Of course the obvious way to create my dream bike would be to start with one of the aftermarket Harley all-welded rigid frames, which sell for around US$700 according to most catalogues.   If I applied Minimal-fuckin'-ist principles to such a frame, and purchased wisely and well from these catalogues, I could come up with something akin to Grease Monkey (one of Indian Larry's more recent efforts) or the turnkey kitbike offered by Nostalgia-cycle, but with a Chief engine in it.

Again, I was standing at a crossroads.  Having already rejected the notion of fitting my Chief engine into a Chief frame, I now had to choose whether to go the Harley aftermarket route or do something totally unheard-of. 

The Harley-frame scheme would certainly be a lot more convenient, though probably also more expensive.  Get a frame for $700, a Revtech four-speed tranny for about $2500, a clutch for $500, wheels at about $400 apiece, a front end for another $500, its all starting to add up!

But the end result would look too much like a Harley.  Which is precisely what I'd been trying to avoid all along, for reasons expounded in Part One.

Nope, I want to do this once and do it right.  Even if it means doing it the hard way.

So now I'm back to gazing at my Ariel basket, studying its frame from all angles.  Except that I didn't want to butcher that particular frame.  After all, I hope to restore it as a fairly straight and original Ariel one day. 

"Aha!!!" I hear you all shout.  Why don't I extend this same courtesy to Indian Chiefs? 

Well, in my view Indians and Harleys are at their best when highly modified, while Ariels and Triumphs are at their best when left well enough alone.  I decided to find another Ariel frame that I didn't mind cutting up.

It just so happened that my dad, who's owned a 1928 Ford Model A since 1962, used to scrounge around the farms of rural New Zealand pulling stuff out of macrocarpa hedges and squirrelling it away in his basement to use as swaps for Model A stuff.  Things like an engine for a four-cylinder FN motorcycle (fabrique en Belgium), crankcases for a 1914 Premier (a marque only ever produced for three years),  and lots of car stuff that I could never recognise.   Most of it he sold off during a family financial crisis in 1976, but in later years he still had a Scripps Booth engine as fitted to a rare Model-T-lookalike American car called a Harvard. 

Grease Monkey.  More Minimal-fuckin'-ism from Indian Larry.
 

An easy way out of my dilemma would be to plug into the vast range of Harley aftermarket products.
 

Or I could throw a wad of cash at the nice gentlemen in Huntingdon Beach CA to get one of these sans motor, then fit my Chief engine into it. 
 

When you're dealing in shit as rare as engines for Harvard motorcars, the negotiations can go one of two possible ways.  Either the purchaser is so desperate to have your engine, because it's so rare, that they'll pay any price for it.  Or they point out that the market for such engines is incredibly tiny, by virtue of these cars' very rarity, that in fact it’s a buyers' market and really I should just give them the motor and be thankful they don’t charge me cartage to take it away.

Naturally these two Harvard fanciers adopted the latter negotiating strategy.  But I neatly circumvented the sordid business of trying to put a cash price on a 1917 Scripps Booth motor by telling them they had to go straight back out into the darkness and find me an Ariel motorcycle frame, regardless of cost.

Two weeks later they arrived at my back doorstep with a 1937 Ariel rigid frame.

Who got ripped off here, them or me?  I'll let you be the judge.  I was happy, anyway.  I'd got my Ariel frame and besides, there's not a lot of call for Scripps Booth motors in our household.

So now the die is cast.  I'm going to chop up this Ariel frame and somehow wrap it around a Chief motor. 

For the transmission I'll use a Triumph gearbox left over from my '56 Thunderbird rebuild. 

Triumph boxes have the advantage that brand-new bits can still be bought for them, since their internals remained in production up until 1984.  Another advantage is that five-speed clusters can go in with slight modifications to the case.  A third advantage is that a later-model triplex-chain clutch assembly can replace the single-row clutch on the pre-unit gearbox, since mainshaft taper remained the same throughout production.  A fourth advantage is that Les Williams Ltd sell space-age 7-plate clutch conversion kits for these triplex-chain clutches, if the stock plates are ever considered too feeble. 

But the main advantage of using a Triumph gearbox is, as I said, the fact that I already had one left over from my '56 Thunderbird rebuild. 

Part 1 "Why Indians"

Part 2 "Why Not Choppers"

Part 3 "Form vs Function"

Part 4 "Chief Likes & Dislikes"

Part 5 "Chopper Chiefs from Mild to Wild"
 
 

More Indian Choppers & Bobbers:

VI Photo Album, Chopper file

"Geronimo" Chief Hot Rod

Chopperdave's Indian page
 
 
 
 

The Ariel frame is going to need major surgery.  As you can see from Pic. 10, there's not enough space in the engine bay for the Chief lump.  The front down-tube needs to be moved forward, which means cutting the top tube and slugging it to make it about 3 or 4 inches longer. 

Another problem is that there really isn’t enough room between the gearbox and the rear wheel.  Well, there is, from a functional point of view.  All Pommie single-bangers are very compact in this area.  But aesthetically speaking, a longer front section will look odd unless balanced by a longer rear section.  Plus I want room behind the gearbox to put the battery, since this is the place God gave for putting batteries on a chopper.  That's if I actually need a battery.  Moen says I don't, and I will be seeking his further advice on this. 

But even if I don't need space for a battery, the frame will overall look too short if I don't stretch it backwards as well as frontwards.

If I stretch the Ariel frame and retain its steering head, the front downtube angle is such that it will end up looking too goose-necked (see Pic. 11).  The bike will look odd if I do it this way.  Some people like a goose-neck frame, but I am not one of them.

That's when I pulled another piece out of the pile of left-over Triumph parts, a front section from a pre-unit swing-arm frame.  Bear in mind here that I'm trying to approximate Indian Larry's Minimal-fuckin'-ist formula of about 32-33 degrees rake, and a 62" - 64" wheelbase.  Triumphs have about a 28 degree rake, but when you offer up a Triumph frame section to the Ariel frame you have to tilt it back to make the top tubes of each frame parallel to each other.  After you've done that, one can see (Pic. 12) that the Triumph steering head ends up giving a rake of … wait for it … 32 - 33 degrees!

So the first option open to me is to make a single-downtube frame by cutting off the Ariel steering head and front downtube, and grafting on a Triumph steering head and front downtube, leaving enough length in the top tubes where they join to provide the necessary stretch for the Chief engine.

Pic. 11.  A stretched Ariel frame will end up too goose-necked, unless the angles of the steering head tubes get changed.  Hard to do on a brazed-lug frame.

Pic. 12.  With a 1956 Triumph front frame section pasted on, things start to look right.  It's still far too cramped around the gearbox department, though.
 

I wrote to a guy named Kent White who runs a website called www.tinmantech.com and we had the following e-mail exchange.

ME: “I have a 1930’s frame for an Ariel Red Hunter which is of brazed-lug construction.  I want to cut off the seat downtube off its lug and move it about 2” forward, re-welding it as a butt weld onto the cast lug again.  Other tubes enter the same lug about 3” either side of where I want to place the weld.  Can you recommend the best technique, and advise of any pitfalls in making such a weld to a frame of brazed-lug construction?”

TIN MAN: “Why not?  The lugs appear to be of mild steel, and the tubes appear to insert roughly 2” into them.  So, cutting off the bit of lug would, I think, leave a hole needing to be filled, and the brazed downtube-and-lug piece needing replacement.  Filling the hole may be done with a machined plug that is then silver-brazed in with 30% and a good flux, keeping a wet-rag heatsink on each nearby (within 4”) brazed joint for good measure.  The downtube is then removed from the lug bit (heat and whack) and a new lug bit made to fit the downtube and the old lug portion still on the frame.  This is avoiding the seepage of brass from the lug bit into the weld – which it is very prone to do – and with nasty and irretrievable results.  The new lug piece is fit to the old, and with heatsinks, is quickly tacked in with Eutectic 680 at four compass points.  Then tacked again between those, and so on until the linked tacks look like a weld.  The downtube is now brazed into the new portion of the lug assembly, making sure that the steel is bright and fluxed throughout beforehand.  Let me know, Kent.”

TIN MAN: “The many considerations for this type of risky endeavor are included in the method I have recommended.  (I owned a Red Hunter many years ago.)  Use only the Eutectic 680, and make no changes to the method without letting me know.  Kent.”

ME: “At the risk of becoming a pain in the ass, let me just ask one further question (having just consulted the person who will actually be doing the welding).  Can we dispense with the brazing and fix my downtube to the new portion of the lug assembly using TIG welding?  We figured the advantage of this might be less total calories of heat transmitted to the lug metal, by using a much smaller (albeit locally hotter) TIG “flame”.  Any drawbacks to that approach?  Thanks for your help and I will leave you in peace now.”

TIN MAN: “Aha!  Joint design and alloy will lend to weak joint if welded.  TIG is hotter by 1000 degrees, no matter the size of the HAZ!!!  Kent.” 

Isn’t the Internet a wonderful thing? 

Instead, I came up with an alternative strategy for expanding the rear, which keeps well clear of the lugs.  I will saw through the frame tubes at the halfway point between the lugs on all of the rear tubes, move the bottom tubes apart by an appropriate distance, then make slugs to fit all of these gaps (following the method in Mike Geokan’s Custom Harley Cookbook).  The welding then becomes very straightforward, as only one type of metal is involved and the joins are just straight cuts.

Now for the frame front section again.  While I already had a 1956 Triumph front frame, I really didn’t want to cut that particular one.  I might be needing it, if I ever again came into close contact with any errant taxi drivers.  A friend of Kevin (my technical consultant) in New Zealand had a 1951 Triumph rigid frame surplus to requirements.  Coincidentally I’ve got a '51 Thunderbird basket stashed under my house in Wellington, which has a bent rear frame section.  If I bought another rigid frame, I would get a front section for the Chief project, and a rear section for my Thunderbird basket.  Smiles all 'round!  The smile was wiped off my face when US$250 later the frame was shipped across and I found that '51 front frames are different from '56 front frames.  The earlier ones have tapered front downtubes which make cutting and slugging quite difficult.