The VFR FAQ Presents:
Wheel conversions for 1986-1987 VFR700F and VFR750F Interceptors.
** DISCLAIMER **
I am not a mechanical engineer; I do not work for American Honda. You are on your own. You are expected to have some mechanical ability, or at least have friends that do. I take no responsibility for any mistakes or accidental omissions in this document. The wheel conversion information is complete to the best of my knowledge and the collective wisdom of the VFR owners that have also performed this conversion. I have converted the rear wheel of my ’87 VFR700FII and it works just fine. Your results may vary.
This document was last updated on February 12, 1998 byDon Zielke
Table of Contents:
Section 1: Why
The 1986 and 1987 VFR was an excellent motorcycle when introduced, as it was at the top of the racing scene in the hands of riders like Bubba Shobert and Wayne Rainey, but was still refined enough to be used in a wide variety of riding situations. Unlike the GSX-R from Suzuki, which was a pure sports machine with no concessions to rider comfort, the VFR was nimble, powerful, and comfortable. However, the then-vogue 16" front and 18" rear is now passe and tire selection is slim.
Question: So why mess with a good thing?
Answer: This is purely subjective. There is no right or wrong answer here, just lots of money spent making a good thing better. Yes there are other bikes that might be better. There’s just something special about this series of bikes. Some of us just prefer the road less traveled. ‘Nuff Said.
The main reason to swap the wheels (at least for me) is to improve one’s selection of tires.
Section 2: Replacing the 16" front wheel
Question: Is there a direct replacement bolt in wheel available?
Answer: Yes. Find a 17" x 2.5" front rim from a Hurricane 600. It can handle up to a 120/80 front tire, uses the same speedometer drive, and has the proper spacing for the calipers.
Question: Are there wider wheels that will work?
Answer: Basically, any wheel that is round can be used with some machine work. Read on…
Question: Can I use the wheel from a CBR600F2?
Answer: With some modification, yes. The F2 front wheel has the speedometer drive at the axle, however the rotors are spaced out farther than stock. The F2 rim will have too tight a tolerance between the rotors and the fork legs. Warp your rotors and you can damage the forks. Machine the rotor posts in (about 11mm, I was told) to fit the stock calipers, don’t move the calipers (due to the above mentioned fork-to-rotor tolerances). The only company that I know that has this all worked out is Cobalt Racing. Either send them your rim or they can find you one. They can be reached at 614-983-3358.
Question: What about the CBR600F3?
Answer: Pretty much same as above, except the F3 wheel lacks the speedometer pickup. You can use a speedometer for bicycles (Sigma), believe it or not. Who would have thought a bicycle speedometer would have to read up to 160 MPH? J
Section 3: Replacing the 18" rear wheel
Question: How wide can I go?
Answer: According to Chuck Crites, proprietor of Cobalt Racing, up to a 6.0" rim can be fitted to the bike. This, however, requires some pretty major surgery.
Question: So what is recommended?
Answer: Cobalt Racing recommends the 17" x 4.5" rim from the CBR600F2, but the 5.0" rim from any modern sport bike should do the trick nicely. (It looks nice if the front and rear rims match, though.) The 5.5" and wider rims require the countershaft sprocket to be moved outboard.
Question: How do I mount the F2 rear wheel?
Answer: Several other things need to happen to use the F2 rear wheel.
Question: Can I use a different shock than the Fox?
Answer: Yes. Initially, Cobalt Racing lengthened my stock shock. Or you can have a shock custom built. I later had a custom shock built from Works Performance. I am very pleased overall, but expect to have to dial it in further. I seem to remember that WP (formerly White Power) will custom build a shock as well.
Question: So how do I mount it?
Answer #1: Here is how VFR list member Steve Mandeville (MADDEVIL@aol.com) replaced the rear wheel with a Kawasaki rear rim:
--- Begin included text ---
I used my stock rear caliper and carrier, it rides on the stock Suzuki rotor, It doesn’t grab all the way on the rotor but I can still lock the wheel. For the back you basically make 3 spacers. Looking at the rear, the left spacer will just allow the sprocket bolts to clear the swingarm. The right inner spacer you make to align the caliper over the rotor and the last spacer fills any gap to the swingarm from the caliper carrier. If you use a 5.50 rear wheel you will need to move the countershaft sprocket outboard. I shaved off the inner lip from one side of the sprocket, made a spacer of equal width and put it BEHIND the countershaft sprocket. You may need to grind a little metal from the inside of the sprocket cover if the chain rubs there.
Last, you need a new rear brake caliper torque arm to clear the tire. Mine is an aluminum bar, which is now mounted on the OUTSIDE of the swingarm lug, (stock is inside.) But a curved arm would work too. My friend’s bike has a braced swingarm by Cobalt and his caliper mounts below the swingarm with a very short torque arm to a welded on lug. Both bikes use the same size axle.
--- End included text ---
Answer #2: Mounting an F2 rear rim. Here is what I did to replace my rear wheel. First of all, I located an F2 rear rim from a salvage yard. I bought mine from J&M Cycle, and paid $175 for the rim, rotor, and cush drive. I took my bike to Cobalt Racing (Asheville, OH), where Chuck Crites did the actual work. He started by trimming the upper caliper arm (the one that runs from the caliper to the forward section of the swingarm) on the inside, in the area where it is closest to the tire, taking it from a ][ shape to a [ shape. Then he installed the rear wheel using the spacers he made and the caliper mount. The caliper will sit higher than the rotor, and must be shortened. He cut the caliper arm and re-welded it so the pads and rotor made full contact with one another. At the time I still had my stock shock, so Chuck welded an extension to the bottom bracket (looks like an inverted U) on the shock, to raise the rear ride height up to where it should be. Then Chuck installed a 15 tooth countershaft sprocket (stock is 16 teeth), a stock 43 tooth F2 rear sprocket, and a 114 link 530 O-ring chain. I think that is a couple links too long, as the last time I replaced my chain I had to cut some links off (it was too long). A word of advice: Use steel sprockets, they last MUCH longer. The smaller front sprocket is necessary due to the overall gearing change introduced by going from the 18" wheel to the 17". Dropping the front sprocket takes you back within a few hundred rpm’s of stock. In a nutshell, that’s how my conversion went. The rear is pretty easy to do.
Section 4: Replacing the entire front end
Question: Has anyone ever replaced the stock forks?
Answer: You bet!
Question: What forks have been used successfully?
Answer: GSX-R1100, CBR600F2, and CBR600F3, so far. Read on…
The following is from MADDEVIL@aol.com and has to do with replacing the VFR’s forks with those from a GSX-R1100.
The GSX-R Front End Option:
--- Begin included text ---
Ok, here goes...
Any front end will work as long as it is from an 1100, NOT a 750. You will use the entire front end EXCEPT you will get a custom steering stem made up. You press the stock Suzuki stem out, (toward the bottom), and press the new custom stem in. I had my stem made by Kosman in SF but any competent machinist can do it. The stem will match the Suzuki lower tree, then match the VFR stem through the frame, then match the Suzuki upper tree. You will buy aftermarket tapered roller bearings for a 86/87 VFR. My stem is billet aluminum, and if you want, have them leave some exposed down below your bottom triple clamp and put a hole in the end for a front-end stand. When you do the stem swap, to get the stock stem out, heat the triple clamp. When you press the new stem in, heat the clamp and freeze the stem.
I use all the stock Honda controls, master cylinders etc. Everything else on the front is Suzuki. The Suzuki speedometer cable will thread on to the Honda speedometer.
--- End included text ---
The CBR600F2 Front End Option:
Any year front end will work, however the front end from the ’94 F2 has the greatest range of adjustment. You will need the forks, wheel, axle, rotors, clip-on’s, fender, and upper and lower triple clamps. You can re-use the calipers and switch gear from the VFR. Have a machine shop pull the steering stem from your old triple clamps and have it pressed into the F2 lower clamp (or just have a new one machined). Now would also be a great time to replace the steering head bearings with a nice tapered roller set. The F2 wheel has the speedometer drive built in to the wheel (just like the VFR does), so your speedometer works as before (although a few MPH off).
The CBR600F3 Front End Option:
Following is a partial account (to be updated as he provides me further information) from Andrew Reveles (Speed.Racer@asu.edu) on mounting the F3 forks to his ’86 VFR750. (He also talks about replacing his steering head bearings at the same time.)
--- Begin included text ---
Just thought I would let you know how the conversion is going. So far taking the races out of the vfr was cake. I followed the instructions in my Clymer manual. Putting them on is another story. After trying to find a way to drive the new tapered races into the frame head unit. I found that you can use the old races (flipped upside down) to drive the new tapered races in to the chassis and stem (WAIT AND READ THE BOTTOM OF THIS MESSAGE BEFORE PROCEEDING WITH INSTALLING THE TAPERED BEARING ONTO THE STEM). Make sure that your old race is clean and free of nicks. I wrapped the old race with plastic wrap just to be on the safe side.
Now for the hard part.
******* Before you install the new tapered bearing onto the VFR steering stem/F-3 lower triple clamp,********
you will need to grind the stops on the CBR F-3 lower clamp. The stops on the vfr lower clamp are squared. Look at both lower triple clamp at the same time and you will be able to see a HUGE difference between the two. The stops on the CBR F-3 lower triple clamp are angled at one end.
This angled stop causes the lower triple clamp from seating properly on to the bottom of the chassis head unit. You can see that the bottom surface of the chassis head unit rests on the stops! Mark how much you will need to grind and use a hacksaw and file to grind the excess cast iron stop. Now clean the whole area off. When you are sure there is no trace of metal fragments. Install the stem and dust shield. Wait! Now install the lower VFR stem/F-3 lower triple clamp once more onto the bike to make sure the lower clamp fits properly. If it does, then proceed with driving the new tapered bearing onto the stem. Now follow you instruction manual with the rest of the installation.
So for all of those out there who are planning on doing the conversion, or who are in the process. Make sure you grind the CBR F-3 stop to match the old VFR stop when you remove all races and stem from the F-3 lower clamp. This way you will not get any metal dust onto the bearing when grinding. It took me three hours of grinding (had to be very careful not to nick the tapered bearing or the dust shield).
If you have already installed the bearing onto to the stem (man I feel you pain now). Take plastic wrap and wrap the bearing. Proceed with the grinding now but make sure you do not touch the dust shield or bearing.
Tools I used:
Hammer, piece if wood (to put on top of the old race to bang on), old races (ball bearing race flipped upside down), plastic wrap, WD-40 (to help with the installation of the races).
Andrew Reveles from Arizona, USA Homepage address:
http://www.public.asu.edu/~gun1234/ I can also be contacted at:
--- End included text ---
Section 5: Related Modifications
Upgrading both wheels will place additional stress on other components, especially if you put the bike on the track. Here are some items that are recommended when you upgrade the wheels.