Sidecar gearing

[paddy]

I was wondering what the best all around motor and trans sprocket setup would be. I would like to do some road runs with it. so blue ridge, Tennessee ect.
it it a 51FL with 3speed with reverse
Thanks

[kitabel]

Empty you can use stock gearing (24/22, etc.). With the chair occupied or ballasted you need smaller sprockets, or 1st gear acceleration will be sluggish. The service manual shows sprocket sizes.
The 3-speed ratios are worse than the 4-speed, 1st gear 2.71:1 vs. 3.00:1, plus much closer shift into high gear. Do you really need reverse?

[paddy]

Kitchen, thanks for the response. I have inherited this rig.Yes I need the reverse. Sidecar will have a passenger. I am on long island. Relatively flat here but I plan to take it on a road run so I guess I won't be going over 55 or so.
I guess I'll just leave it the way it is. Currently has 22motor and 22trans. What do ya think of just bumping up the motor to 23? Or ya think maybe to sluggish if I come across steep grade??? Thanks

[paddy]

That was supposed to say Kitable sorry

[Rubone]

The 22/22 will be fine for what you are doing. I run those gears on my UL SC rig and it will do 55 all day. Long uphill can be tough though, often 2nd is too low but high is too high. You just slow down and enjoy the ride. My SC with passenger and gear has been on several Road Runs in the Rockies including over Red Mountain Pass at 11000 plus. And your Pan should have a good 10 HP+ on my UL.
The pic is my UL on top of Lizard Head Pass (a mere 10,2222) in 1990.... 1990 D-J run.jpg

[kitabel]

I agree, try what you have now.
If 1st gear acceleration is acceptable, and cruising at 55 isn't too "busy" (you're not harming the engine, but it will be somewhat noisy), just ride on!
You can still reach 2nd @ 55 if needed.
55 mph is about 2,770 RPM in high gear.
5,000 RPM in 2nd is 66 mph.
5,000 RPM in high is 99 mph.

[paddy]

Ok great!!! Thank you both Rubone and Kitabel. 22/22 going to have fun is the goal!! Now to find a sidecar windshield setup. Thanks again Paddy

[gharper]

Great picture Robbie, a blast from the past, 1990, or 93 on the Rocky Mtn DJ run!

All 3 of my old sidecar rigs are 3 speed rigs, 39 Knucklehead (74"), 24 chief (74") and 19 Excelsior (61"). They do the job but I've always wanted a 4 speed because I'm in Colorado and ride in the mountains most of the time. I've always geared them higher than recommended in the operators manuals. I do this because I find that on the flats, they just seem to scream and the balance is off enough that it's uncomfortable cruising on the flats. I did have an 84 FXRT with factory RLE sidecar for a number of years, that was a great sidecar rig because it was an 80" Evo, stock solo gearing and a 5 speed. The extra gears made it so nice, you could always find a gear that kept the engine in the sweet spot at any speed.

I've run the knucklehead for decades with a 21 tooth motor sprocket and stock transmission sprocket, can't remember the size. Final gear ratio is 4.08/1 and it does pretty well. However, the motor is a 74 and has an Andrews road grind cam. It pulls very well in the hills, but often 2nd is too low, 3rd is too high so I either lug it and manage the spark advance or wind it up. I'm seriously considering building up a 4 speed for this bike. Reverse is handy at times, otherwise a novelty and a huge disadvantage because of sacrificing the 4 speed and closer ratios.

Robbie, I recall riding with you in New Mexico. I had the 24 Chief and sidecar, with passenger. You had your UL with passenger (and antlers on the spare!). We hit a LONG steady uphill grade and I was maxed out on the chief, pulling as hard as possible, feathering throttle and spark for maximum power. I had to do this to keep the engine in the sweet spot. I slowly pulled ahead and passed you, I think Jan even took a picture as we passed you. I was pretty proud that the old Chief could pass you but I'm quite sure you weren't pushing it that hard. As I recall the Chief was geared 4.85/1 then and hated running over 45! For the Cannonball I changed that to 4.65/1. It helped on the flats, but still too low but it struggled at times on long hills.

So in my opinion, a 3 speed is always a compromise if you're in the hills or mountains. If you're in flat country all the time then gear it up high, it will do fine.

I've noticed that the trend now on national road runs is to run newer and newer bikes. Speeds are faster, days are longer. That's fine if you're riding a solo, late 30's or newer bike, most of which are shovelheads or panheads now. It's hard as hell to keep up on the old bikes and it takes some of the fun out of it. We attended the Badger road run a couple years ago, it was a great ride. I rode the 24 Chief and sidecar. After 3 days and about 450 miles I was exhausted! I struggled all the time to try and keep the pace up, if I was leading I didn't want to slow everybody else down. If I was following I struggled to keep up so I didn't get lost! We must have stopped and turned 90* at least 1000 times on that trip. After it was done I realized that I pushed that bike harder and put more wear on it in 3 days than I did the entire Cannonball! So, guess I need to finally let my training wheels go and ride a solo that I can gear tall!

[T. Cotten]

I ditched gearing my hack 'tall' , Folks,...

When it would go *clack*clack*clack* leaving stop signs.

(That's "busy" in a bad way.)

When 22/22, I found out I had been pitfully timid, and only using half of my powerband!

....Cotten
PS: It would seem the MOCO provided nine different combinations of sprockets:
SPRKTTBL.jpg

[kitabel]

The sprocket choices differ in the MPH of each shift.
The RPM % change is entirely determined by the transmission's internal ratios.

Really useful for a rig: T&O's TorqueMonster flywheels in 4-1/2" stroke.

[T. Cotten]

Off the diminishing top of my head, Folks,....

It seemed like 23/23 was "stock" production for solos, which makes sense to be in the middle of the chart.

Does anyone know what a hack package had in it, fresh from the factory?

Thanks in advance as always,

....Cotten

[kitabel]

For the tapered shaft engines (1930-54) there were 18 and 19 tooth engine sprockets.

[steuerm]

I’ll just add some additional information for what it’s worth. Don’t beat me up. My service manual for a 64FL with 4 speed and sidecar. The manual calls out for a 21 tooth engine sprocket, 22 on the transmission and 51 at the rear wheel. That’s what I currently run. I ride primarily in city conditions up to about 45mph.

[paddy]

Ok so I ordered new engine and trans sprockets 22 on each as discussed. It seems that after ordering 2 of the engine sprocket the sprocket just dont seem to sit right like the origional one that was on the engine. seems like a little sloppy in the key way .It does get tight but looks like it is sitting out a little proud. Has any body else come across this ?? Is there any othe vender producing the sprocket besides V-Twinn??? Thanks.

[T. Cotten]

Curious, Paddy!

The only diagnostic, I can think of, would be to put a smooge of Clover compound on the tapers without a key, (or chain of course), and hand-lap them to read their contact.

Then you might get a clue if the issue is just burrs or taper angle or depth of taper,..

Etc.

.....Cotten