Face Knurling...

I was toying with the idea of making some deep fit acorn style cycle/motorcycle wheel nuts as I cant find a supplier for 3/8 bsc 26tpi x 20mm deep.

I thought it might be a simple project however with commercial wheel nuts they often have a serrated edge to retain on the fork. I know I could use crown washers or some similar option however how would I go about knurling or serrating the face of the nuts?

Take a bog standard knurling tool and set the height either much lower or higher than usual, flip the end up/down so only one wheel is engaged and feed into the slowly rotating face.

Alternative is to set up in the mill and cut two sets of Vee Grooves at 90deg to each other into the face.

Thanks Jason

What about hard steels such as 316 stainless, would the knurler work as well? I presume the above is aluminium..

If you have a rotary table on a mill, you can produce the knurling, it just takes time. Washers with the knurling in association with nuts would be better, then the knurling will grip, but not be rotating when the nut is tightened.

Edited By old mart on 11/04/2021 15:47:35

Jason, you do have a simple answer to most things !

Never needed to do this, but who knows ???

Thanks for the tip.

Jason I'm curious how you machined the hole in that part with the flat

Dave

I've not tried it on stainless but would think it would need a lot of pressure applied to it.

Hole forming here

Just musing out loud, but might there be a way of 'cut-knurling' these.. ..driving the shallow-angled corner of a wheel across the face.. ..can't remember whether I've seen it done or not..

..only posting in the hope it might jog someone else's memory..

Yes you can do it like single point cutting a bevel gear, just rotating the work in a vertical rotary table with a Vee pointed cutter held in a shaft in the spindle.

Also worth noting that cycle "track nuts" are actually in two parts with the knurled "washer" captive on the nut so you don't chew up the dropouts when turning the nut, the knurl is there to stop the axle shifting under side load from the chain not to stop the nut coming undone.

Jon,

Why are you using stainless steel for a critical item such as an axle nut? I certainly hope you're not using it for the axles themselves!

Racing motorcycles are prohibited from using stainless for wheel spindles after the death of Fritz Scheidegger at Mallory Park 50 odd years ago. Stainless has a high 'notch sensitivity' and his front wheel spindle failed under braking for the hairpin corner. Race Scruitineers check wheel spindles with magnets to enforce the ruling, this can, unfortunately, rule out other non magnetic materials such as titanium, although titanium is a far safer material due to its far higher ductility and toughness, apart from its excellent resistance to corrosion.

I would never ride a bike with stainless steel used in such a critical item, its OK for non critical fasteners but that is all.

Martin

From Jon's earlier posts I think it's for a push bike.

Jason,

Accepted that it may be for a push bike - but to quote Jon "....toying with the idea of making some deep fit acorn style cycle/motorcycle wheel nuts". I've seen far too many wheel spindles on custom motorcycles made from stainless due to what I think is referred to as 'a little knowledge can be a dangerous thing'.

Scheidegger's death was a warning that even apparently highly skilled engineers need to be aware of the metallurgical dangers of a 'little knowledge'. The spindle broke at a size transition area due to tool marks even though a radius had been provided, the sudden break then caused a catastrophic failure at the other end of the spindle at another transition point. A front wheel detaching under heavy braking is not a nice experience to witness as I happened to at the time.

The other warning I would emphasise is the practice of chrome plating frame tubing, known to cause hydrogen embrittlement of the tubes; fine to use nickel plating but chrome plating is again frowned upon. In fact a lot of motorcycle racing sidecar frames were left bare metal and just varnished - this allowed for a visual inspection of the tubing for cracking to alert the owner of potential failure.

Martin

It might be a mountain bike ... in which case may be stressed more than a road motorcycle...

Neil

I did not know that stainless wheel nuts could cause problems or chroming of motorcycle frames.

While we are on the topic of exotic metals for wheel nuts I have noticed that a certain well known auction site has anodised aluminium wheel nuts for cycles. Should I be more worried about these as alleys record for metal fatigue is surely more of a concern than stainless on a pushbike even if it is used occasionally off road?

Oily Rag:

Thanks for a most interesting post. What are your views on stainless steel spokes? These seem to be popular on motorcycle restorations these days. My motorcycles are all pre-1930 and not massively powered but I still use non-stainless spokes. I don't know what type of steel they are.

Chas

Oily Rag, Titanium has been banned by the ACU for some time. From Standing Regs

14.20CONSTRUCTION
The use of titanium in the construction of the frame, the front forks, the handlebars, the swinging arm spindles and the wheel spindles is forbidden. For wheel spindles, the use of light alloy is also forbidden. The use of titanium alloy nuts and bolts is allowed.

With spoke threads being rolled rather than cut I would have thought there should be less of a risk

As for Chrome, it was very popular on forks and the rear triangle of all quality bicycles before more exotics came along

When I used to ride my MTB I had aluminium nuts on the titanium skewers, think they were only M5 thread but can't remember what the ali was, probably a 7000series

Plenty of Titanium framed bicycles around too as well as aluminium wheel spindles (On Mountain bikes too Neil)

Edited By JasonB on 12/04/2021 07:49:13

Stainless steel spokes seem to work just fine and are readily available from reputable suppliers such as Buchanans in the USA. Plenty of big horsepower Harleys using them. I have used them on Harleys and on a Rocket 3 (over-) restoration without problems. You can polish them to look like chrome or leave them natural or if you bead blast them they look closer to the old cadmium plated spokes than modern zinc plating does.

Make sure to use anti-seize on the threads if using stainless nipples too, or they can gall and lock up if you ever want to tighten them up down the road sometime.

Stainless steel spokes are original equipment on my RE Interceptor 650 and my wife's Moto Guzzi V7 Special & I rebuilt one of my MZs wheels many years ago with a set of stainless spokes from Central Wheel Components (at one time the supplier of Triumph's spoked wheels). MZ OE spokes were chromed steel.

I recall many years ago there being an on-going spat in the letters pages of the original Motorcycle Sport magazine between two suppliers of stainless aftermarket wheel spindles getting increasingly vitriolic WRT the "correct" grade of SS to use in such an application. Always stuck with OE parts for tcritical parts, but note that at least some wheel and swing arm spindles (BMW & MZ come to mind ) appear to be hard chromed.

Nigel B.

lots of stainless fittings used on aircraft just need to use the right grade.