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Well whatever the case I hope Phil doesn’t get too much heat for speaking on a safety issue.
Spent a lot of time doing reports on broken parts, metallurgical testing and failure causes, we used to spend a ton of money and time on making sure all the parts were perfect, which meant cutting them up to prove it.
I doubt any of the teams do proper analysis on their failures, just throw new bits in and go again.
We had a great offsite lab that would turn stuff round super quick, and looking at failures at the microscopic level, you get to a point where you can eyeball stuff and tell what broke first , just by the colours in the breaks.
I have watched our car break live on TV in China on a saturday, and have the broken parts waiting on my desk on a monday morning.
Zach Osborne used to kill the YZF250's that Dixon built, i believe he used to do 3 GP's on a set of cases and they were done, he was hard as fuck on the bikes, but there are others who are nothing like as hard, and they dont break stuff, and they are still fast.
When you look at how many guys DNF'd San Fran SX, and why , it doesnt take long to understand why. I bet Marvin Musquin wouldn't have cooked a 250F .
Every Yamaha I’ve had has had gearbox issues. They have been like that for years and I’m going back to the first 250 2 strokes I had before going into the YZ426 when it was released.
Sounds super-interesting.
Always liked the real-world build it/test it/break it/figure out why it broke, process. Keeps things interesting and gives the ole noodle a great workout.
And I can absolutely see that with different riders. Sort of how Magoo used to hammer on it until it broke while Bayle aways looked like he was trying to perform ballet on his bike.
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Very likely could be a vendor/ manufacturing/ material issue not design
The fx has a different gear set as far as I know and doesn't share any.
Yet somehow they're able to make transmissions that can handle the power of a 450?
All Factory teams are digging deep to analyze failed parts, similar to what you’d expect in any other industry. Satellite teams will lack some of the resources to go as deep, while also exponentially more reliant upon aftermarket companies for engineering support where parts would otherwise be in-house factory made for the big teams. This could be challenging, especially for a complex subsystem like the transmission. Privateers throw parts at the bike and move on….maybe send some failed parts back to their sponsors with some information.
I’ve been on Yamaha’s for close to 10 years. In the last several years the reliability has gone down hill significantly. Almost everyone I know has had issues out of their 23 450’s. My bike the wrist pin broke at 17 hours. The previous gen bike, rod went at 20 hours. I meticulously maintain my stuff too, it’s not due to lack of maintenance.
It’s unfortunate too because they’re really good bikes. But my next bike will NOT be a Yamaha.
That's not actually a viable solution.
The current YZ250 has had the same gearbox since 1999, with the exception of a ratio change (different part number) to 2nd gear.
The two stroke has a weak gearbox. 3rd gear on the main shaft moves to engage dogs with 3rd and 4th gear... Those gears are prone to failure. The failure is a loose feeling when shifting, false neutrals and jumping out of gear under extreme loads (like jump faces).
I replace the entire gearbox in my YZ250s with YZ450F parts from 2006 - 2009.
You get the same ratios with four dogs on each gear (compared to three dogs on two stroke gears) as well as more width at the teeth and where the gears bear on the shafts.
I also take the shift forks out and change the way they interface the cases. The shift rails move with the forks in the YZ250. Most good transmissions have shift rails that remain fixed in the cases while the shift forks slide on them.
Tons of people have zero issues with the two stroke YZ250.
Myself and a few friends feel them getting loose around 30 to 40 hours and that's just not acceptable.
Back to the four stroke content, sorry if I've derailed the topic.
Who does he use for insurance?
Not sure what your point is here guy, I never said he was racing supercross or hitting random nationals on weekends. Just shared our experience. We bought the bike with about 40 hours on it and as now it has another 273 hours on the meter. As I stated we have not had a transmission issue yet. Sorry that does not seem to fit your narrative. Most of his riding is spinning laps on the track at our house. This is about a month ago when the bike probably had a little over 300 hours on it. My 16 year old was riding and did the edit. He rides 3 to 4 times a week, but would ride every day if I would let him, lol
He’s ripping. I would’ve loved to have a track at my house when I was a kid.
Sweet!
That's one way of keeping a teen from wanting to run away from home!
Kid rides good!
I thought Yamaha's are the most "reliable" OEM?
But now, in MotoGP, F1 , and WRC, a lot of times you dont have the chance to do that, because you cant just change designs because of the rules, and the testing limits.
Parts have to be built to last multiple events, so where we used to have parts we could rotate and refurb, with minimal costs, they now have to do 2 or more events, and when they come back they are fucked beyond belief. So straight in the bin, all in the name of cost saving.
You could modify parts to fix things that now you cant touch for a season.
Progress it isnt
Cool stuff and I agree but WRC is a different application when it comes down to it. I also agree with what you said on the bikes failing in the mud races, it sure seems like certain riders would avoid those same failures (especially the smoked clutches).
Pit Row
Their giant marketing team would have you think that, along with the 250 making the most horsepower when it's one of the weakest, and that cabl clutch being an advantage with zero off-road championships worldwide for like 20 years. Wait until you see them literally break in half and throw timing chains
Do you need a glass of water or something?
Been happening to YZ 250 F models since at least 2018.
If that's the case, I wonder if club is looking into the star transmissions.
All the stories of failed yz250 trannies is what kept me from buying one.
Well be did throw out an uncomfortable “blu cru” after the story so might be why some came to that conclusion 😂
I never implied he was, your son looks like he rides well. My whole point was you can't compare the stress your son puts on a Yamaha transmission to what a rider like Phil would put on it racing supercross. I meant no disrespect to you, but comparing how reliable the transmission in your son's bike is to the issues the ClubMX bikes are having aren't relatable.
My son is lucky enough to ride private tracks locally with friends that are basically almost full on supercross tracks, his buddy just raced the first two rounds of Supercross in the 250 class, made the main at A1 and just missed out in the LCQ for San Fran. They ride the same tracks back home and his buddy just puts way more stress on his bike (frame,motor and transmission) compared to my son.
I stand by what I said, the average rider isn't a good gauge on how durable certain areas of bikes are when compared to pros. Of course the bike might be super reliable in your situation and still be problems for race teams.
That's all I meant by my post.
I find it hard to believe Phil is running a bone stock transmission In supercross. Give me a break. And the Covid vaccine works also. 🙄
With the YZ 250(2t) known failures, it is surprising BRC would put a 500 top end on these. I asked them and they said the issue is sorted for them apparently.
Translation: "We don't have to pay for it once you own it."
Their fix is running more oil in the tranny. Or at least they say that.
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