Repurposed treadmill

[Cyborg]

I know…. It’s only the motorcycle projects that help keep me grounded. I’m off to the garage to fabricate some sort of device to convince the raccoons that this isn’t a good place to hang out.

 

[Magnetoman]

MM had mentioned tie downs to hold the bike if you want to adjust something without removing the bike from the starter,

For what it's worth, here's a photograph of that setup:

The tie-downs don't hold the tire against the rollers tight enough for starting it when not sitting on the bike (at least, I don't think so, although I've never tried), but are useful when sorting out jetting or electrical problems that require me to get on and off the bike multiple times to make adjustments. The bracket is held by two wingnuts so it's easy to remove when I'm only going to use the starter for, well, starting.

I possibly wrote about this before (?) but, for what it's worth, DocZ rollers are powered by either one or two of the starter motors that are for Ford trucks and vans of the 1980s. Rated at 2 h.p., each motor puts out closer to 3½ h.p. at 12 V. Although the rollers came with just one motor that had no problem starting a Gold Star with 10:1 piston, for no justifiable reason I added a second motor.

The deep-cycle marine battery I use is rated 845 MCA, which means it can supply that many amps for 30 sec. at 32 ℉ before the voltage drops below 7.2 V. However, the power available from a battery goes up with temperature, so 845 MCA actually is ~940 A for temperatures in the range 65 ℉<T<105 ℉. It only takes a few seconds of operation to start a motorcycle, but the current drops proportionally with voltage, so by the time the battery is at 7.2 V the power to the motors will be reduced to (7.2/12)^2 = 36% of its fully-charged value. Still, since the pair of motors draws 480 A under full load, the battery will last 940/480 × 30 sec. = ~60 sec. before falling below 7.2 V. Although at that point the power will have been reduced to 36% of the battery's fully-charged value, it still is enough to start just about any motorcycle since 36% × 7 hp = 2½ hp.

 

[Cyborg]

It was the HP rating of those starter motors, and the fact some folks use 2, that made me think the treadmill was doomed to failure. I also wondered about the smaller diameter steel rollers and whether or not they would provide enough traction. I’m still expecting something to go sideways with this thing.
I don’t think I would try using the tie downs for starting, but they’ll come in handy when sorting out the idle jet etc.
The Gold Star looks nice. Robert was trying to temp me with one… and it was very tempting, but I blew the money on a used Cummins diesel truck instead.

 

[Magnetoman]

The Gold Star looks nice.

Some years ago I got a BSA C15S that also has an alloy tank, so it looks very much like the Gold Star on the rollers. I commented to my younger daughter that I liked the looks of the little BSA, but I didn't know why. She immediately answered that the reason was that it looks exactly like a motorcycle a 13-year-old boy would draw if asked to draw a motorcycle. Her observation explains a lot about us...

 

[Cyborg]

You are out of control!

Just so we don’t leave any doubt about that…. I picked up another “free” one yesterday. Well almost free. I owe a few beers to the other 3 folks that helped lift it into the truck. It’s a commercial unit…5 hp 3 phase motor with a circuit board that powers it from 115 V single phase. This will drive the mill! I should have taken a before photo.

 

[rogerphilip]

When I was young man, early 60s, I had a Rudge Special that I stripped and tuned ready for sprinting but couldn't start it so I reinstalled the rear stand, lifted the rear wheel off the ground, and selected second gear. I then lined up the rear wheel to the rear wheel of my Panther, also on its rear stand, started it up in gear with my mate holding the front brake, and 'jiggled' the Rudge so the wheels touched. The tyre friction started the Rudge (11 to 1 c.r.). crude but effective. (It sounded great on its 1.5 inch dia straight thro pipes ).The Panther had a third wheel (sans sidecar body) so was quite stable. Happy days. After many hours burning the midnight oil tuning the Rudge it proved almost as fast as when it left the factory in 1937

 

[Cyborg]

I have a 30’s Inter bitsa with rather high compression. Hopefully it will be ready for the roller starter by next summer.

The latest treadmill has created a bit of a dilemma… the rollers and the treadmill frame are more than robust enough to make a rolling road. There is no room to store a rolling road when not in use… so the only way it would be feasible is if it was incorporated into a motorcycle lift (which I don’t have).
A normal treadmill roller between the two latest ones.

 

[rogerphilip]

I'm surprised we haven't seen the return of the (2wd) vehicle driven rollers. Two rollers ( around 1.5m long) mounted on bearings in a frame.
Jack up a driven wheel and slide the roller frame under the tyre. lower the vehicle onto the rollers. Place the rear wheel of the bike on the rollers.
Sit on the bike, select 2nd gear, and with front brake on, your mate starts the vehicle, selects 1st or second gear and the bike starts.

 

[Cyborg]

I did think about one of those when I saw the size of the rollers. The shafts and bearings are probably sturdy enough and the (farm) truck in the photo above has a throttle on the dash. Karma being what it is…. it’s probably safer for me to just stick with the electric version with a foot operated momentary switch.

 

[vibrac]

Actually my one claim to fame is that I told Mike Hailwood how to change gear.
We were helping him with the Honda 6 at the post TT at Mallory and we had it on rollers on the rear of a Bedford Van (the one with the suicide doors and a steering stick gear change) "which way is reverse?" asked Mike, and my fame was assured