Paugho frame for 45"

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nanonevol
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Paugho frame for 45"

#1

Post by nanonevol »

So I have this Paugho frame built they say to use a '41-'69 4 speed.
This came with some boxes of parts including what looks like a '79 trans case (best as I can tell) with the "ears" cut off.
My Palmers book make some reference to this. Even with this book I have many questions. Can I use this later box? What is it about post '69
that Paugho feels won't work? I understand I need the short mainshaft. Does it matter if I use ratchet top or "cowpie"? Do they interchange?
What might be that bracket for in the photo foreground on the bottom rail?
Thanks for reading.
Image
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Re: Paugho frame for 45"

#2

Post by RUBONE »

nanonevol wrote: Wed Feb 03, 2021 5:25 pm So I have this Paugho frame built they say to use a '41-'69 4 speed.
This came with some boxes of parts including what looks like a '79 trans case (best as I can tell) with the "ears" cut off.
My Palmers book make some reference to this. Even with this book I have many questions. Can I use this later box? What is it about post '69
that Paugho feels won't work? I understand I need the short mainshaft. Does it matter if I use ratchet top or "cowpie"? Do they interchange?
What might be that bracket for in the photo foreground on the bottom rail?
Thanks for reading.
Image
Paughco was wrong if they said through '69, it should say '64, however any of the 4 speed cases can be used if the ears are removed on the e start type. The other issue is '65 up caes do not have adjusters so an aftermarket type is needed, no big deal as they are commonly used on belt drive bikes. The ratchet and cowpie do not interchange, the gearbox casting itself differs. The bracket in the foreground is for the 5th tranny bolt.
kitabel
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Re: Paugho frame for 45"

#3

Post by kitabel »

IIRC the frame should include a special 428 X 2 engine sprocket (available: 20, 22, 24 tooth) to match the BT 37 tooth clutch drum. Looks like a 1930-54 BT but with a smaller taper (1" on the inside). How many teeth? If you don't have one, Paughco is $$$.
These are roughly equivalent to the 45's primary ratio with its 59 tooth clutch drum as follows:
Paughco's 20 tooth = stock 45's 32 tooth
22 = 35 (none exist, too big for the 45 primary chain)
24 = 38 (none exist, too big for the 45 primary chain)
The rear chain is the same pitch (530) but the 45 solo rear sprocket at 41 teeth is very different than the 1936-* BT at 51.
What rear wheel & brake were you planning on?
The primary ratio times the secondary ratio (rear sprocket ÷ transmission sprocket) is the final drive ratio. Most riders are happy with the 34 tooth engine sprocket (largest factory 45 size) which gives 4.185:1.
A stock WL engine will do about 80-85 with that ratio, but the engine will be pretty noisy. The huge BT 1st gear (over 21% more torque) allows the engine to turn much slower ("taller" gearing) without poor low gear acceleration. No, you definitely do not want a close ratio 1st gear.
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Re: Paugho frame for 45"

#4

Post by RooDog »

Go with a disc brake BT rear wheel and You'll be able to juggle the tranny and wheel sprockets to most any sort of ratio your engine can handle.
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Re: Paugho frame for 45"

#5

Post by kitabel »

A 45 suffers more than a BT from insufficient "crawl ratio" (1st gear X final drive ratio = 10:1). I'd like to see 11:1 due to lack of both torque and flywheel inertia.
The stock 45 transmission's 2.47:1 needs at least 4.45:1 drive for this, equivalent to a 31 tooth engine sprocket.
With the BT transmission's 3.00:1 1st gear, drives as tall as 3.66:1 will work acceptably in traffic without killing the clutch.
This ratio allows a hot 45 (big carburetor, open exhaust, big intake valves and cams, relieved, .100" head mill, more breather timing, tight quench, but stock lower end) to reach almost 100 mph at 4,700 RPM.
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Re: Paugho frame for 45"

#6

Post by RooDog »

How about a 5-Speed with its 3.24 1st gear?
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Re: Paugho frame for 45"

#7

Post by RooDog »

A swap meet Softail 5-Speed could be easily put to work here to do the job, all it takes is a little engineering, a base plate, and sprocket alignment. It's really not all that difficult to make happen, add a kicker and it's good to go....
....RooDog.....
nanonevol
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Re: Paugho frame for 45"

#8

Post by nanonevol »

RUBONE wrote: Wed Feb 03, 2021 5:51 pm Paughco was wrong if they said through '69, it should say '64, however any of the 4 speed cases can be used if the ears are removed on the e start type. The other issue is '65 up caes do not have adjusters so an aftermarket type is needed, no big deal as they are commonly used on belt drive bikes. The ratchet and cowpie do not interchange, the gearbox casting itself differs. The bracket in the foreground is for the 5th tranny bolt.
What is the problem with the ears besides the fact that I will not have e start? Do they get in the way of something?
Dosen't the primary cover attach there?
What type of adjusters are missing post '65? Chain tightning? Don't they all shift fore and aft in slots?
There are aftermarket "adjusters"?

Kitabel: I appreciate the advice but I'm more confused than ever. I'll do my homework on the gearing.
I do understand what you're getting at in general. The '51 G motor will have some performance improvements, likely stroked.
I do have a disc brake rear wheel 16", I think with a 51 tooth sprocket but that could be changed.

RooDog: A Softail 5 speed? Sounds good but why does Paugho say to use the '41-'69? Yes, I'll need a base plate and to align the sprocket
in any case.

Appreciate the advise. Paugho has not been so responsive to inquiries.
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Re: Paugho frame for 45"

#9

Post by RUBONE »

What is the problem with the ears besides the fact that I will not have e start? Do they get in the way of something?
Dosen't the primary cover attach there?
What type of adjusters are missing post '65? Chain tightning? Don't they all shift fore and aft in slots?
There are aftermarket "adjusters"?
The "ears" can interfere with other components on a short mainshaft build.
No, the primary on the type of build you are attempting does not attach to the ears.
Post 65 cases do not have centering blocks in the casting nor a cast in hole for an adjuster as they are designed to be fixed position.
Aftermarket "adjusters" are devices to holed the gearbox in line and allow it to slide in the slots with controlled movement.
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Re: Paugho frame for 45"

#10

Post by RooDog »

There are aftermarket transmission base plates to mount an FXST tranny to the 4-speed frame's mounting points.

This is the adjuster you may need.....
https://www.vtwinmfg.com/Instructions/17/17-6655.pdf

There is no primary cover that will work on this app, you will have to whistle up something....

...RooDog....
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Re: Paugho frame for 45"

#11

Post by nanonevol »

Right, now I get it. The case I have is like that with the shaved ears and no centering blocks. Missing the studs even.
Image
But one of these base plates would certainly widen the usable trans, right?
My search turned up a lot of these. Might work? Probably need to buy a base with these while the one above is built in to base.
Image
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Re: Paugho frame for 45"

#12

Post by RooDog »

I used the lower one, Chromed, on my 1950 Panny w/SuperMax belt drive, but it was free and the base plate was from my stash in chrome. I replaced the free running adjusting nuts with nylock nuts and flat washers, so as to make it easier to keep count of how many turns I was making during adjustment. (not in these pics)
DSC01721.JPG
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DSC01722.JPG
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Re: Paugho frame for 45"

#13

Post by kitabel »

I'm more confused than ever

About what?
The only transmission that has the correct width between the primary and drive chains for your frame and engine is the 1936-64 BT 4-speed.
Anything else moves at least one of the chains away from the other.
If your align a 1965-* transmission sprocket with the rear sprocket, you need to fabricate an engine sprocket to move the primary chain to the left. It can be done, but the left main bearing won't like it. Or: you can move the entire engine to the left, but everything on it must move also (all three motor mounts, oil lines, exhaust system). Trust me, it's a lot of work.
If you align the clutch with the engine sprocket, you need to move the rear sprocket (and wheel) to the right. With a 1970-* transmission the rear wheel will be offset about 3/4" and the bike will track sideways.
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Re: Paugho frame for 45"

#14

Post by RooDog »

kitabel wrote: Thu Feb 04, 2021 4:09 pm I'm more confused than ever

About what?
The only transmission that has the correct width between the primary and drive chains for your frame and engine is the 1936-64 BT 4-speed.
Anything else moves at least one of the chains away from the other.
If your align a 1965-* transmission sprocket with the rear sprocket, you need to fabricate an engine sprocket to move the primary chain to the left. It can be done, but the left main bearing won't like it. Or: you can move the entire engine to the left, but everything on it must move also (all three motor mounts, oil lines, exhaust system). Trust me, it's a lot of work.
If you align the clutch with the engine sprocket, you need to move the rear sprocket (and wheel) to the right. With a 1970-* transmission the rear wheel will be offset about 3/4" and the bike will track sideways.
LOL....Nobody said this mosh-up of parts was gonna be easy.
And the costs in both time and money will far outpace the returns.... Yes it can be done, but at what price?
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Re: Paugho frame for 45"

#15

Post by kitabel »

The original concept: how to install an available, robust 4-speed transmission for the 45 engine.
Something better (if more expensive) than the Frantisek 4-speed jockey-shift conversion of the 45 transmission (https://tinyurl.com/y5pkpr6o), or conversion to a British transmission (https://tinyurl.com/y5zq3358).

Paughco provided the package, which mandates a short mainshaft transmission.
The problem: the OP doesn't have one.
The solution: get one.
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