Check out my XS1100 Chain Drive

[mrbisbob]

Hey everybody, I have been lurking here for a couple years now and love the site. I think its one of the best and most informative out there of any bike type not just the XS. I became an XS fan back in 2009 when a friend of mine gave me my 79 XS1100 Special. I have had lots of other bikes, mainly sportbikes since the mid 80's when I started riding while seving in the US Army. I didn't think much of the XS until I had one running under me and I am now an enthusiast. It has some awesome technical innovations at a very early time and of course it is strong in the Force. I love how torquey and flexible the motor is and as a former performance tuner it has a huge amount of untapped potential which is just the way I like my own projects to be. Kind of like a blank canvas. Anyway back in 2009 I bought a chain drive conversion from xschop but then had to sell it without having ever used it. The pictures that hopefully will follow detail my progress at making one myself.





















The next step now is to execute the program in the CNC machine on the 13 pound cube of 6061 T6 that I have.

[trbig]

CNC machines = magic to me.. much like electricity. lol. I'm more the "If it don't work, hit it with a bigger hammer" type.

Though there may be some sort of copyright thing, Yamaha's tuning fork emblem somewhere on there would be cool. But hoestly, it looks pretty dang sexy as it sits.

So, since Chop quit building these, are you in the market to make more than just this one? And if so, do you have an estimated final cost? Seems a lot of work to go through for the programing and molds to just do one. Me? I prefer the shaft drive, but I know you'll get a lot more power to the ground with the chain, and many like the idea. Plus, you can play around with sprocket sizes and get the gearing how you want it. Quarter mile runs one weekend, then a quick sprocket change and you're good for the open highway.

[mrbisbob]

Estimated cost for chain drive

Thanks for the feedback trbig. Yes I would consider making more and have thought about a price. I would be happy to reproduce them at $600 each like xschop was. This next week I will be trying to complete the first one in T6 on the machine so more pics will follow as I progress. Here is a pic of what it will be rotating and a rough idea of the window dressing. I'm a huge fan of early 80's euro sport bikes so I am trying to build my XS as a kind of Honda CB1100R answer by Yamaha an XS1100R if you will. I have high hopes it will turn out like the pictures in my mind. I have already ported the head to coax more power from the mighty XS mill. The ports are actually some of the best designed 2 valve ports I have ever seen, especially when you consider the fact that they had them in 1978. The combustion chambers are awesome too. Sometimes it's rough being a perfectionist.






I made the clevises on the CNC machine too.

[WSL91]

Nice work!

[trbig]

Are you doing flow tests on that head?

[mrbisbob]

Don't have a flow bench, however do have 13 years experience porting heads and half of that was with a flow bench chasing airflow numbers.

[mrbisbob]

Billet Chain Drive progress

Here is some progress on the first chain drive prototype.

[tom clisham]

Very impressive!

Now, where did you get that cool fairing?

[Cuda 69]

very nice work,but I have no idea why someone would change to chain drive when driveshaft has been so reliable for so many years. Always trying to learn, I'm guessing for cornering? does it give more hp to the rear wheel? John

[natemoen]

very nice work,but I have no idea why someone would change to chain drive when driveshaft has been so reliable for so many years. Always trying to learn, I'm guessing for cornering? does it give more hp to the rear wheel? John

Supposedly you loose 10-15% HP through the shaft and nowhere near that from the chain drive. Also it is much easier to change drive ratios with chain drives.

[mrbisbob]

Modern Rubber

The primary reason for me is better tire selection, and then there is more HP to the rear wheel. Plus I'm an incurable tinkerer. I love the older universal japanese motorcycles like the XS11 because they are like a blank canvas to me, full of potential to be what you want them to be. Today's bikes are so specialized that it's much harder to express your individuality IMHO. I had to change to chain drive so I could put a different swingarm and wider rear wheel on the back. I would leave it as is if I were long distance touring with it but I am a corner enthusiast and I love having unusual difficult to identify motorcycles to do my scratching on. I live right in the middle of some of the best roads on the east coast. The Blue Ridge Parkway is 20 miles from my doorstep and I kept dragging metal parts in the curves when I was out playing before. The fairing is from a Honda CBX 6. It's like a lot of the Hondaline accessory fairings from the early 80's bikes. I like it because it's a lot like the european CB1100R fairing. The tail section actually is a fiberglass replica of a CB1100RB.

[daveyg]

Lookin awesome! Keep up the great work! I would do the same but I don't have enough seniority at my shop to play with the big toys after hours yet. Right now I'm lucky they let me use the little hardinge lathe when nobody is around.

[fredintoon]

very nice work,but I have no idea why someone would change to chain drive when driveshaft has been so reliable for so many years. Always trying to learn, I'm guessing for cornering? does it give more hp to the rear wheel? John

Hi Cuda,
chain drive costs less, weighs less and has better efficiency so long as it's not worn and it's properly maintained and lubricated.
Shafties weigh more, cost more and have a consistent though slightly less long term efficiency and need far less maintenance.
There are handling differences that only extreme riders would find a problem with.
I ride like a timid old man because I am one and while the shaftie's climb-on-acceleration is noticeable it's nothing to worry about.
The chain conversion shown above has to be a labour of love, it'll never make a profit.
As elegantly as it's been done here, I'd worry about the 13T sprocket size.
I reckon a good sprocket size would be 17T and put 15T as a minimum.

['OlGuiltyBoy]

Yea, you'd have to run at least a 15T. And that's even going to have you changing it quite often, but still not an expensive thing to do. I wanted to get one myself, but I'm not putting any more money into that bike. Just not worth it right now IMO. At least mine is not worth it.

[fredintoon]

Yea, you'd have to run at least a 15T. And that's even going to have you changing it quite often, but still not an expensive thing to do. I wanted to get one myself, but I'm not putting any more money into that bike. Just not worth it right now IMO. At least mine is not worth it.

Hi 'OlGuiltyBoy,
as I understand it, the chain drive conversion puts the output shaft so close to the transmission case casting that a 13T sprocket is the biggest that will fit.
Even if I had the money, time, skill and enthusiasm to do the conversion that tiny sprocket would kill the deal for me.