Rc51 Front End Swap

[Veefer800Canuck]

OK, due to popular demand, and for the information of Mad VFR Scientists everywhere, here we go again......

{repost of 2005 thread after forum crash(es) for those who aren't aware}

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So tonight, I take hacksaw in hand and cut apart a perfectly brand-new $239 (US) set of Ducati 900SS Helibars.

Why? Why not? I needed a jumping-off point, and this was it.

EDIT: I abandoned the plan of mounting the handlebars BELOW the RC51 triple clamp due to the bars fouling the inner fairings, so I will only post one pic here to show what the first pass of the modded bars looked like. I had to dismantle them and cut down the custom extensions to allow mounting ON TOP OF the 954 upper triple, which allows clearance for the bars at all angles of travel.

And here is the RC51 front end mocked together before installation:

[Veefer800Canuck]

Well, on the weekend, I stripped the Viffer down in preparation for the fork swap.

First off, I removed the rear wheel so I could jack the bike and block it up high enough off the ground to do some good.

Then I started stripping off the bodywork.

At this point, I pumped the brake system out so as to avoid a mess later on when disassembling the LBS plumbing. The fluid still looked very clean from last year's flushing and bleeding regimen.

I also took some detail photos of my dual Fiamm horns. I'm probably going to have to figure out where to relocate them later on.

Here's a shot of my airbox mod where I removed the flapper valve entirely and the actuator plus desnorkelled it. I was without snorkel for quite a few years now, but the flapper mod was done last winter. Bike runs great and sounds wicked.

And another unrelated mod where I drilled my rear disc last winter just because I could. I enlarged all the stock holes to 1/2" as an experiment. Brakes seem to be the same as always, no noticeable loss in braking power or feel. I used a drill press of course. It was slow going but if you didn't know otherwise, you'd swear it was factory.

Here, I am measuring the distance between the frame and the front axle using a fibreglass rod. 20 and 5/16" was what I got. That is my reference dimension for the overall unladen length of the stock fork setup.

You can see the dark line on the fibreglass rod right at the centerline of the axle. Rubbing it on the axle makes a perfect mark so I can get accurate, repeatable dimensions.

This shows exactly how I had butted it up against the steering neck portion of the frame.

[Veefer800Canuck]

Divorcing the rear brakes from the front. I have removed all this plumbing now.

I plan to run all three pistons in the rear, more pics of that plumbing later.

I may wind up using a 14mm CBR600F4i master cylinder for the back caliper if it becomes necessary. I've got one on the workbench waiting it's turn. The VFR rear master is 17mm.

OK, rip and tear is complete. Here is the front end pruned of all it's appendages.

You can see the triple-row oil cooler I mounted up back in 2001. It's still going strong, no leaky-leaky.

First problem fitting the RC lower: the steering stops have to go. They foul the mounting bracket for the instruments and fairing.

So I taped off the lower part of the stem, clamped the beast to the picnic table and brought out the Binford 6000 Grind-O-Matic. Arrrrrrrrh, arrrrh, arrr.

Here's one of the steering stops that was lopped off.

It looked a bit ratty, so some filing and sanding were required to clean things up a bit.

Ahhh, better:

[Veefer800Canuck]

Now it fits without fouling anything.

Next hurdle was the lower bearing. The VFR uses a 30x55x17 bearing whereas the RC51 uses a 35x55x14 bearing. Right away, there is a 3mm difference in height, so a possibility exists of the top surface of the lower triple rubbing on the bottom of the frame's steering neck. Plus, the RC steering stem is a tad longer and you don't want it riding too high in the frame with the upper bearing not able to seat fully in it's race race due to the machined step on the upper part of the steering stem. The RC51 and the VFR both use the same top steering bearing so I'm reusing my upper tapered bearing. It's only been on for one season and is in excellent shape.

So, my solution was to use snap rings of the correct diameters to space the bearing on the top and bottom. Final height = 17mm plus about one thousand of an inch. I can buy that.

Spacing the bearing off the triple:

Spacing the race lower in the frame. Plenty of seating room afterwards. Sits at the same depth as the original.

Here you can see the difference of height of the old and new races:

And with the snap ring underneath they are within a hair:

It all worked very well and the installed height is perfect. Clearance from the top of the triple to the frame is more than adequate and the total boltup to the top of the upper triple clamp including the top nut is excellent with just a thread or two sitting proud of the top nut with everything hand tight. I'll have to disassemble it all and grease/torque/set all the bearings, etc later. This is just to prove the assembly and get all the dimensions set up.

Here's the forks set in the triples.

[Veefer800Canuck]

View from the cockpit, no handlebars yet!

Side view:

I took the same installed measurement from the bottom of the steering neck to the centreline of the axle as before, using the fibreglass rod trick and found I was 1 and 1/16" LONGER than stock. This is due to having the fork tops flush with the 954 gullwing triple. Not good measurements. Must change this.

At this juncture, I decide to play around with the RC51 upper triple that I just happened to have laying around.

By raising the forks so that the first line is showing above the upper triple, I install the fork retaining rings in their grooves, slip the forks down so the rings lightly contact the upper triple and snug a bolt on each side to hold it all together temporarily. Whaddya know? I'm now 1/16" shorter than stock. Hmmm, good starting point with plenty of room to slide the forks up more. There are several little graduated marks on the forks for this purpose and with the retaining rings, it's foolproof to get both forks exactly the same.

This is where I left off, I've got some food for thought for a couple days, plus I'm back at work, so I'll tackle it again next weekend and juggle some more things to see where I arrive.

Here it is with the RC51 upper triple, forks set to within a sixteenth of an inch of stock plus the front wheel slid into place on the axle:

[Veefer800Canuck]

To do list:

Still need to shim the ignition lock down away from the upper triple clamp to get the steering lock to function, fab some steering stops based on the steering lock indexing and plumb the front brakes with custom Galfer SS lines and CBR600 5/8" master cylinder. That, plus index the handlebars for clearance to tank/fairing, remove them and weld the modded bars back together.

Rear brakes have been divorced from the fronts, but the rears are not hooked to the rear master cyl just yet. Still have to remove the proportioning valve and reroute the OE (rubber) rear center piston brake line down to the rear master cylinder. Should be the perfect length to reach.

Then, upon the first test-ride, I'll know if I need to downsize the rear master cylinder to the 14mm CBR unit I have on the bench.

Probably another update next week after more progress is made.

[Veefer800Canuck]

So I got to do a bit of work on the rear brakes this weekend.

First off, after removing the LBS plumbing to and from the front end, I took out the front/rear proportioning valve.

This is also where the main ground from the battery is connected, so I had to reattach the ground cable to the frame afterwards using a much shorter bolt. You can see the ground cable hanging out in the breeze in the pic above.

Next, I took the original line to the center rear piston from it's location at the proportioning valve and moved it down to the rear master cylinder. This will accomplish the actuation of all three rear brake pistons from the rear brake pedal alone. I still need to road test it and see of the brakes will be powerful enough or if I need to downsize the master cylinder from the original 17mm to something smaller like the CBR F4i unit I have on hand.

I tied the lines together using a double bleeder bolt, but the stock bolt would have done as well and probably saved me $26. It does look trick though. I have another for the front brakes whick will be custom plumbed by me using Galfer bulk braided stainless line. I'll go with a two-line setup, one for each caliper straight from the master cylinder, no splitter block.

And I also got the steering lock to function by spacing the mechanism downwards, away from the triple clamp using a washer on each bolt. Simple but effective.

Still have to grease and torque the head bearings, install the bodywork, clearance the handlebars and have them welded plus install the brakes, fab the brake lines and bleed same.

[Veefer800Canuck]

Well, not much progress, but I'll recap what did get done.

I made up custom steering stops using 8x30mm allen head bolts threaded right through the lower triple, held in place by a locking nut and plenty of blue locktite. They strike the pads on the frame that are there for the original steering stops. The steering lock functions properly on both sides and the fabbed stops contact the frame just a couple of millimeters later.

No interference between the lower triple and the radiator hoses whatsoever with these stops in place. I should have just as much steering lock as stock, so U-turns will not be a problem.

I also greased the steering head bearings and installed the triple tree and stem.

Here's a shot of how my homemade steering head socket interfaces perfectly with the special Honda bearing nut.

The next thing I did was reinstall the forks and handlebars (with the controls on the bars) plus the upper triple. After that, I installed the gauge cluster surround, the upper fairing, windscreen and the left and right inner fairing panels.

Afterwards I played around with the handlebar sweep and riser position to try and get clearance for all the necessary bits to coexist peacefully.

After much testing and trying, it became apparent that the riser portion of the bars where it is welded to the fork clamp wants to hit the inner fairing panels when the bars are turned to either extreme. I was able to adjust them in toward the center, but that seems to put the handlebars too close together and also, my Electronic Cruise Control touchpad hits the tank with the bars in close like that.

I considered trimming the inner fairing panels, but there's too much interference plus there's also a bracket that attaches to the coils. This bracket is the mounting point for a couple of fairing fasteners and there's no way to lose that support, it needs to stay.

Sooooo, many steps forward, only to arrive back at square 1.

The 954 upper triple MUST be used, and the custom handlebar extensions I had made at work MUST be trimmed down substantially on the lathe to allow mounting the bars ABOVE the triple clamps.

There's just not enough room inside the VFR's fairing to mount them below without serious compromises being made, and I ain't going there.

The handlebars needed to be cut whether or not they were to be mounted above or below, so that's not an issue. It's just the height of the custom risers that is in question. AND, it's easy to make the existing ones shorter, just a few more turns on the lathe and trim the overall length.

The reason the bars wouldn't work as they were supplied is that the 50mm Duc 900SS Helibars had their upright risers located at approximately 10:00 and 2:00 when viewed from above, whereas the 41mm VFR800 Helibars had their risers clocked at maybe closer to 7:30 and 4:30. So in order to rotate them downwards, they had to be cut and rewelded no matter what.

Either that, or the reach to the bars would require arms like an Orangutan and there's likely to be issues with the master cylinders stroking the windscreen. I want to mimic the previous riding position as closely as possible, and I still have all my VFR bits in one assembly to take measurements from. Hence the need to cut and rotate them.

At work tonight I'll chuck the pieces back up and cut them down and report back later .

[Veefer800Canuck]

Alrighty. I've just refitted the 954 upper triple and clearanced the bars/controls.

This shot shows where the handlebar uprights were previously fouling the inner fairing when mounted -->below<-- the RC51 triple:

That's why I had to abandon that and went with the -->above<-- mounting method instead.

Here's a shot of the bars from above:

There's now adequate clearance between the cruise touchpad and the tank:

And no problem with the windscreen on either side:

Now I need to mark the position of the bars, remove them and have them welded together solidly. I'll shoot a bit of spraypaint over the welded area for the moment, but this winter I'll take them off, sandblast them at work and get them powdercoated along with the upper triple and the front wheel.

Here's the bar modification that allows me to position the controls for proper clearance. I can rotate the clamps around the forks, then tighten and pull the bars fore or aft depending on what is needed to obtain clearance. It's the area that's free of paint. I sandblasted it as the welder is not going to want any paint near the weld area, plus it would get burned off anyhow.....

Overall, the riding position is practically identical to the VFR Helis I had on before with the stock forks. These bars are about .75" taller, but the 954 triple is about .61 lower due to the gullwing shape, so the bars are just a shade higher and it's pretty much unnoticeable. (I'm pulling the numbers from memory, but they're close)

One hiccup is that the VFR's front brake lever is not compatible with the CBR600F4i master cylinder. It bolts on just fine, but the plunger mechanism that actuates the master cylinder piston is entirely different. So, I have to buy a correct front brake lever as well. I guess that detail slipped past. Monday, I'll order one up.

Here's a shot of the cockpit before I got the brake lines sorted:

[Veefer800Canuck]

After getting the handlebars welded in their final position, I set about sizing and cutting the Galfer bulk stainless steel lines to suit. I also got the new front brake lever that I needed. I really really wanted a set of CRG levers, but costs were beginning to get up there, so 26 bucks for a brand new OE lever seemed more reasonable for the pocketbook.

Here's the dual line setup with bleeder bolt at the master cylinder:

And the corresponding run to each caliper:

I got the lines all bled out, but it took awhile. Lots of fiddling as I haven't got a Mity-Vac or similar. Just the old timer's method of pumping the lever. After quite awhile, I got real good flow and was able to chase out every last air bubble. The brakes are rock solid and boy oh boy is there a lot of stopping power with the 4 piston calipers and 320mm rotors! :eek:

[Veefer800Canuck]

After getting the front brakes settled, it was finally time for a test-ride! :yo:

Here's a couple of beauty shots:

[Veefer800Canuck]

Here's my riding impression from the first brief test-ride:

Well, I took the newly-christened GL800RR-SP2 out for it's maiden voyage today. It was $hitty cold, as in just above freezing, and the streets were quite dusty & dirty, but nevertheless, I went.

The front brakes are marvellous, insane stopping power and easy to modulate. DAYUM are they loud though. The EBC HH pads go ZZZZZZZZZTT every time you squeeze the lever.

The rear brake is going to need some work. As I suspected, the VFR's 17mm rear master cylinder is too large to effectively actuate the 3 pistons on the rear caliper. There isn't enough braking force available, or conversely, the lever effort is too high for the amount of braking given. I've got a 14mm master cyl off an F4i that I'm going to slide on there next chance I get.

As for handling, the front end definetly feels more taut and rigid, better suspension action. It's more compliant and firmer all at the same time.

Initial turn-in is slightly slower than with the original forks, but the wider Duc Helibars seem to almost cancel that out. Although I didn't get a chance to really charge any serious corners given the weather conditions plus the brand new front tire, I'd say that with a little more tuning, I can have the turn-in rate pretty much the same as before. Keep in mind that I've got two mismatched tires, a fresh P-road out front and a B'stone 020 in the rear that's just getting down to the wear bars. I may go to a 170/60-17 P-road out back to help quicken the steering even more, we'll see.

[Veefer800Canuck]

Well, I finally got around to reconfiguring the rear brakes with the 14mm F4i master cylinder.

It actually went on quite easily with only 3 mods to the CBR M/cyl itself, and none to the Viffer.

Firstly, there was a nub on the top that located the CBR brake line. It was going to be in the way, so I lopped it off:

I removed the right footpeg bracket to make it easier to access the VFR master and remove it. Thank goodness the swingarm pivot nut was on the right hand side so I didn't have to drop the pivot bolt right out:

When I got both of them side by side, I realized that the CBR unit mounted differently than the VFR's. The CBR part has threaded mounting holes, and the VFR does not:

I was able to use this to my advantage by bolting them together temporarily in order to take some measurements. The CBR unit has a much longer threaded pushrod and it needed to be drastically shortened. As they were bolted together solidly at the mounting points, it was super-easy to find the needed length:

After cutting the pushrod to the required length, I drilled the mounting points of the CBR master to exactly match the VFR master:

Now that it's drilled, it'll slide right into place with the VFR mounting bolts:

After that, it was a matter of refitting the M/cyl and bleeding the brakes. Here's the CBR master all flanged up in it's new home:

Happily, the plastic elbow that feeds brake fluid from the reservior to the M/cyl on both bikes was identical, so I retained the VFR reservior, hose and elbow. The CBR reservoir was quite a bit smaller, and the hose was all wrong, so it was the path of least resistance to use the VFR bits.

[Veefer800Canuck]

I took it out for a run afterwards and the rear brakes are quite a bit more powerful. I can lock the rear brake if I desire, whereas the 17mm VFR master required a LOT of effort on the pedal to do the same.

Brake feel is good, and lever effort is very reasonable. The pedal travel had increased slightly, but it's certainly not objectionable.

[Veefer800Canuck]

The finished product:

Off to Ebay to troll for an aftermarket rear shock perhaps. :D

[Veefer800Canuck]

Well, winter is fast approaching here, temps are never getting any higher than about 10'C during the mid-afternoon, and down as low as -10'C at night. :cold:

Nevertheless, I had the GL800RR-SP2 out on the highway this past week in some +6C weather (after about 60 km of earlier in-town, low speed riding to famiarize myself with the new setup).

I had brought the bike back into the garage after the initial trial runs about town, checked and rechecked all the critical fasteners' torque and then decided it was time to explore the upper reaches of the speed scale.

I started out on a lonely stretch of highway and began coaxing the bike from 100km/hr up to ~160 or so, and back down again. The bike was dead stable, the front end soaked up all the pavement irregularities far better than the original 41mm fork did. Did a few medium-hard braking exercises at this speed level to see how things went. Marvellous they were!

Also did quite a few extended side-to side weaves at around the 100k speed limit, left-right-left-right, again and again. The slightly slower turn-in I'd felt around town seems to lessen with increased speed and the bike responded to the weaving much like the stocker did in terms of heeling over from the one extreme to the other and back again. I wasn't close to scraping the pegs at all, what with the still new-ish front tire and the cold temps, I didn't want to get the bike quite over to the very edge. Still, I estimate I was roughly 90% into what I'd term "full lean" for my own riding ability/comfort level and on a bike that I have to PAY FOR if I wad it up. No dramas found, so on we go to the next level.

The next foray was up to ~200km/hr which I held steady for quite awhile, doing some looong sweeping turns and the bike tracked just perfectly. I could certainly feel that the rear shock is now the "turd in the punchbowl" in terms of ride quality, but it doesn't do anything uncertain or scary, just not as precise as I'd like it to be feeling. The ride quality is nowhere near what the front is. Next season, it'll be shock time.

Finally, I ventured up to 240km/hr and the results were predictable; utterly composed, totally precise and no drama whatsoever.

The brakes are absolutely astounding, scrubbing off speed like you'd tossed a tethered Steinway out of your pocket! Something to be said for 24mm larger rotors and 2 extra brake pistons out front. :eek: I like 'em! :unsure:

There's still more work to be done to get the bike 'exactly' where I want it, and certainly a new rear tire is in order as I'm about 1mm off the wear indicators in the center right now. That should go a long way towards improving the low-speed turning manners. That, and the new rear shock that's on the drawing board. I'm wanting one with adjustable ride height so I can further tune the chassis attitude as desired.

Short version: it all works, I didn't get chucked off, brakes are like a brick wall and it rails around high speed sweepers like never before.

[Veefer800Canuck]

Here's a beauty shot that I took last week. Love or hate the turnsignals, whatever.

[Veefer800Canuck]

Well, I got my front wheel back from the powdercoaters. Had it done silver to match the rear.

I also picked up one of these:

Probably going to have it black anodized to match the rest of the bike. :cool:

[Veefer800Canuck]

Pictures of the Vortex triple now that it's been anodized black:

[Veefer800Canuck]

Well, it isn't a "Performance upgrade" but why start an entirely new thread, Eh?

Got the fuel cap powdercoated black to match the handlebars and the upper triple clamp:

[Veefer800Canuck]

Final pictures, now that spring has sprung, and the front wheel has been powdercoated, etc.

Also, there's a Fireblade shock buried in the rear somewhere.

Now I just need a new rear tire and to have my remaining Ariete' 90' valvestem installed at the same time. :cool:

[zRoYz]

Yes the forum has lost allot of stuff due to the problems, great stuff veefer800canuck

Just a little update on my setup, I had my SP1 forks valving adjusted to suit 5 weight oil (standard is 8) & had the dumb built in 10mm of static sag before forks are even loaded the SP1 forks have fixed (with my preloads would all the way in I could still only get 40mm static). The 9.5 standard springs are perfect for my weight, the static is just a design fault within the forks as the froks where designed by 2 different eng, 1 did valving, the other did the rest so somewhere along the line they didn't really match each others data.

Did it make a difference will be the question, well if you think the SP1 forks standard make a big difference mine now are again another level up from that :thumbsup:

I now have 35mm static sag with just 1 position preload & the hyd responce is so good now the front feels like it is sucking the tar out of the road. It also helped I found a suspension guy who really knows his stuff & if your not happy he will keep doing adjustments till you are happy at no extra cost, he will even go out to the track with you to further sort things at no extra cost.

Edited December 30, 2006 by zRoYz

[NYMBYSS]

sweet !!!!!!!

[Throttlestop]

This is one of those threads that keep coming back to life, LOL!

I'm in the middle of my own RC 51 front-end swap and need a part number for a TAPERED roller bearing for the 2001 RC 51 top steering stem, to match a tapered roller bearing already installed on the lower triple clamp. I understand that the RC 51 top steering stem bearing won't fit in the VFR headstock.

Anyone has the part number readily available? TIA.

Edited January 7, 2008 by Throttlestop

[AB-Oz]

umm, you dont need a top bearing for an RC51 for your front end swap, you need the VFR one.

I have a SP1 steering stem in my set up, I have a lower tapered roller bearing for an SP1, and a upper tapered roller bearing for a 99 VFR. Just in the lower you need the circlip thingys as described by Rob a few pages up there ^^^