How to knurl handlebars ?

[Ian ParkinParticipant @ianparkin39383]

I have a new pair (?) of handlebars in stainless…how can i knurl them where the clamps go?

or a sharp cold chisel every 2mm of circumference?

[JasonBModerator @jasonb]

Straight MTB type bars or drops?

[cogdobblerParticipant @cogdobbler]

Plenty of handlebars don’t have knurling. Do you really need it? Presumably you are not fitting 18″ apehangers?

Rather awkward to put on after the bars have been been bent to shape, short of making a special tool using perhaps 3 knurling wheels set up in  G clamp type arrangement like a Rigid pipe cutter and rotated around the bars by hand. Which could be tedious. Hammer and chisel is sounding better all the time, carefully applied

[Clive FosterParticipant @clivefoster55965]

The hand squeezed “nut-cracker” type three wheel knurling tools will work by being rotated around a stationary workpiece.

Eventually!

Out of curiosity I tried mine running round and round on a piece of aluminium. Got there in the end but took a while. I suspect for stainless steel you’d need very sharp knurls and some sort of screw clamping system to get enough pressure. However its highly likely that the stainless will work harden on you mid job, not good.

My nut-cracker tool, this crew is a depth control not a forcer :-

Instructions for making a replica were published in Model Engineer issue dated 29 January 1999.

A bigger, stronger version was published in Popular Mechanics May 1965 issue. That one has a force screw.

This link to the article still works :-

https://books.google.co.uk/books?id=buQDAAAAMBAJ&q=knurl#v=onepage&q=knurl&f=true

If you do decide to make such a tool and discover its not man enough for the job, probably 50/50 chance, a nut-cracker knurled is still very handy for casual jobs as it needs no setting up. I reckon my knurling jobs split about half and half between the nut-cracker and the (superb) Marlco device.

Not quite a putting on tool but when your light press fit comes out as stiff sliding fit ……..

Clive

[Ian ParkinParticipant @ianparkin39383]

I did a fair few miles on my vincent yesterday and today my backs killing me the vincent straights have to go and a pair of norton commando raised and pull backs have to go on…i’d like to knurl if i can but i only have lathe knurling including the marlco type and 3 others so i may modify unless the cold chisel will work better and quicker..

[cogdobblerParticipant @cogdobbler]

Sacrilege! But I fully understand. My Laverda’s 5-piece adjustable bars started out fully dropped in my youth, then gradually crept upwards over the years, ending up fully raised. And I have a pair of BMW R90S bars with a a 2″ rise ready to replace the flats on my Norton Atlas. A nice compromise.

The high and wide Commando bars weren’t known for moving on the Commando, and it’s clamps were basic. Might be all right on the Vinnie as is? Unless you are attempting land speed records of course.

[Ian ParkinParticipant @ianparkin39383]

I can well imagine i will be drummed out of the voc club for daring to modify a vin but its to ride rather than look at ..i have a Norvin with high and pulled back bars a bmw r100cs with stock bars and a nimbus with sit up and beg bars…its only the comet that gives me trouble over long distances…I’m sat at the very front of the seat and my arms are perhaps less spread than they would like…so hopefully with the commando bars I’ll be more on the seat and with a less curved back..

on another note..the bars i have bought are all stainless but others i have seen are steel with a stainless cladding saying these are stronger than just SS what do you think? Will SS workharden and snap?

[cogdobblerParticipant @cogdobbler]

Never heard of any snapping, and we treated them pretty roughly back in the day. I know Harley used stainless handlebars in the 1970s and they seemed to stand up to the vibration of those things ok. The right grade of stainless is unlikely to snap. EG stainless spokes are widely used.

[JasonBModerator @jasonb]

Could you set it up in a vee block and mill some V shaped grooves rather than knurl, the straight knurl at the top of this oiler was done that way.

 

[BazyleParticipant @bazyle]

Fairly simple as you have a standard lathe knurling tool, which is a clamp type but might not open far enough. First get a tube to go over the mounting bar (the bit that normally goes in the toolpost) to give you leverage.
Next open to suitable width and move it onto the workpiece. Put a rope loop over the mounting bar and round the work, back to the bar(side) with a loop.
Put a piece of broom handle through the loop and over the work. This will be a lever that both pulls the knurl onto the work and pulls it round.

[Clive FosterParticipant @clivefoster55965]

+1 for Jasons suggestion of milling the grooves out.

It’s the way I’d do it if I were too slow to come up with a decent excuse when the job was slung my way.

A thread mill would be the nearest thing to an ideal tool but for a one time job I’d sacrifice a tap using it in similar fashion to free running hobbing to make a worm wheel albeit with the workpiece clamped.

Unconvinced by the idea of using a standard clamp type knurling tool as Bazyle suggests. I don’t think a two wheel tool will be stable enough to stay in place across the diameter of the handlebars. If you get a bit careless with the nut-cracker type and only engage two wheels they are quite capable of camming off the workpiece rather than sliding down between the poured wheels as they re supposed to.

Clive

[John HaineParticipant @johnhaine32865]

Pirsig suggests cutting a thin shim from an aluminium beer can and interposing it twixt bar and clamp.

[Ian ParkinParticipant @ianparkin39383]

The new bars arrived so after removing the old straights the clamps were very smooth and painted gloss…

I don’t suppose theres much of a turning moment with the straights but i decided to clean off the paint with a power file and also powerfile the new bars so they were brushed rather than highly polished where the clamps clamp.

so far all seems good and its a far more comfortable ride..

[Nigel McBurney 1Participant @nigelmcburney1]

Hi   back in the late 1950s  the handlebars on my comp Greeves bike would  move in the clamps when hammering over the rough I was told by a  top southern motor cycle scrambler who rode a 500 AJS that the trick was to smear very coarse grade emery grinding paste around the bars and inside the clamps and tighten the clamps up tight,another trick was stopping rubber handle bar grips from rotating or sliding off  the handlebar was to wind some old type insulating tape around the bars ,tip some neat petrol (not Twostroke) into the grip and quickly slide the grip over the tape ,and  wait a while for the petrol to evaporate .the tape used to come in rolls but in those days the material was a rubberised cloth tape.

[Grindstone CowboyParticipant @grindstonecowboy]

Similar to Nigel’s tip about handlebar grips, my father taught me how to fix new rubber grips to golf clubs – same trick with the petrol, sloshing it around the inside of the grip, but using double-sided tape wrapped helically around the shaft (making sure there were no overlaps so you could get the backing tape off). And a little petrol spread over the tape with your finger to ensure there were no dry spots, otherwise you might end up with it stuck halfway on. And a little twist if required to ensure they lined up with the clubhead properly.

Must have done a few hundred over the years.

Only way to remove them after they’d dried was to cut them off.

Rob

[mark costello 1Participant @markcostello1]

Same with Golf bashers.

[Ian Parkin]

On Ian Parkin Said:

The new bars arrived so after removing the old straights the clamps were very smooth and painted gloss…

I don’t suppose theres much of a turning moment with the straights but i decided to clean off the paint with a power file and also powerfile the new bars so they were brushed rather than highly polished where the clamps clamp.

so far all seems good and its a far more comfortable ride..

LOL. Blimey that will upset the purists, buckhorns on a Vinnie.

 

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