Hi, just bought this rig knowing the 74" was no powerhouse. Don't want to go 80mph but 55 in a 10mph wind would be nice. Bike is very original w/12,800 miles & would prefer to keep it close as possible. Bike has a 51t on wheel, 22t on trans. Got a 22t comp sprocket with bike but not enough adj. to tighten chain. Bought a 80pitch chain to replace 82p. This chain is too short. The box said for 4 speed w/sidecar. Anybody know the ideal gearing in primary etc? Bike still has lead valves so may do a top end with higher comp. pistons & step or 2 up with the cam. Thanks for any advice.
Spudder,
Solos use a 24 tooth motor sprocket, sidecars use a 22 tooth and trikes use a 19. Clutch basket teeth are the same, 44 teeth as I recall. Trans output on my last early one ('77) was 24 tooth with a 51 tooth rear sprocket.
Any final tweaking can be done with rear sprockets from 48 to 51 teeth.
Lonnie
Lonnie, trans. is 22 & rear is 51 now & I believe that's as low as I can go there. If I remember right, the clutch shell was a 37t. Did they have a different shell for an 80 pitch primary chain? I don't think my 82p chain is that worn, it fits nice with the 24t comp. sprocket but way loose with the 22. Thanks.
Originally written by Spudder on 4/13/2009 9:28 AM
Lonnie, trans. is 22 & rear is 51 now & I believe that's as low as I can go there. If I remember right, the clutch shell was a 37t. Did they have a different shell for an 80 pitch primary chain? I don't think my 82p chain is that worn, it fits nice with the 24t comp. sprocket but way loose with the 22. Thanks.
The standard clutch shell was 37 teeth from 1936 all the way to the early Twin Cams. Some of the later Twin cams have a 25 T motor and 36 T Clutch Shell. My 2004 Ultra was like that so when I installed the sidecar I changed to 24 T motor and 37 T clutch shell using new parts from the Evolution series. With 32 X 79 rear belt teeth, that gives me 3.37:1 instead of 3.15:1.
With 22T motor, 37 T clutch, and 22 X 51 on the rear chain, you will have 3.898 on the rear. Assuming that your '76 is a 74 Cu. In. motor is in good tune, that should work OK.
The gearing that you have is probably the lowest you could go without having a custom rear sprocket made, say 53 teeth. That would give you an even 4.0.
IMHO, a better alternative would be to consider changing the transmission gears (or entire transmission) to a 5 in 4 setup. With 5 speeds, you would be able to cruise nicely in fourth until you got on the road and could use fifth.
It is possible that more compression or going to an 80" crank with appropriate pistons would give you more oomph. I had a sidecar on my former 80" shovelhead and it barely had enough power, although I was running 24/367/23/49 ( 3.28:1) so that's not a fair test. With gearing like you have, my bike would have been just fine.
By the way, you can use an evolution crank in your Shovelhead just so you are sure that your cam cover is an end oiler and not a side oiler. The covers are intechangeable. It's almost impossible to find a real 80" Shovelhead crank anymore (-78 or -78A) as they were only built between 1978-1/2 and 1983. Thus, there were few of them and most of them are still in the original engines. NOS spares are almost unheard of. I located a NOS set at an Indy dealer a few years ago and he wanted $500 just for the wheels.
Raising compression in your Shovelhead, if done judiciously, might help, although they run best at 7.5:1 due to the hemispherical combustion chambers. Anything over 9:1 is problematical and likely to cause intermittent pinging unless you also go to dual plug heads at the same time which is a real bother.
Happy Trails.
A final drive ratio of around 4.0 is what has worked well for me with 74 inch Pans and Shovels with a heavy sidecar.
Lonnie
Thanks for the info, had it out today & gave'r the nuts & it seemed to take 55-60 pretty well with no wind or passengers. Maybe I need to look back at the way I drove my shovels in the past. (hard) They'd go from 30 to 90 in 3rd gear. Just puzzles me about the 80 pitch sidecar primary chain.
im assuming it does not have a three speed w reverse? does it have a stock sidecar front fork?
back when i had my 77 e glide the standard way of thinking for sidecars was to go as large of a displacement as you could get - with mild cams and regular gas compression.
i knew one guy in iowa who had a three speed w rev, factory foot clutch, nearly 4:1 ratio - 96" 7.3 compression.. it ran so sweet at 60 - no faster & shift early. he didnt have to shift down on the western iowa hills.
of course every other year we all had our engines apart.. *sigh* and none of two wheel bikes then could keep up with my 07 pulling a sidecar today..
times are changing..
It's got an 85 harley car add on. Stock otherwise. Looks like it'll be a fair weather rider. Border waters open today, we'll see how it does with a kid & fishin' poles. Dean
