Another Frankenviffer

[The Phantom]

Wohoo, got my brakes today. 2004 R1's.

Donny, are they radially mounted brake calipers? That's what the R1 got in 2001. If so, they can't be bolted onto the pre-2004 forks.

See the two images I posted earlier in the topic...

[SAFE-T]

Donny, are they radially mounted brake calipers? If so, they can't be bolted onto the pre-2004 forks.

You might be able to put a set of '04 fork bottoms on your older R1 forks, but it would most likely be easier to either buy a set of '04 forks, or the correct calipers for the forks you already have.

:fing02: Hard to believe you can buy R1 forks for under $50....

[TommyHoffman]

:off topic:

Guy down the street has a RC51 with Ohlins.....

reading these Franken Viffer strings always gets me thinking is he still has the original legs around.

[SAFE-T]

:off topic:

Guy down the street has a RC51 with Ohlins.....

reading these Franken Viffer strings always gets me thinking is he still has the original legs around.

RC51 forks have gotten stupid expensive. They are the nicest option in terms of length and spring rate, and match very well cosmetically. Probably the most 'bolt-on' option, especially if you buy a complete front end.

R1 and CBR929/954 are the next best options. The R1 fork can be done with the stock VFR front wheel and rotors, and has the same spring rate as the VFR. The CBR fork is shorter so you have to look at different handlebars, or perhaps lowering the rear of the bike but definitely do-able.

[The Phantom]

You might be able to put a set of '04 fork bottoms on your older R1 forks, but it would most likely be easier to either buy a set of '04 forks, or the correct calipers for the forks you already have.

I'll see what I can find about that on www.r1-forum.com if Donny confirms he has radial calipers. I have already been given some good info by the guys there.

The R1 fork can be done with the stock VFR front wheel and rotors, and has the same spring rate as the VFR.

You're referring to the pre-radial caliper R1 right? As the radial caliper R1 has rather large rotors compared to the VFR...

So do you reckon the RC51 fork prices have been driven up by Vifferatsi? Surely there's not enough of us doing these mods... maybe there's been a spate of RC51 crashes lately.

[SAFE-T]

You're referring to the pre-radial caliper R1 right? As the radial caliper R1 has rather large rotors compared to the VFR...

'98-'03 R1's used 298mm rotors - close enough that you could get away with the VFR's 296mm rotors.

'04 -'06 R1's have 320mm rotors, while '07 models will have 310mm rotors.

If you have a set of forks from an '04-'06 R1 you get radial calipers. I don't specifically know if a VFR wheel will work, but that you can put Ducati 320mm rotors on a VFR wheel....so if the spacing were to work out that might be an option.

So do you reckon the RC51 fork prices have been driven up by Vifferatsi? Surely there's not enough of us doing these mods...

Limited sales of RC's combined with higher-than-normal attrition on the road and on the track is my guess. After awhile the used parts market thins out. Speedzilla's Sport Twins Classifieds can be a good source of parts sometimes.

I had a very hard time finding a replacement Ducati rear caliper this summer, and wound up paying nearly $50 for a part I bought a year earlier for $10.

Parts can be scarce due to lots of things - in the summer people are busy riding and perhaps not listing what they have for sale; in the fall what is available goes fast as people buy what they want for winter projects. Right now parts are relatively cheap if you can find them as people are spending all their money on Christmas. This will continue until the end of January, after which prices will rise again until about April. Then everyone will be off riding again and so forth.

[Guest DonnyBallGame]

Correction. My Calipers are from an R6. They bolt right up to the R1 Legs. Later on I may be interested in updating again to Radial Caipers, but these are a big enough improvement for now.

I go wheel bearings on the way and will post my findings.

[Veefer800Canuck]

Can you please measure the length of the R-1 forks from the center of the axle to the top of the forks, not including the adjusters and post up?

29.25 give or take 1/32 is what my Stanley Tape is giving me right now. The hunt continues. Thanks for the comments guys. Please keep me in mind if you see anything.

Measured my RC51 forks and they are 28-7/8" So the R-1 forks ARE indeed marginally longer.

Good to know.

[Guest DonnyBallGame]

OK, Here is what I come up with today. I checked with my local Honda/Yamaha dealer and www.allballsracing.com (great customer support :warranty: ).

98-99 R1 Bearing Specs are, Ø47mm OD x Ø22mm ID x 12mm wide

95 VFR Bearing Specs are, Ø42mm OD x Ø20mm ID x 12mm wide

2000 RC-51 Bearing Specs are, Ø47mm OD x Ø22mm ID x 12mm wide

I stopped into a bearing supplier that we use at work. He has access to all the bearings in the world. There is no such bearing that has an OD of 42mm and an ID of 22mm. So, I can either put on an RC-51 Wheel, or Polish down the front axle and sleeve the left fork tube to accept the new 20mm Axle. I think I am going to Polish the front axle. That way I can use the VFR spacers.

[Guest vfrrider]

DBG,

I did not have to sleeve the left fork as it is the one that is screwed into and very tight.

I used a small VFR spacers on both sides and another cut down one on the right plus 1/8 shims both sides. Fit it up and measure first though.

Larry

[SAFE-T]

OK, Here is what I come up with today.

Difficult: Unless by some chance a set of R1 rotors fits or can be made to fit the RC51 wheel, good luck with this one.

Easier: Go get yourself a VFR800 wheel and rotors (or CBR600F4 rotors), put in RC51 bearings, make/modify inner and outer spacers and you're good to go with the R1 axle unmolested.

[Veefer800Canuck]

OK, Here is what I come up with today.

Difficult: Unless by some chance a set of R1 rotors fits or can be made to fit the RC51 wheel, good luck with this one.

Easier: Go get yourself a VFR800 wheel and rotors (or CBR600F4 rotors), put in RC51 bearings, make/modify inner and outer spacers and you're good to go with the R1 axle unmolested.

I wouldn't machine any stock hollow axle from 22mm down to 20mm. You're losing strength there and the OE Mfgr's have analyzed that axle 7 ways from sunday with their CAD/CAM software so it's just strong enough for the job with a decent safety factor.

If you absolutely, positively have to do that, have a new 20mm axle machined from solid high quality steel bar stock and don't bore out the middle.

Then it'll be stronger than the original part and the right size you need.

Slightly heavier, but way better than a cracked/snapped axle and the resultant crash and burn scenario.

[Guest DonnyBallGame]

This is why I post this stuff up. I like the many different ideas and welcome them all. After thinking about it a little, I think I will draw up the new axle and see about getting on made. Plus, if I get on made, I can get rid of the annoying internal hex of the Yamaha axle and maybe use and external hex. Thanks for helping think things thru Veefer800. We'll see how things play out.

[Guest DonnyBallGame]

So, I have done a little more research on machining down the R1 Axle. Not going to happen here. The ID of the HOLLOW axle is 18mm. So doing the math gets real scary. 20mm OD and a 18mm ID equals 1mm thin wall tubing. I will be making a new one from scratch. It will be made out of Stainless Steel, then I do not need to worry about rust.

[Veefer800Canuck]

So, I have done a little more research on machining down the R1 Axle. Not going to happen here. The ID of the HOLLOW axle is 18mm. So doing the math gets real scary. 20mm OD and a 18mm ID equals 1mm thin wall tubing. I will be making a new one from scratch. It will be made out of Stainless Steel, then I do not need to worry about rust.

Stainless steel fasteners have less tensile strength than regular steel ones, so a stainless axle of the same construction would theoretically be weaker than a plain steel one.

BUT, if the SS axle is solid, not hollow, you'll be way ahead in the strength department, owing to the beefy nature of the part.

[SAFE-T]

Go get some Titanium bar stock... :offtopic:

[The Phantom]

Go get some Titanium bar stock... :offtopic:

Actually a very good idea Rick!

I'm pretty certain the two spacers on my R1 front axle are titanium. A solid metal axle is going to add a good bit of weight to the front end, and lower unsprung weight is one of the bonuses of Frankenviffering so it's worth trying to preserve that.

[Guest DonnyBallGame]

Go get some Titanium bar stock... :biggrin:

Actually a very good idea Rick!

I'm pretty certain the two spacers on my R1 front axle are titanium. A solid metal axle is going to add a good bit of weight to the front end, and lower unsprung weight is one of the bonuses of Frankenviffering so it's worth trying to preserve that.

Wow, I just priced a piece of Titanium. That stuff is pricey. Time to call in a favor from my machine shop. That is going to be a tough one to do. Maybe after I get things fit up with my SS axle. It can always be another Mod to make later.

[GSP]

Donny,

If you are using the R1 front wheel you will need to make or source spacers for the axle - the R1 tripleclamps are 210mm fork centre to fork centre, whereas the CBR/RC51 triples are 214mm.

You'll need a 2mm spacer for each side of the front wheel. The axle diameter is 22mm.

It follows that you also need to space the brake calipers* in by 2mm on each side so they line up with the rotors.

With the wider spacing on the RC/CBR triples, is it still possible to use the R1 axle? I'm thinking of sticking with the R1 front wheel as I might go with the radial brake front end.

What did you decide to use for bars?

Have any pics?

Thanks.

Edited December 25, 2006 by GSP

[Guest Tyrmeltr]

So is the type of thing you do just because you can, not because you need to?

I'm not trying to piss on anyone's parade, but my revalved/resprung stock front end allows me to ride ridiculously fast. As fast as anoyne, even insane, should go on the street. The track is another story, but aside from doing it just because you can, there are probably better ways to go around a track really fast than on a VFR.

I only ask this, because when I first got my VFR, having already owned bikes with USD forks (as well as PM brakes and AP master cylinders), I thought that I would find them to be inadequate for agressive street riding. I opted for upgrading the stock forks, just because I didn't want to deal with the project.

Turns out that my suspicions were wrong, and that the stock forks are really quite good now that they are properly valved and sprung. I would go so far as to say that they are likely better than a USD fork designed for a diffent bike that has not been resprung and revalved for a VFR and the rider operating it.

Now, there is the issue of adjustability. While it's a nice feature, it's somewhat unnecessary for a street bike, and even a race bike that only sees the same track. This is because usually once you have everything set, you usually don't need to make any more adjustments.

That being said, even "non" adjustable forks are adjustable. You just have to take them apart and manually chage the valving stacks instead of turning knobs. This is only an issue when you are getting things right in the beginning, and folks like Race Tech have gotten down baseline valving and spring rates down to a science. The only thing I had to do different from their setting is run about 10mm more oil for extra bottoming resitance.

So I was just wondering. Seems pretty cool if it's just done for the challenge of it all, and that it gives the bike a "tricker" apperance. I'm just not seeing at as a performance necessity for a street bike.

Carry on gentlemen, as the detail of all this is still very interesting in regards to what is required and how it all goes.

Edited December 25, 2006 by Tyrmeltr

[The Phantom]

With the wider spacing on the RC/CBR triples, is it still possible to use the R1 axle? I'm thinking of sticking with the R1 front wheel as I might go with the radial brake front end.

Yep there's lots of sleeve left on the large dia bit of the axle to accommodate the reduction in clamping area, and the axle bolt is likewise still threaded securely. The fork lower clamps use two bolts aside so there's no problem with the axle being securely located.

I'm using new rotor bolts of course, I'd like 2mm longer ones just to be on the safe side, so plan to peruse the Yamaha parts catalog to see if another model uses same.

What did you decide to use for bars?

Still a work in progress, but an OzVFR mate is milling up a pair of 50mm extensions to go between the fork clamp and the bar mount on these lovely billet 'Epro' items (Japanese company that specialises in Yamaha performance bits). Got 'em off an R1 at a bike wrecker for $200 AUD. They'll go under the top CBR929 triple and the 2" will give enough rise to clear the fairings (he wants to make two-piece extensions so I can drop it a bit for track duty but we haven't come up with the final design yet).

I haven't taken many pics yet as I'm still doing the mock-up to make sure it all goes together well.

So I was just wondering. Seems pretty cool if it's just done for the challenge of it all, and that it gives the bike a "tricker" apperance. I'm just not seeing at as a performance necessity for a street bike.

Fair question, a few years back I too thought it was fairly pointless doing this even though I've been loosely researching USD forks for 4-5 years. I can't speak for others but my bike project is as much about having a play with the bits and pieces available to me, as it is about improving its performance and looks. I completely agree that you don't need this sort of hardware to go fast and/or have fun, but updating 10-15 year old technology will definitely enhance all aspects of your riding experience. I got an Ohlins for the back to even it out :unsure:

I've ridden a 4th Gen with Eibach springs and modded shimstack and stock rear shock, against a VTR1000 with top-spec Ohlins shock and fork internals, similar riding ability between the riders, and he was no faster than me. He *may* have been a bit more relaxed at the end of each section of twisties than me though, and that's worth the price of admission.

Other benefits include lower unsprung weight (more responsive suspension and steering, very nice to have on less than perfect road surfaces), less stiction due to the more advanced materials and design, stiffer forks for improved 'feel', a wider range of performance enhancements are available to you (rotors, fork internals etc.), and good looks to boot.

The big ticket item you forgot about is the vastly superior braking you get with a late model USD front end - radial calipers and 310mm rotors for sir? yes please :thumbsup:

[Guest Tyrmeltr]

The big ticket item you forgot about is the vastly superior braking you get with a late model USD front end - radial calipers and 310mm rotors for sir? yes please :thumbsup:

First off, thanks for taking the time to answer my question. I can really appreciate your perspective and I think it's cool what you're doing.

I will agree that the brakes are certainly lacking. My last three bikes had at least 4 piston calipers so the VFR braking experience has been underwhelming. HH pads, braided lines and great fluid have helped considerably, but the fact that my rotors are blue are pretty clear I'm really overworking the brakes.

Interestingly enough, the lack of power and brakes on my VFR compared to my last few bikes have re-taught me to carry more corner speed (entry, mid, and exit) and not rely on brakes and power to compensate.

My usual riding buddies are have an R6, GSX-R1000, and R1, and I have no doubt that they work much less to achieve the same results I do on the VFR, simply due to the fact that time marches on. However for a bike that even in it's time was no GSX-R, it amazingly potent to this day once properly sorted and ridden.

I have a set of '98 R1 Calipers and I'm going to have brackets made and run them on the stock rotors. That will be a vast improvment.

Anyways, thanks again for answering my question, and good luck to all of you who under take this project.

[Guest DonnyBallGame]

So is the type of thing you do just because you can, not because you need to?

Mostly because I can. I can't leave anything alone. I also like the look of the USD Forks. I had a hard time deciding on doing this mod. The Original front end worked just fine, so why change it. I am going to keep the VFR. So I wanted to be able to make some adjustments to it as my riding needs change. I do trackdays and commute on the same bike. I also wanted better brakes.

Thanks for keeping me in check.

[Guest DonnyBallGame]

Donny,

If you are using the R1 front wheel you will need to make or source spacers for the axle - the R1 tripleclamps are 210mm fork centre to fork centre, whereas the CBR/RC51 triples are 214mm.

You'll need a 2mm spacer for each side of the front wheel. The axle diameter is 22mm.

It follows that you also need to space the brake calipers* in by 2mm on each side so they line up with the rotors.

With the wider spacing on the RC/CBR triples, is it still possible to use the R1 axle? I'm thinking of sticking with the R1 front wheel as I might go with the radial brake front end.

What did you decide to use for bars?

Have any pics?

Thanks.

I am getting a new axle made. With the new axle, I will be able to use my VFR wheel and rotors. It should be ready next week. Once I get the axle fitted with the rim/rotors and forks, I can measure up what I need for spacers and have them made as well. I will post a pic when it is done.

As for bars, I will probably bit the bullet and buy a pair of Helibars. Still need to make up my mind on the 929 of 954 models. Helibar list some different specs on both of them.

[SAFE-T]

I did a cost-benefit-analysis of three different fork mods, taking into consideration measurable things like increased performance and immeasurable things like pride of ownership.

In the end I picked the high-end route primarily because I was willing to spend the time and energy to make it as affordable as possible.

Honestly, the difference is subtle at best and really only begins to be noticeable when you rail through a big sweeper at 180 km/h+ and hit a bump. Bigger better brakes would be a plus if I actually used them but I've spent so many years riding The Pace that I doubt they actually benefit me personally. I have 320 mm rotors because that happens to be the size that fit. I've ridden other VFR's back-to-back with mine and they feel pretty much the same for my riding style at legal riding speeds. Beyond that I don't feel like experimenting with other people's property.