2 STROKE WORLD .net

The 2-Stroke Garage => General Chatter => Topic started by: IR8D8R on June 01, 2021, 12:26:13 PM

Title: RD hub casting flanges
Post by: IR8D8R on June 01, 2021, 12:26:13 PM
I never even noticed the casting flash(?) on the inside of RD hubs. It makes cleaning them up a drag.

Is there any structural value to these? I somehow find them aesthetically offensive.

I've seen talk of people removing them on other forums. I was considering having them cut off and the inside of the hub skimmed in a lathe.

So are they sprue remnants that Yamaha was too cheap to grind off or intentional ribs to add rigidity? Their placement right on the parting line makes me wonder. I assume these were produced in a multi-gang mold and there don't seem to be any other sign of gates or runners.

Advice ranges from "Don't do it" to "I always remove them". You can see that the factory just jammed them into a grinder to finish.

IR8D8R
Title: Re: RD hub casting flanges
Post by: m in sc on June 01, 2021, 04:14:43 PM
ID NEVER REMOVE IT.  get it vapor honed and have at it.  gives strength to the flanges. thats not flash, thats a rib. my .02

Title: Re: RD hub casting flanges
Post by: Yamaha 179 on June 01, 2021, 05:16:53 PM
The two TZ hubs that I have are magnesium and they have four tabs, smaller (not as tall), but they have tabs also.  I think removing them would be a mistake.
Lyn Garland
Title: Re: RD hub casting flanges
Post by: Striker1423 on June 02, 2021, 07:29:21 AM
I agree with Mark. Having worked in a factory where flashing was a common thing this picture confused me. I was like, where's the flashing?

That BIG THING?!?

That's not flashing, that's a feature sir.
Title: Re: RD hub casting flanges
Post by: IR8D8R on June 02, 2021, 02:24:30 PM
Thanks guys,
There really should be 4. Otherwise it is unsupported in some orientations. I will not remove them.

I saw a thread about removing them on Do The Ton. I was not the mastermind who conceived the idea. I merely looked for info on hub prep.

I was kind of on the fence about this because they are obviously thicker than typical flash but they aren't finished very well from the factory. If the factory had wanted them removed they certainly could have done during the machining process. ...Unless the cursory grinding done was a half-hearted removal sufficient only to clear the spokes. It's pretty crude finishing. I actually think that this is where they put the runner for the sand casting. It is much easier to place at the mold halves.

I highly doubt removing them would cause the hub to break in half. There is a lot of steel in there supporting the load with bearings, steel spacer and axle. Plus the stresses are distributed by the spokes. They just make cleaning up the inside of the hub a lot harder unless you blast them. I thought a machined surface would be more attractive. I have a blasting gun but not vapor...

I had some other advice about the "quality" of suggestions on DTT that I take to heart. I also believe that the quality of thought on 2SW is better than other places on the net.

IR8D8R