I see no way that a dirtbike steering head bearing would be stronger than a bearing designed to carry steering load on a 4800-pound truck.
what I am getting at, is that the load the bearing is designed to see is lower than what it will see in your application, and it is a light duty bearing.
I don't see how having a bigger pin with a smaller bearing will cure our problems of our stock (which are beefier) Toyota bearings going out. Think about it, when something on a Toyota front end goes bad, what is it? Either knuckle studs or trunnion bearings. So why upgrade the pin (which very rarely breaks) making you run a smaller weaker bearing?
It is a fact that the bearing we are using is 54% stronger. This is indisputable. The bearing is officially tested and rated to withstand greater forces without failure.Duffil: You keep saying that the bearing is "designed" for that motorcycle. How do you know this? Sorry for being so defensive, but have you spoke to the engineer for Yamaha? I don't know if your cross reference is correct, but if it is, then I am sure Yamaha did some testing, figured out a design factor of safety, and then found a bearing to suit their needs. That is very impressive to me to see a motorcycle require such a BEEFY and STOUT bearing in their headsets. Coming off of 40 foot jump at 60 MPH and landing at a bad angle on the front wheel must be a far greater load on the headset than we can imagine. I think we'd all be surprised at the forces involved, especially if Yamaha went so far as to use that strong of a bearing. Also, I don't know where you get your figures from, but a stock 1979 Toyota pickup does NOT weigh 4,800 pounds. Probably more around 2,900 pounds (and with little 28?-inch tires and NO power steering).
I've broken one. A friend of mine sheared one too.
slabcs: Broken one what? Sheared one what?
We've tested them in Marlin's truck, numerous local customer rigs, Jon's truck, and the XXRA buggy going on 1-1/2 years now without a single problem. The XXRA buggy has blown up 30-spline Longfields and has broke half a dozen stock 17mm pins.
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