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[Special_Ed]

Reading about the new 96" motor I came across the "B" type motor that has internal counter balances.
Why is there need for two types of motors? Wouldn't it be better to go with the balanced motor in any application? [smiley=nixweiss.gif]

[naitram]

twin-cams have always been rubber mounted or counterbalanced/rigid mouted

[GC_Super]

They've had the A and B motors since the twin cam came out. The B motor is in the softail models because it's mounted solid in the frame, where the A motor is in all the touring bikes and they are rubber mounted. When riding the two different bikes they are ecxactly the opposite. The B motor doesn't shake at idle, but the faster you go, the more the vibration increases. The A motor shake all over the place at idle due to the rubber mounts, but the faster you go, the smoother it gets. There is some horsepower loss attributed the balancers also.

[Special_Ed]

I find it interesting that the two motors are produced for the two different applications. Is there a reason that when the started making the twin cams that they didn't move toward standardizing the mounting systems?

[Fired00d]

I find it interesting that the two motors are produced for the two different applications. Is there a reason that when the started making the twin cams that they didn't move toward standardizing the mounting systems?

First thing that comes to mind is they would have had to redesign the frames for each or one of the applications to make them all be the same. [smiley=nixweiss.gif]

 [smiley=pumpkin.gif]
Ride Safe,
Fired00d
 [smiley=fireman.gif]

[GC_Super]

I find it interesting that the two motors are produced for the two different applications. Is there a reason that when the started making the twin cams that they didn't move toward standardizing the mounting systems?

Just a wild guess here but you have to deal with the inherrent vibration of an HD V-Twin motor somehow, and they came up with two ways to do it. Thinking that the touring riders would want smoother conditions at speed, those were rubber mounted. The softail guys probably don't need the higher speed smoothness as much as the touring guys, so they balanced those motors. Trying to figure out HD will give you grey hair real quick.  LOL  The thing I could never figure out is why HD put the same 88" motor and gearing in all their bikes, excluding the V-Rods and sportys.  To put the same motor in a 600 lb Duece and an 800lb touring bike that will mostly be two up and loaded doesn't make sense at all, except for the bottom line for HD.

[hd-dude]

First thing that comes to mind is they would have had to redesign the frames for each or one of the applications to make them all be the same. [smiley=nixweiss.gif]

 [smiley=pumpkin.gif]
Ride Safe,
Fired00d
 [smiley=fireman.gif]

To make the softail rubber mounted would take a major redesign on the from. In the touring and dyna models the motor, tranny, swingarm and rear wheel are all connected which allows the complete drive train to move together.  

[ultrafxr]

Those counterbalancers in the B motor limit the revs also.  Not a gearhead but probably wouldn't want to hop up a B motor as much due to the extra weight you're throwing around in the bottom end.

[Special_Ed]

Just a wild guess here but you have to deal with the inherrent vibration of an HD V-Twin motor somehow, and they came up with two ways to do it. Thinking that the touring riders would want smoother conditions at speed, those were rubber mounted. The softail guys probably don't need the higher speed smoothness as much as the touring guys, so they balanced those motors. Trying to figure out HD will give you grey hair real quick.

[Special_Ed]

Those counterbalancers in the B motor limit the revs also.

[ultrafxr]

But the two motors are similar from the factory and have the basic same setup. ie. Torque/HP?

Yeah, looks like it.

[grc]

Not only is the engine different for rigid mount versus rubber mount bikes, the trans is also different (just the case, due to the different mounting systems and oil tank location).