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H: Hubs, Wheels and Tyres Buying tyres for Rapide

danno

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VOC Member
Dan, National Bike Tyres mail order, Speedmaster 20 inch front, Roadrunner 4.10 x 19 rear, £74 each, in stock. Rim tapes and Michelin tubes also available, ask about front tube size, current advise seems to be stretch 19". Very helpful, reasonable carriage costs, recommended. Good luck....
Thanks.
Yes, on Velocette owners site, consensus seems to be 19” tube for a 20” wheel. It may crease using 21”.
Wheelhousetyres say that the Michelin 21” tube is a perfect fit for the Speedmaster
20”.
 

Old Bill

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VOC Member
Dan, l have used both 19 & 21 inch tubes on 20 inch rims, neither has caused me any problems. The Avon safety mileage is perhaps not the best tyre to use on the rear of a solo machine hence my reference to the universal (front or rear fitment) roadrunner cover which in my opinion does not look out of place on a standard machine. In fact l think l read somewhere on this forum that Ted Davis prefered this set up, for pressures l would start at 28 front 30 rear and see how it goes. One other thing, security bolts are not really needed with modern rubber and carcass construction, again just my opinion. Good luck, mind how you go.......
 

Robert Watson

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VOC Member
I have several bikes with 20 in Avon Speedmasters on the front and the Avon Roadrunner on the rear. I like the combination. I do have a spare 20" tube which I carry when touring along with a 19 for the rear. I think all of the ones fitted to the bike have 19" tubes in the 20 in tires and have never been a problem. The biggest mileage gets done on the Woolly Mammoth rapide and it has modern 19 and 18 Roadriders with appropriate tubes.
As for tubeless, one Dan Smith used a kit he has purchased on line on both his Shadow and his A twin replica and swears by them.
 

danno

Well Known and Active Website User
VOC Member
Dan, l have used both 19 & 21 inch tubes on 20 inch rims, neither has caused me any problems. The Avon safety mileage is perhaps not the best tyre to use on the rear of a solo machine hence my reference to the universal (front or rear fitment) roadrunner cover which in my opinion does not look out of place on a standard machine. In fact l think l read somewhere on this forum that Ted Davis prefered this set up, for pressures l would start at 28 front 30 rear and see how it goes. One other thing, security bolts are not really needed with modern rubber and carcass construction, again just my opinion. Good luck, mind how you go.......
Thanks.
I’m sure it’s only ever had the Safety Mileage rear fitted. Have always been used to that squared off look.
I did consider Roadriders as I have them on my BMW R60 but then realised I’d need different wheel sizes.
Just wondering what the official sizes are.
The Roadrunner is wider than the SM Mkii but don’t mind the more modern profile.
There’s a security bolt fitted. I remember my father fitted it after a low speed tyre deflation where the tyre rotated enough on the rim to rip the valve off.
 

Old Bill

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VOC Member
Dan, an explanation on the tyre size, 3.5x19 is the old measurement, 4.1 x 19 is a direct replacement in modern parlance, same width which fits the same rim. A further thought, perhaps the offending valve ripping tyre was a little old like the ones you intend to replace in which case the rubber may well have lost its grip on the rim? Same thing happened to me under heavy braking on a Comet and when l examined the tyre date code l found the tyre was over ten years old and when it came to removal time the old hard rubber almost fell of the rim, low pressure may also have been a contributing factor however. Safety mileage tyres may well have a visual appeal but Roadrunners will save on your laundry expenses, mind how you go.......
 

danno

Well Known and Active Website User
VOC Member
Dan, an explanation on the tyre size, 3.5x19 is the old measurement, 4.1 x 19 is a direct replacement in modern parlance, same width which fits the same rim. A further thought, perhaps the offending valve ripping tyre was a little old like the ones you intend to replace in which case the rubber may well have lost its grip on the rim? Same thing happened to me under heavy braking on a Comet and when l examined the tyre date code l found the tyre was over ten years old and when it came to removal time the old hard rubber almost fell of the rim, low pressure may also have been a contributing factor however. Safety mileage tyres may well have a visual appeal but Roadrunners will save on your laundry expenses, mind how you go.......
Thanks. Really useful info.
The tyres have been on the bike for over twenty years but only have 9000 miles on them.
Time for new boots.
 

danno

Well Known and Active Website User
VOC Member
I messaged Avon regarding the Roadrunner rear for the Rapide. They said it would be 10mm wider
than the Safety Mileage Mkii but will fit rim fine.
Also will reduce ride height by 7-8mm.
 

Glenliman

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VOC Member
I haven't seen new Avon Roadrunners for quite a few years.
Are these Roadriders?
Roadrunner was a name used after the Super Venom and before the Roadrider. I had some but can't recall the tread design. I think it was similar to the Roadrider.
Avon has added a Roadrider MK2 recently but still show plain Roadriders listed as well. The MK2 Roadrider listing shows all of the old Roadrider sizes. The plain Roadrider listing just has a few mostly oddball sizes . Maybe getting rid of old stock?
Avon rates the MK2 Roadrider as having better wet and dry grip than the old Roadrider, which already had good grip.
They claim the same wear rate for both types.


Glen
 
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LoneStar

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VOC Member
The Roadrunner is still available - they tend to call it by the 'AM9' designation. I prefer it to the Roadrider as it has a more traditional tread pattern.

 

TouringComet

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VOC Forum Administrator
VOC Forum Moderator
All the Avon info is available here. Go to page 20 for the Classic versions. The 3 x 20 Speedmaster is listed as "Special production only". I gave up on Roadrunners because the tread wore quickly. I switched to Bridgestone Spitfire some time ago. It's technically a front only tire, which is okay on my Comet with a 19" front rim, but on the Shadow rear, I just mount it for the opposite rotation.

 
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danno

Well Known and Active Website User
VOC Member
Thanks for the tyre info. With a 20" front wheel I think my only choice is a Speedmaster MKii 3.00 x 20.
I have one arriving tomorrow.
I'll probably go with a Safety Mileage again on the rear to keep ride height the same. Also doesn't seem to be much mudguard clearance at the front right side or the rear. May need to bent it out a little.
 

Glenliman

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VOC Member
Right, I see the AM9 in one size only, 4.10x19.
I guess that's why they have disappeared from the suppliers I've been using.
I'm not missing them though. The Roadrider is a really good profile.

Glen
 

Glenliman

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VOC Member
All the Avon info is available here. Go to page 20 for the Classic versions. The 3 x 20 Speedmaster is listed as "Special production only". I gave up on Roadrunners because the tread wore quickly. I switched to Bridgestone Spitfire some time ago. It's technically a front only tire, which is okay on my Comet with a 19" front rim, but on the Shadow rear, I just mount it for the opposite rotation.


Steve, what is the tread depth of the Bridgestone?
Generally those tires designated front only give you very little tread depth, which is good on the front, not so great on the rear.
With Avon, the Universal fit are in the middle for tread depth. Again, ok on front , not so great on the back.
The dedicated rear tires generally give good tread depth and wear.
That's one good reason for switching to an 18" rear rim.
Especially nice if running two up.
For example, with 18x WM3 or wider rear rim one can run a 4.00 x 18 rear Roadrider which has a 64 load rating and deep tread depth, 7.5 mm. When loaded with luggage and two up, the 64 rear tire load rating right where we're at with the Vincent. When I had a 19" rear rim on the bike , the 4.10x 19 then later 100/90/19 rear tire was loaded well beyond its load capacity rating.
The front only 19" Roadrider has a 52 load rating and 5mm tread depth.
The universal fit 100/90/19 Roadrider has a 5.6 mm tread depth and 57 load rating.
This size is on my Commando and I really wish I had switched it to an 18" rear rim to take a good sized dedicated rear, as on my Rapides. With the Commando, I get to do lots of tire replacement!
And the existing 19" rear tire is also overloaded when used for two up touring.



Glen
 
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TouringComet

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True, less tread depth with the front designed Bridgestone. I have the luxury of an 18” rear on the Touring Comet, but want to stay with the original 19” on the Shadow. The load rating/index of the 100/90 19” Bridgestone is 507 lbs. Thanks for pointing that out. We did do two up riding, with luggage, on the Shadow for the Italy International, maybe we were flirting with disaster?

When I needed a new 18” rear on my Touring Godet, I did go up a size, to 400 vs the 350 it had when I bought it. The 4 is slightly larger diameter, and I had to modify the rear mudguard mount to provide more clearance. This is the bike we would use now for two up with luggage, it has Cravens.

I think the Bridgestone tread depth value is in units of 32nds of an inch.

 
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bmetcalf

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VOC Member
The units would be interesting to confirm, 5/32" = .156" and 5mm = .196" (26% more)
 

davidd

Well Known and Active Website User
VOC Member
Sorry Marcus. Are you saying that you use tubeless tyres on spoked wheels? Is the silicone used to seal the spoke nipples and the edges of the tyre? Is the rubber band which normally protects the tube from the nipple ends used to help the sealing with the silicone? Just trying to understand.
Tubeless tires have been used on spoked wheels for years. Many have done home-made versions, but Harley Davidson delivers them on brand new bikes. Harley's system is like this:

Harley Tubeless Spoke Wheel.GIF

Harley replaces the rubber inner strip when they change the tire.

The problem with caulk is that there are several problems that have to be kept in mind. If you slather caulk in the drop-center the spokes will not turn without doing damage to the caulk. The cure is to place mylar dots on the spoke ends. This allows them to turn for minor adjustments.

The second problem is that tubeless rims have a safety ridge that keeps a deflated tubeless tire's bead from wandering into the drop-center. You can see the small ridges in the left-hand photo above. Those are not found on traditional spoked rims. Sun rims are the only aftermarket rims that I know of that have the safety ridges for tubeless tires.

I thought that Dan Smith was running tubeless tires on spoked wheels on his Series A?

David
 

Glenliman

Well Known and Active Website User
VOC Member
The Japanese Outex kit is good for this.

 

TouringComet

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VOC Forum Administrator
VOC Forum Moderator
The recommended rim size for tires is typically wider today. We usually have to go by the minimum rim size quoted by the tire manufacturer. The 19" rear is normally a WM2, and the 18" rear is normally a WM3. A WM3 is 2.15 inches. For Avon Roadrider AM26 rear tires, the only size they offer with a minimum rim size of 2.15" is the 4.00-18. This is the one I recently mounted on my Egli. The overall width of the tire is 4.6", and it has a load rating of 617 lbs. For the Avon Roadrider AM26 universal model, there are 4 sizes available with a minimum rim size of 2.15": 90/90, 100/90, 110/80, 110/90. The tire width ranges from 3.8 - 4.6". The 90/90 actually has 2.15" rim as the recommended size. Those universal tires, as mentioned by Glenliman, have less tread depth, and the load ratings are all lower, between 430 - 567 lbs.

For WM2 19" rims, the rim width is 1.85". For the Roadrider, there are no rear tires listed with a minimum rim width of 1.85". For the Roadrider universal, the only choice is the 3.25-19 with a load rating of 467 lbs. Looking at the Classic section, there are choices in the Safety Mileage, a 3.50-19 with load rating of 507 lbs, and the AM9 (old Roadrunner) 4.10-19 with a load rating of 567 lbs. The AM9 does have the 7" tread depth, although it is listed as a universal tire. The SM 3.50-19 has a tread depth of 8.1".

If you are willing to forego the minimum rim width recommendation, there are a few other Avon choices.
 

vibrac

Well Known and Active Website User
VOC Member
Hummm :confused:(thats me considering tubeless on wm2 and WM3 rims)
It does seem a good way to go but I would like to see more data regarding long term use especially with narrow front 20" and the more prevalent 21" tyres and 19" tyres I dont thinkl I can rely on a bunch of MX riders on knoblies and crusers or track day jockies on 18" fat boys

I do think there is more to it than tape and the senario with a deflated tyre on a spoked rim going into the center seems a possibility perhaps a moulded contoured tape would stop that effect.( fitting an air tight security bolt as an option would be fun!)
anyway the small size of our market, the inbuilt conservatism of classic bike riders and low useage will make acceptance and proof a slow process.
 

peter holmes

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VOC Member
If we could still purchase the Metzeler inner tubes that Uncle Ron used to supply there would be no need to covert to tubeless tyres, that were the best so distraught was I when they ceased to be available I hunted some down on the internet thinking I was getting NOS, when they arrived all the way from the USA they were packaged in the same blue and white cardboard boxes, with those magic words "Made in China"printed on the box. I am going to stick with tubed tyres using the best tubes that I can source, just seems such a faff going tubeless, over the 54 years that I have been riding I have not have had that many punctures, 3 in one day on a 500 mile ride back from the Isle of Skye, entirely my fault with a perished tube, but that was 45 years ago, I know better now, If I change a tyre the tube gets replaced also. Fingers crossed I will stay free of punctures for a good while yet.
 

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