Modern sealed o-ring and x-ring chains are remarkably trouble free in motorcycle service. I regularly run 150+ hp. through a 520 (3/8X1/4) chain with no problem using steel sprockets. A shot of chain lube every 2-300 miles takes care of everything. The internals are lubricated for life and sealed. 12-15K miles is average chain life.
When thinking about thos big old trucks-they drove really slow. Most of them probably cruised below 45 mph. The sketch in the first post looks like a dually truck axle without the inner dual wheel mounted.
If you want to go old school... the original Chitty Chitty Bang Bangs were chain drive pre WW1 Mercedes chassis with WW1 surplus airplane engines. One was driven by the owner from England to Egypt. Every once in a while the mechanic would remove the chains, wash them, and lube by boiling them in a pot of tallow mixed with graphite.
The past few days I've been trying to get my head around how dive/squat geometry would work with various chain-drive set-ups. Has anyone got any ideas? For instance, what is the conventional wisdom about motorbike swingarms, torque, and chains?
I saw this last weekend. Not a hot rod but a somewhat restored and very old truck with the body sat on a later (from the looks of it) frame and running balloon tires rather than hard rubber tires with a chain drive to the left rear wheel. It still had the original engine but had what looked like a trailer axle under the rear. I was a lot more interested in the truck that was next to it and didn't pay a lot of attention to that one until it started to leave. A still looking very antique truck that has been updated so that the owner can actually drive it without a lot of hassles.
^ Looks like a Mack Bulldog. The distinctive coal scuttle front was the trademark of the AC model. They were made from 1916 to the 1940s. The first ones had hard rubber tires but later ones were pumped up, same as the ones in the picture. So, that appears to be a stock Mack AC, late model.
Is that a brake behind the drive sprocket? It would be useful to multiply brake action by the sprocket ratio, at the risk of not having a brake on that side if the chain breaks. It allows the brakes to be smaller and lighter.
Even with aaaaall that power out of a Rabbit engine I would be afraid to change gears with any sort of haste. Too many moving parts between the transmission and the rear wheels. If you used both sides for chains however you could get function from a limited slip dif. Just saying.
Look again. There are only drive shafts between the transaxle and the rear wheels. The chains are between the engine, countershaft, and transaxle. That means they see only engine torque, not engine torque multiplied by first gear and a primary or final drive etc. Consider a top-end sport bike. It might make between 90 and 100 lb.ft of torque, and feature an overall first-gear ratio of around 4:1. Therefore, we might see around 380 lb.ft at the drive sprocket in first gear. A VW EA827 that makes 380 lb.ft at any speed is likely to go on to make 550bhp: that is a seriously breathed-upon Golf engine. One producing a third of that can be considered robustly healthy. So, while on the Widgeon-VW we're dealing with rather long chains, which are more prone to stretching effects, and moreover two of them in series, we've also got a huge surplus of torque capacity, and always the option of upping the chain spec to something that will stand up to much more than a stock GSX1300R.
Way cool, I wasn't paying close enough attention. I still think your stressing each small segment vs a large rod and gears in your usual longitudinal layout. You haven't quite convinced me this has any significant benefits. Are you looking for a shorter hood? When I think of chain drives I'm generally not thinking about turbocharged VW monsters. Someone just posted on my facebook a 1013hp AWD Mk1, and I saw an 800+ Horsepower Mk3, with the engine powering the back wheels. Not that these things aren't possible, but why? Honestly, natural aspiration seems like the way to go with this. 4AGE would be my choice but thats just personal preference. I loved the way it felt over the rear wheels of an MR2, I wouldn't mind an AE86 with the motor up front sidways powering the correct wheels. Its such a strange concept. Forgive me for mechanical ignorance but couldn't you only have a 1 way dif with your setup?
By a strange coincidence a colleague of mine just e-mailed me a video clip of a 900bhp Golf Mk2 GTi-16 4Motion running 8.65@165. The challenge I set for myself with the Widgeon idea was something front-engined and rear-driven using the parts out of a dead hatchback and as little as possible else, and not requiring all that much in the way of specialized fabrication. The penny dropped - and led to chains - when I realized that splitting the engine from the transaxle gave two assemblies narrow enough to sit comfortably in a traditional ladder frame when oriented transversely. Not quite sure what you mean by a one-way diff?
I was just thinking in terms of limited slip diferentials, with your usual longitudinal shaft driven car the differential would be mechanically much different than lets say a go kart style solid axle fixed gear setup. I guess any transaxle would have to have some sort of differential but, forgive me if I'm wrong, if you don't have a locking differential you would be spinning power away to one wheel, which will get you around but where's the fun in that when you can get so much more from both... I was under the impression that somehow there were what my father reffered to as 'spider gears' that allowed the wheels to move at different speed. This would be a 'free' differential, without locking. A 1 way differential locks on either acceleration or deceleration, where a 2 way dif would lock on both acel or decel... I'm not sure how, but thats how I've understood it. Either way in a front wheel drive application (Which ironically this is) I have no clue how it works, or if it will work... Heres a great, non chain drive related, video on differential gears. 10 minutes of jaw dropping mechanical boredom, but interesting nonetheless. http://www.youtube.com/watch?v=yYAw79386WI
Twigging differential action is one of those mind-changing-gears things. It takes a while but once one sees it it's obvious. Most true limited-slip differentials work on a principle of limiting the magnitude of any difference in rpm between the left driving wheel and the right one. That is, the left wheel can outrun the right, but only by a certain speed, whereafter a mechanism locks the two together. When tracking straight the whole differential is just rotating at the same speed as the wheels: the whole thing is rotating but no part of it is rotating relative to any other part. That is why differentials and slip-limiting devices are usually unaffected by road speed, overall torque, and direction of motion. I suppose one could devise something that will de-activate the slip-limiting action under either driving or braking torque, but it seems a lot of trouble for questionable advantage. It's not something that arises easily out of the working principle of either the diff or the locking device. The Widgeon was very much inspired by trials specials (see the thread on Specials for more) and those often have separate handbrakes for the left and right rear wheels. The principle is, applying a brake to a wheel that is spinning through an open differential will restore torque to the opposite wheel. (Slip-limiting devices are not allowed in the fascinatingly eccentric sport of observed car trials, nor are aggressive tyre treads. One is expected to do all that by skill alone, by being clever with individual brakes.) What I saw for the Widgeon-VW's brakes was the Golf discs at the back and the dinky little leading-and-trailing drums at front. (I wouldn't run more than a stock 1272 that way. Light weight would still mean lively performance, besides demanding less of the brakes. Any more power and I'd arrange for better front brakes, but that's outside the brief I'd set myself.) The hand- or parking brake would work on the front wheels, but there would be valves much like a Line-Lock in each of the rear brake lines. That would allow one to isolate the brake on the wheel that is slipping. But then, the idea with a trials special is not to get stuck rather than to launch cleanly.
For you chain drive fans, the Strolz - Gassner Special, a 1917 LaFrance touring with a 982 cu in (14.5L) six cylinder engine. Shown here ready to compete in the 2013 Peking - Paris Rally. http://www.hotel-auriga.com/peking-paris/index.php?lang=en Detail shot of the chain drive.
There was an outfit in Canada that converted '90's Dodge trucks to chain drive, to allow the bed of the truck to be lowered to the ground thru cables, for loading cattle mostly. With no differential in the way, the whole floor of the bed could drop right onto the dirt, the cow walks in, tailgate up, and bed is raised. They used swing-arms pivoting off the ends of a regular axle, which was located under the cab as I recall.
They used to haul machinery on big trucks like that. But they were front wheel drive. Seems easier than chains.
Can't forget Brutus. 46 liter Heinkel V12, chain drive. Described as "Germany's attempt at a joke." http://www.topgear.com/uk/car-news/BMW-brutus-2011-07-11
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