Will PreGen fork tube fit NextGen lower??

Jim L · April 19th, 2016, 03:05 PM

Just picked up a 96 and 09 donor bikes. The 09 is destined to be re-engined with a RD400F motor, with about 70+hp.
The 09 has bent upper fork tubes, but the 96 uppers are straight. Both are 36mm.
Question:
Can the 96 tubes be swapped into the 09 lowers?
Or, is there a better solution?

Thanks for sharing your experience and expertise.
Cheers,

RacinNinja · April 19th, 2016, 03:19 PM

Quote:

Originally Posted by Jim L

Just picked up a 96 and 09 donor bikes. The 09 is destined to be re-engined with a RD400F motor, with about 70+hp.
The 09 has bent upper fork tubes, but the 96 uppers are straight. Both are 36mm.
Question:
Can the 96 tubes be swapped into the 09 lowers?
Or, is there a better solution?

Thanks for sharing your experience and expertise.
Cheers,

I would use the 2009 wheel in the 1996 forks. Fairly easy swap.

Jim L · April 21st, 2016, 07:26 AM

Thanks,
So the caliper bolt spacing on the 09 lowers are the same as the 96?

InvisiBill · April 21st, 2016, 09:34 AM

Old forks are 36mm and new ones are 37mm, so no, their parts won't directly mate up.

PreGens have really soft fork springs. If you don't already have other suspension plans, grab the new forks' springs if they're still in good shape. I'm not sure how the engine swap will affect the overall weight, but on a stock Ninjette, the NewGen springs would be better for the vast majority of people.

Jim L · April 21st, 2016, 02:58 PM

OK, 36mm vs 37mm - can you feel the difference on the track? I looked up Progressive and they use the same spring for both Pre/Next Gen bikes. The 09 springs are in good shape, so nice call.

I noticed the Next Gen has additional frame gusseting to take some flex away, so I was leaning to the 09 frame for the engine swap. It's a fairly common swap in the RD circles. The new combo comes in at about 300#, with ABS plastic; and single seat config.

It will be used for track days, along with my CBR600 and R6. Both have tremendous brakes so I guess I'm spoiled. I used to race with the local club and AHRMA, but now I'm quite happy just puttering around at speed on a nice track day.

I will stiffen up the back-end also, probably with a GSXR6 mono from ebay.

Any other ideas that you may have would be greatly appreciated.

Jim L · April 22nd, 2016, 07:11 AM

Hey Invisibill, I found your 2014 thread - Pregen Ricor Intiminator install.
Besides being excellent for the install/results of the Intiminator, it was perfect for my Old/New Gen fork questions.

I'll swap the Old Gen forks/triples onto the 09, and use the 09 springs and Intiminator for starters.

Thanks for the time to write such an in-depth thread.

ROADandTRACK · May 20th, 2016, 09:23 AM

Please tell me about an RD motor in an EX frame.

I'm very interested.

I was going to put EX forks and swingarm on my RD frame but if the engine swap works well I may do that instead.

NinJim · May 20th, 2016, 02:23 PM

R&T, I am basically a 2 stroke guy, for a lot of reasons.
When my GDaughter was in high school, I got her a 07Ninja to go with a TL125 trials bike. I liked riding her Ninja, but it wouldn't go, stop or turn.

Please go to 2StrokeWorld.com. It is basically a RD/RZ Banshee site with lots of conversions to more modern frames for high preformance 2stk engines. Search "Ninja swap". I just did and it came up with about 40 threads. Then sit back and enjoy. The swap has no major fabrication; but lots of little bits to be sorted, especially the electrical system.

I'm planning on the 09 frame. It's heavier than the 96, but you can't get 96 race plastic cheap anymore. You can do a full monty and spend lots, or make it a nice perky street bike. The RD400 I have probably make 60+hp and the weight will be about 300 lbs. The Banshees make 100+. So depending on your wallet's fatness, the mods are endless.

There are several guys on 2StrokeWorld that have made lots of NinjaRD conversions. Chat em up and see what ideas you can conjure up. Cheers,

ROADandTRACK · May 21st, 2016, 08:16 AM

Thanks, I've got a Harry Barlow RD400 w/ 64hp at the rear wheel that I might do this with.
I was going to put the EX triples/forks and swingarm on the RD chassis but this has me interested.

Thanks again for the info.

NinJim · May 21st, 2016, 09:36 AM

That sounds like the perfect mate.
The fabrication is around two down tubes for the front engine mounts. And two extension hangers to pick up the rear mounts onto the cross tube for alignment of the sprockets. The rest is what you want to change to get the look you want.

I have an 79 Daytona that needs work. My first thought was like you, to increase the frame stability of the original weak frame. But to do this is lots of work and engineering. The old frame designs can't handle the new power output, suspension and tires now available. I have learned that from 20+ years of AHRMA racing.

So for me, its easier/cheaper to swap a lighter rock-solid high output engine into a modern frame. The Ninja is perfect, as there is a world of cheap aftermarket and ebay bits to upgrade a good starter frame. I picked up two Ninja rollers, a 96 and 08 for $500. They will be donor bikes. When I am finished, the remains will go to ebay in the $0.99 auction bin. Maybe it will all pay for the build.

Mine won't be raced, but it will share some time on track days with four others I usually take out for a little exercise. I will probably make some basic GSXR suspension changes to stiffen it up some. We'll see.

Hope this helps,
Have fun,

April 19th, 2016, 03:05 PM	#1
Jim L ninjette.org member Name: Jim Location: Salt Lake City Join Date: Jun 2014 Motorcycle(s): Street:72Bonnie, 68BSA, 94KTMEXC400LC4; Track: CBR600, R6, NS125GP, 61Cotton TelStar; Dirt:MX -3, Trials - 5 Posts: 32	Will PreGen fork tube fit NextGen lower?? Just picked up a 96 and 09 donor bikes. The 09 is destined to be re-engined with a RD400F motor, with about 70+hp. The 09 has bent upper fork tubes, but the 96 uppers are straight. Both are 36mm. Question: Can the 96 tubes be swapped into the 09 lowers? Or, is there a better solution? Thanks for sharing your experience and expertise. Cheers,

April 21st, 2016, 09:34 AM	#4
InvisiBill EX500 full of EX250 parts Name: Bill Location: Grand Rapids-ish, MI Join Date: Jul 2012 Motorcycle(s): '18 Ninja 400 • '09 Ninja 500R (selling) • '98 VFR800 (project) • '85 Vulcan VN700 (sold) Posts: A lot. Blog Entries: 1 MOTM - Aug '15	Old forks are 36mm and new ones are 37mm, so no, their parts won't directly mate up. PreGens have really soft fork springs. If you don't already have other suspension plans, grab the new forks' springs if they're still in good shape. I'm not sure how the engine swap will affect the overall weight, but on a stock Ninjette, the NewGen springs would be better for the vast majority of people. __________________________________________________ * Unregistered, I'm not your mom and I'm not paying for your parts, so do whatever you want with your own bike. *

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April 21st, 2016, 07:26 AM	#3
Jim L ninjette.org member Name: Jim Location: Salt Lake City Join Date: Jun 2014 Motorcycle(s): Street:72Bonnie, 68BSA, 94KTMEXC400LC4; Track: CBR600, R6, NS125GP, 61Cotton TelStar; Dirt:MX -3, Trials - 5 Posts: 32	Thanks, So the caliper bolt spacing on the 09 lowers are the same as the 96?

April 21st, 2016, 02:58 PM	#5
Jim L ninjette.org member Name: Jim Location: Salt Lake City Join Date: Jun 2014 Motorcycle(s): Street:72Bonnie, 68BSA, 94KTMEXC400LC4; Track: CBR600, R6, NS125GP, 61Cotton TelStar; Dirt:MX -3, Trials - 5 Posts: 32	OK, 36mm vs 37mm - can you feel the difference on the track? I looked up Progressive and they use the same spring for both Pre/Next Gen bikes. The 09 springs are in good shape, so nice call. I noticed the Next Gen has additional frame gusseting to take some flex away, so I was leaning to the 09 frame for the engine swap. It's a fairly common swap in the RD circles. The new combo comes in at about 300#, with ABS plastic; and single seat config. It will be used for track days, along with my CBR600 and R6. Both have tremendous brakes so I guess I'm spoiled. I used to race with the local club and AHRMA, but now I'm quite happy just puttering around at speed on a nice track day. I will stiffen up the back-end also, probably with a GSXR6 mono from ebay. Any other ideas that you may have would be greatly appreciated.

April 22nd, 2016, 07:11 AM	#6
Jim L ninjette.org member Name: Jim Location: Salt Lake City Join Date: Jun 2014 Motorcycle(s): Street:72Bonnie, 68BSA, 94KTMEXC400LC4; Track: CBR600, R6, NS125GP, 61Cotton TelStar; Dirt:MX -3, Trials - 5 Posts: 32	Hey Invisibill, I found your 2014 thread - Pregen Ricor Intiminator install. Besides being excellent for the install/results of the Intiminator, it was perfect for my Old/New Gen fork questions. I'll swap the Old Gen forks/triples onto the 09, and use the 09 springs and Intiminator for starters. Thanks for the time to write such an in-depth thread.

May 20th, 2016, 09:23 AM	#7
ROADandTRACK R&T Suspension Name: K Hertell Location: San Antonio, TEXAS Join Date: Jun 2009 Motorcycle(s): Too many to list Posts: 175	Please tell me about an RD motor in an EX frame. I'm very interested. I was going to put EX forks and swingarm on my RD frame but if the engine swap works well I may do that instead.

May 20th, 2016, 02:23 PM	#8
NinJim ninjette.org member Name: Jim Location: Utah Join Date: Apr 2016 Motorcycle(s): Ninja250-3x; CBR600 & R6 (track bikes); lots of dirt stuff Posts: 25	R&T, I am basically a 2 stroke guy, for a lot of reasons. When my GDaughter was in high school, I got her a 07Ninja to go with a TL125 trials bike. I liked riding her Ninja, but it wouldn't go, stop or turn. Please go to 2StrokeWorld.com. It is basically a RD/RZ Banshee site with lots of conversions to more modern frames for high preformance 2stk engines. Search "Ninja swap". I just did and it came up with about 40 threads. Then sit back and enjoy. The swap has no major fabrication; but lots of little bits to be sorted, especially the electrical system. I'm planning on the 09 frame. It's heavier than the 96, but you can't get 96 race plastic cheap anymore. You can do a full monty and spend lots, or make it a nice perky street bike. The RD400 I have probably make 60+hp and the weight will be about 300 lbs. The Banshees make 100+. So depending on your wallet's fatness, the mods are endless. There are several guys on 2StrokeWorld that have made lots of NinjaRD conversions. Chat em up and see what ideas you can conjure up. Cheers,

May 21st, 2016, 08:16 AM	#9
ROADandTRACK R&T Suspension Name: K Hertell Location: San Antonio, TEXAS Join Date: Jun 2009 Motorcycle(s): Too many to list Posts: 175	Thanks, I've got a Harry Barlow RD400 w/ 64hp at the rear wheel that I might do this with. I was going to put the EX triples/forks and swingarm on the RD chassis but this has me interested. Thanks again for the info.

May 21st, 2016, 09:36 AM	#10
NinJim ninjette.org member Name: Jim Location: Utah Join Date: Apr 2016 Motorcycle(s): Ninja250-3x; CBR600 & R6 (track bikes); lots of dirt stuff Posts: 25	That sounds like the perfect mate. The fabrication is around two down tubes for the front engine mounts. And two extension hangers to pick up the rear mounts onto the cross tube for alignment of the sprockets. The rest is what you want to change to get the look you want. I have an 79 Daytona that needs work. My first thought was like you, to increase the frame stability of the original weak frame. But to do this is lots of work and engineering. The old frame designs can't handle the new power output, suspension and tires now available. I have learned that from 20+ years of AHRMA racing. So for me, its easier/cheaper to swap a lighter rock-solid high output engine into a modern frame. The Ninja is perfect, as there is a world of cheap aftermarket and ebay bits to upgrade a good starter frame. I picked up two Ninja rollers, a 96 and 08 for $500. They will be donor bikes. When I am finished, the remains will go to ebay in the $0.99 auction bin. Maybe it will all pay for the build. Mine won't be raced, but it will share some time on track days with four others I usually take out for a little exercise. I will probably make some basic GSXR suspension changes to stiffen it up some. We'll see. Hope this helps, Have fun,