Wheely King Spur Gear... Carbon Fiber? I don't think so!

[JavelinSST390]

Okay, so this weekend I upgraded the battery on my WK to a 3000mah NiMh unit, from the stock 1500mah NiCd and the Two Epic packs I had that were the same...

WOW what a difference! I didn't think just a different battery could make such a huge performance gain. It was like strapping a Supercharger to an already powerful Big-Block!

The added power was great, and I couldn't resist some high-speed bashing.

With this battery and my Multiplex 600 motor, with the stock gearing, it now pulls wheelies from a standing start again (even with a 2" extended wheelbase.) and is a top-speed MONSTER!

And then it ate six teeth off the much-publicized rubber spur gear.

No biggie. I run to my LHS to get a replacement (plus a 96t spur so I can put on my Robinson 15t pinion.)

They have no Robinson spurs in stock, so the guy hands me HPI units. The 90t has the same part# as the stocker, but on the package, it says CARBON FIBER SPUR GEAR.

But it's EXACTLY the same as the stock unit.

If this thing is Carbon fiber, I'm the Queen of England.

"We are not amused."

I don't know who HPI thinks they're trying to kid, but there is NO WAY this thing is made of CF. It's WAAAAY too flexible, and it's OBVIOUSLY injection molded (I know this because of the ejection pin marks on the back of the spur, from the pins that spit the parts out of the injection molds) Wouldn't you think a CF part would be machined? Hmmmmm...

But, I got them anyway because I wanted to get my WK up and running again and I didn't want to wait three weeks or more for HobbyClowns (hobbytown... God, what a pathetic excuse for a hobby store) to get some Robinsons in.

So I put the 96t in and the 16t pinion, and hit the rockpile in my yard.

And promptly ate three teeth off that one!!!! (where's the little smiley of banging your head against a wall when you need it?)

Now, if I'm wrong, and this IS CF, please feel free to set me straight. But I doubt it is, because I ain't NEVER seen any Carbon Fiber like THIS!!!

Now I wish I would have waited for the Robinsons... Or is there something stronger out there?

[joemomma95]

I also ate the stock spur gear, went and got the HPI CF replacement....also noticed it wasn't CF but it seems to be holding up better than the stocker...not sure they are exactly the same but could be, the stocker is long gone so I can't compare the two and I honestly can't remember if there was a difference when I swapped them out..

[themerc64]

True, it is not carbon fiber, but it is molded with a resin that contains some type of fibers. Most likely fiberglass. If you look at the HPI spurs that are available in 90, 93, and 96, only the 90T is molded out of plain old poly. The 93 and 96 are available in the fiber content version.

[Power_Wagon]

i think its FRP - Fiber Re-enforced Plastic

[Offroader5]

Yeah, I kinda doubt it was CF...especially from HPI. I'd be intrested in seeing someone form CF into a spur with all the teeth.

One thing to watch, is when a company calls the product "graphite". Many people get this confused with CF...but it's not the same thing. Alot of aftermarket rc parts are made with graphite.

[S1NN3R]

Originally Posted by Offroader5

One thing to watch, is when a company calls the product "graphite". Many people get this confused with CF...but it's not the same thing. Alot of aftermarket rc parts are made with graphite.

It's essentially the same thing. "WOVEN carbon fiber" is what most people think of when they hear carbon fiber, but that's not it's only form. The "graphite" parts to which you refer are still made with the same stuff, but it would be more accurate to think if it as "carbon particulate". It's the exact same chemical structure as that which makes up woven carbon fiber, but in a powder form so as to allow it to be mixed with a plastic bond base and be injection molded. Furthermore, "graphite" is accurate when describing both woven carbon and molded carbon.