Free Ride Mountain bike

New bike coming?!?
I’m making a free ride bike and I would like any suggestions for my design idea’s.
The linkage 3x looks like this:

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Hi Cal, Welcome!

Cool design. I think posting images of your leverage ratio, pedal kickback, and anti squat graphs from Linkage would be very helpful.

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Here I can only send one per post

The only really worrisome thing I see is the Leverage Ratio. 54.4% progressive is kind of a lot. Most production DH/Freeride bikes are closer to 20-30%.
I’d love to see how you plan on packaging all of the shock and linkages into that area by the bottom bracket though. That’s gonna be difficult.

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Yeah the progressivity is a bit much in my opinion. Also, I don’t get how linkage calculates progressivity, it seems off to me. I popped it in my calculator and it came out at just under 120%.

The way I calculate it is this: ((A/B)-1)*100
where A = leverage ratio and 0mm and B = leverage ratio at bottom out. It seems to be in line with what companies are advertising. Here’s a excerpt of my spreadsheet of a few random bikes that I found published information on:

Year Make Model Travel Lev @0mm Lev @end Progression %age
2023 Forbidden Druid v2 130 2.92 2.3 27.0
2021 Forbidden Druid v1 130 2.7 2 35.0
2021 Forbidden Dreadnaught 152 2.65 1.84 44.0
2020 Rocky mountain Slayer 165 3.07 1.86 65.1
2021 Salsa Cassidy 163 2.96 2.4 23.3
2020 Cube Sterio 170 2.9 2.52 15.1
2022 Transition Spire 170 3.01 2.37 27.0
2023 Pi Bikes HP 170 2.82 2.54 11.0
2023 Deviate Highlander 2 145 2.88 2.43 18.5
2014 Blackmarket Roam 160 4.2 1.6 162.5
2023 Orange stage 7 165 3.04 2.32 31.0
2023 Coal bikes TLFS 158 3.42 1.87 82.9
2023 Santa Cruz 5010 130 2.7 2.4 12.5

Sorry if a bit off topic but its been on my mind for a bit. Any correction/input as to what linkage is doing would be appreciated

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Interesting design. I think going above 40% progression is risky. I’d recommend around 30-35%.

Also, careful going below 2:1 at end stroke on the leverage ratio because you might create a deep stroke rebound hang up. Also 3.65 starting will be extremely active and it would be hard to get any support from the damper.

18.5% of pedal kick is too much in my opinion.

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Thanks for the input. It is a high pivot the pedal kick back is high in the bigger gears I wanted a sort of 50/50 climb / descend gear (the picture was taken in a high gear). Can you tell me a little more about the deep stroke rebound hang up?

If you go below 2:1 at the end stroke then it will take a lot longer to recover and might create a packing situation. Most shocks are shimmed to work at or above a 2:1 ratio at end stroke. I would recommend to stay at or above 2:1 at the end or else you will have to get creative with the rebound shim stack.

I would try and have your starting leverage ratio around 3.2 to 3.4 and ending around 2:1. If you want extreme progression then I wouldn’t go above 3.5:1 and finish at 2:1. Do you have a shock you want to use in mind?

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I think I will be using a rockshox Super deluxe coil or a vivid