Looks like something off my 1981 BMW R100RS, anti rattle spring retaining clip? So as you say, the taper is not critical, is just there to hold the pin centralised, roughly between the two pads.

I would start one end and work to the other, sliding the material out of the chuck a little for each step to minimise overhang. Turn the first section to the 4.85 diamter first so you have a reference for when your taper is right size. Do the end taper with topslide set to correct angle, with just that part sticking out of the chuck. Then slide rod out a bit more and use turning tool moved back and forth to machine the groove to diameter. Then finish off the square shoulders on the groove with turning tool turned to 90 degrees from the job to make a nice square shoulder. Then slide it out a bit more and do the final taper with topslide set around to the opposite angle. Then cut the job off from the blank with a parting tool.

I would go along with hopper, but the groove in the middle I would use a parting cutter. Noel.

The hard part is making sure the opposite tapers are identical.

No problem if the job is machined between centres – even if the central part is fairly short for the drive dog.

Cut outer taper with tool at the back while running in reverse then taper nearest the stock with conventional front turning.

I do it a lot when machining a bore and tapered spindle just leave the topslide set at the angle and both will match.

This is not a critical taper like a morse taper. No need to use a DTI to set the topslide. The two tapers could be several degrees different and still work ok so setting by the graduations on the topslide will suffice. And no need to use a tail stock if the job is done in three stages and the bar moved out of the chuck for each stage.

If you start with something like 10mm dia bar and then do it in stages from the end there is no real need to use tailstock support or slide the work out for each stage of the work

I would assume Brembo put a taper on there for a reason, most likely to move the pads outwards so they dont drag. Not that hard to replicate the original. Plus if you know the Bevelhead Ducatisti, no end of "experts" would be pointing out to the owner that his anti rattle pins were not original because they are supposed to be tapered. I kid you not. My brother has 1977 900SS that he restored and those guys are freakin nuts.

As a would-be hotrodder, I know exactly what you mean!

A couple of conversations spring to mind;

I was told that the late Mini clutch master cylinder and 155/80 tyres on my sister's daily driven Morris 1300 "spoilt the car", although he hadn't noticed the Ford Radiant Red paint on the bottom half of an Old English White car wasn't factory.

one bloke whinged about how long it took to find parts, yet claimed we made thing difficult by using more modern ones

We had another chat with some woman who was complaining she couldn't find anyone to paint her car in 'proper' cellulose paint because "2-pack always looks wrong. I want it to look like that" – pointing at a friend's Model Y. She was most upset when Jon told her it was painted on his drive, using 2-k base and clear. And being early seventies, her car should have been painted with acrylic….

The best one was overheard at a show, when an adenoidal anorak asked an owner what the car was "before he ruined it". The answer " A bucket of resin, it's a fibreglass replica" got a big laugh.

As most callipers use a pretty stiff spring between the pins and and pads to stop the pads rattling, I suspect that is one of those ideas that isn't really necessary. The disc on a push bike will knock the pads back enough for the brakes not to bind, which you really notice.

Where did I even imply that the springs retract the pistons? The small runout of the disc knocks the pads back. I've never seen a caliper that wouldn't function perfectly as a brake with the anti-rattle springs, of whatever design, removed. Some calipers don't have them.

My suggestion was to not taper the parts but reduce the ends, with a larger diameter in the centre for the spring, like this —+—. The shoulder would be nowhere near the pads, unless the disc wore right through. I have seen that, also solid discs fitted instead of vented, and in both instances sticking pads would have been an improvement…..

I guess I was confused when you said: I suspect that is one of those ideas that isn't really necessary. The disc on a push bike will knock the pads back enough for the brakes not to bind, which you really notice.

Apologies if I was confused by what you said.