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Motorcyclist Seeking Advice


cbrian

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The chassis it will be put into is an Aprilia RS250.  There have been many RS/RZ conversions out there and the Two Stroke Shop sells the cradle and mounts.  Nova Racing in England is set to have a close ratio transmission in production for the RZ350 engine ready later in the year. My tranny concern is that the RZ and Banshee have different shifting drums and the RZ part is no longer in production.  I'm trying to source one used right now.  I would appreciate an education on the shift pattern and particulars on the Banshee shifting mechanism.

I think that 95 HP would be acceptable with this bike since that is what my 2002 Honda CBR600f4i makes right now, but what I am really after is as smooth a torque curve as I can get.  I love the two stroke hit, but don't want it when I'm cranked over really deep into a turn.  Thanks for all of the replies, this helps.

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The Banshee trans has a tighter ratio then the RZ does... The shift drums are identical, the shift forks, however ARE different.. Banshee forks have solid guide pins, where as the RZ forks have a roller for the guide pins.  Some say it doesn't make a difference, some say it does.

 

I have a nice set of extra RZ forks and drum, that I might be willing to part with.. Be careful of the 2 Stroke Shop.. there has / had been lots of drama surrounding that place on the RZ / RD forum. I, however DON'T know from experience.

 

Mike 

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Yeah, what he said. ↑

 

Only the 1st few years of RZ350 had the roller forks. Later years had the solid guide pins.

 

Here's a good thread about ratios. You can swap between the RZ350 and Banshee trans to get the ratios you want.

 

Also, you can put the neutral light contact into the Banshee shift drum.

 

http://bansheehq.com/forums/index.php?showtopic=466

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The main criteria I was looking at when I voiced my proposal was 20 minute solid run times on the throttle. Yes, HP goals could be met on smaller displacement engines, but with power curve requirements, smaller engine sizes would require higher piston speeds(sustained) in order to produce the power delivery styles and top-end speeds needed to be competitive.

By over-shooting required displacement slightly, this would allow for HP goals to be met with safe port area margins, lower piston speeds, and increased reliability. Not to mention faster release rates of heat due to larger ex. flanges and lower velocity feeding the expansion chamber.

In this manner we can build the power we need, keep piston speeds down ,and outrun the competition with gear ratio instead of rpm....Jim

PassionRE, in no way was I trying to say you were expensive, just telling the op that banshee engines can get expensive. Its obvious you know engines.

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The Banshee trans has a tighter ratio then the RZ does... The shift drums are identical, the shift forks, however ARE different.. Banshee forks have solid guide pins, where as the RZ forks have a roller for the guide pins. Some say it doesn't make a difference, some say it does.

 

I have a nice set of extra RZ forks and drum, that I might be willing to part with.. Be careful of the 2 Stroke Shop.. there has / had been lots of drama surrounding that place on the RZ / RD forum. I, however DON'T know from experience.

 

Mike

The Two Stroke Shop is supposed to be recovering. Wayne and Stephen are splitting ways and Stephan I believe is taking the reigns 100%.
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Forgive me but what kind of tranny are you guys talking about?

Paulie, we are referring to what is known as the Stock Cut, EZ Shift, EZ Cut Pro Mod, Stock Mod.

What most people believe is that they just cut every other dog out of the gear engagement areas. That is OK, but a good prepped on over ride tranny is so much more then that. My Pro Mod has so much work in to it, it is friggin rediculous. I set it next to a normal Un touched tranny to really see the differences and they really add up. I can shift it like butta' every time the way it is set up now and if I do it right I shift with out the clutch.

 

Greg at WCR did a fantastic job but I'm just not a fan of his business practice any more so I'm seeking out a new tranny guy.

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PassionRE, in no way was I trying to say you were expensive, just telling the op that banshee engines can get expensive. Its obvious you know engines.

No problem 1shee, some would think a DM is over-kill but if you detuned it from a typical Banshee set-up, you could easily meet the performance goals and not have to run it very hard. Afterall, those 600's can run hard all day long.

And yes, it gets pretty expensive to build one...they are a lot of work...Jim

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So Jim, I made another post about this same sort of package (http://bansheehq.com/forums/index.php?showtopic=163092#entry1435579), but my only concern in the set up is is it possible to get it to run cool? I keep hearing the horror stories about them over heating. Just wondering if there is much more that can be done after adding coolant capacity. Maybe tweak the water jackets? I've even been pondering a fan.

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  • 10 months later...

I have quite a bit more information now than when I first posted. I am told by others that have done the Banshee/Aprilia hybrid that the stiffness of the Aprilia frame translates a  lot engine vibration to the rider and anything over 7 mm extra stroke results in unacceptable discomfort.  With that in mind, and the extra cost involved, I'll stick with the 4mm stroked crankshaft. The 68mm bore (421cc) serval engine is the minimum engine size I'll use but I am curious of increasing the bore to 72mm. This would make it a rather oversquare engine and I would like to hear from you forum members on your opinions of the pluses and minuses.

 

I have selected a builder and have discussed my build with him but before going any further, I would like to have your opinions on this (72mm bore) alternate.

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I have quite a bit more information now than when I first posted. I am told by others that have done the Banshee/Aprilia hybrid that the stiffness of the Aprilia frame translates a  lot engine vibration to the rider and anything over 7 mm extra stroke results in unacceptable discomfort.  With that in mind, and the extra cost involved, I'll stick with the 4mm stroked crankshaft. The 68mm bore (421cc) serval engine is the minimum engine size I'll use but I am curious of increasing the bore to 72mm. This would make it a rather oversquare engine and I would like to hear from you forum members on your opinions of the pluses and minuses.

 

I have selected a builder and have discussed my build with him but before going any further, I would like to have your opinions on this (72mm bore) alternate.

 

I'd stick with the 68mm bore. The 72mm is more money and I doubt you will notice the slight increase in HP.

 

Did you get your builder's opinion?

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I have quite a bit more information now than when I first posted. I am told by others that have done the Banshee/Aprilia hybrid that the stiffness of the Aprilia frame translates a lot engine vibration to the rider and anything over 7 mm extra stroke results in unacceptable discomfort. With that in mind, and the extra cost involved, I'll stick with the 4mm stroked crankshaft. The 68mm bore (421cc) serval engine is the minimum engine size I'll use but I am curious of increasing the bore to 72mm. This would make it a rather oversquare engine and I would like to hear from you forum members on your opinions of the pluses and minuses.<br /><br />I have selected a builder and have discussed my build with him but before going any further, I would like to have your opinions on this (72mm bore) alternate.

<br /><br />Who did you select as your builder?
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