Wheels and Tires

The main concern is the rear wheel. The rear wheel is 18" x 5.5"; thus there are no super sticky modern tires in the original tire size. If you want the latest in tire technology there is no option but to change the rear wheel. Honda claim the 18" rubber was to reduce tire wear during endurance racing as a result of the relatively larger circumference. The circumference is about 4% greater than a 17" tire.

The much less problematic wheel is the front. Honda got the diameter right, but then selected a 3" wide rim. The 3" wide front was selected to allow the front wheel to be removed easier for quicker pit stops. That's all history now, we just need to know is the 3" wide wheel is a poor choice for most modern rubber. A 3-1/2" wide rim looks a lot better than a spindly 3".

You do have a few choices for both the rear and the front. All choices have some monetary implications.

Just as reference this what comes on most RC30s when new. All stock wheels are plain gloss white, not the pearl white as used on the bodywork. The Honda RC30 paint codes are here. Tires are a radial rear and a bias ply front. Open this PDF to learn how to decode a tire's DOT manufacturing date. The pictures below show the original Bridgestone rubber, some RC30's came with Dunlop tires.

POSSIBLE SOLUTIONS - REAR WHEEL and TIRE

Use an RC45/RVF750 17” x 6” wheel. This sounds easy. Especially when lots of people have put 6” wide wheels on the RC30 and HRC sold them. As a general rule it doesn’t work without other modifications. Consider these topics prior to making a decision.

1. Even the stock 5.5” wide wheel with the narrowish section Bridgestone tire is close to the swingarm and rear fender. The tire comes very close to the chain on an RC30. Inner fenders are not available from Honda anymore, keep that in mind with any tire and wheel choice.
   
2. Some guys use spacers with the RC45 wheel to move the wheel to the right to gain the necessary swingarm and chain clearance. I'm too retentive for this, if the wheel was supposed to be 6mm to the right then Honda would have made it that way. They did not, and something just seems fishy to me. If your rear tire is now a 180 width on your 6" wide rim, it will shred the inner fender on the right side (or still both sides). The right tire edge will have effectively moved approximately 13mm to the right. Many people will do a poor job of the installation too. Longer pins should be installed in the axle to accommodate the spacer that would slip over them. There will never be any engineering awards for this even if it does "work". 
   
3. You could grind/cut or otherwise remove the interfering part of the left side of the tire (and maybe the right if it hits the inner fender). The less said about this the better. Something has to be sacred here. Let us make it the actual construction of the tire.
   
4. A ride height adjuster or adjustable length damper is needed to regain the lost static ride height (about ½”+ in height). HRC made these but they are made by others such as Maxton and Moriwaki. This applies to any 17" wheel or an 18" wheel with a 160 tire (see Solution No. 5).

Rear - Solution 2

Rear - Solution 3

Buy a cast or forged aluminum aftermarket rear wheel in 17 x 5.5. This is a good option if you can find a nice one, preferably new with some type of road approval like the Japan's JWL. An aluminum alloy wheel is more durable than magnesium alloy. Cast wheels are sometimes possible to repair but I'm with Honda on this one, get a new one if it's damaged. Cracked, bent or repaired wheels make nice garden hose reels.

There have been both cast and forged aluminum wheels made in a variety of designs from hollow 3 spoke old school, to trim looking modern forged designs. You will need special tools to test an RC30 rear wheel for trueness or to balance it. As with all 17" wheel options a ride height adjuster is required.

1. Dymag
2. PVM
   
3. Maxton
4. Carrozzeria
   
5. Duomo
   
6. Marvic
7. Marchesini
   
8. Brembo
   
9. Tecnomagnesio
10. Delkevic :-(
    

Rear - Solution 4

Buy a new carbon composite or carbon/alloy composite wheels. Carbon fiber is poor with impact loads. That is a fact, but you will normally only read or hear statements about high tensile strengths, monumental stiffness, light weight, and other truths that don't mitigate the low toughness concern enough to satisfy me. Though the carbon fiber wheel manufacturers design around the poor material properties there are fundamental differences between a wheel made from a (relatively) ductile material like cast or forged aluminum and those made from a brittle (in the true engineering sense) matrix of plastic and carbon fiber. The manufacturers push performance gains such as lower polar moments, less unsprung weight and such. Yes, they can have street approvals but that is little consolation. You have to be prepared to deal with wheels that are not as robust as something made of 100% metal. beside being outright tacky these wheels are expensive and finicky, not what I normally look for in a purchase.

OK now, lets look at it from a less technical angle. Even if these wheels possessed some real value and were truly race and roadworthy it does not stop them from being cheesy. I have done some intensive research, just as the gurus did, and developed this simple formula to explain partially what I am talking about. The equivalency is plain to see even to the most technically challenged.

Rear - Solution 5

Rear - Solution 6

Convert to a 1990 to 1993 VFR750F wheel that is the desired 17 x 5.5. The 1994 to 1997 VFR wheels were 5" wide. They might also work if you don't mind a narrow wheel and a different spoke style. This always looked plausible to me, but sadly getting wheel information that is complete from anyone is difficult at best. Again, I’d love to have complete wheel and axle dimensions from a 1990 to 1993 VFR-F but unless I buy them myself this probably won’t materialize. I will go out on a limb and say that a modified RC30 axle and this wheel would work. Take that for what it’s worth, I haven’t done it. If you do go this route you may lose the single nut attachment, depending on how it is done. The offset is probably a bigger concern than attaching it to the RC30 axle. VFR wheels are held on with four lug nuts like a car. The 8 spoke pattern matches that of the original 18” RC30 item so it won't look too silly, even with lug nuts.

Rear - Solution 7

Use an RS250 Race wheel. These aren't too hard to find and aftermarket ones are available from Marvic and Marchesini et al, but the spokes are swept the wrong way as the RS wheels mount/dismount from the port side of the bike. It makes the bike look retarded. These also have the same problem as any ex-race wheel when used with respect to damage, age etc. I wouldn’t waste my time on them if for no other reason than the clumsy look.

Rear - Solution 8

• Delkevic New   $175 (polished for $240)
• Honda Used     $100 to $250
  
• Honda New      $600