Technical Questions: 1928 Model C

[cmfalco]

As a very brief introduction I've had a variety of British bikes for 50 years and have a very well equipped shop (including lathe, mill, TIG welder, etc.) where I do essentially all the maintenance and restoration work myself. Making a long story short, I joined the AOMCC two days ago because a 1928 Ariel Model C is on its way for me to use in the ~4000 mile cross-USA Cannonball Rally for pre-1929 motorcycles. That two-week rally will start 17 months from now in September 2018.

Although the bike is complete and "restored," all too often restorations are only skin deep so I will completely rebuild it myself (if problems develop on the ride I will have only myself to blame). 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 this AOMCC forum, etc.).

With the above as brief background, after having gone through all the information I could find, I am left with a number of questions that I hope some of you will be able to answer. 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.

Thanks very much for your help with this (which is quite unlikely to be my last post about this bike).

Charles

[simon.holyfield]

The answers to these questions, and the account of your trip across the US promises to be a long and interesting thread.

We're looking forward to it already!

[cmfalco]

I found a two answers to the following questions, but I'm still hoping someone here can provide more:

-- 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?
47T
-- a modern grease to use in the gearbox?
*[see below}
-- a modern equivalent for "Crimsangere" grease?
-- the diameter and number of steering head balls?

Since a search of this site turned up only four references to Morris grease for the Burman gearbox, none of which mention the grade, I thought it worthwhile to say something about this. I contacted Morris and they recommended their K400 EP "semi-liquid" grease for this application. Checking the specs, it has an NLGI consistency of 00 which is one step softer than NLGI 0 "very soft" and one step stiffer than the softest grade 000, also listed as "semi-liquid" like the K400EP. These specs match the physical requirements so it seems to be a good recommendation for this application.

Unfortunately for those of us in the U.S., the U.S. distributor only handles the Morris range of 'classic oils'. However, they were willing to add a 3 kg container (the smallest Morris supplies it in) to their next order at the the end of May. I should add that reliable sources recommend adding some gear oil to the mix to lubricate the small clearances where the grease alone may not reach.

[chris.shearwood]

I should add that reliable sources recommend adding some gear oil to the mix to lubricate the small clearances where the grease alone may not reach.

Be careful of the type of gear oil you add to the mix. This is from a previous topic "Gear Box Oil Types" from a couple of years ago:

I would not use an API GL4 in a Burman box. The "4" indicates a high level of Extreme Pressure additives which are evidently required by the hypoid gears found in recent automobile rear axles but can attack and degrade yellow metals (brass, bronze copper etc.). A GL1 or GL2 would be suitable for these old boxes. For the GB box on my VH I have been using Dentax API GL1 80W-90 since putting the bike together about 3,500 miles ago with no problems so far.
It can be difficult to find GL1. Here in Canada I had to order a 5 gallon pail from a Shell products wholesaler but that was OK for me as I have various uses for it in my old tractor and various farm implements. Morris Lubricants sell GL1 in viscosities of 90, 140 and 250 but I don't know the container sizes. They have a distributor in the U.S. but not in Canada as far as I know.

[cmfalco]

I would not use an API GL4 in a Burman box... It can be difficult to find GL1.

Thanks for your post. I should have mentioned that issue in my post. It certainly is difficult to find GL1 gear lube, but two bottles of Morris "Golden Film Classic Gear Oil" will be on their way to me from the U.S. distributor when the semi-fluid grease arrives with their next order from the UK.

[john.whiting]

I love the "Cannonball" reports in the AMCA magazine.Last one was pre 1916,so no brits to speak of.Prev was pre 1936,so quite a few.One guy with a 1929 sloper BSA blew up nine spare motors,then took a wrong turn into a river.The winners seem to me to have completely "re" manufactured Harleys and Hendersons.It also helps a bit if youre a billionare.Regards John.

[cmfalco]

One guy with a 1929 sloper BSA blew up nine spare motors,then took a wrong turn into a river.....It also helps a bit if youre a billionare.Regards John.

Since "everyone" in the 2018 Cannonball will be on large American bikes, I wanted something else. Although I'm American, other than a Honda 50 when I was 15, I have an unbroken history with British bikes starting with a ~20-mile ride on the back of a Triumph Thunderbird when I was eight or nine. However, before buying a bike for the Cannonball I spent time researching past results to determine what (non-Harley) bikes seemed most likely to succeed. This is how I ended up with the 1928 Ariel Model 'C'.

Looking at the results for the 2012 run (also for pre-'29 bikes, like the one will be in 2018), six bikes failed to complete even ~750 miles of the total 3956. On the first day alone 12 of the 66 bikes (18%) didn't even make the full mileage that day. In 2014 (pre-'37), eight failed to complete 750 miles. At the risk of jinxing myself, these low-mileage failures indicate to me that preparation is much more important for success in the Cannonball than is money. It doesn't matter how much money someone spends to buy badly-rebuilt engines, badly prepared bikes will break.

From what I've been able to learn a fair number of the bikes in each Cannonball weren't rebuilt by the owners, but instead were purchased and ridden as-is with very few preparatory miles before shipping them to the starting line. Unfortunately, as most people reading this should know, all too often "restorations" are only skin deep, so it's not surprising there were internal engine failures.

After I bought the bike I found a letter from a satisfied customer in the 1928 Ariel catalog that says:

"Having just completed a tour of Scotland, the Lake District and Wales, covering 2008 miles,.. [on my] Model 'D' Ariel.
During the whole of this tour, over some of the most atrocious roads it is possible to imagine, the machine was splendid, the engine functioning perfectly... An absolutely trouble free tour.
...I have covered 5500 miles, and so far the machine has not cost me one single penny for replacements, and it is still in perfect running condition."

Taking the above letter at face value, it indicates a 1928 Ariel 'C' properly rebuilt to as-new condition, with proper maintenance every evening after ~200-250 miles, should be capable of dealing with the 4000-mile Cannonball.

The questions I asked in my first post (for which I'm still hoping for answers!) are because I will completely rebuild this already-rebuilt motorcycle myself using modern components where necessary (e.g. valves and valve springs). Whether or not I am capable of covering 4000 miles on a rigid-frame motorcycle is one thing, but I have good reason to believe the bike itself is capable of the trip.

[john.whiting]

Youll need to be pretty fit too.Last run a rider pushed to the top of the high point in the race,after a 20 mile climb to 10,800ft.More than 2 miles high.Regards John.

[iansoady]

You'll know about Kevin Water's successful 2016 ride on a 1915 Sunbeam......

I have to say I'm in absolute awe of anyone attempting this event.

http://www.motorcyclecannonball.com/rid ... vin-Waters

[cmfalco]

Youll need to be pretty fit too.Last run a rider pushed to the top of the high point in the race,

As you must know, that bike was a 1914 belt-drive single. An important factor in my choice of the higher-h.p., chain-drive Ariel was not wanting a line in my obituary to read "Cause of death: heart attack. The fool tried to push a motorcycle over Loveland Pass."