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Only $10 for all 2026 SX, MX, and SMX series.
Why? Unless your in bad crash plastic should be long lasting.
I was relying to @philG but, well I forgot to actually reply.....
I friend of mine did testing on a bike equipped with instrumentation such as strain gauges. Quite a bit of telemetry data is collected these days. Good to see too, as I'm sure you know, it's so hard to know what good enough is! When I first did a KX500AF I broke the frame pretty quickly. I ended up modeling the entire frame and basing the loads on known suspension velocities and adding a lot is material to prevent another failure. It was the best SWAG I had. Based on what I learned, I'd be pretty hesitant to jump on a random AF conversion someone does and hit a big jump too! Especially since most people don't precipitation harden them afterwards.
Regardless, I do know telemetry data acquisition is being done.
To answer what little I know from the OP, one team was allocating 3 frames per rider for a SX season.
They give the plastic out in the pits if you’re able to stick around / get back there
Lots of those broke, in all sorts of places, seen them break under the front of the seat , on both side tubes.
In the past i have seen parts designed in a way that you can draw a 'snap here' arrow on them, and they usually do.
The biggest issue is that nobody full understands the true load cases involved, so they make design something that doesnt work, and fails in test , and then beef it up , without getting to the bottom of why it really failed. Unless your load model is accurate, you are just guessing. I actually had a guy who properly got that , and worked out that for the part to break, the load must have been at least this, so i will update everything based on that , and ended up changing bits that didnt break, and leaving the bit that did alone, and it never broke again.
We had rod ends with Strain gauges in them and all sorts of other data kit , but Rallying had a lot of over max loads that were impossible to predict.
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Hard to know exactly what loads a frame sees, and in what directions and in what combination. Without accurate load data, any FEA model has limited value. Maybe Mr Honda has tons and tons of strain gauge data, but I reckon they also use a lot of empirical rules (corporate SWAG) and some big safety factors on anything for production.
Either way, every pro rider's frame I've ever seen is fkd after a few months. That's probably weeks in SX. Crushers have their uses...
Your Username is ironic considering we are talking about frames...
I am almost finished building a John Hand JBR and the sizes of the tubes scares me LOL... i broke a CCM125 frame as 60KG schoolboy .
The KSI frames are strong as, Phil. Top quality tube, top quality brazing. Not a computer in sight, just somebody with vast experience who knows his trade - inside out, back to front and upside down. Very, very few of those guys left sadly.
My KSi is almost 50 years old with no cracks or welds. I have an (Eatough) CCM frame the same. Later CCMs were made of cheese, and most Japanese etc production frames ditto. (It's not that they are stupid, just built to a far lower cost point and probably designed by a bloke who isn't a time served tube craftsman ). I'll allow Swedish Husky's an exception, seems to be good steel.
John Hand's brazing is fine. I have no idea what tube he uses, but the JBR design was/is solid.
Ally frames still scare me far more - all that vibration and fatigue cycles...
Curious what parts are they flying with now a days? Just was wondering how much gear a rider even brings himself now.
Pit Row
Post a reply to: Factory bikes - how much of a bike is brand new every weekend?