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My younger brother finally got bored of his little 2005 yamaha zuma and upgraded his arsenal with a 2006 650r.



One of the issues his bike has, is the forks. The stock conventional forks look like this and are ever so slightly bent:



I encouraged him to look at a 636 swap for the future like many have done here (i did GSXR swap on my bandit- so i know the process a little)

with the front swap, does it matter the year ? would zx6rs also fit? was nothing needed to be swapped or machines pressed?, like the steering stems or whatever?


regarding the rear wheel, i'm sure he would want to go with a 180 tire, so whats the easiest way to make this happen? do we use a 636 rear wheel + tire? would it fit into the stock swinger? do spacers need to be fabricated? Any clearance issue with the chain?

I PMed a member who did a swap, so i hope to hear from him, but I also made this thread incase somebody out there has something to say... I appreciate it greatly.


here is how his bike sits at the moment with his first few mods... mine is the bandit below. He went with a cheap headlight, but plans to modify it for better light output, or swap it out entirely once his budget increases







edit: he will sign up here and make his own introductory thread soon enough, i hope he enjoys his bike and build as much as I did, with the help from all you guys.
 

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Breaking shit...
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Blue Ridge Performance makes a 180 hub kit. If I remember correctly, the kit uses a 636 wheel and different spacers for your stock hub.

Theres also a shit ton of info on fork swaps for the 650r at riderforums in the 650r section. I think the 03-04 will be a direct bolt on as long as you have the complete front end (wheel, axle , brakes, triples and forks) but don't quote me there....
 

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Nice looking bikes both of you have there. I am a big fan of Bandits and I love what you've done with it. As for the Kaw, I personally pull the triples off and take a look at the bearings and head tube and measure everything you can get a tape measure or calipers around and then log it all. The more information [measurements] you have, the easier it is to cross reference other parts. Takes alot of the guess work out of the process. I had a few Honda mechanics tell me I couldn't put gsxr 1300 triples and forks on my 94 cb 1000....but I did some research on the steering stems and found they were exactly the same diameter on inner bearing race and base only the CB tube was longer to reach through the longer CB head tube. So, I took both triples over to a friend and we pressed both stems out and pressed the CB stem into the GSXR triple and used the factory CB bearings and simply bolted the 1300 front suspension on to the bike.
Of coarse, I had to show the same guys who told me it wouldn't work without having machined a completely new steering stem and upon seeing the bike ridden they thought "I" was the idiot!? lol!
MORAL OF THE STORY IS....DON'T BELIEVE EVERYTHING YOU'RE TOLD. TAKE A LITTLE TIME TO DO SOME RESEARCH OF YOUR OWN AND YOU WILL THEN HAVE KNOWLEDGE BASED ON YOUR OWN FINDINGS.
And that my friend is priceless. Good luck and have fun!
 
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In hindsight I wish I started a project thread.

Anyways, when I purchased the bike the triples were lowered about an inch from the top of the forks. I'm not sure if the forks bottomed out on the triple or just before, i didn't pay too much attention to them at first.

I liked the initial stance and I would never have touched the forks/triples if it hadn't been for a Renthal bar clearance issue.


After the forks were moved back to stock positon, I noticed there was barely any sag in the front. So onto a suspension adjustment.
I realized I do not have the luxury of owning a super sport when I ran into a fork suspension adjustment issue.

tldr, the inner fork tubes jumped out and the bike is slammed, I thought that it was still possible to increase sag in the front by shortening the fork tubes at the expense of decreasing the range of motion of the forks. So i went ahead and bought a pipe cutter from Lowes.


Before I planned to cut anything vital to the front suspension system, I raised the bike off the ground to see where the inner fork tubes sit when the forks are fully extended. To my surprise the forks stayed stuck. That's where I am now. Called it a day,planning on cleaning the air filter and replacing the fork lube/oil tomorrow.

QUESTIONS: How do I reassemble the inner fork tubes back inside of the forks? Would cutting the inner fork tubes 5mm-15mm be irresponsible? Would the tool I bought even cut the fork tubes?

QUESTIONS about other things: In neutral my bike makes a ticking noise when the clutch is engaged (clutch lever not pulled in) and it greatly decreases/goes away completely when the clutch is disengaged (clutch lever pulled in) . I know all the rave about a twin and how things just sound weird all the time, but I SWEAR i remember the exact moment it started happening.

Side Notes: My bike has ran a bit too hot at times since ive had it due to a radiator cap issue and messing with a new reservoir & air in the system. Never hot enough to turn on the indicator light. I'll post a youtube video of the sound tomorrow.
 

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Capt. Slow
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For setting your sag:
When you say inner fork tubes I'm assuming your referring to the short tube between the fork cap and fork spring which is also called the preload spacer. If so then shortening them will decrease the amount of preload on the fork springs and increase your static sag. I recently installed some adjustable preload caps that I believe are from an SV650 (I purchased them from blueridgeperformance.net) that made setting the sag up front a breeze but require a bit more room between the bars and triple. I have my triple about 5mm down from flush with my dirt bars on and have plenty of room for the adjusters. But you should be able to use your pipe cutter to trim that tube down a little bit at a time until you get your desired sag numbers (usually 30-35mm for street). A quick google search will provide you with how to properly determine static sag.

In regards to your forks being stuck:
Are you saying they are stuck fully compressed? If you haven't straightened/replaced the inner fork tubes they could be binding up. Or in my case I had the plastic spacer that holds the damping rod at the bottom of the outer fork sticking at full compression for some reason. I wound up sanding it down a bit around the circumference till it moved freely like the other side. I would consider replacing the bushings when you do the fork seals since you'll already have the forks taken apart.

Disclaimer: I am by no means a suspension expert but just recently rebuilt my 650R forks with some RaceTech goodies and have been doing a lot of reading on setting up/dialing in suspension so I'll try to help as best I can.
 

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Ah yes, I definitely was referring to the preload spacer. I honestly thought I would only be adjusting a 10mm bolt on the top of each fork to get to the desired suspension. I had no idea what I was getting myself into. I'm not planning to replace much on these forks as it'll be wasted effort. Only the oil after I assemble it back together and maybe something I can slip on as a replacement fork seal cover without taking the forks off the bike.
I plan to cut the preload spacer since it's already out.

Now back to the forks being fully compressed. Is there anyway I can continue to do this without taking the forks off? Have I damaged the forks further and do I need to replace components because of it?

I'm a college student doing this with a set of $10 tools in a garage at the bottom of my apartment building, please tell me I didn't screw up too bad. I was planning to replace the forks completely, but not here.

ALSO, the bottom couple of threads on one of the fork screw caps ( the one that came off second) are messed up. I can't screw it on and I'm scared to start applying torque on it when it's crooked on the fork.
 

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Capt. Slow
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Ok so the fork seals themselves aren't leaking, just the dust cover is shot? How soon are you planning on your 636 front end swap? If the forks are bent fore/aft then your not going to be able to straighten them while assembled. If your lucky they might just be twisted and the triples are out of line which is an easy fix. Let me know if that seems like the case. As for them being stuck compressed... If how you have it suspended is good and solid see if you can yank the forks back down. If it's the spacer like mine was then there's no way to get at it without disassembly. Honestly though in the 10k mi I put on the bike before I disassembled the forks I never had an issue with them binding up. I just noticed it when I had them off the bike with the springs and everything removed so it may never actually touch that when everything is assembled. If you can't get the cap to line up straight and engage correctly you can probably snag a good one for little money off ebay.

TL,DR
Lift the bike, yank the forks down, you'll probably be just fine once everything is assembled. Replacement fork cap should be inexpensive.

I hear ya on the working on a bike at college thing. I think I had a total of 4 different bikes in my college apt living room for service while I was there and removed/reinstalled the engine from a Buell XB12R in a small storage garage also.
 

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Dude you're amazing, thanks. Big fan of your build too. Im pretty sure its the triples out of line as you suspected. And yeah only the dust covers are shot.
When I raised the triples/lowered the forks I used an ammo container under the muffler... Needless to say I felt bad for allowing so much shear stress on the exhaust bolts. What could I use instead to properly yank on the forks and where should it be placed?

Edit: the 636 swap is happening 2-4 months from now.
 

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Capt. Slow
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Aside from a front stand that lifts at the steering stem/lower triple you can use ratchet straps attached to the frame running up to some rafters if you've got access. Jackstands or something under some frame sliders or where they would attach. Basically any way you can find to support a solid point from the middle to front of the bike that gets the front wheel off the ground. I think when I was installing my triples I used a block of wood between a jack and the flat portion of the oil pan. That was with the exhaust out of the way though. However you support the front make sure it is secured and wont tip. Once it's up a good swift yank should do the trick, especially with the weight of the wheel assisting. Once that is fixed you can fix the twist issue.

Also, you loosened the top triple clamp bolt to remove/install the fork caps right?
 

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Aside from a front stand that lifts at the steering stem/lower triple you can use ratchet straps attached to the frame running up to some rafters if you've got access. Jackstands or something under some frame sliders or where they would attach. Basically any way you can find to support a solid point from the middle to front of the bike that gets the front wheel off the ground. I think when I was installing my triples I used a block of wood between a jack and the flat portion of the oil pan. That was with the exhaust out of the way though. However you support the front make sure it is secured and wont tip. Once it's up a good swift yank should do the trick, especially with the weight of the wheel assisting. Once that is fixed you can fix the twist issue.

Also, you loosened the top triple clamp bolt to remove/install the fork caps right?
Oh man, I want to say I did, however it only struck me once I had already removed the caps. How would I go about with the twist issue?
 

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Capt. Slow
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For the purpose of this example we'll say that the wheel is twisted to the left, so that when it is pointed straight your bars are turned slightly right. So to correct find a nice solid post or wall that you can put the left side of the front wheel against, then loosen ONLY THE TOP triple clamp bolts. Give the bars a quick twist to the left to line them up correctly with the front wheel.

I've used this method on a few different occasions. It may not be the most precise route in the world but it's quick and easy.
 

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The good: I cut the fork tubes

unstuck the forks


fitted the problem fork cap back on
& straightened the handlebar


The bad: When attempting to find a good point to jack it up I dropped my bike. The makeshift coolant reservoir is now ugly, the clutch cover is marked, renthal bar & front brake lever scratched & possibly crooked, passgenger footpeg scuffed. All of this on top of a coolant issue, fughhhhh.






I thought I wasn't going to be able to get the forks loose, until I used leverage between the tire and bottom triple. I also slightly marked the top of the forks since my patience drew thin. Dammit man .

Now my main issue: the cooling system. I wish I never messed with it after I fixed it the first time. I ordered a used radiator cap and expelled any air bubbles I saw at first in the line. Any worry I had about the engine getting hot was gone. I decided I didnt want the ugly thermos anymore so this badboy was put on:




Made the bike feel like a cool little toy. air started coming out of the radiator again though. I decided to change back to a more aesthetic bottle & flush the system. Air is still in the system!

I regret not paying an extra $10 for a new radiator cap. I'm not sure where to start my troubleshooting.

When I open the coolant drainage valve, it drips.
Water pump gets really hot
air bubbles sometimes come at rapid rate out of the radiator when engine is on.
Should I set up a gravity fed reservoir to make my life easier?

Possible causes?
radiator cap
radiator
head gasket
water pump gasket
 

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How she sits now





I also have a question as to how these forks work. The spacer dictates the preload on the spring, which controls how extended or compressed the fork is when holding the bike up, correct?

So to raise the bike a little I would add some sort of spacer ? How long is the spring inside of these forks?? I didn't expect a 15mm cut to the preload spacer to yield such drastic results.
What notch do you recommend the rear spring to be set to for a 180lb rider? There are currently two notches above the metal bracket on my rear spring.

THANK YOU so far for everything! All I really want to do is ride her without things getting too hot.

And a lot of other mods... but for later.

edit: the reason I ask about the forks is because now that I'm looking at the pictures I'm not sure if the forks were fully extended when I placed the preload spacers back in. Would the fork maintain this length because I kept it there upon reassambly? Or is the new stance of my bike solely based on me shortening the preload spacer?
 

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I'm a little confused on your goals for this fork adventure.

So, biggest problem you have with your forks is the ride height?
Why did you cut that preload spacer?!!
You wan't the ride height to be higher? Why?
Are the forks too spongy for your liking now?
Is it a firmer front fork your end goal?


If so, first thing is change the oil. It will help A LOT with soft forks with more than likely shot fork oil. If changing the fork oil doesn't help out then you could add to the level of fork oil in the fork to firm up the ride. If changing the oil and then adding to it still doesn't accomplish what you are after the next logical thing to do is to change to a heavier weight fork oil.

This is of'course assuming the forks, seals, and bushing in the forks are in proper working order. IF you are going to do anything like the above for fuck sake change those seals too :D
 

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Not sure if I overdid it, I was asking in case. (I think I prefer the look of the bike sitting higher up as opposed to the pictures I just posted) I messed with the forks for a more forward stance and more rider sag. The front is now lower as desired, however I realized the latter barely improved. Not too surprised there to be honest. I have yet to take it for a real ride. The forks probably will be fine with new oil till the next set of forks come in.
 

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Capt. Slow
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Ok... lets slow things down and back up a bit. Do you have a service manual that you are working from? If not, here. Now, static sag is the amount of compression of the suspension measured from full extension (i.e. front end in the air) to weight of the bike and rider in full gear and riding position. That measurement should be 30-35mm. Read about it here. This is a suspension performance thing, not an aesthetic thing and the same process is used for the rear. 15mm seems like a lot to remove, but if it was too much you can probably get some aluminum or steel tube that same size for pretty cheap to go back to stock. Raising/Lowering the fork tubes in the triples changes your rake/trail. Flush to 10mm is the generally recommended adjustment range to stay within a safe stability range since if the trail is reduced too much the bike can become unstable at high speed but makes the agility/flick into corners quicker. I would want to take those things apart, replace the seals, check the bushings and make sure the tubes are straight. Conventional forks like this are really simple in their function and design.

So here's what I suggest at this point. Grab a buddy, figure out what your sag is front and rear, change/flush/fill your coolant IAW the service manual. Get those dust seals swapped out (which can be done without fork disassembly, Just have to remove them from the triples), and let us know where your at. And remember, small changes in the suspension can make a big difference. So just do a little at a time and see where it gets you.
 

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This Wednesday I'm ordering:
Seal dust covers
Fork oil,
Coolant drainage gasket (aka a washer, can I pick up anywhere?)
A new radiator cap (should I just get a whole new radiator for double the price??)
Should I also get thermostat/water pump gaskets just in case??
I think I compressed one side of the exhaust gasket too much, it definitely needs to be replacsd


This fork adventure was just to increase rider sag, but I realized the progressive spring isn't changing so I essentially increased total sag. I'm glad I did this, forks in general don't seem so cumbersome anymore. I'll measure the total sag when I put in the fork oil and adjust the preload spacer as needed. Possibly paint the beatup looking forks and triples while I'm at it as well.

Non urgent things to buy courtesy of dropping her:

Thermos bottle
Front brake master cylinder (ugly and now possibly bent)
Shorty levers (can I just buy a brake lever?)
Barend mirrors


I'm currently running 50/50 watter wetter and distilled water, should I order engine ice?
I want to knock out every possibility for this coolant issue, before I have to take it to the shop for a head gasket replacement.
 
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