Avon Roadrider 120/90-18

Is anyone running an Avon RoadRider 120/90-18 on a Mark III ? Just wondering if it will clear...I'm having a new rear wheel laced up and wanted to make sure it will fit.

I haven't used a 120/90-18 RoadRider, but I have run a 120/90-18 Dunlop 591 on a WM3 rim on my production racer replica. It clears...barely. I notched the chainguard for a little extra insurance.

I have since replaced it with a 110/90-18 RoadRider. I didn't like the way the 120/90 handled. The turn-in seems much quicker with the 110/90.

Ron L said:

I haven't used a 120/90-18 RoadRider, but I have run a 120/90-18 Dunlop 591 on a WM3 rim on my production racer replica. It clears...barely. I notched the chainguard for a little extra insurance.

I have since replaced it with a 110/90-18 RoadRider. I didn't like the way the 120/90 handled. The turn-in seems much quicker with the 110/90.

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Thanks for the input. I was thinking of the 120 to try and keep the height the same front and rear, I knew going to an 18" rear would lower the rear a little. Don't know if it makes that much of a difference?

I have the tyre you ask about but in a pre-Mk3 swingarm with clearance about 7mm each side. I don't like the handling and will go 110 next time the 18" gets replaced.

It fits too tight in my opinion, i took it away and went back to 100/90/19 which clears perfectly

I use a 4.00 x 18 Roadrider on my 850. This is the same dia. as the standard 100/90/19" tyre & clears the chain guard. The added bonus is 7.5mm of tread compared to 5.6mm for a 110/90/18". The handling suits me fine.

I've had an Avon Roadrider 120/80-18 on the back with a WM-3 rim and it just barely fit in the swingarm (about 3 mm each side) - so the 120/90 should be OK. Now I'm back to 110/90. The big tire on the back looks silly nowadays and doesn't do anything for the handling.

I had a conti super twin 400 v 18 which is 4.69" wide on my MKIII.
It fit but I hated it.
Back to stock 19".
gonna sell this wheel...akront 18 x 2.15" stainless spokes

dynodave said:

I had a conti super twin 400 v 18 which is 4.69" wide on my MKIII.
It fit but I hated it.
Back to stock 19".
gonna sell this wheel...akront 18 x 2.15" stainless spokes

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Why did you hate it and how much for the wheel?

I can just work/squeeze/sweat/swear a 120x80x18" on WM3 rim past fender and drum on my 2 Combats with chain clearance but feel like too heavy a boot for spirited fun on ordinary Combat power band but does give ~1/3 more mileage and better for low traction off road if a dual use tread pattern. On Peel power though the 110 would spin out too easy on or off road so liked 120 best on her. On Trixie that's similar to everyone else's ordinary power un-linked Cdo's a 120 also seems to on-set weaving-wobbles sooner as if more conflict with front steering so took a tad more effort to fling around in more pensiveness so ain't going back to 120 on factory Trixie even if more economical. Same 110 on both ends even if 18" rear seems to suit my ordinary Combat power and brakes the best. Only like `1/2" difference in height of 18" vs 19" in same profiles 90 or 80.

Avon shows a bit over an inch of difference in diameter between same profile and width Roadrider 18s and 19s. Perhaps you mean only a half inch in ride height difference ?

Glen

Decisions, Decisions.... Avon Road Rider 110/90-18 or 120/90-18 ?

Dirty, shaken, not stirred - fitting a wider than recommended rear tyre will not do anything for the handling of 70s road bikes that came with narrow tyres. From my experience, one of the best rim/tyre combinations is a WM-3 rim shod with a 400 x 18 or 19 or 110 x 90 because it spreads the tyre better and gives a better contact profile with the road from upright to steep lean angles.

You haven't mentioned the rim width you are lacing up with. If you fit a 120 section tyre on a WM-2 rim (i.e. standard fit on a Commando) this would not be a good move. The narrow rim would pinch the wide tyre too much where the beads sit on the rim. You would probably need a WM 4 rim or wider to fit a 120 section tyre. Even then, you would have a mismatch with the slim front tyre.

Avon gives a table of tyre sizes and rim widths here: http://www.avon-tyres.co.uk/sites/defau ... asheet.pdf

There are good safety and performance reasons for matching tyres to rims and matching front and rear tyres, not just in width but also profile.

ugh various 18" & 19" tire brands and profile & models vary in mounted heights so I lucked out mine were so close. If using a Command well enough to appreciate tires behavior optimizing you should be wearing close to cords ~every 4000 miles or less, which could be over a season or a month or a single long trip > so flip a coin and try something different each time till settling on your favorite combo - till they stop selling it and change again.

daveh said:

Dirty, shaken, not stirred - fitting a wider than recommended rear tyre will not do anything for the handling of 70s road bikes that came with narrow tyres. From my experience, one of the best rim/tyre combinations is a WM-3 rim shod with a 400 x 18 or 19 or 110 x 90 because it spreads the tyre better and gives a better contact profile with the road from upright to steep lean angles.

You haven't mentioned the rim width you are lacing up with. If you fit a 120 section tyre on a WM-2 rim (i.e. standard fit on a Commando) this would not be a good move. The narrow rim would pinch the wide tyre too much where the beads sit on the rim. You would probably need a WM 4 rim or wider to fit a 120 section tyre. Even then, you would have a mismatch with the slim front tyre.

Avon gives a table of tyre sizes and rim widths here: http://www.avon-tyres.co.uk/sites/defau ... asheet.pdf

There are good safety and performance reasons for matching tyres to rims and matching front and rear tyres, not just in width but also profile.

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I am going with a WM-3 18" rim. Sounds like the 110/90-18 is the way to go....

Why not 4.00 x 18" as this is the same width as the 110 at 4.6"(116mm), but unlike the 110, it also has the same diameter as the original 19" tyre at 26.4"(671mm) The added benefit is 7.5mm tread depth compared to 5.5mm for the 110 which would give you another thousand plus miles between changes. The reason the 110 has less tread, is it is a universal fitment. Too much tread depth would cause instability on a front tyre. All this info. is on the superb Avon website.

That's interesting. I looked at the 4.00 and a couple of yrs ago emailed Avon why the tread depth was greater than the 110. They were going to check and get back to me, never did. I went back to BT45 but still have the AM26 front, now cracking at the bottom of the sipes as they do.

Keith1069 said:

That's interesting. I looked at the 4.00 and a couple of yrs ago emailed Avon why the tread depth was greater than the 110. They were going to check and get back to me, never did. I went back to BT45 but still have the AM26 front, now cracking at the bottom of the sipes as they do.

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Becuase its a 'universal' meaning it can go on front or rear. Rear only fitments have deeper tread.

I have the 110 90 18 Roadrider on the back of my Norton. I have worn out two so far. They last about 5000 miles (completely worn out right past the wear bars but still a bit of tread). These tires look like they are worn out before they really are because there is only about 1/8" of tread before the wear indicators are flush. After about 2500 miles the wear indicators are only 1/16" below the tread and it looks like the tires are finished but actually they are only half worn at that point. I bought a 4.00-18 to try but after looking at it I decided it looks too wide so I have installed it on my Vincent instead. It looks alright there. The Vincent being heavier may benefit more from the extra load capacity. I am going to get another 110 for the Norton. I had a 120 80-18 Avon Super Venom on the back of one of my Triumphs and I though it made the handling less steady than the 110 Roadrider I put on when the Venom was worn out. I managed somehow to put 15,000 miles on the Super Venom. The 110 tire leans over more easily than the wider one. When I installed the Venom on the Triumph I thought the wide tire looked good for some reason. In the end you get used to the look of tires and it is not what they look like that is important.

Nigel

Funny how styles change. In the 80s and 90s it was fashionable to fit a spoke type 18" Harley rim to the rear of Commando and then mount a tire that looked almost like a small car tire. Often the first thing that gets changed out now, when one of those bikes is improved, is to put back the original Norton wheel, although maybe in wm3 rather than 2 just to cope with requirements of new tire designs.

Glen