Any turbo guys run S&S carb on street?

Putting together my first turbo bike this winter and need some advice. LOOKING FOR CONSTRUCTIVE ADVICE. Don't want to run an HSR since it will stand out as the only "new" piece on the bike.

Purely a STREET bike. Lots of cruising and especially highway use. Only occasional WOT blasts on the highway to show up my friends and nay-sayers. Currently I ride this bike nearly everyday in the summer and whenever I feel like it the rest of the time.

Plan is to run a Super B with an accel pump, and maybe a thunder jet if needed. 1200 MTC turbo pistons, welded 1000 crank, GPZ1100 cams, stock 900 head, Magnum turbo kit with E flow turbo, 16/35 gearing, 5.00/16 tire.

Just so you know how serious and crazy I am, here is what it's going on. And it IS going on it.

Let me make sure I understand....

A 1200cc turbo KZ with no front brake? You make have graduated out of the world of crazy into the world of suicidal.

I don't know about the carb question, but my best constructive advice is that you seriously consider installing a front brake since that provides roughly 80% of a bike's stopping power. A bike that can go fast should also be able to slow down and stop fast. Ed

Ever ride a bike with a 20" over springer?

Prayers sent.

Really ?....... :ohmy: :huh: :blink: :S I've used S&S SUPER's on street turbos.....better carbs are available now.....Not being negative , :huh: But I rode stuff with springers back in the 70's...........turbo engines on chopped bikes with long front ends were for LOOKS only. :ohmy: :S not really a place for a high performance turbo engine...............GOOD LUCK with that.

Mercury Kid wrote: Ever ride a bike with a 20" over springer?

No, but I have ridden a bike with no front brake and it is a bad idea! I don't see how the length of the springer front end will change the laws of physics. Regardless of the type of front suspension stopping a bike still requires converting the kinetic energy of a body in motion into thermal energy, and a skidding rear tire doesn't do this effectively. But it's your bike and if you are ok with the risk it doesn't bother me (assuming you don't run into me). Ed

With all that rake in the front end it should be pretty stable at high speeds as long as it doesn't start to wobble.
Id be more worried about the frame doing something weird from all the torque and hp a 1200 turbo makes even with low boost,having ridden a few big inch turbod kaws Id definitely go with Ed on the more brakes the better idea.Id just be concerned how much braking force the springer can actually hold up to is all.
As far as the carb it will work if youre going for the look,check with mr turbo for carb stuff.

The laws of physics dictate the braking is done where the weight is. Putting standard brakes on the front of an extended chopper will cause the wheel to lock up since there will be less weight on the front compared to a standard bike. Since there is less weight transfer from rear to front on a longer vehicle, the rear brakes will actually do more (percentage) than a standard bike.

A thought experiment easily shows the logic.
As the front forks get longer, less percentage of the engine and rider weight is carried by the front wheel. If we extend it infinitely, 0% of the engine and rider weight is on the front wheel. Also, as the vehicle length approaches infinity, the amount of weight transfer from back wheel to front wheel approaches 0%. So that leaves 100% of the rider and engine weight on the back wheel, even during braking. The front brake would only have the weight of the front wheel to use for braking. Since the front carries no weight of the engine and rider, we can make the front wheel very light weight. This means there is no need for a front brake at all since it would do nothing.

Now take the opposite extreme... imagine the rider and engine on the front wheel with an infinitely long extended swing arm. The back brake would do nothing since all of the weight is on the front wheel.

The chopper is just a marginal step away from the standard bike, toward the first extreme. This means it needs less front brake and more rear brake than a standard bike.

The front brake will still do a significant amount of braking on the chopper, but standard brakes will just make the front end lock up sooner. That's why choppers can often get away with no front brake. The rear does more on a chopper.

Has anyone seen what look like (anti)wheelie bars on the back of a front-drive drag car? Seems silly, but if you extend the rear contact point further backward, it maintains more weight on the front drive wheels for better traction. It's not anti wheelie, it's an anti-weight-transfer device.

Insanely fast choppers with no handling are nothing new, been done for years, and yes they are dangerous as all hell... half of what makes them fun.

My brother has a '53 Harley that was chopped in 1966 by Satan's Cycle works in MN. Has a '66 shovel head with modern internals, stoker crank, cams, etc. Still kick start with manual timing advance. It has a drum brake on the back with a chrome plated chain connecting it to the pedal, the front brake... what front brake? It was suiside shift for the longest time, not now though. So it was a one handed driving experience.

It is really fun to drive, so long as your living will is updated and your square with God...

I say go for it!! Choppers are not supposed to be safe, or maneuverable, or even make any practical sense at all.. that's the whole point isn't it?

Loudvhx, is right, the moment arm from the front wheel to the CG is very long compared to the rear. The front wheel experiences less down force during breaking, the back wheel actually has more grip because the rider and engine are closer to the rear axle. The rear tires skids though from lack of a suspension more than anything. That and locking up a front wheel on a chopper would probably be more dangerous than just crashing into whatever you were trying to avoid...

Wouldn't the weight still shift forward when braking and therefore load the front wheel? Ed

650ed wrote: Wouldn't the weight still shift forward when braking and therefore load the front wheel? Ed

Yes, but by a lesser degree. That, in addition to the fact that it starts out lighter to begin with means the total percentage of braking, produced by the front wheel, is drastically less than that of a standard wheelbase bike.

Static load sharing:
if two people carry 100 lbs on a 2x10 plank, if the weight is in the middle, each carries 50 lbs. If the weight is all the way at one end, one guy carries almost all of the weight, the other guy none.

Weight transfer:
The Center of Gravity, along with the contact patch of each wheel forms a triangle. The lower the triangle, the less the weight transfers during braking or acceleration. If we could flatten the triangle to the height of the road, there is no weight transfer at all. If we go further, and lower the CG below the road... (think of a single, short, monorail train car hanging below the rail, where there is one wheel at the front, and one wheel at the back, on top of the rail and the car hangs from them), the weight actually transfers toward the back wheel while stopping, because the train car tries to swing forward, and upward like a pendulum. In an extreme stop, the front wheel would come off the rail, thus the back wheel is then doing 100% of the stopping, and the front wheel 0%.

The chopper starts off with more load on the back wheel, and by virtue of a longer triangle, has less weight transfer. These two factors greatly reduce the braking effectiveness of the front wheel, and move it to the back wheel. However, the front wheel braking is still significant, and may even still be the majority, depending on how heavy the rider is and how tall the seat is, whether there is a passenger, etc. etc. So a front brake is still a good idea, and an upgraded rear brake is called for.

Suspension is also a big factor, but for simple apples-apples comparison, assume all vehicles are totally rigid.

My buddy has a Honda 750 single cam, in an Amen frame, and he often finds himself over-riding the stopping ability. I can't imagine a KZ1000, much less a turbo one, in that frame. He and I have discussed the handling and brakes of that bike for years. It is really a highway bike, and that highway better be smooth.



One of these days I'll get the nerve to ride it.

Loudhvx got it right, but still without the real world aspects. After having ridden this bike more than 3k miles this year and actually SEEING the forks flex, hop, twist, and pogo I won't put a brake on the front. Won't do any more good than paying close attention to traffic and having an escape route planned.

I explained that the turbo is more about audacity than speed but this bike will get ridden, as much or more than I think most turbo bikes. I also know there are better carbs, just looking for advice or direction with this one. If I can't sort it out myself I'll likely go to an HSR but I'm trying to keep all the components era specific.

I feel like nobody does wild stupid stuff like this anymore, so I guess its up to me.