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Here is a question for you ME types out there, what would be the approximate torque required for a small dc gearhead motor to drive the chain in reverse on a DL650? I'm just fantasizing, but can imagine a small motor with a sprocket that could be manually lowered (or raised) against the chain with all the proper safety interlocks (-:
 

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Torque-wise, probably only a few foot-pounds. The 650 only has about 35 ft/lb max. However you can't do it with one gear, it will take a reduction gear set. The pinion will have to be quite small or the starting current and low-speed current will be horrendous.

The biggest question is, Why???
 

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If you are adding a sidecar some people are buying HF winches and gutting them for a reverse gear.





Les
 

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The GoldWing does use the starter motor and gearing of course for its reverse. But, an 800 pound bike being pushed backwards in gravel benefits from reverse.
 

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Hey, the guy is just asking! Sometimes the stupidest ideas lead to brilliance (I'm not saying your idea is stupid, I'm just saying).

Assumptions:
1. DL1000 wet weight = 523 lbf
2. Rider weight = 250 lbf
3. Passenger weight = 120 lbf (hey, that's what she told me) :confused:
4. Nice assortment of farkles, unpacked = 100 lbf
5. Slope angle of the hole you managed to get your front end stuck in = 5 degrees
6. Drive sprocket on the Super Deluxe V-Strom Reverse Contraption = 3" diameter (about the same size as the drive sprocket from the engine)

Shaft torque requirement for your motor will be 328 in*lbf, just to keep it static on the 5 degrees. The motor will be able to move the bike on any slope less than 5 degrees, and anything more you'll be doing the reverse shuffle with your feet to help it out.

However, sprockets can't engage and actually put power to a chain that isn't wrapped at least 120 degrees or so around the sprocket, and that's with serious tension and/or idler sprockets. The rollers want to climb out of the valleys of the sprocket when power is applied, and there's nothing stopping them with small amount of engagement. You'd need a couple of idler gears and a lot longer chain to allow it to snake its way around the reverse sprocket.

You'd be better off putting a friction wheel against the back tire. Your torque requirement would go way down. The same 3" drive (now a rubber wheel rather than a sprocket) would require about 130 in*lbf.

I think a 623-pound bike would benefit from reverse also. Maybe not to the extent of an 800-pound bike, but tell that to your 120-pound passenger as she's pushing on the front of the bike while your 250 pounds is steering it.

Edit (disclaimer): I doubt this info will ever be used, but if it is please let me know. If you're gonna use it, you should understand and take responsibility for the calculations. Therefore, make sure you either work through them yourself and verify my results or inquire how I did it.
 

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Now THAT is a reply. What a guy.
 

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Kudos to coveter for doing something all-too-rarely seen on this forum: giving specific and relevant advice without indulging in second-guessing the questioner's motives, judgment or sanity.

I wish there were more good forum citizens like him.
 
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+1 on the coveter praise. Interesting to read the info, even tho I'll never need it.
 

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Kudos to coveter for doing something all-too-rarely seen on this forum: giving specific and relevant advice without indulging in second-guessing the questioner's motives, judgment or sanity.

I wish there were more good forum citizens like him.
Word. +1. Yes.
 

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Discussion Starter #13
>I think a 623-pound bike would benefit from reverse also. Maybe not to the extent of an 800-pound bike, but tell that to your 120-pound passenger as she's pushing on the front of the bike while your 250 pounds is steering it.<

My sincere Thank You ! As to the why...well, I have a unique driveway situation. My wife would prefer that I not drive over the lawn as it makes a nice 'game trail' look after a few runs. So I need to come off the street at a 90, go downhill in our gravel driveway that is a sharp down slope then it reduces grade but still downhill. I have to turn the bike another 90 to the left in several moves to get under a roof overhand where LeLoo Tso-Lo lives (bike name).

I can't back from the street through the gravel swale because my feet won't reach well enough to get stability in the gravel with the each wheel elevated. If I come in forward, I've got to make several back and forth moves to get the bike turned parallel to the house. That 'back' part of the back and forth is going against gravity and it is very difficult.

So option 1 would be to level and pave the driveway - thousands of dollars and involve the city bureaucracy. Option 2 is build a new shed or garage. Option 3 would be to make a hydraulic lift and turn table. You can see why a small DC Gearhead motor, maybe a worm drive 80:1, with a sprocket that would engage just behind the engine sprocket to ensure coupling and brought against the chain with a hand operated lever began to look like a reasonable idea.

Thanks again. I'll post the results if I go ahead with an experiment.
 

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Option 4 would be to put pavers or similar across the grass as some sort of feature that you could then use to ride on.
 

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In real life.

Fun to think about. But probably not practical. And depending on the design (sprocket engagement, worm-drive motor) perhaps life-threatening if that drive accidentally slips into engagement while riding. In my limited experience, mechanical design and construction always takes way, way longer than you expect, usually costs more, and results are sometimes unsatisfactory. Here's some old-guy advice. Pave what you need, if only a leveled pad at the parking spot to turn the bike around. It will work on every bike you ever own.
 

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There are a bunch of motorcycle turntables and wheel caddies available. Also, the bike can be spun on its kickstand.

 

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OK, since we are just brainstorming here, how about this totally hypothetical suggestion:
If -- BIG IF, because I'm just speculating here -- the starter motor can be induced to run backwards by reversing the polarity it might be possible to add another switched circuit directly from the battery to the starter motor so that it can be energized without going through the ignition circuit. With the bike in 1st gear the starter motor might be strong enough for brief use. To make things easier on the starter motor -- and if you happen to have one of the dual-spark plug models -- you might even want to add a cable-actuated compression release to each cylinder.

OK, I said it was just brain storming. I didn't say how much brain and how much storm was involved.:mrgreen:
 

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You can't use the starter motor. The the starter clutch mechanism is directional.
 

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You are aware of the KISS principle? It applies most of all to mechanical things. +1 for swivel it on the kickstand Greywolf.:thumbup: It's only 90* too. Anyway if you must build a Rube Goldburg, here is another train of thought. How about mounting the drive motor under the swingarm just in front of the rear sprocket, so that it can engage with and drive the rear sprocket in between the chain's paths.
 
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