Tires and rims

I am building a pair of Rapides, a C touring rapide and a B rapide that will be a bit of a hot rod. The C touring rapide has WM3 -18 rear and WM2 - 19 as standard. I am inclinded to use road rider IIs and wonder what sizes people are using . I believe I can use a 100/90-19 on the front but wonder if the 90/90 would be better. Also, should I use a 100/90 or the 4.0 x18in on the rear?

Re the B, I will probably use 19 and 18 rims front and rear. Does anyone know what size tires will fit the shorter b RFM and does anyone have any experience with using wider rims such as a wm4 rear, wm3 front? I am planning to build this bike with coil overs front and rear, a speet front brake, reasonable engine mods inc. mk2 cams, 32mm concentrics and a "somewhat" silenced lighting exhaust. Thinking of using Takasago alloys painted with center painted. Not much done on this bike yet, just assembled bottom end.

Any advice on tires and rims would be appreciated.
best, M

M,
I also have the short "B" RFM on my bike and am running the 19" WM II rim with the Avon Roadrunner 100/90 4.10H/19. No problems fitting in that space. Up front, I run the Avon RoadRider 90/90-21 on a WM I rim.
I can't provide any input regarding running wider rims.

Regards and cheers.
Russ

Memory is a little hazy on the specifics here and the bike was sold some time ago but, I ran a 3.25 19 on the front and I believe it was a 4.00x18 on the rear. Rim sizes were as per Avons recommendation (shown on their web site).

This bike had B RFM.

Thornton dampers front and rear, but threw the Thornton springs away and replaced with Godet springs as the ride height was all wrong.

Handling was excellent.

However, before buying rims etc you should check out what tyres are actually currently available as Avon is going through some re-structuring right now and it is effecting supply. If you can find what you want, buy two pairs and keep the spares wrapped up and stored in a cool dark place.

The bike with the Avons mentioned above. It ‘sits’ well on them IMHO:

For the last ten years or so, I have been using the 4.00 x18 RoadRider on the Vincent rear and a 100/90/19 Roadrider on the front.
I used the bike with stock wheels and RoadRunner rear/ ribbed Speedmaster front for a few years prior to making the wheel size changes.
With stock wheels it handled ok and was very light turn in effort with the skinny 20" front wheel. It was horrible on expanded metal bridge decks or ground asphalt, some of which we always seem to encounter.
The switch to 18 and 19 alloy wheels with the bigger Roadrider tire sizes changed the handling. The bike requires slightly more turn in effort now. I got used to that in about 30 minutes of riding.
The 400 18 is a big tire compared the old 100/90/19 and has a higher weight rating.
It is about right for the weight we carry when 2 up with luggage. The old 100/90/19 or 4.10 x 19 (I tried both)
was overloaded when 2 up.
I like the new setup much better than the old. I've never felt the Roadriders slide and I've ridden the bike hard at times.
They are also a lot better on expanded metal/ ground ashpalt/ Tar snakes than the skinny old ribbed Speedmaster was.

Glen

Thank you all for the comments. Since the c is a touring rapide I am going with the 4.0x18, 100/90 -19 roadrider combination. As to the b I am inclined to use the same size but am considering a wm4(2.5) on the rear and wm3 on the front. As I don't have much vincent experience I am concerned about the extra about .3 to .35 in of width but the tires should fit the rims better.

I really appreciate the input.

Russ and fast eddie, particularly appreciate the b comments. Fast eddie, love the front brake, grimeca?

Best to all, M

It’s a magnesium MV replica front brake that Dresda used to sell, it was a fabulous brake. I built the bike from a basket case, the fork legs were already drilled to take a double sided BSA brake that weighed a ton (and I never used).

According to Avon, recommended rim size for the 100/90/19 is 2.50. Minimum is 2.15.

I fitted the 3.25/19, recommended for that is 2.15. Minimum 1.85.

Recommended for the 4.00/18 is 2.5. Minimum 2.15.

Unfortunately I really can’t recall what rim widths I used, but I definitely followed Avons advice. If in doubt go with the minimum shown as they will still work fine, and honestly, rims too wide just won’t look right on a Vincent.

I changed from the originals coz I used the bike on some old bike track days and when I saw the scrub marks on the original front tyre I crapped myself, practically cornering on the sidewall !

Avons rim advice is all on their web site:

I used WM3 width front and rear, the minimum required width for the tyres I'm using. At the time that was the widest flanged alloy rim that Devon Wheel could offer. We discussed the Avon table and he assured me that the WM3 would be fine, and as Nigel suggested, might look better than wider rims on the Vincent.
I have really cranked the bike over and tossed it side to side on many occasions, no problem at all.

I'm not sure what I would do today faced with making the same decision.
2.5" flanged alloys are available now, so it would be a tough call. Do the 2.5" come with safety beads? If so this would permit tubeless conversion.
I'm not sure if that is a great idea either.
I've done the conversion on the Thruxton R but it started to leak after 2 years. In checking around I found that this is quite a common problem with tubeless conversions. At the moment I've added a sealer sold by Outex, the tubeless conversion supplier. It is working but time will tell.

Glen

I am building a b rapide now that will be a bit of a hotrod. I am thinking of using takasago shoulderless alloys with the anodizing removed, polished and painted with original black and red. I am thinking a 18 or 19 WM4 (2.50) on rear and 19 WM3 or 21 WM2 on front. Tending toward smaller diameter sizes as larger tires seem to be going away. Think the WM4 will fit in the shorter B RFM.

Best and thenks for the comments. Michael.