Topic: R6 Fork Swap information gathering

[Scott S]

 I've decided to follow in the footsteps of FunJimmy, Franky, Camrector, et al, and do the R6 front end swap. I've read through several threads and saved some pics and the diagrams that Franky posted. I've made a (partial) parts list.

 Some of the things I see in my vision are stock (appearing) gauges, controls and a front fender. And handle bars. The bars seem easy enough. Gauges might be tough if I need a speedo drive, so I might just settle for something in the stock looking category. And a stock size/appearing headlight.
 What about a fender? Any way to run a chrome fender with this swap? Maybe a CB350 fender for an 18" wheel?

 So far, the parts on my list for eBay and Craigslist searches are:

* '99-'02, '03-04 R6 calipers (other options that work?)
* '95-98 Honda CBR600 F3 rotors
* Buell M2 Cyclone headlight brackets

 For the forks, can you tell me what year R6 forks and triples to look for? I think that some of the earlier.... '99-ish.... are the same diameter but longer? Which ones are the preferred years for this swap?
 I'm sure I'll have more questions soon, but this is to just get me started.

[FunJimmy]

Hey Scott,

I can't confirm fork length between the model years. I thought they all had the same length. What I did discover is a difference in offset. If memory serves, the early triples have a bit more offfset. Not as much as your stock CB triples but something to consider. Yamaha continued to use these forks on the '06-'09 R6S too so keep that in mind while shopping.

Speedo drive was my issue as well. It's difficult finding a 20mm ID mechanical speedo drive. Kawasaki ZRX models use a mechanical speedo drive. I had considered investigating at the time but went the GPS route instead. Still might be worth considering.

With a little ingenuity a chrome fender is easy. Look for something like a CB650 with the riveted fender stays and make new ones as needed.

Buell headlights are good too.

Cheers
FJ

[Camrector]

Do it! You won't be dissapointed at all.
I rebuilt mine using Racetech springs, and gold valves. Way over kill but they are butter. I used the Cognito top tree and Hub for the conversion. The off set of stock 04
Triple is 45mm compared to 55mm stock 550. Do your measurements and decide on a trail number that you want, and cognito will build a tree to the corrected offset for you. I stuck with the stock r6 45mm and have a trail of 4.25.
With the cognito hub Devin recommends 04-05 gsxr rotors. I still encountered clearance issues with the spokes and calipers (04 r6 calipers) that just required a little grinding of the caliper. This was because of the spoke angle of the 18 wheel.
Just some all ball bearings and your good to go. And a little oven cleaner and scrubby gets rid of the horrible blue anadizing!

Fender is easy just have to make some mounts. I used a moto lanna cb550 fender from ebay

[Scott S]

 When you say the early triples have more offset, is that good or bad? Which direction is preferred?

[Camrector]

Depends on what your trying to do, but more closer to what stock cb550 offset would be. But that would all depend on fork length, wheel height(w/ tire),etc etc, to find your trail number. With my 18 in wheel,  Avon 100/90 tire, 04 length r6, 50mm offset was measured to be damn near perfect stock cb550 trail numbers. I left it at 45mm to have a slightly better high speed stability, and slightly slower turn in. It's not a track bike

[FunJimmy]

Depends on what your trying to do, but more closer to what stock cb550 offset would be. But that would all depend on fork length, wheel height(w/ tire),etc etc, to find your trail number. With my 18 in wheel,  Avon 100/90 tire, 04 length r6, 50mm offset was measured to be damn near perfect stock cb550 trail numbers. I left it at 45mm to have a slightly better high speed stability, and slightly slower turn in. It's not a track bike

All things being equal, a 5mm difference in offset is barely noticeable.
Due to the improved confidence gained with suspension mods the additional stability is a good thing. 

[Scott S]

 What about single disc vs. dual? Is there a difference in the hub mods and spacers?
 

[FunJimmy]

What about single disc vs. dual? Is there a difference in the hub mods and spacers?

The hub spacers on my build are the same so I could run dual disc if needed but I honesty don't feel a need for more than this Brembo setup.

[Camrector]

I went dual mainly for looks. With the stock r6 master and calipers stopping power is incredible. Smooth but I bet I could get my rear tire off the ground if I wanted to

[540nova]

What about single disc vs. dual? Is there a difference in the hub mods and spacers?

The hub spacers on my build are the same so I could run dual disc if needed but I honesty don't feel a need for more than this Brembo setup.

That looks great!


Sent from my iPhone using Tapatalk

[Franky]

I mounted the original CB550 chrome fender. It wasn't that hard and looks classic. Check these out: http://forums.sohc4.net/index.php/topic,118983.msg1433623.html#msg1433623 & http://forums.sohc4.net/index.php/topic,118983.msg1450119.html#msg1450119

[Franky]

And yes, one disc is more than enough. The stopping power with two discs is REALLY strong.

[Scott S]

 Excellent information. Keep it coming, guys!

 Are there any other rotors that will work with the swap? What other models should I be keeping an eye out for?

[Camrector]

Well if your using the stock cb550 hub and making your own spacers like Funjimmy, the 89-96 fzr and yzf 600 rotors fit the 6 bolt pattern perfectly. They are 290mm I believe maybe 298 I'd have to check my notes. I'm going to use these on a set of cb550 Lester's I have. Remember though to check caliper clearance with the spokes.
If you cheat like I did and use a cognito hub use what he recommends 04-05 gsxr rotors

[Scott S]

 As of right now, planning on using the 550 hub.

[calj737]

Its not so much the hub that alters the spoke angle as the diameter and width of the rim. When you use an 18/19" rim thats wider than stock, the spoke flares outward earlier and conflicts with the caliper backside. If you use the stock hub, and 18" 2.5" rim (aluminum now, Scott!) you should not encounter any interference. And quality aluminum rims would be very appropriate for the suspension upgrade.

[Scott S]

 Aluminum rims are the plan. I actually don't want to get TOO wide. I prefer the look of close to stock width tires and the skinnier tires keep the bike flickable, in my opinion.
 I understand that I'll gain a lot of that back with better suspension, modern tire profiles and less unsprung weight. I'm not doing this solely for the sake of having the fat tire look.

[Camrector]

An 18in rim WILL encounter caliper clearance problems, wheather it's one side or both. The spoke angle is lower with the smaller wheel. A 19in wheel most likely won't, as the spoke angle is greater. It's not a big deal and a few minutes with a grinder takes care of it. I mentioned this already though earlier. The rotor diameter though should be considered too. Putting something too big on there will cause fitment issues with the stock mounts, then again caliper clearance  issues if you have to move them.

[FunJimmy]

Its not so much the hub that alters the spoke angle as the diameter and width of the rim. When you use an 18/19" rim thats wider than stock,the spoke flares outward earlier and conflicts with the caliper backside. If you use the stock hub, and 18" 2.5" rim (aluminum now, Scott!) you should not encounter any interference. And quality aluminum rims would be very appropriate for the suspension upgrade.

Rim width has no impact on spoke angle or clearance. Spoke nipples are centre of the rim regardless of width.

[FunJimmy]

An 18in rim WILL encounter caliper clearance problems, wheather it's one side or both. The spoke angle is lower with the smaller wheel. A 19in wheel most likely won't, as the spoke angle is greater. It's not a big deal and a few minutes with a grinder takes care of it. I mentioned this already though earlier. The rotor diameter though should be considered too. Putting something too big on there will cause fitment issues with the stock mounts, then again caliper clearance  issues if you have to move them.

If Scott intends to use Yamaha R6 calipers (as I believe he is) rotor diameter is fixed at 298mm. R6 calipers are wide and to minimize clearance I had to trim the mount tabs as well as back cut the calipers.



 

[FunJimmy]

Take a look at Franky's thread.
He did an amazing job of documenting the fork swap (including drawings) and made no mention of calipers clearance issues.

http://forums.sohc4.net/index.php/topic,118983.0/all.html

[Camrector]

"In FunJimmy's original build, he had to shave off quite a bit of the calipers to make enough clearance for the spoked wheels.

It turned out, I only had to shave of a little of the right caliper to make things work. Everything looks quite balanced though, so I can't really tell why the left side didn't need any extra clearance...



So I have been riding this setup all summer now, and the new fork and brakes are performing amazingly well.  The fork feels good going into turns and not too stiff as Jimmy mentioned in his thread. But, I'm also 191 cm (6"3) and 95 kg (200 pounds) + I may not be a good enough rider to be able to properly judge such things!

I'll update the thread with some pics of the 'finished' bike soon. (Never ending build ;-)"

Franky thread


Yes he had clearance issues as well. Also used a 19in wheel

[Franky]

Yes, I had to do some minor grinding on the caliper(s) to make enough clearance. I just went out and had a look, and wow it's tight! I only shaved off a bit of the left caliper, but I think I'll take some of the right one as well.


Left caliper - hardly any clearance at all! I think I'll shave a bit off this winter. Never had any troubles with it though.


Right caliper - a little material has been removed. The clearance is maybe 3-5 millimeters.

[Scott S]

 I've done similar clearancing on Brembo calipers when used on an XS650. Just buzzed them with a grinder.

[Scott S]

 I have a set of risers from a CB350 that bolt on. As long as the shaft is long enough, why couldn't I drill the upper triple and use them?