Chain drive VS Shaft drive.

Just fantasizing about XJ's: Shaft drive is a debit on a cafe style bike because of weight, the torque induced undulations and an extra two drivetrain change of directions. So a chain is better in that application.

BUT we all know that only the 550 has the chain drive.

AND that we also always want bigger. (could be just me?!)

SO, is it possible to take the transmission case of a 550 and put a 650/750 or even a 900 crank, jugs and heads on it? 8O

P.S. On a 5 day paid holiday weekend, I can afford to relax, and dream. 8)

 

Not really. The "transmission case" is integral with the crankcases; plus the chain driven bikes have a different design of primary drive than the shafties. The only one of the "shafties" that lends itself to this type of conversion is the 1100 because it has a separate "middle gear" case.

That being said, the XJ600 and Radian motors will drop right into a 550 frame.

 

The guy I bought those parts from had a Radian. It's an intriguing motor. It looks very compact and light.

 

Perfect!

 

The FJ1200 might fit with a really big shoe-horn and some welding -

it would even look like it belonged there !

 

Shaft drive is a debit on a cafe' bike?
I don't see why. Shaft drive was not a debit on a race bike of the same era.

http://youtu.be/tdLHhx7ltP0

http://www.motorcycleclassics.com/classic-italian-motorcycles/moto-guzzi-daytona-zmmz13mjzbea.aspx#axzz36oAMzHSC

http://youtu.be/sW60SLtuUx0

It would be cool to see an FJ engine shoehorned into an XJ frame though.

 

It's an XJ/FJ600-style 4-cyl motor in a Maxim frame with "new" cycle parts.

 

I STILL am trying to figure out what the "chainies" are talking about when they go on about the shaft undulations, pumping, etc....

I have NEVER felt anything like that on ANY of my bikes ...... Makes me wonder if that is more a result of bad swing arm bearings, worn tires, weak forks, or such like that ......

Dave

 

Something odd was going on with the rear end on mine back in the day. I could be wrong as to the culprit.

Still, weight and two extra drivetrain turns.

 

I'll always remember my Dad getting the XS1100 - slightly used in 1979.
The dealer sent the mechanic out to make sure it was running perfect.
The kid came up the road in 1st gear around 60 MPH - jacking the throttle,
the bike was nearly jumping off the pavement with each twist of the wrist !

In comparison, chain-drive bikes tend to squat a little because of the way the chain pulls.

 

What "torque induced undulations" might those be? If you're talking about the bike twisting to one side when leaning on the throttle, I believe that was a BMW issue because of...

The crankshaft on a BMW is in line with the driveshaft. Not the case with the XJ.

Chains were also part of the drivetrain of delivery trucks back in the day. Guess what? They don't do that anymore.

Also, is a chain "better in that application" when it comes off in the middle of traffic? Is it "better in that application" when the sprockets are rounded off and the chain keeps slipping?

I picked this bike for a reason... and it was to get the hell AWAY from chain drive.

 

I will say that my XJ does squat a bit when rolling off the throttle mid-turn, which occasionally results in peg scrapeage that would not occur on a chain driven bike under the same conditions. The remedy seems to be to not enter a corner so hot that you need to roll off of the throttle mid-turn (not always easy to judge, even on a road that you know).


Somewhat unrelated:

I got an interesting comment from my son last night. We went riding after dinner for the first time since he moved away for college. He's been riding for two years now. I had lead and figured from watching him the first hour (when he had lead) that he was good enough of a rider that I wouldn't need to ride like a grandpa with him.

What was his comment?

"I didn't think your bike could pull away from me so fast."

He's been rethinking what a sportbike is.

 

Anachronistic point that I don't get.

If a rider lets his chains and sprockets get that bad, there is probably NO mechanism safe from him.

 

I think the basic point with shaft versus chain is that that with shaft you don't have to do all that chain and sprocket stuff, replace adjust oil, replace adjust oil, clean off the gunk etc. The feel of shaft is constant, no variations like with a variable tensioned chain. With the XJ I wipe a finger under the bottom of the diff' .. no oil just dust, all is well. Before the XJ I had 3 chain drive and did a lot of miles and liked 'em but was glad to change to a shaftie. Since the XJ I now have 2 chain drive bikes and I like 'em. You makes your choices.

 

I knew the post title would be attention grabbing, and perhaps provocative but dang, I meant no disrespect to shafties. I like the trouble free aspect of the shaft drive myself and it is also one of the reasons I liked Maxims' in the first place.


BUT.....


What I said. 8)

 

I think you were dying to use the term anachronistic. . . . . .

 

for 40 freekin" years! :lol:

 

A cafe bike and a 1000cc racer are hardly the same thing.

Sure, the cafe crowd styled the bikes after the racers of the day, but a cafe bike is something that was homebuilt and one of the defining characteristics is light weight. And a chain drive is lighter, which would matter on a smaller displacement bike a lot more than on that 1000cc Guzzi.

 

If a shaft drive wasn't a disadvantage for a privateer racing bike competing against factory teams who had chain driven bikes, it won't be a disadvantage for a street bike that's made to look like it could go racing.

From my perspective the shaft/chain debate is just a matter of preference when it comes to a streetbike.

I still want to see an FJ1200 mill stuffed into an XJ650 frame though. There would be cutting and welding, but the result would be fantastic.

 

The definition of a muscle machine. 8)

edit: You did mean XJ550 right?

 

Either one will do.

220. 221. Whatever it takes.

 

No one mentioned this?
Any reason this isn't/couldn't be cafe.
http://www.motorcyclespecs.co.za/model/ ... 50s_75.htm
Chains noisy,dirty,High maintenance.
Shaft? need new rear tyre?Grease spline ride for thousands of K's wash occasionally,repeat.
I wouldn't refuse a new bike because it had a chain,modern chains have come along way but shafts are nice and easy.

 

chains are cheaper for the manufacturer, chains are more efficient.
so the 550 got a chain because it was a "entry level" bike, and didn't have overwhelming HP. so it was cheaper to make and gained a few RWHP.
the 650/750 had a few HP to spare, cost a little more and the shaft was a "feature".
something marketed at, price and/or performance is going to have a chain.
if the target was, long distance endurance, deluxness, bells & whistles it got a shaft, and cost more.
nobody mentioned the belt drive

 

From what I've seen, and heard my neighbors talk about, belt drives are great for the most part. The drawback being needing to remove the swingarm in order to change the drive belt. Even so getting 100k miles out of a belt is not uncommon.

 

How often do they need to be adjusted? I no someone with a harley that's never adjusted the belt even though I've told him to look it up at least.

 

I don't know the maintainance schedule, but they do need to have the belt tension adjusted. There is a special spring scale that HD specifies for checking the tension.


Tell your friend that cog-driven belts wear out really fast once they go out of adjustment. They tend to break the teeth off of the belt when they get loose. I would not want to change one on the side of the road.