Custom handlebar clamps

[MadNick]

Afternoon,

I had a busy evening.

The first task was to separate the two halves of the clamps -



Ending up with -



Very pleased at this point that there was plenty of meat left between the clamping bolt chambers and the handlebar hole. I did realise however that the amount of thread in the 'cap' was nowhere near enough to support the clamping bolts - I reckon there was so much swarf in there from machining the tap wouldnt reach the bottom.

I tapped these out a bit more but really need a bottom tap to finish off - ive got a brand new spiral flute tap here, would that be ok to use?

Preliminary fitting -



They look good although you can see where the clamps are not quite closing properly (thats black paint in the picture) - I guess my 1" slot drill must have been quite worn. When fitted, one side of the clamps make the handlebars look a close fit whilst there is some air at the other. Having blacked out the bore and rotated the handlebars around a bit we can see the following high spots on one pair -



Do you have any suggestions for taking the high spots out and getting a closer fit whilst keeping a uniform radius parallel to the base? Have to be careful because if too much is taken out the clamps wont close enough on the handlebars.

Any suggestions are very welcome.

Nick

[hopefuldave]

To get the high spots down, you could go Retro (appropriate for anything to do with a Harley...)

A bearing scraper: take a triangular riffler file (preferably old and worn!), heat to "boiled carrots" and allow to cool slowly to take the hardness off, then grind off the teeth and sharpen the 60-degree edges, harden (boiled carrots again, quench in water or oil), polish up with emery cloth and temper to light straw, then hone the flat faces on a fine stone until you get "razor sharp" edges - eeeh, takes me back... A decent file's steel will be almost glass hard after this, and should scrape the high spots down fairly well, even in stainless.

Just my ha'pennorth,

Dave H. (the other one)

[The Steamer]

One thing ive noticed over the years is the handle bars are very often far from round.  the bending process of the bars  makes the tube oval and a right royal pain!!!

[Jonny]

How do you set the centre, position and tighten up the handlebar when on the bike?
Unless you drill through the top yoke.

Theres quite a lot of force on the bars, when done give it some see if they move.
Ive had bars collapse not nice, with M8X1.25 pitch bolts going in 15mm cranked up.

You could try lapping the alum with an undersize bar for a tight fit, mind you dont roll the edges. Or spin up slow a 25.2mm bar with fine grinding paste when mounts are loosely clamped, just close up mount with one hand.

[MadNick]

Morning,

I agree with your thoughts - some kind of lapping arrangement is needed.

Im toying with the idea of a kind of brake shoe assembly wrapped in emery cloth and then inserted into the assembled clamps and spun, moved up and down.

How do you set the centre, position and tighten up the handlebar when on the bike?

The clamps are attached to the bike with the handlebars removed - the clamping bolts are hidden, flush with the base. It will be a pain to set up but the bike is a custom build and all about aesthetics.

Will let you know.

Nick

[Fergus OMore]

Sorry Nick- wrong! Wrong engineering principles

Looking at what your 'blueing' showed was that the high spots were in the centre of the clamps. To mess about with emery is simply going to make the whole- hole(sorry) even more barrel shaped.

Quite correctly, you were advised to make and use an engineer's scraper. Properly applied, it would have removed some of the barreling in the centre of the clamps. Further blueing would have shown you the next step and where to scrape next. Ideally, you want the outer edges of the clamp to be doing the clamping and not what is now- a free air fit.

Being of a lazy disposition, I would have got rid of most of  this ring of offending metal with a rotary burr or stone but it would still bring me back to eventual scraping for an exact fit.

If you read or ask about internal freehand grinding, you will get barreling which in your case will be more of the same.

Apologies but I hope that this information will be of positive assistance.

[MadNick]

Thanks Fergus, I feel positively assisted!

And sincere apologies to daveH whose sound, engineering advice I appear to have completely ignored - I am no longer considering my brake hub assembly lol

I dont have the facility to heat metal so will have to buy rather than make something

Nick

[Fergus OMore]

Problems, problems!

Think about a triangular file and grind the three flutes hollow and then sharpen the edges. Far more awkward but then?

Again, with a cheap worn out flat file, you can grind a neck about an inch or a bit more down. Then sharpen a cutting edge.

It should look like  a bloody big boring tool . Now where did I hear that- before?

Again, old technology but it works.

Cheers

[MadNick]

Ill give it a go - I have a couple of old files in the scrap bin.

We are looking at a radius cutting edge then? Any suggestions for dimensions approximately please...

Nick

[Fergus OMore]

Nick,
        I'd settle for something with an inch long blade  itself but a gap longer than the depth  of the clamp so that you can 'get in' comfortably and fettle the beast- once and for all.

As for a cutting edge, you will have to do a sort of radius to avoid fouling but the edge need only be a 7-10degree cutting edge.

A bit like a boring tool- as I said. Don't forget your gloves to avoid barking your knuckles! Said he with rubber gloves on-- and still picking out splinters out of his wizenned claws!

Great thing- get a pair of surgeon's glasses. Mine came from a rather good orthodontist who realised her Pop had a white stick!

It will be slow, but it works

Cheers

[MadNick]

Thanks Norman, ill post the results of course

Nick

[MadNick]

Morning!

Well I made my scraper and was scraping away like a good 'un. It certainly works well and one set of clamps was finished and ready for the bike.

The other clamp, not so i'm afraid. I realised the air gap was not getting any smaller with the handlebar rocking around inside I knew something was up. Out with the vernier caliper - somehow the hole that I drilled is an hourglass shape - spot on in the middle and then something like 1mm oversize at both ends.

This wont clamp anything down!

I cant see how to save this. To be honest I'd rather start again and get it right after all that  time and effort scraping the damn thing.

I imagine the 1" slot drill I used wasnt sharp enough or the table moved or something - next time Ill use my boring bar.

Shame about those two nice pieces of stainless...bollocks!

Nick

[Fergus OMore]

Nick,
          Shim it- drink a beer- re-cycle the tin- cut into a thin strip for each side.

I promise not to tell anyone- if you dont

Come on- we all do things like that. Why do you think people 'make' shim stock-- and manage to sell it?

[MadNick]

Fergus, up with the lark this morning?!

You are right, yeah why not! lol I expect too much of myself sometimes...

Good call on those scrapers though, get blunt quickly though cutting through stainless but yeah, good call.

I tried to take some photos but the glare made everything look like a high spot.

Will have another look later - just cracked open a can of beer in preparation...

Nick

[Fergus OMore]

Fergus, up with the lark this morning?! Joys of old age!

You are right, yeah why not! lol I expect too much of myself sometimes... ( You'll learn

Good call on those scrapers though, get blunt quickly though cutting through stainless but yeah, good call.(  Drop of cutting oil might ease things

I tried to take some photos but the glare made everything look like a high spot. ( Pass, I don't know how to post pictures- well, I can't be good at everything )


You see!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Will have another look later - just cracked open a can of beer in preparation... ( I'm not just a pretty face )

Nick

[MadNick]

Afternoon,

Well I think I have finished them for the meantime.

As it turned out there is some deep knurling on the bars, where they fit the clamps, so as I tightened the clamps up it all squeezed together very nicely.

Fitted -







There is a little more machining to do to make these sit square on the top yoke - Ill wait before I do this as I would really like a nice pair of slab yokes made from ali. Im on the lookout for the raw material or a good used pair.

I would say they are a good tight fit - I was able to pick the front of the bike up (a bit) by the handlebars.

Thanks for your help.

Nick

[DaveH]

There you go Nick - I told you, you could do it
A nice job well done

Most of my jobs are done that way. Hand crafted made to fit

What could be better.

I'll tell you now Nick I wouldn't have scraped it, I would have put some emery on the tube, "rubbed" it 'till it did fit.
If they closed up too much - just a case of removing a bit off each face.
 
DaveH

[Divided he ad]

Looks like a job well done Nick. Radius turner worked out I see 

That's a nice looking machine. Is it all your own work?  Looks like you have the OCC bug!  (Hope that's not swearing in enthusiast circles?)


I like the super close mudguard      (I like the rock welding too  )




I'm not a bike kind of guy (I'd fall off!) But I do like seeing the work and the results of these projects     Always wonder how your arms don't fall off holding those bars for a long ride 





Ralph.

[jiihoo]

Nice job, man! The clamps blend in beautifully with the look of the rest of the bike. The bike looks very nice, too (and this from a guy who usually does not dig H-D...)

Jari

[MadNick]

Thanks for the kind comments

Frame building, now theres a real skill - I have to say that part isnt my own work.

I use my machines and tooling to make wheel spacers, tank and seatbase mounts, seatbase, oil filter perch, footrests and as I get more proficient make my own tools, like the radius turner, to do a nicer job and have round, instead of flat surfaces.

Nick

[Divided he ad]

Ahh yes... I recall those chaps at OCC buying frames too... Suppose you don't want a bike that turns it's own corners eh!?

Sounds like you're enjoying yourself with it too.... You and your tools are making plenty of worthwhile additions 



I'll have to look out for the other parts appearing in other threads 




Ralph.

[MadNick]

Thanks Ralph,

My interest in building the bike comes and goes so I'll have plenty of time to try some other projects on Madmodder too.

Nick