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nuerburgring

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Discussion starter · #1 ·
I am about ready to buy a brand new NSR mini to get the required parts for my ZB50 to ZB125 conversion as I do not trust used stuff and price is about similar after i sold the new engine, frame, tank etc. It might be more safe with those disc brakes and real shocks........

After checking old threads i think I have the correct understanding but I would like to confirm this with you guys that have already worn out the T-shirt. hehehehe......



http://www.planetminis.com/gallery/files/9/9/0/4/e0_3.jpg



My understanding from past info is that:

-Front fork and wheel will fit without modification.

-Rear swing arm and wheel will fit without modification.

-Rear shock needs spacer on top or cutting/rewelding shock mount on the swing arm.

-Rear sets can be fitted but need custom bracket and hardware.



Please let me know if I am missing anything or misunderstood.



Thanks in advance for the support !!



I will start posting pictures when all the parts are there as there is nothing to see at the moment.
 
nuerburgring said:
I am about ready to buy a brand new NSR mini to get the required parts for my ZB50 to ZB125 conversion as I do not trust used stuff and price is about similar after i sold the new engine, frame, tank etc. It might be more safe with those disc brakes and real shocks........

After checking old threads i think I have the correct understanding but I would like to confirm this with you guys that have already worn out the T-shirt. hehehehe......



My understanding from past info is that:

-Front fork and wheel will fit without modification.

-Rear swing arm and wheel will fit without modification.

-Rear shock needs spacer on top or cutting/rewelding shock mount on the swing arm.

-Rear sets can be fitted but need custom bracket and hardware.



Please let me know if I am missing anything or misunderstood.



Thanks in advance for the support !!



I will start posting pictures when all the parts are there as there is nothing to see at the moment.


If you are buying a new NSR50mini from 2004, the forks will not fit without modification. The steerer tube is longer then what is needed on the ZB50 frame, and you won't have a steering stop.



You can purchase an adapter kit from Japan or contact the PM member, Reynolds_Brad as he may have an extra one floating around to attach the rear shock to the ZB50 frame, or you can cut and reweld your swingarm.



The 2004 NSR50mini won't have a speedometer drive, and you'll have to source one along with the speedo cable.



The rest of the information you have is correct, but you'll find there will be a bunch of little snags along the way. It's a fun conversion and highly recommended..
 
I think I've got a bottom clamp and stem that will work, it's off an older NSR50. Fits XR50 frames so I think it's the right stem length for the Z50 frames. I've also got a top clamp, but it requires that you use NSR50 clipons from the earlier machines, which I don't have.
 
Kurlon said:
I think I've got a bottom clamp and stem that will work, it's off an older NSR50. Fits XR50 frames so I think it's the right stem length for the Z50 frames. I've also got a top clamp, but it requires that you use NSR50 clipons from the earlier machines, which I don't have.


That's the lower stem you want. It doesn't cure the steering stop problem, but Kurlon has the correct stem that can be used with the OEM NSR top clamp, or one of the aftermarket ones that has a provision for standard bar clamps.
 
Discussion starter · #5 ·
Thanks, that is just what I was looking for.

On the fork, is it possible to just shorten and tap new thread on it, or do I need special adapters? Steering stop should be possible to fabricate with some effort....

Speedo drive is no issue as I plan to go digital anyway (see other thread on gauges from Germany)



I would think that people recommend this conversion as I keep having nightmares of driving downhill with flames coming out of my poor little drum brakes.



How is the stability at high speed after the conversion is done?

Acceptable or would a steering damper be required as well? (looks cool and professional but does it work)?
 
You can shorten up the stem.

I'd get an NSR50 speedo drive and cable rather then having a complete digital system. They aren't that expensive and are bolt on and will replace a spacer that currently resides on the front wheel.



The NSR50 forks need work to be a really good set of forks. If you don't have a suspension expert in Germany (Mad Maexla), talk to Ray Perez here in the USA at bikeworldmotorsports.com and he'll rework your forks to make them safe at high speeds.



I don't think you need a steering stabilizer, but if you want one, go for it.
 
I just bought a set of nsr wheels a couple of days ago and i will be starting my nsr/zb125 conversion very soon. its nice to have 2 people working on a project at the same time hopfully i can help with any question you have.
 
Are'nt the stock brakes and shoes the same fitted to an older full size Honda XL125 ?? and also are not the forks the same size as the nsr, 31mm. I was going to do a conversion too but don't think it's really necessary. I can do stoppies with my drum brake and if it can stop a full size XL125 it seems appropriate. Wow buying a whole bike for the bits, what about aftermarket parts? G-Craft, Kitaco, etc.??
 
Discussion starter · #9 ·
I believe that the NEW 2006 NSR mini actualy has adjustable front forks which should be at least a bit better then my old ones.



Image




http://www.takegawa.nl/products_en.php?partcode=0606010&catid=10



It seems strange to me as well to buy a new bike and then take it apart for parts but I believe it will be much cheaper once the left over bits are sold via E-bay or other. Getting the separate parts from Honda will cost a fortune and used parts are difficult to get in Europe and not reliable.



I may need to get a new top plate to fit a normal steering.
 
davez said:
I was going to do a conversion too but don't think it's really necessary. I can do stoppies with my drum brake
davez.. Wait till you get your ZB up in the 60 -70 mph range and then try stopping.???Little different. A disc brake set up in the front and rear will make it safer at higher speeds. Are you still running the 50cc motor? 40 mph tops?

tmas
 
nuerburgring said:
I believe that the NEW 2006 NSR mini actualy has adjustable front forks which should be at least a bit better then my old ones.



http://www.takegawa.nl/products_en.php?partcode=0606010&catid=10



It seems strange to me as well to buy a new bike and then take it apart for parts but I believe it will be much cheaper once the left over bits are sold via E-bay or other. Getting the separate parts from Honda will cost a fortune and used parts are difficult to get in Europe and not reliable.



I may need to get a new top plate to fit a normal steering.


Those are preload adjusters and don't do all that much. The forks have progressive springs and are going to be soft with little dampening and rebound. Trust me, they need work to be a really good front fork.
 
z88R said:
Those are preload adjusters and don't do all that much. The forks have progressive springs and are going to be soft with little dampening and rebound. Trust me, they need work to be a really good front fork.


Agree!!
 
ffRich said:
What needs to be done to the forks?


They need stronger springs and have the valving reworked. I wouldn't even waste time screwing with it yourself and just send them to Ray Perez at bikeworldmotorsports.com to be worked. Ray is fair on price and has done dozens of these forks for me and others.



Ask Kurlon his experience of messing with the forks himself and then how he likes the forks after getting them back from Ray. That alone, will speak volumes.
 
I got two sets of NSR50 forks, an OEM set off a late 90s machine, and aftermarket clones new. I then tracked down stock and stiff springs for both the early and late style NSR50 forks. Even putting late model fork springs into the shorter early style units I was left with far too little spring rate. Note I also bought the preload adjuster caps, and tried stacking in preload spacers. All you end up doing is coil binding the soft portion of the wind, with the remainder still being far too soft. By the time you pile enough preload in to get sag where it should be, you're just about at coil bind for the whole spring.



I couldn't get proper damping even going up to 40w oil, compression or rebound. I researched updating my damping rods, but the port setup on the late model forks is identical.



Ray ended up cutting new bushings, replacing all the seals, reworking my damping rods, cutting new springs, and doing some other work, essentially rebuilding the internals from scratch to make the forks work. The result is I've got a front end that feels like a full size bike, proper sag, good damping, stable at speed both flat out and swaping through twisties. This front end STICKS on cold concrete now, which surprises the crap out of me.



Net result, if you're going this route, plan on having someone rework the forks. It'll save you lots of time and effort trying to duplicate what people like Ray have already worked out.
 
Kurlon said:
I got two sets of NSR50 forks, an OEM set off a late 90s machine, and aftermarket clones new. I then tracked down stock and stiff springs for both the early and late style NSR50 forks. Even putting late model fork springs into the shorter early style units I was left with far too little spring rate. Note I also bought the preload adjuster caps, and tried stacking in preload spacers. All you end up doing is coil binding the soft portion of the wind, with the remainder still being far too soft. By the time you pile enough preload in to get sag where it should be, you're just about at coil bind for the whole spring.



I couldn't get proper damping even going up to 40w oil, compression or rebound. I researched updating my damping rods, but the port setup on the late model forks is identical.



Ray ended up cutting new bushings, replacing all the seals, reworking my damping rods, cutting new springs, and doing some other work, essentially rebuilding the internals from scratch to make the forks work. The result is I've got a front end that feels like a full size bike, proper sag, good damping, stable at speed both flat out and swaping through twisties. This front end STICKS on cold concrete now, which surprises the crap out of me.



Net result, if you're going this route, plan on having someone rework the forks. It'll save you lots of time and effort trying to duplicate what people like Ray have already worked out.


What did ray charge you for that service? Sounds awesome but $$$
 
$100 labor + Parts + Shipping.



In total, I spent $380 with him. Between importing three sets of springs from Japan, two sets of forks, etc, I spent that much just playing around myself trying to get the job done 'on the cheap.'
 
Ray has reworked my NSR forks that i run on my monkey bike as well. Im not going to go into all the details but i stand by his work that it is the best out there as far as a street mini bike fork gos. Great to work with, A+ suspension guy.
 
Discussion starter · #20 ·
OK, if it does not work out with the Germans nut cases (they have build some very funky stuff), then i will send the bits to Ray.

Any comments on the 2006 NSR mini rear shock? Is that one adjustable enough for fast street usage? I see that the German guys frequently use a modified R1 shock in their projects.
 
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