What's in a fork swap?

[Benyen Soljax]

I'm swapping the regular forks out of my 2004 R6 with inverted forks from a 2005 (same bike, inverted forks) when I return from Iraq. This works for people with the 2003-2004 R6 and 2006-2009 R6s, but what about other unfortunate souls? My questions is that if you didn't have a convenient setup like the yammies with the one year of inverted forks on the 2005 R6, what considerations must one take when swapping regular forks with inverted ones? Are there only certain forks that you can use? Do the dimensions of the bike change if using forks from a different bike? I would appreciate it if someone with much more experience than I could enlighten me on this subject of fork swapping.

edit: I bought a whole front end swap for my bike (Forks, TT, Clip-Ons, Brakes, No need for new wheel), as I understand there is different levels of swapping, maybe the issues of each level can be explained?

Edited March 19, 2010 by Benyen Soljax

[Zach]

I'm swapping the regular forks out of my 2004 R6 with inverted forks from a 2005 (same bike, inverted forks) when I return from Iraq. This works for people with the 2003-2004 R6 and 2006-2009 R6s, but what about other unfortunate souls? My questions is that if you didn't have a convenient setup like the yammies with the one year of inverted forks on the 2005 R6, what considerations must one take when swapping regular forks with inverted ones? Are there only certain forks that you can use? Do the dimensions of the bike change if using forks from a different bike? I would appreciate it if someone with much more experience than I could enlighten me on this subject of fork swapping.

A fork swap is mainly dependent on the steering stem and bearings. Many bikes can swap easily because manufacturers use the same steering stem and bearing specs over many different models.

Sometimes it takes swapping to different bearings to make one stem fit another bike. Other times it requires changing steering stems by pressing out the original from the bottom triple tree and pressing in one that fits.

[redkow97]

i'll take a quick stab at this, but I admit I haven't done it.

there is no simple answer. it really depends on the bike, but...

- if you swap forks of the same diameter, there's probably no need to swap triple-clamps.

- if you're changing from conventional forks to inverted forks, then it's highly likely that the top portion of the inverted fork is thicker, and you'll need to swap triple-clamps as well.

All of this may or may not effect what front wheel and brake setup you can use.

In my case, the 2003-2004 600RR has conventional forks, but the 2005 model has inverted forks. That's essentially the ONLY difference. that said, I'm pretty sure I would have to switch to 2005 triple clamps to make the 2005 forks work.

Front wheels may or may not be identical, but then you also have to consider the braking systems - the mounting for brakes on inverted forks is rarely the same as it is on conventional forks, so you may be buying new calipers as well. If the calipers are different, the master-cylinder may be different.

Before you know it, you've basically put an entirely new front end on... so "fork swap" makes it sound a lot simpler than it is.

[Benyen Soljax]

@redkow: Yeah, I know what you're saying about the parts adding up. The only thing you can take off the front end that I didn't buy is a wheel and the fairings/gauges and all related parts to that. The rotors are different but the wheel is the same, I had to look up the part number on Bikebandit.

So aside from the triple clamps, the main concern is the stem length and the bearing type? I'm assuming that various stems have different widths as well, meaning you couldn't just press any stem into any triple clamp?

[Zach]

So aside from the triple clamps, the main concern is the stem length and the bearing type? I'm assuming that various stems have different widths as well, meaning you couldn't just press any stem into any triple clamp?

correct.

fortunately, most manufacturers buy their suspension components from outside companies and therefore there is a LOT of compatibility with various parts. Unless you're working on a rare or really old bike, usually you can find at least one person on the interweb that's done the swap you're looking to do.

[Benyen Soljax]

Does it change the steering dimensions or how long the rake/trail is? Are those things you need to measure out to keep the bike the same?

[Zach]

Does it change the steering dimensions or how long the rake/trail is? Are those things you need to measure out to keep the bike the same?

there's no definite answer. some bikes yes, others no.

My specific experience is with SV's. It's common to install gsx-r forks on them and they are 10mm shorter than the stock forks. Some people make up the difference by installing a 120/70 tire instead of the stock 120/60, others purchase replacement fork caps that act as a 10mm extension piece.

I know it doesn't give you the pure "I figured this out" feeling, but searching for your specific swap online will help you find out what to expect.

[natedogg624]

Does it change the steering dimensions or how long the rake/trail is? Are those things you need to measure out to keep the bike the same?

you'll need to measure from the center of the axle to the bottom of the lower triple clamp and write this distance down

when you install your new forks, youll need to adjust the height of them within the clamps so that the distance from axle center to bottom of the lower triple clamp is the same to maintain the same trail.

rake should stay the same, look up the tech specs between the two bikes and see if there is a difference.

[Zach]

rake should stay the same, look up the tech specs between the two bikes and see if there is a difference.

unless the specs specify whether the rake is done in the steering head or in the triples, you won't be able to 'look it up'.

Also, USD forks are typically shorter than the OEM forks so you can't usually adjust them to match the original ride height.

[serpentracer]

that conversion on a R6 only requires the

1. forks

2. top and lower tripple

3. brake master cyclinder

4 rotors

5 calipers

6. front fender

7 and the brake lines (because the radial master cyclinder has the hose mount under instead of coming out the side like yours does) the banjo fittings on the lines are at a 90 instead of straight like they are on yours

8 and possibly the spacers for the rim. I'm not 100% sure on that.

Edited March 25, 2010 by serpentracer

[Benyen Soljax]

You're forgetting that you would need a new axle and new clip-ons as well

I just checked the schematics on bikebandit and the wheel assemblies look identical except for the axle, so hopefully I should be good.

I keep forgettign about that fender too...I'll probably be without one for a while until i remember/care to pick one up.