Topic: 25mm Knuckle Pin Upgrade Kit Review

[BigMike]

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.

[Yoat Goat]

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.

Real World testing? I think so.

[BigMike [OP]]

These pictures are up on the Store site and figured I'd include them here also.

Do this with your stock 17mm pins! HA! 42" ROCKER tires with a Tundra V8 powerplant:





And more to the point of the incorrect doubt of the KOYO bearings we use (despite their higher manufacture load rating), in our experience it is the pins that fail in large impact loading, not the bearings.

Our kit tackles both concerns/issues:

• Stronger Chromoly Pins
• Stronger Bearings

Regards,
BigMike

[Burl]

Marlin used to use KOYO bearings that were not NSK they were way better than the NSK what happened?  I saw on ebay last night there were some knuckle service kits out of OZ that utilize KOYO bearings for the stock size pins.  I think if the stock knuckle service came with KOYO bearings they woiuld last longer than the NSK.

[zippo]

This kit is quality! well designed and built and just looks awesome installed.

I did have a small issue with the bearing cage contacting the axle housing, due to the smaller bearing race. This was solved with a file and a diegrinder. The price you pay, when you start to play.