Rc51 Sp1 Forks Vtec Install

I have been asked what I did to fit RC51 (SP1) forks to my VTEC so thought it was better to do little write up for the masses.

All the info you need is already here on VFRD but due to no specific write up for a VTEC I list parts I used & what I did. For major detail read all the other threads because that’s where all my info came from.

There are pics thoughout site which show what to do so no real need to post more of the same :P

Parts I used:
1. RC51 SP1 forks (not SP2)
2. RC51 Brake Calipers
3. RC51 SP1 Lower Triple Clamp (not SP2)
4. RC51 Axle
5. RC51 Wheel Spacers
6. RC51 Wheel
7. RC51 Rotors
8. RC51 Master Cylinder
9. RC51 CF Front Guard
10. RC51 Head Bearings
11. CBR954 Top Triple Clamp
12. CBR929 Hellibars
13. Braided Brake Lines Front (any kit long enough will do I used VFR750 kit)
14. Braided Brake Lines Rear (had made 1200mm long x2)
15. Custom Spacer 4mm thick to sit between Lower Triple Clamp & Lower Head Bearing (any eng shop can make it on a lathe)
16. 7.5W Race Fork Oil

Process to install:
1. Remove all brake fluid from bike; you really do need a vacuum bleeder for this to remove all fluid, but can be done messy way.
2. Remove standard front braking system, including lines that connect to blocks both sides of frame. If your going to leave hard lines that travel from front to back of bike either seal off with plug or zip tie small plastic bag over ends to keep out road grit.
3. Remove standard calipers, wheel, guard , clip-ons & fork tubes.
4. Remove standard upper lower triple clamps.
5. Remove standard head bearing outer race from frame (there is cut away in frame to allow you to tap out with punch).
6. Install RC51 head bearing outer race into frame top & bottom, I just use copper pipe to press into place hitting with hammer. You need to be very careful & make sure outer race is going in as square as possible & not hit with such force like you’re driving in a nail. You will know when seated due to thud feel felt through copper pipe.
7. Cut off RC51 SP1 lower triple steering stops.
8. Slide 4mm thick custom spacer onto lower triple clamp & install RC51 lower bearing on top. This is needed so lower triple clears oil cooler mounts on fairing frame, you can gain more clearance by moving oil cooler forward 5-10mm & redrilling some mount holes but only needed if still fouling oil cooler mounting bolt heads. You still need spacer to make sure you clear fixed position fairing mounts.
9. Install RC51 SP1 lower triple & 954 upper triple clamps, don’t apply grease yet if you need to fit steering stops due to test fit needed to mark there position on lower triple clamp.
10. Slide RC51 SP1 forks through triple clamps until fork length above 954 triple clamp & height of Hellibar fork clamp, ball park for fork position to make up for trail change (ball park measurement from bottom of frame to centre axel is 530mm standard forks, 510-515mm RC51 SP1 forks).
11. Install Hellibars with standard clutch & RC51 brake master cylinders to setup position for turning circle. Mark lower triple at this point for new steering stops if needed (I haven’t done steering stops; don’t need them & info on how to do is in other write ups).
12. If not doing steering triple clamp stops you then fit new brake lines etc, if you are you need to take apart again & then reassemble again with grease (note if your not doing stops you should apply grease step 9)
13. Fit guard, calipers, braided brake lines etc so front end is complete & front brakes are now not linked so add fluid & bleed.
14. You now have to address rear brake & I just used 2x 1200mm braided lines linked from standard master cylinder to rear standard caliper so all pistons are engaged. I found feel to be fine once I got used to it.

To adjust suspension for feel & turn in is a individual preference from person to person but with raising rear ride height to lowering front triple clamps through forks it’s easy to find the setup you want. At moment my bike has 3mm height raised at rear shock & top of RC51 SP1 forks are 40mm above 954 top triple clamp (VFR base fig is 1mm raised at shock = 3.4mm raised ride height rear)

Thanks for that listing. I have just started doing this for my 5th gen so this helps plenty (I have collected everything on VFRD that I have seen on this topic)

1. Veefer800Canuck did not need such a thick spacer under the lower stem bearing (just a large circlip) He has a 5th gen. I assume there is a slight difference on a 6th gen necessetating the slightly thicker spacer.

2. Veefer used the existing tapped holes in the lower triple for the steering stops. He screwed 8mm (?) cap screws into them. It is interesting that you did not need to do this. What finally stops the forks turning any further (what hits what?). Or do you simply not allow it to go to full physical lock & leave it at that?

[image: View Post]tok tokkie, on Aug 23 2006, 07:10 AM, said:

Thanks for that listing. I have just started doing this for my 5th gen so this helps plenty (I have collected everything on VFRD that I have seen on this topic)

1. Veefer800Canuck did not need such a thick spacer under the lower stem bearing (just a large circlip) He has a 5th gen. I assume there is a slight difference on a 6th gen necessetating the slightly thicker spacer.

2. Veefer used the existing tapped holes in the lower triple for the steering stops. He screwed 8mm (?) cap screws into them. It is interesting that you did not need to do this. What finally stops the forks turning any further (what hits what?). Or do you simply not allow it to go to full physical lock & leave it at that?

1. I haven't done a 5th gen but my problem was due to lower triple clamp RC51 SP1 would hit the oiler cooler steel mounts on fairing frame, which restricted bar movement. By adding the 4mm spacer as part of lower triple ass there is no hassel with things moving or clip falling out. From memory Veefer800Canuck added clips mainly to add thickness due to thiner bearing height with bearings he used compaired to standard VFR bearings. I just used standard RC51 SP1 bearings. If I didn't need to clear oil cooler mounts no spacer would be needed at all.

2. On the 6th gen full lock either side will hit radiator hose first before instruments so I don't really feel the need to fit steering stops, I just have clip-ons adjusted that way, radiator hose when bike running will swell if anything with pressure so it's not like it's going to squash. The lock to lock is really only a issue doing U turns & just incase there is give I have a little rubber pad stuck on fairing insert where levers might hit if ever they want to. If I crash well the bike is going to be stuffed anyway so extra damage is a no brainer to me with no stops fitted. Before you ask my insurance company knows about new front end & had no problem with it, infact they raised my cover due to extra value :)

Here you can see the radiator hose which works like steering stops
[image: Posted Image]

Here you can see hose from top
[image: Posted Image]

This is clip-on veiw, you can see rubber pad on right & it wouldn't even be needed if Pazzo lever didn't stick out further than standard RC51 lever by 10-15mm (but I like the Pazzo's). The internal fairing top plastic covers fit no problem I just don't bother with them due to always pulling things apart (just incase some 6th gen person asks)
[image: Posted Image]

thanks for the info mate.

[image: View Post]AB-Oz, on Aug 23 2006, 07:03 PM, said:

thanks for the info mate.
Hehe I feel there may be another local FE mod coming soon... Roy has imported this new virus called RC51 and everyone seems to be catching it! :salesman:

At this rate the October track day will see 3 or 4 of them...

Maybe I should have convinced SWMBO that we did not need a bigger house, because I need a bling front end on my bike :D

Hey Kirbs, the OzVFR gang take over the thread :)

see my sig? See how it says "+ stuff"? I like stuff :) Got a swedish bit arriving next week - always wanted to bounce up and down on a swedish bit...

[image: View Post]kirbster, on Aug 23 2006, 11:59 AM, said:

Hehe I feel there may be another local FE mod coming soon... Roy has imported this new virus called RC51 and everyone seems to be catching it! :salesman:

At this rate the October track day will see 3 or 4 of them...

Maybe I should have convinced SWMBO that we did not need a bigger house, because I need a bling front end on my bike :D

You don't need one your to fast now, us old farts need al the help we can get.

Plus you have a track bike to play on with more ground clearance than before, but it does need a wash which is your department :P

Great post, thanks!

So, for anyone that's done the frankenfork, what'd you think? I rode an RC51 last weekend and I was blown away by the absolutely rock-solid handling. The steering was heavy, but nothing phased it in a turn. The brakes were great of course.

What I reallly want is an RC51 with a bigger fuel tank and near-VFR ergos (I'm real tall). But, maybe a 5th or 6th gen with franken-fork and rear shock would be close enough. Less weight and liter twin torque would be nice, too. I've never ridden a Superhawk, that might be worth trying, also.

Good info. Do you use your bike as your daily commuter or is it strictly a fun bike? Just wondering as I have wanted to do the SP1 route, but I don't want to take away from the city bike that it is most of the time.
:lurk:

[image: View Post]chonsey, on Aug 23 2006, 08:44 PM, said:

Good info. Do you use your bike as your daily commuter or is it strictly a fun bike? Just wondering as I have wanted to do the SP1 route, but I don't want to take away from the city bike that it is most of the time.
:lurk:

I use my bike for fun, but this setup with adjustments to suit your riding style will only improve things for any type of riding. The reason the VFR's suspension can have so many rake angle etc adjustments is because from factory it's setup as such a neutral steering bike, it's just a matter of finding the adjustments to suit your style of riding & what you like. It takes 10-15 minutes to adjust forks through triple clamps or stick another shim in rear shock so adjustments are endless. The bigest improvemet with front end comes from compression adjustment which standard forks don't have.

I haven't yet seen (maybe because I'm not looking hard enough) why the 954 upper triple clamp is used. Does the RC51 upper not work?

thanks zroyz this is really appreciated.like this info,well done.

[image: View Post]Ikazuchi, on Aug 24 2006, 04:02 AM, said:

I haven't yet seen (maybe because I'm not looking hard enough) why the 954 upper triple clamp is used. Does the RC51 upper not work?

It all comes down to fork unloaded factory length, not all forks are same length & the standard VFR forks are longer than most. The reason for 954 upper triple clamp is gullwing shape which allows for fitment of clip-on above top triple clamp due to lower mounting position where as standard RC51 top triple doesn't have this. In the mods section on this site it's all explained in detail as others not me pioneered this setup.

And while on this, it's worth pointing out that both the CBR929/954 and RC51 lower triple will work, but the CBR one is likely to foul the oil cooler - RC51 gives more clearance (it's gullwing like the CBR upper).

[image: View Post]tok tokkie, on Aug 23 2006, 01:10 AM, said:

Thanks for that listing. I have just started doing this for my 5th gen so this helps plenty (I have collected everything on VFRD that I have seen on this topic)

1. Veefer800Canuck did not need such a thick spacer under the lower stem bearing (just a large circlip) He has a 5th gen. I assume there is a slight difference on a 6th gen necessetating the slightly thicker spacer.

2. Veefer used the existing tapped holes in the lower triple for the steering stops. He screwed 8mm (?) cap screws into them. It is interesting that you did not need to do this. What finally stops the forks turning any further (what hits what?). Or do you simply not allow it to go to full physical lock & leave it at that?


1: I did indeed space to ~3mm using TWO snap rings, one below the bearing on the triple and one above the race up inside the frame neck. Did this due to the RC51 using a 14mm thick lower bearing Vs. the VFRs 17mm thick bearing.

[image: Posted Image]
stem.JPG


2: There were no existing tapped holes in the lower triple, I drilled those holes and tapped them to place the allen head bolts. Did this from measurements taken with the front end mocked up using the ignition/steering lock as a guide. Turned the bars to one side, locked the steering, mapped out where the stop needed to be placed, repeat for the other side. No fouling of the oil cooler, lines or rad hoses for me.



[image: Posted Image]
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[image: View Post]veefer800canuck, on Aug 25 2006, 08:02 PM, said:

2: There were no existing tapped holes in the lower triple, I drilled those holes and tapped them to place the allen head bolts. Did this from measurements taken with the front end mocked up using the ignition/steering lock as a guide. Turned the bars to one side, locked the steering, mapped out where the stop needed to be placed, repeat for the other side. No fouling of the oil cooler, lines or rad hoses for me.



[image: Posted Image]
100_0298.jpg


Thanks for the additional details; I'd love to do this mod.

Your steering stop bolts look like they'd work for normal low-speed maneuvering, but in a crash I'm sure they'd bend, and probably not provide much protection to the oil cooler (you may have mentioned this in an earlier post). That's probably about the best solution though, short of welding on some additional bosses.

[image: View Post]fallzboater, on Aug 25 2006, 09:51 PM, said:

Thanks for the additional details; I'd love to do this mod.

Your steering stop bolts look like they'd work for normal low-speed maneuvering, but in a crash I'm sure they'd bend, and probably not provide much protection to the oil cooler (you may have mentioned this in an earlier post). That's probably about the best solution though, short of welding on some additional bosses.


*If* I crash, thinking about the steering stops bending is about #1768 on my list of "things to do". :o

I'm sure there will be a lot more important things broken, hopefully not me! :(


But yes, they work fine for everyday usage. No problems yet!

[image: View Post]veefer800canuck, on Aug 26 2006, 05:02 AM, said:

1: I did indeed space to ~3mm using TWO snap rings, one below the bearing on the triple and one above the race up inside the frame neck. Did this due to the RC51 using a 14mm thick lower bearing Vs. the VFRs 17mm thick bearing.

[image: Posted Image]
stem.JPG


2: There were no existing tapped holes in the lower triple, I drilled those holes and tapped them to place the allen head bolts. Did this from measurements taken with the front end mocked up using the ignition/steering lock as a guide. Turned the bars to one side, locked the steering, mapped out where the stop needed to be placed, repeat for the other side. No fouling of the oil cooler, lines or rad hoses for me.



[image: Posted Image]
100_0298.jpg
Thanks Rob. I was writing from memory so got it wrong. I had noticed the tapped hole that shows in the bottom right corner of the second photo & asumed you had been able to make use of that.

I didn't use any spacers/circlips on my 5th gen and never noticed any interference issues with the radiator.

Swiffer had to curve his radiator on his 4th gen, but I don't know of any problems with the 5th/6th gen.

[image: View Post]SAFE-T, on Jan 3 2007, 04:16 AM, said:

I didn't use any spacers/circlips on my 5th gen and never noticed any interference issues with the radiator.

Swiffer had to curve his radiator on his 4th gen, but I don't know of any problems with the 5th/6th gen.

6th Gen
8. Slide 4mm thick custom spacer onto lower triple clamp & install RC51 lower bearing on top. This is needed so lower triple clears oil cooler mounts on fairing frame, you can gain more clearance by moving oil cooler forward 5-10mm & redrilling some mount holes but only needed if still fouling oil cooler mounting bolt heads. You still need spacer to make sure you clear fixed position fairing mounts.

These are the mounting tabs which the 6th Gen oil cooler bolts to.

I just put the RC51 front end on ('99 VFR) and decided to make up some steering stops. These probably wouldn't survive a crash but they keep my dash from becoming even more scratched up than it is. The L shape is so the hole drilled through the triple misses the underside rib.

[image: Posted Image]
[image: Posted Image]

Great stuff. I'm always playing with the suspension settings and never seem to get them quite right. Now that I've front ended the VTECker, I am seriously considering this mod. I imagine the SP1 parts and such come cheaper second hand due to their being more ubiquitous right? Anyone?

My main doubts are these two points:

14. Braided Brake Lines Rear (had made 1200mm long x2)
15. Custom Spacer 4mm thick to sit between Lower Triple Clamp & Lower Head Bearing (any eng shop can make it on a lathe)

Perhaps there are aftermarket braided lines long enough not to have to have them made?

What did you have your spacer made out of? What are all its dimensions?

How much height do I loose up front?

It seems you raised the rear as well, while having already lost height up front with the fork swap, thus obtaining an even more radical rake than before. Most people would be inclined to try to do the opposite, would they not? Unfortunately, if I lower the rear, the whole bike is then lower to the ground right? Perhaps without touching the rear I'd just end up with a slightly sportier feel to the cornering right?

Oh yeah, must go look up what the story was with a XX Blackbird rear shock in terms of altering height...

How did you address the de-linking of the CBS braking system up front? Two lines from the master, or 1 into 2, or 1 line: Master to RH calliper to LH calliper????

If you have time to answer would be much appreciated.

I can answer the brakes question.

Fronts get replaced by 1 braided line each from each caliper to a double banjo bolt on the front master cylinder.
For the rear, you can get another double banjo and take the line that goes to the PCV under the seat, and put this to the rear master cyl. Or you do this with 2 braided lines.

Then you can yank the PCV and the hard lines from front to rear that run under the tank.

I can answer some of your questions Auspa�ol.

For the custom spacer, all you need to do is get some snap rings. It only costed my $2.26 to get mine from the local hardware store and they worked great.

[image: Posted Image]

With the RC51 front-end, you do lose a little height up front, but that's not the real problem here. The real problem is the increase trail you get with the RC51 triples. Don't quote me on this, but I believe the VFR triples had a 40mm offset and the RC51 triples have a 32mm offset. With increase trail, the bike because more stable for straight line speed but it looses some of it flickability.

The reason you'd want to raise the rear of the bike is to steepen the rack angle and thus decrease the trail, restoring the nimbleness and flickability of the bike. This is why fellow VFRD member Cassandtim is currently designing a set of custom triples for his RC51 front end swap. He wants to retain the stock VFR offset with the RC51 forks thus keeping his trail the same.

Now, I've personally have had any zero problems with the increase trail or lowered front end. And, I also had a Blackbird shock on my bike too. The Blackbird shock was good for about a 1/2 inch raise in the rear (it won't be as much for the 5th gen since the 6th gen shock is shorter than the 5th gen). Out on the track, I had no problems scrapping my kickstand and rear brake pedal, and my headers never touched down once!

[image: Posted Image]

I think everybody been running two lines from their brake master cylinder to each of the front calipers. You could do a single line down to one caliper and then run another line from that caliper to the other side (like Triumph does on their Daytona 675). I don't know of anybody running a single line down and then splitting it to each caliper.

Hope that helps!

[image: View Post]AB-Oz, on Feb 7 2008, 11:49 AM, said:

I can answer the brakes question.

[image: View Post]Darth Bling, on Feb 7 2008, 07:02 PM, said:

I can answer some of your questions Auspa�ol.

Thanks guys. I had forgotten about the difference in offset. So I was thinking... if the forks are shorter, I'm effectively lowering the front end and creating less rake (relatively speaking) and less trail, so why would I want to raise the rear, as it would just exacerbate this even more, and while you could probably handle the change if the offset were the same, jacking up the rear would just make her impossible to handle... :blink: :blink:

Of course it all makes sense now you've reminded me!! The difference in offset outweighs the effect on rake/trail caused merely by the difference in height, so much so that it has the opposite effect... increasing trail!!

No worries!! I actually like the idea of raising the rear a little, I'm 6'4" and could handle more cornering clearance as well...

I reckon I'll go with braided lines, they're not all that exy and I've had trouble with the rear lines expanding under heat on the track!! NOT FUN TO HAVE TO PUMP THE PEDAL TO GET REAR BRAKES HAPPENING ON APPROACHING CORNERS, especially when you're on the track, as you tend to push your limits more there!! Of course I came right on into the pits to let her cool down!!!

I'm collecting info and knowledge on this mod as my VTECker decided to argue with a guardrail, and I reckon it's the perfect opportunity to improve on what is a great base, the VFR!!! Waiting on insurance payout and then must locate bits and pieces, second hand hopefully... if I do decide to Fankenstein her, I may as well go all the way and rip out the Cat guts, deflapperate her and such... it's going to be a long project...

Maybe I should open a thread and collate all the data there as a How-to??? But I mean a proper how-to, photos, videos, data, prices, explanations, vamos, an Idiot's Guide...

FYI, the RC51 SP1 fork offset (as well as 929/954 and RC45--if you forget about the offset axle) is actually a measured 30mm. I've never measured a VTEC triple, but the 800Fi offset is 39.5mm, and the RC36s use 40mm.

(And I think you want external circlips, rather than the internal one pictured above. There's a pic in veefer800canuck's thread.)

Ciao,

Thanks 4 the info JZH.

I have brushed over Veefercanuck's thread, and one of zRoyz' threads as well... I want to have it all clear as a whistle in my head before I go about attempting the mod because once installed, there's no manual to turn to...