Rephasing, What is it?

I rode a rephased cafe racer several years ago at the Dogwood XS650 rally. A bunch of us gave it a try. My take on it was that at low RPM, vibration was very harsh and torque seemed late to develop. It was very much alive at the top of the RPM range. I felt that if I wanted to really flog an XS650 every time I got on it, it's great. Most of those who rode it, praised it. They praised it a lot. I think I said nice things too, but I was being polite. I didn't care for it. I like the 360 much better. I should say here that I'm not really a fan of 270 twins that are by design. For example, I'm not crazy about the Super Tenere with its crossplane twin. It's just not my cup of tea. :twocents:

YMMV
 
those torque curve differences are almost certainly cam change induced not rephase artifact
Quite possible. I remember nothing about the cam on that bike. I also don't know enough about cross-plane vs. flat-plane to know how an when they are applied. My comment was simple seat of the pants recollection. Suffice to say the vibration moved.
 
don't want to feel like I've been sitting on a paint shaker all day. More power, probably (purists would say definitely) not, but in my mind vibration is wasted energy and additional load on critical parts. If vibration is reduced running at higher RPMs, in the higher gears, stands to reason these critical parts will subjected to less stress.

I agree with Steve C the reduction in vibration Results in less lost power, doesn’t make more but more, albeit small, gets to the pavement. It makes the bike more pleasant to ride for longer distances.

I have a rephased 650 with no base gasket. I also correctly reindexed the cam for the gasket removal. I have Norton muffles and the sound is awesome! The bike is a hoot to ride.
 
If anyone is interested in the sound this is my old 270 Rephased XS650 powered custom motorcycle:
The XS motor in the bike is equipped with a 270 degree re-phased crankshaft and a billet camshaft, plus a high ratio primary gear set and clutch assembly with the machine work being performed by Heiden Tuning from the Netherlands. The cylinder head porting work was done by Gary Hoos Racing, uses 2mm oversize Inconel Alloy valves. The motor is also equipped with a Mikes XS 750 big bore kit and myriad of other performance parts from both Heiden Tuning and Mikes XS. Ignition chores are handled by a 270 degree re-phase Pamco Ignition System and a Sparks Three Phase charging system keeps everything running. Various engine parts both internal and external were sent to Performance Coatings for thermal and ceramic engine coatings. In choosing to make the bike very period correct, most of the sheet metal and the running gear required extensive reworking to fit the custom built XS650 hard-tail frame and motor combination. A set of custom made header pipes was also fabricated for the project that flow into a set of modified Big Twin 36 to 40 style mufflers. The XSLA project features 18 inch black Big Twin Star Hub wheels with stainless steel spokes, Avon Safety Mileage tires, Edart front and rear Disc Brake conversion kits and Jay Brake master cylinders for both of the front brake and hydraulic clutch controls. The rear brake control assembly is fitted from a 58 to 69 Big Twin FL and the hydraulic clutch conversion uses a slave cylinder assembly from a Honda VFR.
 
I agree with Steve C the reduction in vibration Results in less lost power, doesn’t make more but more, albeit small, gets to the pavement. It makes the bike more pleasant to ride for longer distances.

I have a rephased 650 with no base gasket. I also correctly reindexed the cam for the gasket removal. I have Norton muffles and the sound is awesome! The bike is a hoot to ride.
I bet those mufflers do sound good,do have a video?
 
If anyone is interested in the sound this is my old 270 Rephased XS650 powered custom motorcycle:
The XS motor in the bike is equipped with a 270 degree re-phased crankshaft and a billet camshaft, plus a high ratio primary gear set and clutch assembly with the machine work being performed by Heiden Tuning from the Netherlands. The cylinder head porting work was done by Gary Hoos Racing, uses 2mm oversize Inconel Alloy valves. The motor is also equipped with a Mikes XS 750 big bore kit and myriad of other performance parts from both Heiden Tuning and Mikes XS. Ignition chores are handled by a 270 degree re-phase Pamco Ignition System and a Sparks Three Phase charging system keeps everything running. Various engine parts both internal and external were sent to Performance Coatings for thermal and ceramic engine coatings. In choosing to make the bike very period correct, most of the sheet metal and the running gear required extensive reworking to fit the custom built XS650 hard-tail frame and motor combination. A set of custom made header pipes was also fabricated for the project that flow into a set of modified Big Twin 36 to 40 style mufflers. The XSLA project features 18 inch black Big Twin Star Hub wheels with stainless steel spokes, Avon Safety Mileage tires, Edart front and rear Disc Brake conversion kits and Jay Brake master cylinders for both of the front brake and hydraulic clutch controls. The rear brake control assembly is fitted from a 58 to 69 Big Twin FL and the hydraulic clutch conversion uses a slave cylinder assembly from a Honda VFR.

What did Heiden chargé you to split and rephase that billet cam?
 
What did Heiden chargé you to split and rephase that billet cam?
I spent way too much money but it was over 7+ year period I believe. This was over a decade ago but this is what I found:
270 Rephase billet Aluminum camshaft = $257.25
270 Rephase Crank = $588.00
Shipping = $153.03
I also paid for a High Ratio Gear set because of the large sprotor brake/sprocket we used. I don't recall how much that was.

This is a video of the project if you are interested:

I would not recommend this for anyone else to do. I sank way too much money in this project and ended up selling it and using that money to buy a 2007 Harley Springer Classic. DaddyG is doing my current XS650 desert sled/Scrambler project. I took his advice and skipped the 270 rephase on this and didn't even get a 750 big bore kit either.

70028895_10157800050559236_8005182723159228416_n.jpg
 
TT1, how was that cam in performance? I have the exact cam, Trying to decide if I want to
use it or dig deep for the megacycle cam.
 
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TT1, how was that cam in performance? I have the exact cam, Trying to decide if I want to
use it or dig deep for the megacycle cam.
It was the most fun bike I ever rode but was underpowered compared to my other bikes.
I sold it for a Harley because the gearing did not make highway rising comfortable enough. It was working hard at 65mph.
 
The biggest fault I have with rephasing and I have been around a few of them is they sound like crap ,they need a particular muffler for a decent
sounding exhaust note. With a XS 360 firing order you can slap just about any style muffler on and it'll still belch out that distinctive 360 twin exhaust
note I grew up listening to.

I thought I was a minority in thinking that but I also think it's a function of most people rephasing are going for performance at the same time so I don't see many or any with bigger mufflers that would tame out the sound of it. Most bikes I know of with a similar crankshaft timing (Ducati, FZ-07, newer Triumphs) tend to have either 2 into 1 systems or a catalytic converter or X pipe that functions as a 2-1-2 setup. It seems to take out a lot of the bark and popping and just leave a slightly aggressive but still deep and smooth exhaust note to it.

Something like a 2 into 1 setup on a rephased XS with an 18" or so muffler would probably sound amazing.
 
I thought I was a minority in thinking that but I also think it's a function of most people rephasing are going for performance at the same time so I don't see many or any with bigger mufflers that would tame out the sound of it. Most bikes I know of with a similar crankshaft timing (Ducati, FZ-07, newer Triumphs) tend to have either 2 into 1 systems or a catalytic converter or X pipe that functions as a 2-1-2 setup. It seems to take out a lot of the bark and popping and just leave a slightly aggressive but still deep and smooth exhaust note to it.

Something like a 2 into 1 setup on a rephased XS with an 18" or so muffler would probably sound amazing.

One of the very first rephasing of the Xs in the US besides Bob Bertaut that I know of was the 277 Cherokee Scout and there are a few members here besides myself that have heard the Scout run and the exhaust note had a growl than no ducati could match and the exhaust system consisted of two XS Bub mufflers with louvered baffles,don't know if the mufflers were packed but it sounded great.
scout-_003.jpg
 
I remember the bike from 650 Society rallies, but can't recall who built it. Do you remember, Jack?
Edit:
Memory is fuzzy on this, but wasn't that one of Tommy Pollard's bikes?
 
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Thanks, Marty. (Should have figured; that Bub system would have been a few shekels more than Tommy would have been inclined to shell out!)
 
It was Mike Davis. I believe he still has the bike.
I read some where Mike refurbished the bottom end if I'm not mistaken. There use to be Video
of the Scout running. Mike used a Web 59A cam and a Newtronics for ignition ,can't remember what he used for carbs or other engine mods but it sure sounded good.
 
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