Why doesnt MXA or Keefer do a simple weight test

soggy
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soggy 3/17/2025 7:07am
3/17/2025 7:07am
greg570 wrote:

Imagine a world where shootouts would be won by a bike with the fastest laptime (and not a bike some test geezers prefer)...

Wouldn’t make a lick of difference. Too many varaiables. Different riders would be faster on different bikes and then you’d have to figure out if you ride more like rider A or B. 

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Tyler D
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Tyler D 3/17/2025 7:21am
3/17/2025 7:21am
CarlinoJoeVideo wrote:
Yeah, I have that. I melt it down and pour in the spindle. Lots of places to hide it, but personally I don’t think it’s enough...

Yeah, I have that. I melt it down and pour in the spindle. Lots of places to hide it, but personally I don’t think it’s enough, so I just strap lead scuba weights under the BB.


Back to the topic, when we did some of the vital shootout bikes tests I don’t remember any riders saying one bike or another felt heavier or lighter on the track from physical weight standpoint.  But I think good and bad mapping can do more to make a bike feel heavy/lethargic or lighter/flickable.


 

ML512 wrote:
Agreed, qMapping / engine character effects a bikes weighted feel more in my opinion. For years when KTM was chasing having the lightest 450, I commented...

Agreed, qMapping / engine character effects a bikes weighted feel more in my opinion. For years when KTM was chasing having the lightest 450, I commented that the Kawasaki that weighed nearly ten pounds more felt lighter in action, due to the connected feel and response of the engine at that time. The KTm then just felt like a tractor…

PTshox wrote:
Don't for get that brilliant shock linkage ratio they came up with so they could put on a lighter shock spring to save weight! Even though...

Don't for get that brilliant shock linkage ratio they came up with so they could put on a lighter shock spring to save weight! Even though that linkage was horrible. I fought that thing with various valving changes to the shock (light LS compression and lots of HS compression shims to try and valve around it). I wasn't getting the feel I wanted.... lt wasn't till I ran into this guy down the street that had a garage full of Alta motorcycles that I got a clue what was going on. l stopped by one day and started talking to him.... Ask him where did he get all the Altas'.... he told me he was the chassis engineer (as was his room mate) for them up till they closed. He bought a few on the cheap as the doors were being shut. I said ... "interesting" and started talking to him about the shock valving challenge I was running into on the KTM. He said "oh - here is what happened" and he pull out a felt marker and some cardboard and drew the linkage curve of the earlier KTM linked bikes and the 2016 + ones. Told me Alta adapted the 2015 ish curve for their bikes. I said interesting... how does he know this about KTM ... He said "You know who Dave Arnold is?" I said the guy from Honda? He said - "yes - we hired him as a consultant and I worked with him on the chassis and linkage curves. He did some work for KTM before we hired him". 

That's rad. How does the linkage curve differ? 

 

https://linkagedesign.blogspot.com/2022/09/evil-epocalipse-2023.html?m=1

 

1000085168.gif?VersionId=Nu8FwmN0Cj

 

lukerichards 3/17/2025 8:27am
3/17/2025 8:27am

I remember max doing something like this when the aluminum frame yz250 came out so probably 20 years ago, stripped down and water bottle for a gas tank 

rbspecial138
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rbspecial138 3/17/2025 8:39am
3/17/2025 8:39am

Radical Idea, but have they considered doing tests with actual real life parts intended for a motocross bike instead of melted down fishing weights from my uncles tacklebox?

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CarlinoJoeVideo
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CarlinoJoeVideo 3/17/2025 10:20am
3/17/2025 10:20am Edited Date/Time 3/17/2025 10:21am
ML512 wrote:
Agreed, qMapping / engine character effects a bikes weighted feel more in my opinion. For years when KTM was chasing having the lightest 450, I commented...

Agreed, qMapping / engine character effects a bikes weighted feel more in my opinion. For years when KTM was chasing having the lightest 450, I commented that the Kawasaki that weighed nearly ten pounds more felt lighter in action, due to the connected feel and response of the engine at that time. The KTm then just felt like a tractor…

PTshox wrote:
Don't for get that brilliant shock linkage ratio they came up with so they could put on a lighter shock spring to save weight! Even though...

Don't for get that brilliant shock linkage ratio they came up with so they could put on a lighter shock spring to save weight! Even though that linkage was horrible. I fought that thing with various valving changes to the shock (light LS compression and lots of HS compression shims to try and valve around it). I wasn't getting the feel I wanted.... lt wasn't till I ran into this guy down the street that had a garage full of Alta motorcycles that I got a clue what was going on. l stopped by one day and started talking to him.... Ask him where did he get all the Altas'.... he told me he was the chassis engineer (as was his room mate) for them up till they closed. He bought a few on the cheap as the doors were being shut. I said ... "interesting" and started talking to him about the shock valving challenge I was running into on the KTM. He said "oh - here is what happened" and he pull out a felt marker and some cardboard and drew the linkage curve of the earlier KTM linked bikes and the 2016 + ones. Told me Alta adapted the 2015 ish curve for their bikes. I said interesting... how does he know this about KTM ... He said "You know who Dave Arnold is?" I said the guy from Honda? He said - "yes - we hired him as a consultant and I worked with him on the chassis and linkage curves. He did some work for KTM before we hired him". 

Tyler D wrote:
That's rad. How does the linkage curve differ?  https://linkagedesign.blogspot.com/2022/09/evil-epocalipse-2023.html?m=1   

That's rad. How does the linkage curve differ? 

 

https://linkagedesign.blogspot.com/2022/09/evil-epocalipse-2023.html?m=1

 

1000085168.gif?VersionId=Nu8FwmN0Cj

 

I believe the progression rate stays the same, they just lower starting and ending rate so you can use a softer spring. On paper the forces to sag and bottom out should be same. 

Does it “feel” the same? It should, but riders can argue that.  

I’ve tried this on mountain  and maybe if I was  I wouldn’t know the difference but to me, I  get it to feel exactly the same.

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Falcon
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Falcon 3/17/2025 12:03pm
3/17/2025 12:03pm

Don't forget the placebo effect. 

I am 100% sure I go faster on a clean, light bike while wearing new riding gear. How am I sure? I don't know, I just am. 😄

When replacing parts, I always go for the lighter option when I can. 

PTshox
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PTshox 3/17/2025 1:05pm
3/17/2025 1:05pm
PTshox wrote:
Don't for get that brilliant shock linkage ratio they came up with so they could put on a lighter shock spring to save weight! Even though...

Don't for get that brilliant shock linkage ratio they came up with so they could put on a lighter shock spring to save weight! Even though that linkage was horrible. I fought that thing with various valving changes to the shock (light LS compression and lots of HS compression shims to try and valve around it). I wasn't getting the feel I wanted.... lt wasn't till I ran into this guy down the street that had a garage full of Alta motorcycles that I got a clue what was going on. l stopped by one day and started talking to him.... Ask him where did he get all the Altas'.... he told me he was the chassis engineer (as was his room mate) for them up till they closed. He bought a few on the cheap as the doors were being shut. I said ... "interesting" and started talking to him about the shock valving challenge I was running into on the KTM. He said "oh - here is what happened" and he pull out a felt marker and some cardboard and drew the linkage curve of the earlier KTM linked bikes and the 2016 + ones. Told me Alta adapted the 2015 ish curve for their bikes. I said interesting... how does he know this about KTM ... He said "You know who Dave Arnold is?" I said the guy from Honda? He said - "yes - we hired him as a consultant and I worked with him on the chassis and linkage curves. He did some work for KTM before we hired him". 

Tyler D wrote:
That's rad. How does the linkage curve differ?  https://linkagedesign.blogspot.com/2022/09/evil-epocalipse-2023.html?m=1   

That's rad. How does the linkage curve differ? 

 

https://linkagedesign.blogspot.com/2022/09/evil-epocalipse-2023.html?m=1

 

1000085168.gif?VersionId=Nu8FwmN0Cj

 

CarlinoJoeVideo wrote:
I believe the progression rate stays the same, they just lower starting and ending rate so you can use a softer spring. On paper the forces...

I believe the progression rate stays the same, they just lower starting and ending rate so you can use a softer spring. On paper the forces to sag and bottom out should be same. 

Does it “feel” the same? It should, but riders can argue that.  

I’ve tried this on mountain  and maybe if I was  I wouldn’t know the difference but to me, I  get it to feel exactly the same.

The 2015 and earlier KTM linkage was apparently just like what  Yamaha was doing. The 2016 stuff was stiffer initially - to allow for the softer spring and yet get sag numbers to work - but didn't ramp up as well as I recall. 

The Luxon guy should be able to comment as he and N2Dirt came up with a different knuckle to address this. PR2 and Procircuit did as well (in their case knuckle and dog bone). Bike works better with the Luxon/PC/PR2 parts vs stock. I don't know where the newer bikes are at with the curve - but again the Luxon guy should be able to add context to it (as to if it changed and what years). I know some of the Husky link bikes had different curves that were better. But can't recall what years/models. . 

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Luxon MX
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Luxon MX 3/17/2025 1:16pm
3/17/2025 1:16pm
ML512 wrote:
Agreed, qMapping / engine character effects a bikes weighted feel more in my opinion. For years when KTM was chasing having the lightest 450, I commented...

Agreed, qMapping / engine character effects a bikes weighted feel more in my opinion. For years when KTM was chasing having the lightest 450, I commented that the Kawasaki that weighed nearly ten pounds more felt lighter in action, due to the connected feel and response of the engine at that time. The KTm then just felt like a tractor…

PTshox wrote:
Don't for get that brilliant shock linkage ratio they came up with so they could put on a lighter shock spring to save weight! Even though...

Don't for get that brilliant shock linkage ratio they came up with so they could put on a lighter shock spring to save weight! Even though that linkage was horrible. I fought that thing with various valving changes to the shock (light LS compression and lots of HS compression shims to try and valve around it). I wasn't getting the feel I wanted.... lt wasn't till I ran into this guy down the street that had a garage full of Alta motorcycles that I got a clue what was going on. l stopped by one day and started talking to him.... Ask him where did he get all the Altas'.... he told me he was the chassis engineer (as was his room mate) for them up till they closed. He bought a few on the cheap as the doors were being shut. I said ... "interesting" and started talking to him about the shock valving challenge I was running into on the KTM. He said "oh - here is what happened" and he pull out a felt marker and some cardboard and drew the linkage curve of the earlier KTM linked bikes and the 2016 + ones. Told me Alta adapted the 2015 ish curve for their bikes. I said interesting... how does he know this about KTM ... He said "You know who Dave Arnold is?" I said the guy from Honda? He said - "yes - we hired him as a consultant and I worked with him on the chassis and linkage curves. He did some work for KTM before we hired him". 

Tyler D wrote:
That's rad. How does the linkage curve differ?  https://linkagedesign.blogspot.com/2022/09/evil-epocalipse-2023.html?m=1   

That's rad. How does the linkage curve differ? 

 

https://linkagedesign.blogspot.com/2022/09/evil-epocalipse-2023.html?m=1

 

1000085168.gif?VersionId=Nu8FwmN0Cj

 

2016-2022 KTM/Husky linkage curve vs a more traditional curve (our knuckle):

luxon-suspension-linkage-knuckle-lux-ktm-ss-p0003-n2d-image d03
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