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1000N isn’t a massive load. Assuming a 75kg rider with a 50/50 weight distribution, it’s only 2.7g. Your 30g is probably at a much higher frequency than what would typically cause frame displacement. For your 28 vs 32h question. A frame and a wheel are essentially springs in series. Deflections would add together for greater total displacement. You can’t “use up” the force.

Great article, and it would be amazing to see rider feedback Vs each of the changes (of course run blind, with a sock over the modified parts). But it got me thinking about the front to rear balance in compliance - how does the relative stiffness to wag and roll for a fork compare to the rear - mental FEA says stiff in roll but fairly soft in wag. Would it be useful to balance both ends, and how would you do it? Machine down the axle interface to do an anti-torque-cap? Take material off the lowers around the axle?

Hey Ryan, again, awesome work, I really love this stuff, and it is why I got into using data acquisition on my bike! I read this over a few times and have some questions! Why did you decide on 1000n of force? With my data acquisition, I have recorded 30g at the rear axle of lateral force, which isn't convertible to N, but say 1 "gravity" is considered as the force of gravity on Earth, is roughly 9.8 N/kg. So, let's say I hit the max of 300n, could you run the calculations on that and see what % difference...

Amazing article, thanks a bunch!

That’s a great read, appreciate your time writing that up!

Reckon norco can successfully design flex for both Danny and Greg? Or they stop chasing an infinitely stiff for Greg?

Amazing write up! Thanks so much for the insights Ryan!

What a superb article!

Unfortunately this won't be happening, as the donor frame is dead haha. Maybe if I can find another donor frame from someone to destroy to test I'll look at doing it, but my old frame cracked so I won't be able to modify it safely. I saw this on pink bike this morning, it's obviously a joke/gag bike, but from what little riding we saw, it really does highlight some interesting characteristics of front triangle flex. Worth a watch for sure.

A bit late to the party. This one is a though provoke for sure, looking at what the wheels do theoretically you need completely different things flex wise from the front and the rear... As for rear wheel steer on cars, it's mostly counter steer under way 50 to 80 kph, costeer above that and no steer when things go sideways. It is to add agility at low speeds (because cars are getting bigger) and stability at higher speeds.

I grew up riding dirt bikes and never really felt comfortable with MTBs. This thread brings up a lot of what I was feeling. I had a hard tail, and I would occasionally catch a hidden stump or square edge and that thing would throw me over the bars. I moved to full suspension and had the flexing issue with the Gery Fisher, then had a specialized camber pro 26inch wheel. It felt pretty good, but still seemed to be a bit too ridged and unforgiving in some instances. Last year I picked up a polygon colossus N8e and feel...

Developed for a frame designed for trunnion mount shocks. 1 step forward, 2 steps back.

I had a Gery Fisher full suspension bike way back in ~2010, don't remember the model but it was 100mm travel front and rear. The seat stays were carbon which I thought was cool, but they had no bracing between them. On climbs where I would start to pedal hard the chain would skip on the cassette. I would go through the cable tension settings after a ride and everything looked great on the stand. Would be interesting to see if it was the BB or the rear triangle torsionally twisting screwing with the chain alignment.

I like this idea on the top or bottom shock mount. I don’t really see a negative to it.