jimsschwinn

So I've been rebuilding Sturmey-Archer AWs for a little while now, and I keep coming across these knurled washers to go on the outside of the dropouts. My question to you is this: are these required? I get hubs in that don't have any washers, but I have been using my depleting stock. The washers measure 4mm thick, inside diameter is 10.5mm, outside diameter is 20.5mm.

Do these hubs require these, and if so, where on earth do I source the washers?

I've been installing new knurled anti-rotation washers with each rebuild, since they are usually crushed or mangled beyond re-use.


Thanks for everything, you're all aces in my book.

JohnDThompson 

The anti-rotation washer is needed, but the other washer can be a plain, unknurled washer from the hardware store.

jimsschwinn

Outstanding answer. I've got a GREAT hardware store with an entire double-sided aisle dedicated to bins and bins of washers, bolts, stainless hardware, nylon, nearly every machine screw/nut/bolt you could imagine. I'll stop there after teaching today and pick some up, bringing this lone washer along as an indicator of what I need.

Thanks, Mr. JohnDThompson!

FBinNY 

This is about the importance of bite. Good bite means greater holding power against slippage in the dropout with lower torque on the axle nuts. Improving that ratio means reducing chances of stripping the nuts.

Compare to the holding power of a pair of pliers with smooth or dull jaws vs. one with nice sharp biting teeth.

The same issues of bite apply to any wheel used with horizontal dropouts where bite is needed to prevent slippage.

However, you may not need serrated washers if the axle faces provide the necessary bite, or if chain tension loads are low enough. So it's a mechanics call, if the wheel slips, bite the bullet and use serrated washers.

cny-bikeman

I agree. The anti-rotation washer already has some bite to it. I worked on a huge number of 3 speeds and did not notice much of a problem with regular washers.