08-10 zx-10r Fork on 250/300 (Stock Front Wheel)

Fred659 · July 25th, 2023, 09:40 AM

Hi,

It looks like I can't keep from doing upgrades on the little bike. I want to share this one with you guys cause I'm pretty glad / proud f the result. I always wanted to put a "better" fork on the 250 and the previous mod (zx-10r cartridges) was good, but I wasn't fully satisfied. So last fall, I decided to try to fit 08-10 zx-10r tubes on the bike while keeping the stock front wheel.

The first good find was that the 13-16 Triumph Daytona 675r triple tree has 54mm/50mm clamps and are a bit narrower than the ZX one while having a smaller shaft. It allowed me to only change the lower bearing seat. I needed to fabricate a stopper as the nobs on the 675 triple tree are way off and I need to control the movement to avoid damaging my steering damper.

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I managed to keep the stock front axle (only had to file hex faces to allow it to enter the ZX axle bushing). I need a washer on each side (wheel bushings) to get the proper dimension I need.

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For the brakes, I went with the 06-07 Yamaha r6 Rotors and the 2016 Triumph Daytona 675 Nissin Monoblock caliper (and some Galfer pads). You only need to bore out the screw holes a bit and shim the rotor whit some m10 washers (goes around the shoulder part of the screw). I also had a ss braided brake hose left for the prior build. I treated myself with a Brembo 15 RCS Corsa Corta Master Cylinder (Same as my ZX, which is 17 RCS...) and TWM clutch lever. I didn't what to have the brake supports on the left fork so I put the grinder into it ( i didn't butcher it too much).

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As I went keyless, I decided to do a bracket for the SOLO 2 Lap Timer using the key barrel threaded holes.

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Fred659 · July 25th, 2023, 09:44 AM

And here's the final result. I hope it could help someone with his project.

Cheers.

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*****Little Update:*****

I had to modify the belly pan as the front tire was rubbing when braking.

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superkain · July 25th, 2023, 11:04 AM

holy cow, that's awesome! how does it ride, now that it's together?

Fred659 · July 25th, 2023, 11:24 AM

Quote:

Originally Posted by superkain

holy cow, that's awesome! how does it ride, now that it's together?

just finished it today. I need to go to the track to be able to tell you how it goes.

The brakes feel awesome so far (street shake down).

Glad you like it.

sharky nrk · October 28th, 2023, 04:54 PM

Wild man, good job.

Fred659 · October 28th, 2023, 05:08 PM

I did try the bike on the track (rain and dry) and the bike is way more planted than before.

I can lean on the front way harder and it's exactly what I was hoping for. I no longer have to balance the bike on the gas on corner entry.

I will put the 2nd softer spring cause the combined value of 0.925 (1.00 + 0.85) is a bit to firm. I had .90 on the modified stock fork and it was pretty good so I will try the .85kg setup next spring. If too soft, I will buy son used zx-14 springs that are .90kg/mm

sharky nrk · October 30th, 2023, 07:30 AM

Did you happen to have those springs handy? Notice any issues running such different rate springs left and right? I have known people to run one step difference springs left and right to make a half step, but not that big of a gap.

Fred659 · October 30th, 2023, 07:59 AM

Quote:

Originally Posted by sharky nrk

Did you happen to have those springs handy? Notice any issues running such different rate springs left and right? I have known people to run one step difference springs left and right to make a half step, but not that big of a gap.

No real problem to be honest. Forks are "rigid" assembly by definition (you don't want the wheel to twist when the fork travels). I'm sure it's best to have close matching springs, but if you look at mountain bike forks (ex: Fox) you have 1 spring / air chamber in one leg and hydraulics in the other.

I felt way more flex with the stock fork than the modified zx-10 one.

Tin foil hat moment: I would not be surprised if the "no big difference in rates" comment came from springs manufacturer or seller. I have no proof if either are true or false. I just have my experience (14 years on track and 10 in suspension setting). I never saw a problem, but I would really appreciate if someone have a definitive answer backed with data.

...and for the springs, I have a set of stock zx-10r 1.0, a set of 03 gsxr-1000 0.85. I can buy zx-14 0.90 on eBay. (you only have to enlarge the tapered end as I did with the gsxr ones

njshore2002 · February 22nd, 2024, 03:03 PM

Hey Mate love what you have done with the engine swap and the fork change. I actually recently engine swapped my 250 to a 300 just like you did and now im looking to do the front fork. the fork im looking to use is a 1998 ZXR250 fork. now im not too worried about getting it to fit, its more the fact that i want 4 Pot calipers on the front and im wondering if you know of any models of bikes that have 4 pot calipers that will bolt straight onto a zxr250 fork and rotor

cheers in advance.

Fred659 · February 23rd, 2024, 01:52 PM

Quote:

Originally Posted by njshore2002

Hey Mate love what you have done with the engine swap and the fork change. I actually recently engine swapped my 250 to a 300 just like you did and now im looking to do the front fork. the fork im looking to use is a 1998 ZXR250 fork. now im not too worried about getting it to fit, its more the fact that i want 4 Pot calipers on the front and im wondering if you know of any models of bikes that have 4 pot calipers that will bolt straight onto a zxr250 fork and rotor

cheers in advance.

I personally don't know, but if you have one stock caliper on hand, you can measure the c/c dimension and try to match it from other caliper dimensions. I asked some eBay vendor to take some measurements when I was looking for a fork.

try a google search for: zxr 250 front calipers swap. you should be able to find something

I saw fz6 mentioned a lot.

it's a dark art the one of bike modification.

good luck.

July 25th, 2023, 09:40 AM	#1
Fred659 ninjette.org member Name: Frederic Location: Quebec City Join Date: Jan 2020 Motorcycle(s): 08 Race Prepped ZX-10r, 09 Race Prepped Ninja 250 (300 motor). 74 Norton Commando 850 (Project) Posts: 54	08-10 zx-10r Fork on 250/300 (Stock Front Wheel) Hi, It looks like I can't keep from doing upgrades on the little bike. I want to share this one with you guys cause I'm pretty glad / proud f the result. I always wanted to put a "better" fork on the 250 and the previous mod (zx-10r cartridges) was good, but I wasn't fully satisfied. So last fall, I decided to try to fit 08-10 zx-10r tubes on the bike while keeping the stock front wheel. The first good find was that the 13-16 Triumph Daytona 675r triple tree has 54mm/50mm clamps and are a bit narrower than the ZX one while having a smaller shaft. It allowed me to only change the lower bearing seat. I needed to fabricate a stopper as the nobs on the 675 triple tree are way off and I need to control the movement to avoid damaging my steering damper. 20230721_143445.jpg 20230721_155738.jpg 20230721_142314.jpg 20230721_155539.jpg I managed to keep the stock front axle (only had to file hex faces to allow it to enter the ZX axle bushing). I need a washer on each side (wheel bushings) to get the proper dimension I need. 20230725_093445.jpg 20230725_093507.jpg 20230725_094237.jpg 20230725_094211.jpg For the brakes, I went with the 06-07 Yamaha r6 Rotors and the 2016 Triumph Daytona 675 Nissin Monoblock caliper (and some Galfer pads). You only need to bore out the screw holes a bit and shim the rotor whit some m10 washers (goes around the shoulder part of the screw). I also had a ss braided brake hose left for the prior build. I treated myself with a Brembo 15 RCS Corsa Corta Master Cylinder (Same as my ZX, which is 17 RCS...) and TWM clutch lever. I didn't what to have the brake supports on the left fork so I put the grinder into it ( i didn't butcher it too much). 20230725_093616.jpg 20230722_120005.jpg 20230722_114830.jpg 20230722_114835.jpg 20230520_100417.jpg 20230520_100831.jpg 20230520_114526.jpg As I went keyless, I decided to do a bracket for the SOLO 2 Lap Timer using the key barrel threaded holes. 20230723_124756.jpg 20230723_125439.jpg 20230723_125604.jpg Last futzed with by Fred659; August 3rd, 2023 at 04:54 AM.

July 25th, 2023, 09:44 AM	#2
Fred659 ninjette.org member Name: Frederic Location: Quebec City Join Date: Jan 2020 Motorcycle(s): 08 Race Prepped ZX-10r, 09 Race Prepped Ninja 250 (300 motor). 74 Norton Commando 850 (Project) Posts: 54	And here's the final result. I hope it could help someone with his project. Cheers. 20230725_110254.jpg 20230725_110311.jpg 20230725_111010.jpg 20230725_110328.jpg 20230725_110347.jpg 20230725_110629.jpg 20230725_110621.jpg 20230725_110610.jpg ***Little Update:*** I had to modify the belly pan as the front tire was rubbing when braking. 20230728_122309.jpg 20230728_123225.jpg 20230728_123257.jpg Last futzed with by Fred659; July 28th, 2023 at 09:55 AM.

October 28th, 2023, 04:54 PM	#5
sharky nrk Fighting Texas Aggie '05 Name: Neil Location: Hutto, TX Join Date: Feb 2009 Motorcycle(s): '07 ZX6R, '08 Versys, '09 250R Track, '93 F2/F3 Track Posts: A lot.	Wild man, good job. __________________________________________________ Keep it rubber side down and enjoy the ride Get healthy - Get Fit - Change Your Life Click Here Or PM Me To Find More - Advocare

October 30th, 2023, 07:30 AM	#7
sharky nrk Fighting Texas Aggie '05 Name: Neil Location: Hutto, TX Join Date: Feb 2009 Motorcycle(s): '07 ZX6R, '08 Versys, '09 250R Track, '93 F2/F3 Track Posts: A lot.	Did you happen to have those springs handy? Notice any issues running such different rate springs left and right? I have known people to run one step difference springs left and right to make a half step, but not that big of a gap. __________________________________________________ Keep it rubber side down and enjoy the ride Get healthy - Get Fit - Change Your Life Click Here Or PM Me To Find More - Advocare

July 25th, 2023, 11:04 AM	#3
superkain ninjette.org member Name: Super Location: NC Join Date: Feb 2009 Motorcycle(s): k6 GSX-R 750, 2008 Ninja 250R Posts: 27	holy cow, that's awesome! how does it ride, now that it's together?

October 28th, 2023, 05:08 PM	#6
Fred659 ninjette.org member Name: Frederic Location: Quebec City Join Date: Jan 2020 Motorcycle(s): 08 Race Prepped ZX-10r, 09 Race Prepped Ninja 250 (300 motor). 74 Norton Commando 850 (Project) Posts: 54	I did try the bike on the track (rain and dry) and the bike is way more planted than before. I can lean on the front way harder and it's exactly what I was hoping for. I no longer have to balance the bike on the gas on corner entry. I will put the 2nd softer spring cause the combined value of 0.925 (1.00 + 0.85) is a bit to firm. I had .90 on the modified stock fork and it was pretty good so I will try the .85kg setup next spring. If too soft, I will buy son used zx-14 springs that are .90kg/mm

February 22nd, 2024, 03:03 PM	#9
njshore2002 ninjette.org newbie Name: Nathan Location: Victoria Join Date: Feb 2024 Motorcycle(s): Ninja 250 Posts: 1	Hey Mate love what you have done with the engine swap and the fork change. I actually recently engine swapped my 250 to a 300 just like you did and now im looking to do the front fork. the fork im looking to use is a 1998 ZXR250 fork. now im not too worried about getting it to fit, its more the fact that i want 4 Pot calipers on the front and im wondering if you know of any models of bikes that have 4 pot calipers that will bolt straight onto a zxr250 fork and rotor cheers in advance.