Bike Fit Recommendations

[brw0513]

Hi All.

I'm getting better at this eMTB caper. And it seems "a bit better" translates to much more confidence and a whole lot more fun on the trails.

And I want to improve some more to justify my next eMTB purchase But at 188cm tall, I'm on the cusp for most bikes between the L and XL frame size.

My current bike is a 2018 Merida e160 900e in size L. Reach is 460mm; stack is 644mm. I'm 120kg (but losing weight) and about as flexible as a broom stick. And 54 years old.

When I started riding my local trails on the e160, I was spending $99 of my $100 brain just staying upright. Lots of bashing into and over things. Even things I could have steered around. No finesse at all and not a care in the world about bike fit. The bike/suspension was very tolerant and the E8000 just a tractor up the climbs.

But for the past 6 months or so, I've been wondering if the e160 Large is truly a good fit for my body. When I watch others who seem to float over challenges on the trails, they seem to be much more "in" their bike. I thought I could look more like that if I found an e160 in XL, and began looking.

It turns out that finding a 2018/2019 e160 in an XL frame size, here in Australia at least, is going to be very difficult. Maybe impossible.

But recently I've started to look at bike geometry more seriously. And I've drawn quite a few frames in AutoCAD using the published geometries. This made me realise that an XL frame might not be required. With my 160e in Large, I already feel I'm too stretched out in basic skills like lifting the front wheel and manualling. I was beginning to wonder if my bars needed to be closer but higher.

I've found the RAD and RAAD sizing method described/published by Lee Likes Bikes. It makes sense to me, but of course there are those on the other side of the argument.

The undeniable thing about RAD and RAAD, right or wrong, is that the measurements can be drawn in CAD. And then different bike frames in different geometries and different sizes can be superimposed for direct comparison.

As it turns out, my e160 900e Large frame can deliver a reasonable RAD and RAAD with appropriate choice of stem, bars and spacers. I'm going to try it to see how it feels. It will be a reasonably expensive exercise.

My theoretical RAD is 840mm; RAAD is 58 to 60 degrees. The RAD on my e160 Large, with current cockpit, is currently 890mm and approximately 55 degrees.

I'm interested in others opinions about RAD and RAAD who have done what I'm about to try.

And if you don't like RAD and RAAD, how do you size your frame and cockpit?

Good advice appreciated.

 

[Hybrid Lou]

I came across this app the other day.
Make sure it’s safe to install - Never know these days

The World's First AI Powered Online Bike Fit

MyVeloFit provides AI powered Online Bike Fit in the comfort of you own home. No more expensive in store bike fits or guessing at your position.

www.myvelofit.com

 

[Ark]

Bike fits a scam imo... especially if your buying it from the same place your spending 4k+ on a bike

should be free to get a sale

 

[Hybrid Lou]

Bike fits a scam imo... especially if your buying it from the same place your spending 4k+ on a bike

should be free to get a sale

Sorry to here that. I haven’t had any problems with Biktix.

 

[skinnyboy]

Hi All.

I'm getting better at this eMTB caper. And it seems "a bit better" translates to much more confidence and a whole lot more fun on the trails.

And I want to improve some more to justify my next eMTB purchase But at 188cm tall, I'm on the cusp for most bikes between the L and XL frame size.

My current bike is a 2018 Merida e160 900e in size L. Reach is 460mm; stack is 644mm. I'm 120kg (but losing weight) and about as flexible as a broom stick. And 54 years old.

When I started riding my local trails on the e160, I was spending $99 of my $100 brain just staying upright. Lots of bashing into and over things. Even things I could have steered around. No finesse at all and not a care in the world about bike fit. The bike/suspension was very tolerant and the E8000 just a tractor up the climbs.

But for the past 6 months or so, I've been wondering if the e160 Large is truly a good fit for my body. When I watch others who seem to float over challenges on the trails, they seem to be much more "in" their bike. I thought I could look more like that if I found an e160 in XL, and began looking.

It turns out that finding a 2018/2019 e160 in an XL frame size, here in Australia at least, is going to be very difficult. Maybe impossible.

But recently I've started to look at bike geometry more seriously. And I've drawn quite a few frames in AutoCAD using the published geometries. This made me realise that an XL frame might not be required. With my 160e in Large, I already feel I'm too stretched out in basic skills like lifting the front wheel and manualling. I was beginning to wonder if my bars needed to be closer but higher.

I've found the RAD and RAAD sizing method described/published by Lee Likes Bikes. It makes sense to me, but of course there are those on the other side of the argument.

The undeniable thing about RAD and RAAD, right or wrong, is that the measurements can be drawn in CAD. And then different bike frames in different geometries and different sizes can be superimposed for direct comparison.

As it turns out, my e160 900e Large frame can deliver a reasonable RAD and RAAD with appropriate choice of stem, bars and spacers. I'm going to try it to see how it feels. It will be a reasonably expensive exercise.

My theoretical RAD is 840mm; RAAD is 58 to 60 degrees. The RAD on my e160 Large, with current cockpit, is currently 890mm and approximately 55 degrees.

I'm interested in others opinions about RAD and RAAD who have done what I'm about to try.

And if you don't like RAD and RAAD, how do you size your frame and cockpit?

Good advice appreciated.

Hi BRW,

I'm similar age and height as yourself, but have been riding for quite a while, and currently do about 500 km a month. Bike comfort, steering precision, and downhill composure are important factors, to me, when determining bike cockpit setup.

I find my perfect reach to fall between 455 and 465 mm, so perhaps your current bike is very good.

Longer reaches/larger seat tube angles pedal more efficiently. They do, by increasing the angle between your torso and legs. Raising and moving your handlebars back accomplishes the same thing, without the drawbacks of putting more weight on your hands (which can cause wrist nerve damage, especially for us older riders). Higher and more rear set bars also allow you to get back behind the cranks better while descending, and make dropping your saddle less critical when the terrain gets sketchy. Good thing is different bars, stems, and spacers are relatively cheap and easy to swap to find your happy place.

Moderate reach and chainstay lengths allow a happy balance of weight between the wheels, allowing minor shifts in body weight position on the cranks to get the bike to do what you want. Heels up=front end bites, heels down=happy descending. .

Perhaps of some interest:

Perspective: Size Up or Size Down

PERSPECTIVE SIZE UP OR SIZE DOWN? How to Pick the Right Size Bike. PIVOT SHUTTLE LT | LARGE VS. MEDIUM Are you struggling on picking the right size bike for you? You’re not alone. With current bike geometry trends making big moves, deciding what size bike

theloamwolf.com

Cheers.

 

[unclezz]

Hi,

A few years back I started riding again MTBs. I followed manufacturers recommendations based on my height (177cm) and ended up buying a Mindraker Foxy in size L with a very long reach (I think it was 470mm).
Initially all was good but when I started to ride a bit “better” I had a problem on a shoulder after trying to lift the front wheel.

This is when I started questioning the size of my bike. I thought I was probably using wrong muscles to ride it.

Long story short: I started looking around and ended up finding the Lee McCormack RAD theory.
Well… I discovered that my bike was waaaaaay too long in reach!

Then I made myself a favour and bought a new frame. This time - following the RAD theory - I did not look at vendors recommendations but I did my math (mainly using the madscientist calculator web page).

You know what?
I now have a bike in size S (always been a size M/L according to manufacturers) and I LOVE my bike! Much more fun and easy to ride!

When I bought my Turbo Levo I also downsized it (went for S3, but I could go for S2) and changed the cockpit to go back to my RAD measure: again pure love in riding!

For my next bike I will 100% go for a smaller frame. I actually love my wife’s emtb which is even smaller frame than my analog mtb in size S by 20mm in reach

 

[brw0513]

Hi,

A few years back I started riding again MTBs. I followed manufacturers recommendations based on my height (177cm) and ended up buying a Mindraker Foxy in size L with a very long reach (I think it was 470mm).
Initially all was good but when I started to ride a bit “better” I had a problem on a shoulder after trying to lift the front wheel.

This is when I started questioning the size of my bike. I thought I was probably using wrong muscles to ride it.

Long story short: I started looking around and ended up finding the Lee McCormack RAD theory.
Well… I discovered that my bike was waaaaaay too long in reach!

Then I made myself a favour and bought a new frame. This time - following the RAD theory - I did not look at vendors recommendations but I did my math (mainly using the madscientist calculator web page).

You know what?
I now have a bike in size S (always been a size M/L according to manufacturers) and I LOVE my bike! Much more fun and easy to ride!

When I bought my Turbo Levo I also downsized it (went for S3, but I could go for S2) and changed the cockpit to go back to my RAD measure: again pure love in riding!

For my next bike I will 100% go for a smaller frame. I actually love my wife’s emtb which is even smaller frame than my analog mtb in size S by 20mm in reach

I've decided to buy some SBLab bars and stem and spacers that get me very close my RAD of 840mm and RAAD of 58 to 60 degrees. My local SQLab retailer is also a physiotherapist and bike fitter. I'm going to pay for a bike fit to see what his process is for MTBs and the difference in result to my RAD and target RAAD. It's an experiment I'm willing to pay for.

 

[unclezz]

I've decided to buy some SBLab bars and stem and spacers that get me very close my RAD of 840mm and RAAD of 58 to 60 degrees. My local SQLab retailer is also a physiotherapist and bike fitter. I'm going to pay for a bike fit to see what his process is for MTBs and the difference in result to my RAD and target RAAD. It's an experiment I'm willing to pay for.

Bike fit is worth every penny

 

[JP-NZ]

To go along with what @unclezz says I would say the majority of people on MTB and EMTBs in general will be on bikes that are too long for them. In the last 3-4 years there has been a huge shift by bike companies to "longer and slacker is better" when it doesn't actually help fit people into bikes.

179cm with 455mm reach here and couldn't be happier

 

[Robstyle]

Here's a hot tip. The Atherton bikes website has a sizing calculator.
Remember this is a manufacturer that makes many many sizes and custom should be that way inclined so it gives very accurate numbers.
It was bang on for me.
Choose a dh bike too.

DH bike geometry is more on the money than enduro stuff and is more relevant to ebikes too.

 

[Nomad1]

Here's the thing bike sizing is really a recommendation and one may want to up size or down size a size especially if your on that line. Also keep in mind two people of the same height may require a different frame because there torso longer or shorter or other variances including how you ride.

 

[unclezz]

I just finished one more bike build using a Levo SL (first gen) frameset.
I used MadScientist RAD calculator to compare between frame sizes and I could not be happier with that!

According to vendor, with 177cm, I should buy a frame in Size M if not L.
Well, I bought a frame in size S and I LOVE it!

The reach of the Size S is only 415mm, but that does not mean too much until you start playing with angles of the geometry and cockpit setup. My neutral RAD is 81cm (a bit higher than average) but I wanted a RAD- setup. So I did a build that gives me a 79.5cm RAD.

The result? Yesterday I went for a ride on one of "my test trails" and: WOW! I just love this setup. Bike is so nimble and fast!

So, long story short: this is my 3rd bike setup using the RAD theory. To me it works extremely well and I would never go back to any other way of finding the right size.