Britbike forum Forums British Motorcycle specific Brands Ariel forum 1928 Ariel Model C

An edited and illustrated version of the following appeared in the August 2018 issue of the Ariel Owners Motor Cycle Club (AOMCC) magazine Cheval de Fer. For anyone coming to this thread for the first time it serves as a ~1500-word "Executive Summary" of what follows in the 1400+ posts that currently total the equivalent of 250+ single-spaced pages of text.

"Executive Summary" of this Thread

Background
At the time of this writing in early July 2018 the start of the two-week, 3750-mile, cross-U.S. Cannonball ride is less than two months away. Eighteen months ago I was one of approximately 110 people from a large pool of applicants who were informed they had succeeded in obtaining entries for this event, which is for machines built prior to 1929. However, that posed an immediate problem since I didn't own a machine old enough to qualify.

Harleys and Indians are a dime a dozen in the U.S. (well, more like $30k+, but still relatively common), so they make up the bulk of the entries. However, I've ridden British bikes "forever" so I wanted one of them, if for no other reason than to be on something different. Making a long story short, after three months of following dead-end leads, a 1928 Model C Ariel that was collecting dust at a friend's house in Dublin revealed itself and soon was on an airplane headed to me.

I've never had an Ariel before, but it has a special appeal because it was designed by Val Page and I have three of his later BSA Gold Stars and even have written a book about these machines. Although the dealer sold the Ariel to my friend as having been restored, and externally it was in great condition, I fully expected I would have to rebuild it myself, which is what I spent the next year doing. In the course of this I found that although some of the mechanical work had been done correctly, there were so many bodges that the bike would have failed within a few hundred miles. So, over the past year I've restored the bike down to the last nut and bolt.

Starting the Rebuild
The first problem I faced in the rebuild was there appeared to be essentially no technical information on this machine. But, I slowly started collecting photocopies of whatever little I could find and, starting from nothing, my "shop manual" has grown into two binders holding nearly 700 pages and with tabs separating the material into appropriate sections. Also, I measured every piece that came off the bike to create a 'General Data' section that's now 8 pages long. In hot rodding terms I "blueprinted" the Ariel, but in many cases that required first figuring out what the original specifications would have been.

My original plan was to ride the bike for a while before rebuilding it but before I realized what was happening it somehow found itself on the lift with enough parts removed that the restoration was underway. Here I'll only touch on some of the highlights, but my rebuild is extensively documented on the web in the equivalent of over 250 single-spaced pages. Search for the words Britbike and 1928 Ariel to find it.

The first "major" task I undertook was to fabricate brackets for a headlamp, which has an unusual mount consisting of tapered lugs on the forks. For this I machined a die from a large block of Al and used it with my 30T press to form stainless tube into the necessary 'S' shape, brazed them to tapered end pieces I had made to fit the lugs, and pressed flats into the end with a form to give a curve where the flat portion meets the rounded tube. The forks then came apart so I could Magnaflux them and do repair work on the spindles and bushes. The steering damper assembly was a rusty mess that didn't fit so it took some machining to set things right. I turned both drums on the mill, which were a fair bit out of round, and new high performance brake linings are properly arced to the measured IDs of both.

The Engine
With the forks and wheels taken care of it was time for the engine. Thanks to finding two people who had original pistons and rings to weigh I was able to calculate the factory's original balance factor which I then used with a new Omega piston. I machined a torque plate for the cylinder, which my measurements showed made a significant difference, and then used it while boring and honing the cylinder for the +0.060" piston. I machined and honed the valve guides from G2 Gray Iron and made a new timing-side bush from phosphor bronze for the crankshaft and line-bored it on the mill. In case it's not already obvious, considerable precision machining was needed to restore this "restored" motorcycle.

The recess in the case for the drive-side bearing was oval so I took off enough material to make it round and then plated Cu on the new bearing to give it the necessary press fit. The pushrods were in bad shape so I made a set of new ones using CrMo tubing along with welding and grinding Stellite to shape for the ends. The connecting rod was slightly bent so it took two jigs and several trips back and forth between the press and surface plate to get the small end accurately parallel with the crankshaft.

Although the cam faces themselves were fine, both ends of the camshaft were in bad shape so I masked most of the component, plated the ends with hard chrome, and then used a tool post grinder to remove the excess. I then made bushes from phosphor bronze of appropriate ID to match. I took the time to machine a "universal" crankshaft assembly jig for pressing the two halves of a singles crankshaft together in close alignment (to minimize the need for adjustment) since such a jig would be useful for other rebuilds in the future. I also very accurately aligned the crankshaft axis on the milling machine and faced the crankcase mouth parallel to it.

Turning to the head, measurements showed significant distortion of the valve seats when the head was torqued so I used the torque plate with a cylindrical spacer against the sealing surface when cutting the seats for new valves. I used Neway cutters and did 4-angle jobs on both seats. The faces of the rockers were in bad shape so I made a jig to rotate them at the correct radius and used the toolpost grinder to recondition them.

Gearbox Issues
Once the engine was assembled and back in the frame it was time for the gearbox. It is stamped 'QL' so when I saw an advertisement in the December 2017 Cheval de Fer for new QH gear sets I immediately ordered a set. Unfortunately for me, when I finally got to the point of opening the gearbox I found it already had QH gears in it. Oh well. The main issue with the gearbox was the open-ended bush at one end of the layshaft was enlarged so grease and oil would have easily oozed out so I made a blind bush to replace it. I also made a spacer/baffle from Teflon for a gear on the mainshaft in the hopes it would slow oil exiting via that route into the kickstarter housing.

With the gearbox back together attaching the drive gear proved more work than it should have. Aftermarket gears are flat, rather than with the necessary spacer/hub as part of them. Although that is easy to solve by machining a separate spacer, I discovered that aftermarket gears are broached incorrectly and don't fit on the splines, forcing me to spend time with a file to hand fit the sprocket to the gearbox.

Final Assembly
Once the gears were sorted out and the bike reassembled, which requires dealing with a myriad of associated details, it was time to start it. It started and ran great, except for the oiling system. Making another long story short, the plunger of the oil pump had excessive clearance so I rebuilt it with a new plunger I fabricated from W1 tool steel and with necessary clearances obtained with Sunnen internal and external hones. I also needed to wind my own replacement spring since the spacing between the plunger and housing doesn't allow for any standard spring I could find.

As of this writing the last task is to completely rebuild the magneto. The magneto is working now so I'm using it on shakedown runs, but shortly will temporarily swap it for a rebuilt magdyno so I can continue those runs while working on the magneto. Before the middle of August the Ariel along with necessary tools, spares, and supplies has to be crated and on its way to Portland, Maine for the initial events starting September 4 so the clock is ticking.

Final Note
Like many (most? all?) commercial restorations, the Ariel's beauty was only skin deep when I got it. However, thousands of dollars and countless hours later, this "restored" Ariel now actually is restored. Stay tuned to find out if it has a trouble-free ride across the U.S. in September, or if I overlooked something critical.

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This forum has very low activity so starting this thread represents true optimism.

A 1928 500cc Ariel Model C is on its way to me to ride in the 2018 Cannonball which takes place in ~17 months. Although the bike is complete and "restored," all too often restorations are only skin deep so I will completely rebuild it myself. In preparing to do this I've assembled my own ~250-page "shop manual" by gathering and organizing technical information from a wide variety of sources (e.g. D. Barkshire's Black Ariels, G.S. Davison's The Book of the Ariel, the Owners' Guide, Burman manuals, the relevant posts on the Ariel owners' club forum, etc.).

With the above as brief background, and after having gone through all the information I could find, I am left with a number of questions. In no particular order, what is:

-- the balance factor?
-- the connecting rod length?
-- the free length and diameter of the valve springs?
-- the head diameter, stem diameter, and length of the inlet and exhaust valves?
-- the carburetor size (i.e. ID of the inlet tract)?
-- a modern spark plug for this bike?
-- the number of teeth on the rear sprocket?
-- a modern grease to use in the gearbox?
-- a modern equivalent for "Crimsangere" grease?
-- the diameter and number of steering head balls?

Of course, I'll be able to answer many of these questions for myself once the bike arrives and is in pieces. However, I plan to ride it for a while to learn its idiosyncrasies before disassembling it, and the 17 months will pass quickly, so I'd like to get as much of a head start on this as I can.

Hi MM,

I checked what the pre-war AJS & Matchless guys are using and it seems like either Penrite or Morris Lubricants semi-fluid grease is the right stuff for Burman gearboxes. Crimsangere appears to be similar, but developed for Sturmey Archer 'boxes. Recommendations are to add an "eggcup" of 50 wt oil to the grease.

These are listed on the Classic-oils.net website.

Rob C

Thanks very much for this information.

Penrite seems to be nearly unavailable in the U.S. but I've sent an email to the one place I can find who supplies it. If they do handle it I guess I should buy a lifetime's supply.

your lifetime or your ariel's?

your bike has a running start on you.

There are actuarial tables for the former but not the latter so the best I can do is stock up on enough oil to see me through to my end. After that, the Ariel will have to find its own Penrite distributor.

The grease thickens. One might think the issue of "grease" is a simple one, but the more I look into it, the less I know. The contemporary grease recommendations for the Ariel were:

Gearbox:
Castrolease Light
Mobilubricant Extra Soft

For all other uses:
Crimsangere Light
Mobilubricant Soft
Castrolease Light

Unfortunately, there is essentially no information to be found for any of these on the web, let alone recommendations for modern equivalents. It appears Castrol L/EPO might be appropriate for the gearbox, but it doesn't appear to be sold in the U.S. Sometimes seemingly-simple problems take the longest to solve. Sigh...

Check Royal Enfield forum - older indian bikes are also using some kind of grease in their gearboxes.

Other bikes used Burman gearboxes as well, but I'm hoping for an "authoritative" recommendation for the best equivalent modern liquid grease. I've sent queries to Morris Lubricants and Castrol and am waiting to hear back from them, as well as from the Penrite distributor in the U.S.

I know several Henderson riders had gearbox failures on the Cannonball. I never did learn whether it was caused by an inappropriate lubricant, but the pictures I saw of the repeat failures sure looked like it.

I'm thinking that one of them must have sorted out a suitable lubricant since then.

.. Gregg

It would be easy to decide that any lubricant is way better than no lubricant and ignore this question. But, lubricants actually do matter, even in 90-year old gearboxes. For example, some additives attack bronze bushings and if a grease is too thick it will cavitate and result in inadequate lubrication. I hadn't heard of the Henderson problem but in light of issues like these it isn't surprising.

AFAIK older gearboxes used a high viscosity lube due to poor sealing, typically a mix 50:50 of axle grease and a heavy oil, this would sort of set up at rest and not leak too dramatically. Castrol changed lube names regularly, none of the oil specced for our plant in the 60s had the same names but had modern equivalents, maybe some old records are left at Castrol. Seagull outboard engines use a very heavy gear oil EP 140, , something like that mixed with the mineral grease of choice may be a good compromise if the exact stuff isnt available anymore. Modern seals mean that lubes that set up when it cools down are no longer required. It may be possible to fit sealed bearings to your Ariel gearbox if the sizes arent too weird, meaning you could possibly use real oil rather than runny grease.

Not that my Matchless gets out much these days, but what I used in the four speed Sturmey Archer was Castrol LM grease ( now I think called Castrol All Purpose Grease) with the 50 weight engine oil I used ( Castrol CRB 50 ).

In 1928 Ariel used a Sturmey-Archer gearbox for one of their models and Burman for all the others. For the Sturmey-Archer the Owners' Guide recommends Speedwell Crimsangere while for the Burman it's to be Mobilubricant Extra Soft. So, different gearboxes, different greases.

Yes, MM, Matchless recommended "Castrolease Light " for Sturmey Archer, and "Castrolease Medium " for Burman. I used what I could, and it seemed to work OK. When I finish mucking about with my Triumphs, I'll get stuck into the Matchless for some overdue attention, then I'll know how the SA stood up to my youthful depredations ! ( have'nt had the gearbox apart for years !)
It was recommended that " a small amount of oil ( half a teacup !? ) is of benefit with non fluid lubricated gearboxes ".

I don't know the usual mileage put on 90-year old bikes these days, but I want to avoid finding out after 2000 miles of day-after-day usage that I picked the wrong lubricant.

It's interesting that this thread started only yesterday and already it has more posts than any of the other 236 in the Ariel Forum

It's an oil thread. They always do that.
Wait until you ask about fitting electronic ignition.

MM, I'm not a world renown academic. I was only trying to help, using my experience as the criteria. I'll bet London to a brick, using modern grease, and the oil you use in your Ariel's engine, the bloody gearbox will be OK ! Got that ! Just going on what I know from previous posts, I think I've had a bit more time with a grease box than you ! OK ?
But I do know better , now, than to contribute my limited magneto experience !

Trying to help, I have a pitmans guide to Ariel motorcycles "The Book of the Ariel",, 1932 on. I have scanned some of the relevant lub pages. I hope this is of interest. Some of it may be useful.



Sadly it only covers the Burman box, not the earlier Sturmey archer.

Yes, Gavin, this gells with my Haycrafts ( Pitman ) " The Book of the AJS ", " The Book of the Matchless " and my "AJS, FW Neill "(Pearson) all of which cover to a degree, both SA and Burman gearboxes.
What else did we mere neophytes have to go on ?

The rear sprocket on my 1927 Model A is 47T. From memory, your bike is the same.

Richard

I'm sorry if my response to your earlier post came across as dismissive. In no way did I intend it that way. I intended my response to be an explanation of why I might seem obsessed with a matter that appears it should be simple.

I found the following succinct explanation for why Burman used grease in the days before rotating shaft seals were up to speed, as well as why it can't be too thick. It was written by the late "Big Sid" Biberman of Vincent fame:

-----------
Burman Gearbox Oil: It can be a cause of rapid bushing, etc. wear if the grease is too thick and does not flow readily. The gears will tend to cut a track through it after which it does not flow into them continously. Also it will not enter tight bushing clearances. I suggest a small quantity of soft grease followed by sufficient 90 wt. gear oil to acheve the correct level. This way the soft grease gets carried into any leakage paths sealing them while the job of real lubrication is delt with by the gear oil. This works nicely in our Meteor and if not overfilled it rarely shows any seepage. Sid 6/18/07
----------

Thanks very much for scanning and posting those pages. They bring the brands and grades of oils a step forward in modernity, helping the search for current replacements.

Meanwhile Morris Lubricants responded: "With regards to your enquiry for a Burman gearbox, our K400 EP Semi Fluid Grease would be our recommended alternative.". The relevant specs of that grease are an NLGI consistency rating of 00 and worked penetration value of 400-430. Thanks to a link from Shane in Oz these values make it a "semi-fluid" grease, one step softer than "very soft" grade 0 and only one step stiffer than the softest grade 000 which is also described as "semi-fluid."

Given that the specs and description matches well with the required properties it appears to be a good recommendation. But, that's the good news. The bad news is only Morris's range of 'classic oils' has a U.S. distributor. But, the good news is I emailed them anyway and they quickly responded that would be happy to add it to their next order from Morris at the end of May. I'm waiting to hear back how much 3 kg (~1 gal.) will cost me. That should be more than a lifetime supply even if the gearbox leaks like a sieve and I live to be 100.

Addendum: the price will be $51 + shipping, which is in line with the price/lb. of (thicker) lithium-based greases. I ordered it, so that makes one more line I can cross off my to-do list.

Thank you very much. That's one more blank I can fill in on the 'general data' chart.

Are you saying they might sponsor MM on the Canonball? :bigt

Rob C

I was going to recommend John Deere Corn Head grease because it seems to function the same as the mentioned Morris grease....Corn Head grease is about 4 bucks for a 16 ounce grease gun cartridge...However, Corn Head grease is specified for slower moving gears and don't know exactly how this compares to the very expensive Morris lube...

Maybe because of all the stories this past week on '420 day', when I read your post I wondered why people smoke corn husks, and why they need grease. But, thanks to the web I've now learned there is a farm implement called a 'corn head'. Not having seen a corn head in operation I visualize it slowly munching its way through a corn field so, as you said, the gears may be moving slower than those in an Ariel at 50 mph. But, I have Morris's recommended sem-liquid grease coming to me in a month so this particular problem is under control.

Speaking of things coming to me, the Ariel is in the air right now, due to land at LAX in six hours. Given what I the shipper told me are expected times to clear Customs and then be carried by truck to me the soonest I might have it is Friday, although early next week is more likely.

Trying to clear the deck to be ready for it I decided this weekend to rebuild my BB Gold Star's Magdyno. The bike runs great and a few months ago it successfully didn't strand a visiting Australian on a ~100-mile trip so there was a chance the previous owner had installed proper replacement capacitors. However, making my decision easier to fix something that didn't seem broken was that I found the inside of the Catalina's magneto, from the same guy, was a mess.

Anyway, when I opened the Magdyno I found the original Lucas condenser inside it . Its room temperature resistance was 7.6 megohm at 250 V so it still would (barely) exceed the Mil-Spec requirement at operating temperature (yes, there is a Mil-Spec for magneto condensers). But, the fact Lucas condensers started life at over 100 megohms shows it's well into its death spiral and that the Magdyno definitely was living on borrowed time.

The earth and HT brushes were fine so I treated it to new capacitors and grease, magnetized it, and ran it for 30 minutes at 2000 rpm. I had to quit before I tested how low in rpm it would go but will do that before I reinstall it.

While the bike is on the stand, and before the Ariel shows up, I'm going to completely wire it using LED bulbs and a NiMH battery pack. I bought a Podtronics regulator from John Healy a year ago that I originally had intended to use when I wired this bike, but since then I've been happy not to have any more lead acid batteries in my life. The 8-hour lighting provided by the NiMH packs I've been using is good enough for me and this is what I intend to use on the Ariel as well rather than swap its magneto for a Magdyno.

combine with a corn head



with a grain head



the difference is in the width of the fingers separating the stalks. corn for large grain production is generally planted in fairly wide rows, and these fingers separate the stalks so the combine can thresh the ears and toss out the chopped straw. if the corn is to be cut green for silage, it's planted really close together and then is just chopped up and shot into a truck or a trailer alongside the tractor-- no combine.

small grain, like wheat, rye, or barley is just reeled into the sickle bar and threshed in-masse. no fingers on the small grain header.

my folks in oklahoma didn't use a combine. they would bring a stationary threshing machine out into the field and turn it with a belt drive off the side of the tractor, or pay somebody else to bring in a huge wheeled unit. later on one of the neighbors bought one, and they would hire him to do the work.