Chain Drive Conversion Power Gain

[Big Daddy Funk]

I just read through XSchops chain drive conversion. A genuine piece of technical wizardry. The handling advantage and fat tire aside, I didn't see any mention of torque and horsepower gains as a result of the conversion.(maybe I missed that part)
I have no experience with this mod but I would think that there would be a gain in the order of 10% (at the rear wheel) by switching to chain drive.
I have always assumed that shaft drive would use a substantial amount of torque and HP to do the same job as chain drive. Weight savings and the tunability of sprockets to the engine would also enter into the equation.
I might be all wet on this as I am sure this must have been questioned before now.
Has anyone done a before and after dyno pull to see what gains there were?
Or would any of our guru's be able to give an explanation to me on this matter?
Thx Rick

[clemsonxs]

I just read through XSchops chain drive conversion. A genuine piece of technical wizardry. The handling advantage and fat tire aside, I didn't see any mention of torque and horsepower gains as a result of the conversion.(maybe I missed that part)
I have no experience with this mod but I would think that there would be a gain in the order of 10% (at the rear wheel) by switching to chain drive.
I have always assumed that shaft drive would use a substantial amount of torque and HP to do the same job as chain drive. Weight savings and the tunability of sprockets to the engine would also enter into the equation.
I might be all wet on this as I am sure this must have been questioned before now.
Has anyone done a before and after dyno pull to see what gains there were?
Or would any of our guru's be able to give an explanation to me on this matter?
Thx Rick

Rick,
Gearing differently or having a drivetrain that can handle more power by no means says that it is making more power. There are no power gains had by switching to chain drive. The only possible "power gains" are if the chain drive is perhaps less rotating mass or drag and then only the power output from the rear wheel is changed, however the actual power output of the motor is unchanged. It is the same basic principle for any drivetrain be it from a car or motorcycle or whatever.
Max

[xschop]

goin Chain

I gained more power to the ground for sure. I believe the real gain came just recently as I actually sat down and read everything possible on our CARBS....I had no idea where pilot jets were located until now and I gave the carbs a complete makeover......I haven't got the sync tool yet and that's next.....
Yes there is definitely a power gain, But what I like most is the handling now with a 200 rear Battleaxe tire. And most importantly there is no more "Jack-Shaft" reaction goin on that scared the sheezy out of me when I had the shaftdrive and gunned it in the corners..... After I get it synced, I will take advantage of the extra torque there and swap my 13T for a 14T front sprocket........I am also going to the truck stop and weigh the beast.....if it will ever stop raining.....

[Big Daddy Funk]

Making sense of this

I'm not sure if I was clear on my thoughts. I was refering to torque and hp at where the rubber meets the road, as that is where a dyno measures it, as well as where it matters most. A stock XS1100 is rated at 95hp at the clutch but actual numbers on the dyno drop to the area of mid to high 70's hp. The torque and hp loss betwwen the clutch and the road is a result of the rest of the drive train. If I can make an analogy, a alternator on a race car engine can use up 5 hp to drive it. Therefore most drag cars don't use them. Tranmissions, clutches, drive shafts, differentials all use up hp before the tire moves the vehicle. A shaft drive motorcycle has a great deal of friction points and mass transfering the power to the tire. A chain drive by design has less mass , friction points and power transfer areas and thus able to use up less power getting the hp and torque move the bike. More hp and torque make it to where the rubber meets the road and can be measured.
I'm now starting to confuse myself but technically this makes sense to me.
Changing to chain drive would not increase the torque and hp numbers on the engine but it should increase the numbers available at the tire. It should be an increase that you would definitely feel.
I do not understand why this would not be the case but I am wide open for opinions. Thx Rick

[xschop]

At the wheel

I should have edited the sentence to state "at the wheel" after power gain.....there is more power and torque getting to the ground now.....You eliminate 2 right side bevel drives when going to a chain-drive.....Not to mention these newer rims and brakes are WAY lighter than the stock XS11 stuff and rotational weight reduction is a big help here too....
I am building a custom housing for an XS850 at the moment for a guy in New Zealand that is building a cafe racer. There is a lengthly discussion of shaft to chain power increase on the triples site somewhere. 10% rubber to road power increase seemed the correct figure IIRC.....

[fredintoon]

I just read through XSchops chain drive conversion. - - - I didn't see any mention of torque and horsepower gains as a result of the conversion. - - - I would think that there would be a gain in the order of 10% (at the rear wheel) by switching to chain drive. - - Rick

Hi Rick,
a typical shaftie is about 85% efficient and given routine care it stays that way for the bike's lifetime.
A typical chain drive is about 95% efficient but only when it's new.
If you don't keep the system scrupulously cleaned, adjusted and lubricated it won't stay new for long.
Even when properly looked after they lose efficiency with wear. A typical chain-drive is worn enough to be down to ~80% efficiency and in need of replacement every second or third rear tire change.

[Big Daddy Funk]

So.....Bang for the buck...

Can we agree that we would expect approximately 10% gain in rubber to ground power by changing over to chain drive? Not to mention the handling improvement?
I'm not trying to sell anyone on the conversion, but that has to be the most bang for the buck of any modification I've seen. For approximately the same price as installing a big bore kit you get a superior handling bike, with about the same amount of hp/torque improvement. (yes, at the backtire which is the only place it matters anyway) Wow. Kinda surprising that this didn't come up before.
Sounds like a great winter project for me. With before and after dyno tests. (If there are still some conversions available then.)
From what I saw on the thread a number of guys ordered these conversions.
It would be great to hear what they thought of the switch now that they had the chance to run it for a little while.
Dissenting comments are always welcome.
Thx Rick

[79XS11F]

Can we agree that we would expect approximately 10% gain in rubber to ground power by changing over to chain drive? Not to mention the handling improvement?
I'm not trying to sell anyone on the conversion, but that has to be the most bang for the buck of any modification I've seen. For approximately the same price as installing a big bore kit you get a superior handling bike, with about the same amount of hp/torque improvement. (yes, at the backtire which is the only place it matters anyway) Wow. Kinda surprising that this didn't come up before.
Sounds like a great winter project for me. With before and after dyno tests. (If there are still some conversions available then.)
From what I saw on the thread a number of guys ordered these conversions.
It would be great to hear what they thought of the switch now that they had the chance to run it for a little while.
Dissenting comments are always welcome.
Thx Rick

I think you would be surprised how much additional HP you can get from a properly tuned performance header. Kerker, RC engineering and a few others are good for a 10% increase. I went chain drive for the weight savings but that set will be combined with an 1179 kit, polished head, K&N PODs and Kerker pipes. I'm hoping that when I get it all sorted out and properly tuned, that I will see at least a true 20% total increase in power on a bike that handles much better.
Rob

[Big Daddy Funk]

Priceless

My point being Rob, is that no matter what kind of numbers you get on the dyno (and they are the only numbers I trust) changing over to a chain drive should give the bike an additional 10% HP & torque. Wether it's stock or built.
This isn't additional power from the engine by adding headers, cams or whatever. It's just a more efficient way to get more of the engines power to the rear wheel. We have amazing guru's on this site that have scienced out engine performance and shared their results.
With your bike having the conversion I would expect your bike would have 10% better numbers on the dyno as compared to a similar equipped bike without the conversion.
As for cost effectiveness,
Big bore Wiseco kit plus machining and related costs $900.00
Good cams about 700.00, good header $600.00,
Rebuilt & Ported head with related flow testing $1000.00
Cam chain, carb rejetting/rebuilding Tuning & dyno pulls $200.00
For 20% power gain
Finding out you got another 10% power gain in addition to getting a better handling bike. PRICELESS

[trbig]

Now if XSChop could just prove all this and quit getting whipped up on by a big, heavy, shaft driven XJ!!


Tod

[Big Daddy Funk]

Dropping the gloves

Oh, Oh, the gloves are off... In this corner we have XSchop. And in this corner we have trbig. XS vs. XJ........This may not be suitable for all viewers.