three riding styles, relaxed, neutral, and aggressive, and lets you change that if you want later. It will then suggest bikes from it's database based on your proportions and selected riding style, often giving you two adjacent sizes to choose from. You can then click bikes you're interested in to compare and look at how you would sit on that bike.. one cool thing I figured out a bit later was the app will let you change some bike parameters like stem length or rise (it will default to what comes on the bike at a selected size). This is cool as if you are at the edges of the back or shoulder angle graph (stem rise and length respectively), you can adjust and see where that puts you.. for example you can effectively flip the stem if your back angle is too low for a given size..

I haven't done a fit yet on the app yet, but this is a good tool to see how certain bikes might fit you.. I have no idea if that initial video will play into a fit on a bike since it's in my profile..

while I'm sure MyVeloFit isn't the same as an in-person fit, it's more informative for me at this point as the two fits I've done on my Roubaix were just to try and make that bike fit, even thought I told both fitters to tell me if I needed a smaller bike, etc.. if I ever do another in-person fit, it will be with a fitter that has a size cycle..