636 fork swap

gt_turbo · April 24th, 2012, 07:11 PM

as some of you know I purchased 03-04 636 front fork parts from a member here on the forum who sold his 250 and was not able to install them. he pretty much took care of the hardest part, which is taking the 250 steering stem and getting it welded into a 636 lower triple. more on that later. but the forks i received had a broken fender mounting bracket which was unknown to me before purchase and the front wheel had a dent in the rim which was shown in the forsale pics. luckily i was able to pick up '05 636 fork set and front wheel assembly locally.

back to the steering stem. the 250 steering stem is welded in the lower triple so you'd have to have it cut out and then welded into a 636 lower triple. the 636 steering stem is press fit into the its lower triple so you have to get that pressed out i believe. i'm not sure if any additional machining is required with sticking the 250 stem into the 636 lower triple. here's a few pics showing my stock 250 stem vs. the 636 lower triple with the 250 stem welded in.

picture of a stock 05 636 lower triple with 636 stem.

basically lift your bike up securely, take off your fairings and tank, lift the front end up, take your front tire off, loosen up the lower and upper triple tree clamp bolts, careful the forks can drop right out. next you need to take the upper triple off by removing the large 22mm nut. it will reveal a splined locking nut. this nut holds the lower triple and upper triple together. the manual says to use a special tool, but i found that the spanner tool for the rear shock also works quite well. or a screw driver and hammer also works. be very careful removing the lower triple as there are (19) bearings under the splined nut and (20) bearings above the lower triple. the bearings will fall out all over the place, so be careful and pay attention. after this you basically reinstall with all the 636 parts. grease up the bearings again, follow the manual to re-install the bearings properly. this part is a pain, which i will probably need to redo, since i think i didn't seat the bearings properly. more on that later.

you'll have to drill out the 250 ignition switch from the 250 upper triple. here's where you have to do some modifications to the upper 636 triple clamp. the ignition mounting tabs on the 636 are about 1/2" too long. i took a rough estimate and hacked it off with a hack saw and then decided to use my orbital sander and some 40 grit paper to sand it down. you'll have to drill and tap new holes to secure the 250 ignition switch. even then the 250 ignition key switch is too small in diameter compared to the 636 ignition switch ring.

what i did was went to the hardware store with the 636 triple and 250 ignition switch and found the closest rubber o-ring that would fit. ended up with something in the plumbing section. there's still a 1mm gap, but doesn't look too bad. my ignition lock no longer works. if you do some more fiddling maybe you can get it to work.

another issue i ran into is that using the stock 636 clip ons, there's hardly any clearance over the black plastic surround.

so i had to order a set of woodcraft 50 mm 2" riser clip ons.

for now i set the fork height at the stock 636 level indicated by the ring on the fork. after a quick ride, the new forks definitely feel better than stock. i'll have to fine tune them.

things i still have to do:
1. get my new bt016 120/70/17 mounted and balanced so that the front tire matches the rear.
2. redo the bearings on the stem head. the forks/triple move when the front tire is lifted in the air and pulling on the forks.
3. fine tune the suspension.
4. wait for my 05 636 front fender to come in, paint it and install.
5. upgrade rear shock next

here's a couple pictures of the final product so far.

k-os · April 24th, 2012, 07:15 PM

What did you end up doing for the speedometer?

gt_turbo · April 24th, 2012, 07:22 PM

at the moment nothing. planning to get a phone mount on the handle bar or something, run a usb cord, and use an app on my phone. probably more accurate anyhow.

Alex · April 24th, 2012, 08:54 PM

Nice!

leed · April 24th, 2012, 09:15 PM

The Ninja looks so strange without the fender! The install though, is very clean! I do like it

if you've gone this far, you may consider a digital gauge.

k-os · April 25th, 2012, 04:26 AM

Quote:

Originally Posted by leed

The Ninja looks so strange without the fender! The install though, is very clean! I do like it

if you've gone this far, you may consider a digital gauge.

I could recommend either a Koso or Vapor as I've used both. The Vapor is quite a bit easier to get hooked up, and its only around $100.

gt_turbo · April 25th, 2012, 05:13 AM

I love the koso but the price alone is equal to what I spent on the fork swap. I'll check out that vapor gauge. Seems more in line with my budget.

Graugaard · April 25th, 2012, 09:03 AM

where did u get those right and left front turn signals?! i love them

Also love the fork upgrade u did there, looks sweet.

oreX · April 25th, 2012, 10:56 AM

Quote:

Originally Posted by Graugaard

where did u get those right and left front turn signals?! i love them

Also love the fork upgrade u did there, looks sweet.

looks like the ones from: http://www.modmy250.com/

Graugaard · April 27th, 2012, 12:11 AM

Quote:

Originally Posted by oreX

looks like the ones from: http://www.modmy250.com/

BAHHH

only us and canada shipping.

must find them! ebay it is. :P

CZroe · April 30th, 2012, 09:24 AM

Looks higher than it should be, but maybe that's just due to the lack of a fender.

gt_turbo · April 30th, 2012, 06:42 PM

yes, i think it does sit higher up front. still need to tweak the fork height length.

gt_turbo · May 21st, 2012, 10:27 AM

Update: So I fixed my fork/triple moving during braking issue by replacing the steering stem bearings/races which lead to other important discoveries. While I had the triples out, I compared the lower triples, the stock 250 and the modified 636 I had bought. Doing some measuring from the top surface of the lower triple to the end of the stem tube. The lower triple was incorrectly machined/pressed about a quarter inch too deep. This created a lack of threads for the stem nut to grab onto and possibly why there was slop in the steering stem bearings. I took the modified lower triple to a machinist to correct. He also determined that the lower triple was bent! This explains why my front tire is not straight when the triples appeared to be straight and the wobbling tire issues.

Luckily, when I picked up the '05 636 forks, the lower triple also came with it. So my machinist basically re-did all the work on the lower triple. He said whoever did the original job did piss poor job. The stem tube was about .005" off in circular runout with respect to the welded on adapter piece that is slightly larger in diameter than the 250 stem tube and press fitted into the 636 triple. The adapter also did not have a stopper lip, so the stem tube could have potentially been pushed right out of the triple over time! After getting my straight 636 lower triple modified and the steering stem bearings replaced with the All Balls kit, my bike now rides straight and I can finally take it with confidence into the twisties. Time to play around with the fork height/rake angle to find what suits me best.

alex.s · May 21st, 2012, 12:42 PM

thats disappointing

good thing you got passed the road blocks. nice job they look sick

willi777 · May 23rd, 2012, 07:32 AM

Please let us know how it performs after you do some riding. It looks awesome on your bike, hopefully it rides as good as it looks. Glad you got the triple clamp/stem issue worked out- hard to believe the machine shop that did the work previously would do such a half-assed job on the stem swap... it's not rocket science.

cuong-nutz · May 23rd, 2012, 09:11 AM

You should have your machinist start making extra parts for a kit.

gt_turbo · May 24th, 2012, 03:44 PM

Quote:

Originally Posted by cuong-nutz

You should have your machinist start making extra parts for a kit.

lol, i told him to start a bike shop.

gt_turbo · August 4th, 2012, 04:31 PM

after taking the bike out to track with the 636 forks, i thought i'd update this thread for anyone who is thinking about doing this swap. two words: SIMPLY AMAZING! in the corners, it holds the line perfectly. you don't get that squirrely feeling when you're leaned over and wondering, is it gonna hold or will it slip out from under me. future mod will be an aftermarket rear shock. gotta start saving.

cuong-nutz · August 4th, 2012, 04:57 PM

Quote:

Originally Posted by gt_turbo

after taking the bike out to track with the 636 forks, i thought i'd update this thread for anyone who is thinking about doing this swap. two words: SIMPLY AMAZING! in the corners, it holds the line perfectly. you don't get that squirrely feeling when you're leaned over and wondering, is it gonna hold or will it slip out from under me. future mod will be an aftermarket rear shock. gotta start saving.

Yep, that's what happens when you have tunable suspension

jman511115 · August 30th, 2012, 12:23 PM

Hey, did you use the stock master cylinder? And how come only one rotor?

gt_turbo · August 31st, 2012, 03:46 AM

Quote:

Originally Posted by jman511115

Hey, did you use the stock master cylinder? And how come only one rotor?

I used the stock one for about a month until I was able to collect parts for a zx6r master. One rotor because 250's come from factory with one only. You could put two if you like the looks of it, but it's just added weight imo.

Jetfoi · March 16th, 2015, 07:07 AM

awesome write up!

sharky nrk · March 16th, 2015, 08:18 AM

Looks good, did you have to clearance the fairings or shrouding to fit the wider forks?

April 24th, 2012, 07:11 PM	#1
gt_turbo ninjette.org sage Name: L Location: WI Join Date: Apr 2011 Motorcycle(s): '09 250R, '13 CBR500R Posts: 709	636 fork swap as some of you know I purchased 03-04 636 front fork parts from a member here on the forum who sold his 250 and was not able to install them. he pretty much took care of the hardest part, which is taking the 250 steering stem and getting it welded into a 636 lower triple. more on that later. but the forks i received had a broken fender mounting bracket which was unknown to me before purchase and the front wheel had a dent in the rim which was shown in the forsale pics. luckily i was able to pick up '05 636 fork set and front wheel assembly locally. back to the steering stem. the 250 steering stem is welded in the lower triple so you'd have to have it cut out and then welded into a 636 lower triple. the 636 steering stem is press fit into the its lower triple so you have to get that pressed out i believe. i'm not sure if any additional machining is required with sticking the 250 stem into the 636 lower triple. here's a few pics showing my stock 250 stem vs. the 636 lower triple with the 250 stem welded in. picture of a stock 05 636 lower triple with 636 stem. basically lift your bike up securely, take off your fairings and tank, lift the front end up, take your front tire off, loosen up the lower and upper triple tree clamp bolts, careful the forks can drop right out. next you need to take the upper triple off by removing the large 22mm nut. it will reveal a splined locking nut. this nut holds the lower triple and upper triple together. the manual says to use a special tool, but i found that the spanner tool for the rear shock also works quite well. or a screw driver and hammer also works. be very careful removing the lower triple as there are (19) bearings under the splined nut and (20) bearings above the lower triple. the bearings will fall out all over the place, so be careful and pay attention. after this you basically reinstall with all the 636 parts. grease up the bearings again, follow the manual to re-install the bearings properly. this part is a pain, which i will probably need to redo, since i think i didn't seat the bearings properly. more on that later. you'll have to drill out the 250 ignition switch from the 250 upper triple. here's where you have to do some modifications to the upper 636 triple clamp. the ignition mounting tabs on the 636 are about 1/2" too long. i took a rough estimate and hacked it off with a hack saw and then decided to use my orbital sander and some 40 grit paper to sand it down. you'll have to drill and tap new holes to secure the 250 ignition switch. even then the 250 ignition key switch is too small in diameter compared to the 636 ignition switch ring. what i did was went to the hardware store with the 636 triple and 250 ignition switch and found the closest rubber o-ring that would fit. ended up with something in the plumbing section. there's still a 1mm gap, but doesn't look too bad. my ignition lock no longer works. if you do some more fiddling maybe you can get it to work. another issue i ran into is that using the stock 636 clip ons, there's hardly any clearance over the black plastic surround. so i had to order a set of woodcraft 50 mm 2" riser clip ons. for now i set the fork height at the stock 636 level indicated by the ring on the fork. after a quick ride, the new forks definitely feel better than stock. i'll have to fine tune them. things i still have to do: 1. get my new bt016 120/70/17 mounted and balanced so that the front tire matches the rear. 2. redo the bearings on the stem head. the forks/triple move when the front tire is lifted in the air and pulling on the forks. 3. fine tune the suspension. 4. wait for my 05 636 front fender to come in, paint it and install. 5. upgrade rear shock next here's a couple pictures of the final product so far.

April 24th, 2012, 08:54 PM	#4
Alex ninjette.org dude Name: 1 guess :-) Location: SF Bay Area Join Date: Jun 2008 Motorcycle(s): '13 Ninja 300 (white, the fastest color!), '13 R1200RT, '14 CRF250L, '12 TT-R125LE Posts: Too much. Blog Entries: 7	Nice! __________________________________________________ Montgomery Street Motorcycle Club / cal24.com / crf250l.org / ninjette.org ninjette.org Terms of Service Shopping for motorcycle parts or equipment? Come here first. The friendliest Ninja 250R/300/400 forum on the internet! (especially Unregistered)

May 21st, 2012, 12:42 PM	#14
alex.s wat Name: wat Location: tustin/long beach Join Date: Sep 2009 Motorcycle(s): wat Posts: Too much. Blog Entries: 5 MOTM - Oct '12, Feb '14	thats disappointing good thing you got passed the road blocks. nice job they look sick __________________________________________________

May 23rd, 2012, 07:32 AM	#15
willi777 ninjette.org member Name: Willie Location: Hampton Bays Join Date: Jun 2010 Motorcycle(s): Ninja 500, VFR750 Posts: 51	fork swap Please let us know how it performs after you do some riding. It looks awesome on your bike, hopefully it rides as good as it looks. Glad you got the triple clamp/stem issue worked out- hard to believe the machine shop that did the work previously would do such a half-assed job on the stem swap... it's not rocket science.

May 23rd, 2012, 09:11 AM	#16
cuong-nutz RIP Alex Name: Cuong Location: Houston, TX Join Date: Apr 2011 Motorcycle(s): '10 250r, '09 265r Posts: A lot. Blog Entries: 2	You should have your machinist start making extra parts for a kit. __________________________________________________ HalfFast Racing Team Serving Greater Houston Area Riders:WFO Riders MotoHouston HPC CMRA Ride Smart Fastline Lone Star Track Days

April 24th, 2012, 07:15 PM	#2
k-os ninjette.org sage Name: Andy Location: Sheboygan, WI Join Date: Dec 2008 Motorcycle(s): 1988 Honda Hawk NT650, 1989 Honda Hawk NT650, 1997 GSXR750 Track Bike Posts: 890	What did you end up doing for the speedometer?

April 24th, 2012, 07:22 PM	#3
gt_turbo ninjette.org sage Name: L Location: WI Join Date: Apr 2011 Motorcycle(s): '09 250R, '13 CBR500R Posts: 709	at the moment nothing. planning to get a phone mount on the handle bar or something, run a usb cord, and use an app on my phone. probably more accurate anyhow.

April 24th, 2012, 09:15 PM	#5
leed ninjette.org sage Name: David Location: Loves Park, IL Join Date: Feb 2011 Motorcycle(s): Time will tell Posts: 969	The Ninja looks so strange without the fender! The install though, is very clean! I do like it if you've gone this far, you may consider a digital gauge.

April 25th, 2012, 05:13 AM	#7
gt_turbo ninjette.org sage Name: L Location: WI Join Date: Apr 2011 Motorcycle(s): '09 250R, '13 CBR500R Posts: 709	I love the koso but the price alone is equal to what I spent on the fork swap. I'll check out that vapor gauge. Seems more in line with my budget.

April 25th, 2012, 09:03 AM	#8
Graugaard ninjette.org member Name: Elias Location: Denmark Join Date: Nov 2011 Motorcycle(s): Ninja 250r Posts: 152	where did u get those right and left front turn signals?! i love them Also love the fork upgrade u did there, looks sweet.

April 30th, 2012, 09:24 AM	#11
CZroe CPT Falcon Name: J.Emmett Turner Location: Newnan, GA Join Date: Apr 2009 Motorcycle(s): '08 CP Blue EX250J, '97 unpainted EX250F, 2nd '97 unpainted EX250F (no engine), '07 black EX250F Posts: A lot.	Looks higher than it should be, but maybe that's just due to the lack of a fender.

April 30th, 2012, 06:42 PM	#12
gt_turbo ninjette.org sage Name: L Location: WI Join Date: Apr 2011 Motorcycle(s): '09 250R, '13 CBR500R Posts: 709	yes, i think it does sit higher up front. still need to tweak the fork height length.

May 21st, 2012, 10:27 AM	#13
gt_turbo ninjette.org sage Name: L Location: WI Join Date: Apr 2011 Motorcycle(s): '09 250R, '13 CBR500R Posts: 709	Update: So I fixed my fork/triple moving during braking issue by replacing the steering stem bearings/races which lead to other important discoveries. While I had the triples out, I compared the lower triples, the stock 250 and the modified 636 I had bought. Doing some measuring from the top surface of the lower triple to the end of the stem tube. The lower triple was incorrectly machined/pressed about a quarter inch too deep. This created a lack of threads for the stem nut to grab onto and possibly why there was slop in the steering stem bearings. I took the modified lower triple to a machinist to correct. He also determined that the lower triple was bent! This explains why my front tire is not straight when the triples appeared to be straight and the wobbling tire issues. Luckily, when I picked up the '05 636 forks, the lower triple also came with it. So my machinist basically re-did all the work on the lower triple. He said whoever did the original job did piss poor job. The stem tube was about .005" off in circular runout with respect to the welded on adapter piece that is slightly larger in diameter than the 250 stem tube and press fitted into the 636 triple. The adapter also did not have a stopper lip, so the stem tube could have potentially been pushed right out of the triple over time! After getting my straight 636 lower triple modified and the steering stem bearings replaced with the All Balls kit, my bike now rides straight and I can finally take it with confidence into the twisties. Time to play around with the fork height/rake angle to find what suits me best.

August 4th, 2012, 04:31 PM	#18
gt_turbo ninjette.org sage Name: L Location: WI Join Date: Apr 2011 Motorcycle(s): '09 250R, '13 CBR500R Posts: 709	after taking the bike out to track with the 636 forks, i thought i'd update this thread for anyone who is thinking about doing this swap. two words: SIMPLY AMAZING! in the corners, it holds the line perfectly. you don't get that squirrely feeling when you're leaned over and wondering, is it gonna hold or will it slip out from under me. future mod will be an aftermarket rear shock. gotta start saving.

August 30th, 2012, 12:23 PM	#20
jman511115 ninjette.org member Name: John Location: Buffalo NY Join Date: Sep 2009 Motorcycle(s): Ninja Posts: 122	Hey, did you use the stock master cylinder? And how come only one rotor?

March 16th, 2015, 07:07 AM	#22
Jetfoi ninjette.org member Name: Thom Location: Virginia Join Date: Dec 2014 Motorcycle(s): 2013 zx6r and 1995 250r Posts: 69	awesome write up! __________________________________________________ spend all the spare time on two wheels

March 16th, 2015, 08:18 AM	#23
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.	Looks good, did you have to clearance the fairings or shrouding to fit the wider forks? __________________________________________________ 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

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