RC51 front end swap

[Blue Viffer]

This is my Front end super uber mod. Please don't try this without much thought and get all your questions answered by a professional before you begin.

I decided to change my forks out to RC 51 forks after much thought about rebuilding. Rebuilding with new springs valves and possible F4 internals would run somewhere between $700.00 - $1000.00. I figured with a little luck I could change my front end for about the same and come out ahead with trick upside down forks and better brakes.

Now after much looking on this forum and VFR World and even STNet. I read about and saw pictures of Murphy.

Having a few years back looking at Superhawk forks and decided that I would not gain enough for my money I shelved that thought.

Now comes along an ill timed pass on a Van that did not see me and Voila instant money. Insurance.

Again don't try this at home.

Getting back to the story....Well I read that you could put on 929,954,RC51,R-1 or any fork of the 43mm dia using Honda triple clamps. You can use 929, 954 or RC51 clamps and use the other forks with their corresponding wheels,axle, brakes and fender. Make up some brake lines and there you have it a new front end.

Well guys and gals it isn't quite that easy but almost.

You see Cars Trucks Motorcycles or anything on wheels have to be stable when moving in a straight line or even turning so we have what in the auto industry is called alignment of a vehicle. Now being an Auto Mechaninc and not a Jet Aircraft Fixer I knew enough to understand ride height and a little about what we call caster and kingpin inclintaion or rake and trail on a motorcycle. So.... looking at my bike all stripped down and reading about Safe-t and Whylee putting RC51 forks on their bikes I looked more into that than the other options. I also have a 954 sitting in the garage so could look at that front end and forks and picture them on the VFR and also compare lengths of fork tubes. Now with Safe-T's measurements of Fork tube lengths and my own 2 bikes to measure (VFR & 954) I decided the RC forks were closest in length and looked oh so CUTE with the adjuster at the bottom of the front of the fork tube. Kinda like the old superbike forks of old.

Any way back to it. Now having decided on the forks you have to decide on the clamps to hold them.

Whylee had already finished his bike and posted the fact that the 929,954 Steering stem or bottom clamp hits his radiator hose when turning. Not to good. So looking at the RC steering stem or bottom Clamp it has a gullwing shape and drops down at that point. The other good thing about this is you can use shorter fork tubes in this bottom clamp and still maintain the proper ride height that your VFR had to begin with. NOW THE CAUTION!! Ride height is not all that you need to be aware of. Larry of Busy Little Shop will tell you the RAKE (TRAIL) is also important for stability and ability to turn or not to turn.

Ask Whylee. Not Having the computer knowledge or previous years of experience with Motorcycle Rebuilding that Larry has but having Auto Experience I know you need the right Caster in a car or RAKE TRAIL combination on a bike to turn etc. Again this is the reason I chose the RC51 lower clamp to allow adjustment up or down of the fork tubes to gain that Caster or RAKE TRAIL NEEDED. If you choose the top plate or clamp of a 929, 954 you also have a gullwing shape. It allows if you have the shorter than RC 51 fork tubes you a chance to use those tubes and maybe adjust them up or down enough for proper rake trail combination.

If You use short tubes like 929 or 954 or maybe even R-1 or gixxer tubes you will absolutely need to use the 929-954 top plate and the RC51 bottom clamp combination to give you any chance of adjustment....Or you could have Larry or someone of his calibre make you up custom clamps.

If any of you FRANKINVIFFER'S out there would like my Opinion after doing this modification listen up.

Advice. Think carefully about what you want out of your bike. Handling will only improve if set up right. The forks will only be able to soak up bumps better if set up for your weight.

Money, always add a little extra for any unforeseen problem in any modification to your vehicle.

If you want to continue then this is what I recommend.

954 top plate or clamp. Same as 929. 2000-2001 RC 51 steering Stem. I do not recommend the use of the RC 51 top plate at all. It will work but it limits the ability to adjust the forks only so far down for those of you using shorter fork tubes.

Forks to use.

Your choice but I would look hard at something of comparable length to the VFR.

RC 51 is my choice but you could use others. Probably but I am not sure in length the Suzuki SV1000. You could also probably use the FZ1. More likely longer than an R-1 with the same brakes.

Possibly the Suzuki V-Strom 1000 also. Any of these will require their brakes wheels axles and fenders.

After you are done with any modification take it slowly at first to get a feel for the results. Make or have made the proper adjustments to get the right alignment (Rake Trail) for proper steering. And be really careful on your first test ride. Then recheck your work. Tighten or check tightness of all your critical bolts and nuts. Always check your brakes before riding a modified bike like this.

After my modifications I am still fine tuning. First I need to get a little less trail or caster in my bike so it steers a little quicker. My bike has been raised in the rear 10mm for clearance of exhaust and is not stock rake. It turns like a stock VFR with my combination right now. Yes it soaks up bumps better and has better front suspension and brakes but I still need to fine tune it. With this mod I no longer have linked brakes and need to change my rear master cylinder to get better brake response from the rear. I went with the RC front Brake Master for better Clearance around the windshield area. And now want to complete that with a Hydraulic master to match for clearance around the left side area.

I am not real happy with my convertibars so I am going to 929-954 handlebars on top of the top plate as I have plenty of room to do this with the combo 954 top plate and long enough RC51 fork tubes.

I think this is a very good mod for those of you who are capable or willing to learn....But this mod is NOT FOR EVERYONE! Some of you should not even think of a mod like this. Your bike is fine the way it is being used and works great.

Again this is the way I did it and just my HUMMBBLLEE OPINION.

For those of you interested I am sure if you ask you will get honest opinions from Safe-T, Whylee, or Larry as to how and why they did or do modifications.

Good Luck and Hope this is better insight than the rest of us had when we decided to make a leap into FRANKENVIFFERING.

frankinviffer is a trademark of Safe-T inc.

vince

Sorry Whylee I did not put this in print before your get off. Hope your bike isn't too badly damaged.

Edited March 13, 2005 by Blue Viffer

[Veefer800Canuck]

..

[dude]

:idea3: Vince, thanks for the write up. I will definetly keep this for future reference. Maybe one day i'll tackle this major mod, but in the meantime, i'll make due with a change of fork oil . :rolleyes:

:thumbsup:

Gary

[Blue Viffer]

This first picture is of what I consider the first thing to do when making a modification of this type, getting a baseline or measurement of your current ride height. This shows the measurement to the ground from the bottom of the frame at the point the steering stem ataches to it. 28 3/4" on my Bike.

Here I am removing the circlip to remove the stock handlebars.

This shows the start of the removal of the Top plate of top clamp.

With this picture you need to remember the warning on the 2000-2001 Steering Stem vs the 2002 and up. The 2000-2001 is on the left.

Now this picture shows the adjustability of using the RC 51 steering stem with shorter forks. Here I am using RC forks and the line above the clamp is the start of the tube taper from 50mm back to 43mm. With shorter forks that line would be closer to the clamps giving you less adjustment. If you use 929-954 lower clamp the line would be closer to the clamp and allow less adjustability. Especially if you were using shorter forks ie R-1 or others.

This is the current 5 Spoke wheel for a RC it is lighter than the previous 6 Spoke wheel and I thought having a 5 spoke wheel on the rear already it would be nice to add one to the front. Maybe a 6 spoke would look as good because you really don't see much of it through the brake rotors.

After putting it all together without bodywork.

Now for the completed work, you be the judge was it worth it or not? Looks yes, performance for me yes but still adjusting.

Hope this quiets the gents and their not worth anything with out pics.

At 1:00am in the morning I was a little bit leary eyed and thought you would appreciate proper posting of pictures.

Enjoy!

vince

Edited April 29, 2009 by Blue Viffer

[ULEWZ]

I know the VFR is heavier, but how does it handle now compaired to the 954? Better handling and brakes on a VFR would really be a plus to me.

[Guest whylee]

Great write up, My bike got only minor scrapes and a broken mirror. The good part is that I dont really like red that much so I get to change color now. I should have it all back in a week or so.

I really want to go with the early RC51 lower but I can never find one. If you have a line on one let me know. I understand that I want the 2000-2001?

Your bike looks very good, let us all know how the adjusting goes for you.

I really feel my little dumping incident was a combination of events, but mainly due to sand on the road. I feel even with the original front end I still would have went down, but ill never know forsure.

Im just looking forward to getting my back back together and getting on the road again.

[dude]

:beer: Vince thx for the pics too. The bike looks amazing. Even looks good without bodywork too IMHO

Oh and the colour....... sweet :beer:

Now if only i could get your to give me your wolf pipes? :goofy:

Thx again for the effort Vince

Now go for a ride . :wheel:

[Beck]

Thanks for the great writeup Blue Viffer! :thumbsup:

One big question, do you think everything applies for a 4th gen bike like mine??

This would be the ultimate mod I'd like to do on my baby, but Unfortunately I still have my helmet out waiting for some money to fall from the sky before I can even think of doing it! Maybe I should go on my old poor college boy diet to make it happen! (Ramen and Hotdogs...yuk!) :wheel:

Anyway, I printed this post and put it in together with my shopmanual binder just in case that lump of gold does fall from the sky soon!! :thumbsup:

Beck

95 VFR with the weedy RWU forks

Edited March 12, 2005 by Beck

[Blue Viffer]

nice write up vince.....but i saw no mention of torsion bar any where in the whole thing?

<{POST_SNAPBACK}>

We have a hidden Paralever design on the drawing board for those of you still in the 60's.

Actually it is Fixer's assignment to find a fool who will help him with the design construction, fitting and testing to a 6th Gen bike that is of the faster red color that is a one of a kind with mig pipes. :wheel:

He is now hard at work in the basement of the mad scientist's lab. :goofy:

Pictures to follow. :beer: :beer:

vince

[SAFE-T]

Really good writeup, Vince :thumbsup:

If I was still running the stock 98-01 wheel on the bike I would definitely have chosen the 5-spoke version of the RC51 wheel like you did. It is the lighter version, and within a few ounces of some aftermarket wheels. 3rd or 4th generation owners will find the earlier 6-spoke RC51 wheel is a better match, albeit with a slight weight penalty. It also looks like the later version RC51 front wheel has machined spokes, whereas the early version spokes are left rough-cast...

As for the rear brake, you might want to try a CBR600F4/F4i rear brake master cylinder which has a slightly larger bore.

If I had not decided to change several components on my bike, I would have stuck with the stock forks and put in CBR internals (F3 for 98-01 VFR and F4 for VTEC) along with heavier springs and either Racetech or Traxxion valves. Changing over to an USD fork means you have to change the entire front end - I think the only thing you CAN use from the VFR is the steering head bearings and the ignition. It also means delinking the brakes on 98 and newer VFR's. All of this stuff is neither easy nor hard but somewhere in the middle. Mostly it takes time and patience and I can certainly attest to that.

I've enjoyed helping out a few others with their questions about the RC51 front end mod - I know I will be taking my bike to Rod at RMR Suspensions when he's here for a trackday or race weekend so he can check what I've done since you can only do so much via a forum or email. Having a suspension tuner get their hands on the bike helps to confirm whether you are headed in the right direction or not.

I do find it interesting that since I started the Murphy project on this forum, at least four other board members have asked how to do it. Two have completed it (whylee and BlueViffer) while two others are part-way through (Swiffer and VFRLarry). Others like Beck and Joe Foe look like they are still considering it. Busy Little Shop has supplied some invaluable technical input regarding rake/trail, Blue Viffer brings a different and useful viewpoint to the discussion, and Swiffer is helping to confirm some brake caliper measurements on a single-nut rear wheel conversion for 94-97 VFR's.

IF YOU OWN A VFR, VFRd IS THE PLACE TO BE.

[BusyLittleShop]

   

   

Larry of Busy Little Shop will tell you the RAKE is also important for stability and ability to turn or not to turn.    

   

   

<{POST_SNAPBACK}>

   

Great narrative Vince make that trail not rake... changing the triple tree off set does not alter rake... it will increase on decrease trail accordingly... it works like this... more offset less trail... less offset more trial...

Question??? did your new triple clamp allow you to still use your steering lock???

[SAFE-T]

Did your new triple clamp allow you to still use your steering lock?

I know it works on my '99 and whylee's '04 and we both have CBR929/954 top triples like Blue Viffer.

[JoeAsheville]

Question: will an RC51 00-01 or 02+ front wheel be the one to use with a GSXR front axle? I thought I knew where my micrometer calipers were but apparently they were misplaced during the move.

I now have a CBR954 upper triple, an 01 RC51 lower triple, 01 GSXR1000 forks/rotors/calipers. Still casting about for a front wheel and Duc Marchesinis are still quite spendy at $300 plus all in on eBay when the auction's done.

Edited September 17, 2005 by JoeAsheville

[SAFE-T]

The RC51 uses a 22mm axle. I believe the GSXR axle is 25mm. If you want to put the RC wheel on the GSXR fork just use CBR929/954 bearings as they have a 25mm ID.

[JoeAsheville]

Roger that...thanks Rick, you are (as always) appreciated.

[Guest vfrmonkey]

Here's where I am....

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Only missing a few parts...

[SAFE-T]

Only missing a few parts...

Might have an SP-1 lower triple and CBR upper for you.

[Guest vfrmonkey]

might or do? I have an SP2 lower on epay now, and I bought a 954 upper that turned out to be a broken F4i upper; it's getting sent back...

[SAFE-T]

PM me...

[ULEWZ]

Any ride reports yet? Are the USD forks really an improvement worth doing (better feel, more compliance)? Do the brakes stop on a dime now? Any comparison of which bikes the converted VFR feels like? Thanks.

[JoeAsheville]

Jeez Monkey you're just having rotten luck.

Can you use a stock RC51 upper triple at all? I'll be glad to GIVE that to you if Rick can't help you out...I don't need it since I was able to find a 954 upper triple.

It's a shame a stock GSXR1000 set of triples won't work, since I have a low mile lower triple plus a Vortex upper rusting away in the basement for a 00-01 GSXR1000.

Hey Monkey...what is that front brake master from? A 929/954? I would really want to use that style to make it look symmetrical to avoid what Swiffer was using temporarily there (all plastic master).

[JoeAsheville]

Any ride reports yet? Are the USD forks really an improvement worth doing (better feel, more compliance)? Do the brakes stop on a dime now? Any comparison of which bikes the converted VFR feels like? Thanks.

<{POST_SNAPBACK}>

I think there is a ride report at the very end of the thread "Swiffer's new front end". He was very impressed with it, and I think Rick has been riding Murphy for some time now so he would be well qualified to comment.

[SAFE-T]

The front brake master is from a CBR600F4, isn't it ? Swiffer changed over to one from a Hayabusa.

The Ohlins suspension front and rear do make a difference - the front end is much more compliant over bumps when leaned over. Other bikes I have owned would skip a bit if you were going through a turn and encountered a bump, but the Ohlins pretty much suck it up and keep the front wheel planted.

Whether or not you could get this same control with stock components I can't say. I DO know a local racer who had Ohlins on his ZX10R and actually went back to his stock forks that had been professionally setup by Traxxion. Phil Douglas at AfterShocks has said it's sometimes better to retain/use/modify stock components these days as the design and component materials is quite good, and in some cases better than what's available in the aftermarket. Other tuners have told me this as well.

As for the RC51 fork, I was told I could make work as good as an Ohlins unit for about $1000, plus the cost of the RC51 forks, of course. As that would work out to just a little less than I paid for the Ohlins forks in the first place I kind of took that with a grain of salt...

I did get a chance to ride Rob McKinnon's VFR800 pre-frankenviffer and I thought it handled just fine. I recently also rode a CBR900RR with front forks that had Traxxion stuff, while the CBR's owner rode Murphy. I thought his bike felt just fine compared to mine, but the first thing he said when he got off Murph was "THAT SUSPENSION IS AMAZING..." so maybe there was more of a difference than I thought. At least for him.

Bottom line is how picky are you and what do you really want ? I would be happy with a stock bike with suspension that had been tuned by AfterShocks or Traxxion, and I was originally planning to put F3 fork internals in the OEM forks. At some point I made the decision to see if I could make a bike that I could get in a magazine, and from there sprang the whole inverted fork/Ohlins thing.

Would I start from scratch with a different bike ? I don't think so. It was fun, I'm glad I did it, and I am more than willing to share what I think I know to help others out. But it probably ate up 300 hours of my time that I wouldn't want to give up again.

[JoeAsheville]

CBR600F4 would make sense. I'm looking for something that has enough hydraulic actuation leverage (piston size) to get 'er done with 12 pots (dual 6 pot calipers), while still looking like the clutch master. That's why that one caught my eye. I now know what I'm going to be looking for on eBay for the next few weeks.

Unless, of course, Swiffer used the Hayabusa one because it worked with the brake setup from the donor bike? Hmm. Any reason why the stock master won't work? Not enough hydraulic pressure/too stiff to actuate?

Edited September 17, 2005 by JoeAsheville

[SAFE-T]

Unless, of course, Swiffer used the Hayabusa one because it worked with the brake setup from the donor bike?  Hmm.  Any reason why the stock master won't work?  Not enough hydraulic pressure/too stiff to actuate?

I believe Swiffer's bike has 6-piston GSXR1000 calipers, which is why he used the Hayabusa m/c

Apparently the VFR's master cylinder bore is too small to drive that many pistons, or even the 4-piston Nissin calipers for the RC51.