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Discussion Starter #1
Hi there... With some encouragement and details from Thrux-Tonup (and others) regarding the Honda CBR600F3 cartridge fork conversion, I went ahead ad did it!

I won an ebay auction for a nice complete F3 front end assembly, fork legs w/ internals, sliders, triple trees... the whole shebang for under $200 delivered. The forks appear to have had little use, good overall condition. BTW...you only need the tubes & internals...the F3 sliders are not used.

So... I tore into the F3 forks, and removed the fork tubes, bushings & internals from the lower sliders as an intact assembly.

Here are some details that are fairly important:

1) The lower screw that secures the damper to the slider is a different size on the F3 than the Triumph screw. Use the F3 screw when assembling the hybrid fork (meaning use of Triumph sliders on F3 legs & internals) Also, be sure to use the Triumph copper washer for a seal, and replace if worn

2) Use the F3 lower (split) bushing on the F3 fork leg. Replace if worn per Honda specs, i.e. teflon coating is worn away.

3) Use the Triumph upper (non-split) bushing, washers, and seals in the Triumph legs.

4) Fill each leg with 460ml fork oil. I used 15W, and it might be a bit thick but I like the increased damping

That's about it! Not too hard really. The F3 legs are about 1.3" longer than the Triumph legs, so they must stand proud of the upper triple clamp. I mounted my clip-ons up there and have a much more comfortable bar position.

The F3's have adjustable spring pre-load. I set it on the lightest setting for now but may tighten it up a bit. The forks also offer adjustable rebound damping. I have it set on the minimum setting and it feels just about right.

In looking at the workshop manuals for the Triumph and the F3, the exploded view drawings are confusing. I believe the drawings are actually drawn incorrectly, but hey...I only do that kind of thing for a living.

I made a composite drawing using AutoCAD of the two separate drawings, and labeled the parts either (H) or (T) for either Honda or Triumph parts that are placed in the new assembly. I did not spend too much on it so don't look too closely!! Also, any input on the drawing is appreciated in case I mislabeled something or perhaps got the order wrong. These parts really can only go together one way, so the only thing that might throw you is if you are missing some parts.

Here's the drawing (jpg) You can PM me if you would like a PDF with much better clarity. (Photobucket will not accept PDF's currently...)


BTW, I just took the bike for a shake-down cruise today over to the 7-11 for some gas & munchies. Everything felt fine...no noises, nice firm ride with no wallowing, overall it feels good.

I'll give it a better test report on Laureles Grade later this afternoon and let you know the verdict on handling effects.

Cheers,
BLIGHT
 

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Blight,

Nice bit of documentation...it actually saved me having to figure out the bushing arrangement on my own (thanks!!). I'm glad the bits went together well for you.

My turn to change out my forks has to wait for winter since I'm not slowing down until its too cold to ride...

Cheers,

--Rich
 

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Discussion Starter #3
Blight, Nice bit of documentation ... it actually saved me having to figure out the bushing arrangement on my own (thanks!!). I'm glad the bits went together well for you. My turn to change out my forks has to wait for winter since I'm not slowing down until its too cold to ride...
Cheers,
--Rich
Thanks Rich, and your information was helpful as well from earlier posts! I really haven't lost any riding time... with the swap. I did this last night out in my garage after dinner. Took about 2 hours. The hardest part was getting the %^&*# damper fixing bolt out of the bottom of one of the Thruxton legs!!!!!

It was torqued in so hard at the factory I bent one of my big hex wrenches trying to loosen it! Then, after it finally broke loose, it spun the damper inside the leg. I eventually figured a way to stop the damper from spinning...whew, that stupid screw cost me about 45 minutes!

Anyway...if all goes well you can do it easily in one evening, and be ready to ride the following morning. I just took it on a quick run over Laureles Grade at around 80% of my usual pace...just to feel it out. Verdict? Very impressive! I like a firm front end, it is definitely firmer (compression damping), but still not harsh. You can really feel it working to absorb the big bumps, and damp them out. There is no mushy wallowing as with the stock forks.

I haven't even tried adjusting them yet for rebound compression or pre-load. Just getting a baseline feel for the new front end. If you get all your parts together and want to do it-- just go for it!

Hope my diagram is useful for you and others wanting to do the swap. Here's a coupla pics of my new zero-degree bend clip-ons up on top of the triple clamp. I adjusted the pull-back angle to my liking.

Just out of curiousity, I went over and grabbed the SuperBar I had purchased (in case I ever do a bar conversion) and held it up to the clip-ons...it's a darn near exact match for pull back and flatness! The new setup is 28" end to end.




Cheers!
BLIGHT
 

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Thanks Blight, nice drawing. I've got that project on the bench right now waiting for new seals. Good to have confirmation on what to use from each fork.
Mike
 

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Blight, Good job as always. I recently went down the Intiminator path and was happy with the results. Had I not had any success with this then I was looking at the F3conversion. What clips on are you using? I don't recognise them. They look hollow - how's the vibrations (if any)? I have a vibration with my OEM clips ons which I am trying to reduce.
 

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Discussion Starter #6
Blight, Good job as always. I recently went down the Intiminator path and was happy with the results. Had I not had any success with this then I was looking at the F3conversion. What clips on are you using? I don't recognise them. They look hollow - how's the vibrations (if any)? I have a vibration with my OEM clips ons which I am trying to reduce.
Hey Matt... thanks very much! The billet clip-on bars are from Rockwall Performance (purchased on ebay for $95 USD). They are 41mm with zero degree bend. And yes... they are hollow 7/8" bars. The stock Triumph clip-ons have about an 8 degree downward bend that is uncomfortable for me. The 'flip and flop' option is too 'upright' for me, so I chose to get the flat bars. Incidentally, the CBR600F3 came with zero degree (flat) clip-ons, and among sport-bikes was one of the most comfortable in it's day.

I think there must be an amount of 'flex' in a tubular handlebar that can either eliminate vibration or enhance it depending on vehicle harmonics. All I can say is there is no discernible bar vibration with this setup. My bar-end mirrors show the rear view clearly at all rpm. The riding position is very comfortable with the 'flattening' of the bar angle, and the adjustable pull back to suit your comfort level.

I was actually pretty happy with the OEM forks after I installed the Progressive spring kit, and put in 15W BelRay fork oil. However, I was still looking for a more comfortable bar position. Having looked at tubular handlebar conversions (about $500 USD) I thought, why not get some flatter clip-ons, and mount them up high, on top of the triple clamps.

So, the F3 conversion makes sense for me because the fork legs are 1.3" longer, allowing the same bar mounting as the Honda CBR600 over the top clamp. The adjustable rebound damping is a definite plus... the preload adjuster is welcome, but already a feature of the Thruxton forks.

For the bars, I wanted some adjustable, flat (zero-degree) bars with some rise, and found the billet Rockwall units fit the bill for a reasonable price.

Anyway... I hope this information is useful to you!

Cheers,
BLIGHT
 

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Discussion Starter #8
What year model is the F3? It isn't called that over here so I'd like to know what yeats to look out for.
From the BikeBandit online 'fiche' it shows the CBR600F3 was made from 1995 to 1998. I know in 1999 the F4 went to 43mm legs so you'll want to stay away from that model.

Still very happy with the new front end performance by the way... it's been a few days of riding here and there and it feels great! Especially with my new higher and flatter bars!!!

Cheers!
BLIGHT
 

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blight,

Excellent job on the CBR 600 F3 Conversion for the Thruxton. I completed the conversion with zero trouble. I was wondering what you wound up with on the preload and dampener adjustments? I haven't figured out the best settings for me yet.

Pictures to follow!

Cheers!
 

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Nice looking conversion, I like the look of the clip on bars better than the dropped bars on the later (my) model but they are a bit to extreme for me, longer forks and mounting on top is an excellent solution. Nice colour too.
 

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Discussion Starter #15
Sorry for the rain on the parade...

Hi guys... yeah, I'm still here! The F3 leg swap is pretty simple, and requires very little fitment work. The problem with going with the later F4 legs and internals is that you can't use the the Thruxton/Bonnie sliders with the 43mm Honda F4 legs.

If you were to go with the full F4 fork setup, you are committing to a total front end change that would best use the original Honda upper and lower triple 43mm clamps. First task: Dealing with the different steering head bearings, which can be a bit of a hassle.

The other factor is then adapting the Honda F4 sliders to the Triumph front wheel axle, along with all the internal & external spacers. That would almost certainly mean a wheel bearing size change too. The last hurdle is adapting the Triumph (or one Honda) single caliper to the left Honda fork leg and lining it up with the Triumph rotor. It's not impossible, but it could be a ton of work.

The other way to go with an F4 fork assy. and triple clamps would be to mount the Honda cast 17" x 3.5" front wheel and dual discs to your Thrux or Bonnie. It will handle a lot better, especially if you have a 17" rear with a 180. Sport bike rubber is the only way to go IMHO.

I did a laced 17" x 3.5" single disc front and 17" x 5.5" rear on my Thruxton and love it.

I just completed a 17" x 3.5" cast Buell dual disc front wheel on my H-D XR1200 and love it too. So... bottom line? Don't be afraid to do whatever you want! (as long as it makes sense!)

Cheers,
BLIGHT
 

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I helped a few friends do the F3 fork conversion last weekend. It was ridiculously easy! Now the hard part is finding more good F3 forks. Thanks for all the help blight, your diagrams were invaluable.
 

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Hi guys... yeah, I'm still here! The F3 leg swap is pretty simple, and requires very little fitment work. The problem with going with the later F4 legs and internals is that you can't use the the Thruxton/Bonnie sliders with the 43mm Honda F4 legs.

If you were to go with the full F4 fork setup, you are committing to a total front end change that would best use the original Honda upper and lower triple 43mm clamps. First task: Dealing with the different steering head bearings, which can be a bit of a hassle.

The other factor is then adapting the Honda F4 sliders to the Triumph front wheel axle, along with all the internal & external spacers. That would almost certainly mean a wheel bearing size change too. The last hurdle is adapting the Triumph (or one Honda) single caliper to the left Honda fork leg and lining it up with the Triumph rotor. It's not impossible, but it could be a ton of work.

The other way to go with an F4 fork assy. and triple clamps would be to mount the Honda cast 17" x 3.5" front wheel and dual discs to your Thrux or Bonnie. It will handle a lot better, especially if you have a 17" rear with a 180. Sport bike rubber is the only way to go IMHO.

I did a laced 17" x 3.5" single disc front and 17" x 5.5" rear on my Thruxton and love it.

I just completed a 17" x 3.5" cast Buell dual disc front wheel on my H-D XR1200 and love it too. So... bottom line? Don't be afraid to do whatever you want! (as long as it makes sense!)

Cheers,
BLIGHT
Back to looking for a nice F3 set I guess.:eek:
 

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Hi all.

Has anybody done the full F3 front end conversion?

I'm wandering about doing it to have better brakes and wheels on my Thrux. (complete front end + rear wheel)

The SV 650 swap looks great, and also cheap, but then you might have to change the speedo. I think the CBR conversion could be a good idea as you have one less problem to solve.

Can anybody give me some advice?
 

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numberpi,

I've yet to do this work on my thruxton, but I have the bits sitting and gleaned as much info as possible off the various forums. The following blurbs are what I have related to swapping to F3 wheels...the fork tube info out there is much more comprehensive:

"Everything was easy, once I got the spacers and bearings on the rear tire swapped around. You have to use the bonnie axle and bearings. The front is a bolt on as long as you use the F3 lowers. I only had to swap sides with the spacers because I changed the direction of the spokes to match the rear. "

"...its a rear wheel from a cbr600 f3.you need to knock out the cbr bearings and replace them with thruxton/bonnie ones.use the thrux/bonnie axel and spacers.a small amount of machining is necesarry to get the cush drive bearing to fit and the cush drive spacer needs machining down a little.you will also need to swap over the brake rotors.sounds a bit complicated but when its all there in front of you its easy to see what needs to be done."

"sorry i have no pics. i done the mod quite a while back now but i will try to be as helpfull as i can. the mod requires a mixture of f3 parts and bonnie/thrux parts.
triumph- wheel bearings,wheel bearing spacer. cushdrive bearing, cushdrive spacer, axel, wheel spacers, brake rotor.
honda-cush drive,wheel,(bearings removed and triumph ones fitted)this is a straight swap the o/d of the bearings are the same. you need the triumph ones in there as the i/d is smaller on the triumph to fit the axel.dont forget to fit the triumph wheel bearing spacer between the bearings you can hold it in place by partialy inserting the axel.
you need to use the triumph cush drive spacer as it has the correct i/d for the axel i cant remember how much i needed to remove to make it the right lenth.but all you need to do is measure the honda one and make it the same lenth.dont forget you need to remove excess material from the fat end of the spacer!!!
after removing the honda cushdrive bearing you will find that the triumph cushdrive bearing is a bit too big to fit in the housig.measure the o/d of the triumph bearing and machine out the cushdrive bearing housing accordingly remember it is a press fit.remove both brake rotors and fit the triumph one to the honda wheel this is a sraight swap the triumph rotor is just a bit smaller.
i think that is it bolt it up and off you go! these instructions are for the f3 wheel.the f3 is 5.5 inches wide the earlier f2 is only 5.and i dont know what other differences there may be so make sure you have the same wheel."

That's all I have...sorry, I cut and pasted this out of various posts and didn't record the author's names. Be aware that, while the F3 front end swap is just that, it does NOT include swapping out the triple trees...you use your stock yokes (and stock front axle). Simplifies things quite a bit since you take fitting the triple trees off the table as something you need to work out.

Anyway, good luck and enjoy the spanner work.

Cheers,

--Rich

PS - you had a question regarding the speedo drive...no worries there since you toss it into your spares. The F3 has an electronic speedo, so you'll need to come up with another arrangement to get that to work.
 

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Thanks Rich, and your information was helpful as well from earlier posts! I really haven't lost any riding time... with the swap. I did this last night out in my garage after dinner. Took about 2 hours. The hardest part was getting the %^&*# damper fixing bolt out of the bottom of one of the Thruxton legs!!!!!

It was torqued in so hard at the factory I bent one of my big hex wrenches trying to loosen it! Then, after it finally broke loose, it spun the damper inside the leg. I eventually figured a way to stop the damper from spinning...whew, that stupid screw cost me about 45 minutes!

Anyway...if all goes well you can do it easily in one evening, and be ready to ride the following morning. I just took it on a quick run over Laureles Grade at around 80% of my usual pace...just to feel it out. Verdict? Very impressive! I like a firm front end, it is definitely firmer (compression damping), but still not harsh. You can really feel it working to absorb the big bumps, and damp them out. There is no mushy wallowing as with the stock forks.

I haven't even tried adjusting them yet for rebound compression or pre-load. Just getting a baseline feel for the new front end. If you get all your parts together and want to do it-- just go for it!

Hope my diagram is useful for you and others wanting to do the swap. Here's a coupla pics of my new zero-degree bend clip-ons up on top of the triple clamp. I adjusted the pull-back angle to my liking.

Just out of curiousity, I went over and grabbed the SuperBar I had purchased (in case I ever do a bar conversion) and held it up to the clip-ons...it's a darn near exact match for pull back and flatness! The new setup is 28" end to end.




Cheers!
BLIGHT
Encountering the same problem with the screw spinning the damper inside. How did you stop it from spinning?
 
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