Paughco 45 and Magnum frames

Hi. I am just curious. I have seen on several threads how many of you do NOT like the Paughco 45/BT 4spd frames. I'll admit my first reaction when I heard of these was "Yay! Someone out there has read my wish list!!" I have seen one of them "in the flesh" and the welds are very good, but I must agree with some of you out there, the overall look is kinda fugly. Obviously it isn't intended for resto's so floorboard mounts, tank mounts, seat tube and the like are not an issue for an enterprising chopper builder. (just a little clarification - I am NOT building a chopper) What throws me is the offset motor mounts. The modern chopper guys have been building offset motor mount frames for a while now to accommodate the obscenely obese rear tires that are all the rage with the TV biker crowd and there has been plenty written about the left leaning tendencies leaving a stoplight and the resistance to right turns. Most of these have been big inch/high horsepower bikes with 6 inch belt drives hanging way out into oncoming traffic. So, getting to the point - do you think a little 45 motor with just several hp and about 120lbs soaking wet would cause much of a handling issue leaving said stoplight if it were offset? Also, not having the giant rear tire would eliminate the difficulty turning into a corner those new age choppers have, but do you think having the 45 motor/BT tranny offset would adversely affect handling at highway speed? The gyroscopic force of the reciprocating mass would have a stabilizing effect, I would think, even if it was 1.5in" left of center.
So, if someone were contemplating building a frame to accept a 45, a 45/K or a 45 Magnum with an early HD 4spd, what would be the design factors that you would change from the frame mentioned that you didn't like? I know all about using Brit transmissions, but I am interested here in BT4spd.
Ok, fire away!

The motor mounts are offset in order to line up the primary drive on the Big Twin transmission. If the tranny were offset instead the drive chain line would be way off for the rear end. It is not a big deal having the 45 engine offset like that. A 45 engine has right side weight bias anyway so it isn't going to cause the bike to handle, track or lean any more than normal.
But Then I've never understood why anyone would want a big, heavy, BT 4 speed behind a 45 anyway. It takes about half of the 45s output just to drive that big box! Why not just build a UL!
JMHO
Robbie

Thanks for the input. I have a couple of reasons for wanting a BT4spd over a Brit box. 1st is I already have one, and 2nd is I am quite a bit more familiar with the innards of the Harley box. (read: I've never been inside a Brit tranny). I suppose I could add I prefer the look of the Pan tranny as well. A UL project would be great, but I don't have the time or money to start a third project bike. For now.
I am curious if anyone who has ever put together a 45 with a 4spd behind it found power to be reduced that drastically. The bike I am building has a K top end and will be in the "bobber" style so I will have a few more horse and it will be lighter than stock. I have ridden a stock 45 servi-car with a full beer box and a bunch of camping gear and didn't find it lost too much oompf so I hope a Pan tranny won't ruin the whole shootin' match.

Scaryguy..

I got to chime in if ya don't mind.

The British M-21 gearbox internals are built like a freaking tank. I have one for my WL/KH project.

http://www.hydra-glide.com/phpBB3/viewt ... =55&t=7618

Currently, I have a standard HD 3 speed that I intend to run. But the 4 speed brit box it there as a option once I get the cradle mount that I want to have completely figured out, at the moment the cradle is just a wood mockup to see how it would work mounting and fitting.

Look for Piet Jan's thread on his bike. His is running his with the British 4 speed WL bottom end, K top.

George

Here in the San Fernando Valley there is a guy running a Brit box in his Knucklehead. I can only imagine the sound of disintegration if he actually wound it up and dropped the clutch. You should see the damage that was done to the frame to fit it in.

Chris,

That is why I am making a cradle to fit the frame and the transmission, so I don't make any mods to the frame.

That was one of my beginning promices to myself............NO frame mods...work around all other fitment issues.

George

Old post, but....I did build a 45 with a big twin 4-speed gear box behind it. A friend made the frame, it was a double down tube just like a big twin frame and from a distance or casual glance it did look like a VL/UL/ULH etc. (I think that's why someone stole it) One thing I don't understand is why Paughco brought it out as a single down tube frame.

It worked absolutely perfect...there was no reduction in power from the 3-speed. It pulled high gear just fine. I loved the bike.

When I was thinking about doing that, I spoke to a lot of people to get feed back first, and everyone said it would not work. (this was in the mid 1970's) One very old and well known Harley mechanic in town told me: "you can monkey around and get the four speed behind a 45, but it will never pull 4th gear". It all turned out to be bad advice and the bike ran and performed perfectly.

Never listen to anyone else! The advice that it wouldn't pull top gear is horseshit. Depends on sprocket size.

I had never noticed that the 45 had a weight bias to the right, then again riding in the UK it would be against the camber of the road, so it would be beneficial

No Wilko I didn't listen to them. The interesting thing was that EVERYONE, at the time, said the same thing. Horse apples indeed.

On that bike that we built, there certainly was no "weight bias" that I could detect. It handled, cornered, and tracked perfectly, to the best of my memory. We did build the frame completely from "scratch", perhaps that is why. ??

I suspect that the reason Paughco didn't bring it out as a twin downtube frame is that there would be no market. I've seen two or three such bikes converted from old BT frames simply by reconfiguring the engine mounts to line up the motor.

Of course, a lightweight twin downtube frame for a 45 to give a bike about the same overall size as the original would be great, the Motor Company experimented with racing frames of this type for the WR, but no matter. I don't know quite how a 4speed BT transmission would fit into this, but that what AutoCadd is for.

That's probably true...but there could be a market, it does make a neat bike. The frame my friend made was light weight, and the engine area, backbone, was sized more for the 45 engine so it looked like it belonged. I would imagine that a 45 in a BT frame leaves a lot of wide open spaces. The frame was as long as a BT frame though, or at least from the seat post tube to the rear axle so that the oil tank, rear fender, etc. fit normally. I'm not super tall, but tall enough that I didn't want a short and squatty little bike. Thought it was a good looking bike, but don't have any pics of it! Do'h. Only one with a panhead sitting in front of it, so you can't really see much.

That bike was stolen out of my garage in Spokane Washington in 1976 I think, and I'm pretty sure they thought it was a BT, unless it was someone I knew. But it happened in the spring, a week after I had it out for the first time, so I think someone just spotted it driving by.

If anyone has ever seen such a frame or bike I'd be interested in hearing...not for revenge or to get it back, I'm sure the parts and frame, or possibly the bike, have changed hands many times, and the stat-o-limitations has long since past. But I'd sure buy that frame back if it still exists in someone's garage or parts pile. Had square tube/stock for the motor mounts, but that's about it for I.D.'ing it. I think I'd know it if I saw it.

Okay how's that for hi-jacking? Sorry.

personally, I'd say a 45 frame should be a small, light thing like an Indian Scout. That would be a neat bike, especially with a stroked engine, but how you would get a BT transmission into it I couldn't say.

I think that 99% would agree with that. But it worked good for me in "mini-BT" form. And the bikes using the Paughco frame are certainly very neat bikes.

http://www.youtube.com/watch?v=u4J6eoMdFf8 45 in BT frame here

That didn't look too bad...but I sure have to scratch my head to see someone riding in short pants. !!! Someone's going to learn a hard hard lesson. Anyhow, yeah, not way too much open spaces, a little bit but not bad.

It's not so much the open spaces, as the engine really looks too small for the bike.

To my eye, it's the open space around the engine that makes it look small, if you close those up it's not too bad. But I would agree that a big twin in there would look a lot better. But again, I've seen worse.