Tires - What are you running?

Just getting this bike back on the road after 3 years.
I just bought a rear tire, the K81 4.10x19 but have a Dunlop MM90 x 19 on the front.
It is hard to push into a turn than I remember. I only bought it because of the rain grooves they have on these roads were shaking the front end so bad.
Now I want to go back with the K81 on the front but not sure what size it is supposed to be.
I have a 19 rim on the front.
Should it be skinnier than the back?

Nothing feels as good as the same narrow size that factory supplies, or 90 fr/ 100 rr but the rear wears out even with easy riding in about 4000 miles. Front should always be smaller than rear and about 2 lb less air or it fights with the rear traction to sort of fight back into the bars, ugh. Rod links especially the front helps to solve the Ghost Pilot in the forks on grooves and wood plank bridges. You should practice with each tire 1/3 low to know sense of slow leak before a tube blow out or learn the sudden reverse controls the hard way, but can't hardly feel a blow out at highway speed going straight, till you lean or slow a bit Whammo!

Most settle on 110 rear 100 front. Past strapped ridders put same size on so could rotate front tire to rear to double the mileage.

We have this discussion now & again in the pub.
Boils down to whatever you prefer.
How many of you actually regularly corner hard until you hit your foot on the ground, then you know what tyres are good.
I have my preferences, & it ain't Avons.

I like Bridgestone Battlax BT45s on my Mk 3.

18 inch front 100/90 and 18 inch 120/80 rear.

Lovely job - very solid wet or dry. Feels quite modern in handling with the HW head steady.,

L

I have the Avon Roadrunners on my 74 850. I don't like the way the bike rides on the rain grooves, feels skittish. I have been wondering if it is just me, haven't ridden in years and my last bike was a heavy Harley, or is it the tires? Maybe both.

How many of you actually regularly corner hard until you hit your foot on the ground, then you know what tyres are good.

Click to expand...

OMG NOT ON AN UNTAMED Commando, though I can cause them to scrap stand or muffler in very special places in very special mood after enough tire warming creeping up on the handling quirks and tire grip. But its scary level work to me so hardly never ever do that but to know what I could get away with if needed, maybe.

Now on my impossible to believe in Ms Peel, I had to hold back going in way harder harsher than I could on race tire track bikes or my similar set up SV650, shocking to not know how far over you are when All the forces are straight down through rear suspension into tire patch, and suddenly a foot is jerked right off the pegs even with toes pulled way back till I have to put leg our stretched on axle nuts to clear knee space next to tank with road so close. Held way back to stay tight in my lanes d/t constant oncoming free flyers to dodge. This equates to a gear shift faster turning than moderns can pull off and 2 shifts faster than floppy eared factory C'do's can. Narrow tire traction is not the limiting factor on C'dos, their ever loving isolastics is, yet also is allows what Peel can do in effortless glee that no others can, yet... I never ever ride hard to point of scared just thrilled to the marrow refreshed. Balance tho air by trail-error of course.

lukeya said:

I like Bridgestone Battlax BT45s on my Mk 3.

18 inch front 100/90 and 18 inch 120/80 rear.

Lovely job - very solid wet or dry. Feels quite modern in handling with the HW head steady.,

L

Click to expand...

That is exactly the set up that Norman White recommends.
Been using BT45's & they do grip good.
I have now gone 19" front, 18" rear with a 110x90 Lasertec on the back & I think it is the best it has ever been.
My 750 has Avons, because I bought it like that, I don't seem to have the confidence to chuck it over anywhere near as far as my 850, & it is not good in the wet.

Note most of my Cdo riding was on 18x120 rear / 19"x 110 front, but that was on Ms Peel with extra spunky power and when I used this combo on current Trixie Combat to initially run in, I could feel the sluggishness extra effort to turn, then got a sense of more ease to lean and zoom when a rear blow out made me put on a newish 19x110 Avon on rear. But but but if ya ain't trying to ring the max power out a tire edge just sane thrills, then 120 gives at least 1/3 more mileage and its fairly subtle mass effect mostly a Gravel rider appreciated on taking it easy.

I made new Peel wheels so have 3 sets of rear wheels, all WM3 rims, one 18".
I have switched immediately from fat non race rubber on SV650 to 18" 120 and back and 19" and 100 to 110 in same day back to back riding so was pretty plain what was what. Best stick I've got so far goes to hard dual purpose 18"x120, so looking forward to a full street tire like the Roadmasters mounted and waiting...
Worst was the 17"x170 even though could run circles around the other sports bikes on their racy DOT tires.

I do a lot of riding in the mountains of NE TEN. and ride as hard ANYBODY and have NO complaints with the AM 26 roadriders. I also run a 90/90/19 front and 100/90/19 rear IMHO a commando DOES NOT need wider tyres

Flo said:

How many of you actually regularly corner hard until you hit your foot on the ground, then you know what tyres are good.
I have my preferences, & it ain't Avons.

Click to expand...

Windy if the road area smoothness allows it and there's an air station along the way, besides my low air practice preaching, have ya ever tried those 'narrow' tires aired up rather harder? Up to a point its like sharpening ice skates. It also makes the isolastics absorb vibration even better yet lets more feel of grip through as well as lowers the forces to maneuver. Ballerina shoes on C'dos pirouette the best.

I found that a large120 rear section tyre was a big contributor to high speed weaving, the problem got worse as the tyre wore.

Currently running 19" front 90/90 and 18" rear 100/90 Avon Roadrunners, no complaints but I'm a fair weather rider so not a lot of wet miles lately.

any suggestion on the tyre pressure?

There's the cook book way that say inflate so that as hot as tires can get it increases PSI by ~10%. Then there's the by gosh and by golly trail and error way I do. But best you start too low to get that sense in as it repeats on the upper PSI just more subtle until its too late to react too. If road lumps make bike hop then got to back off some. I kick my tire with boot heel to see if I can dent it to the amount of road texture I expect to want it like that most. I get rear right-ish first then bump front down 2-3 lb less or for least sense of front rear conflicts steering or road following.
Center zone 32 front 34 rear for 170 lb rider. At some point its fun to over inflate some, iso's smooth out even more and steering gets light and more razor edge accurate, then the road gets too rough to enjoy that ice skate like interface. ugh.

Tires take a while to warm up to best function so take care having a blast.

From my enquiries, posts on this forum and speaking to others, I seem to be the only man in the world with 19 inch 2.5 inch rims, front and rear. I run Avon 100/90 Roadriders with 32 psi front and 34 psi rear. This combination is the best I have tried on any Commando I have ridden and has been commented on by all who have ridden my bike. I don't see the point of using 18 inch rears except for "more choice of tyres", which I think, is irrelevant as long as Roadriders are available. My Norton man had never sold one before I started buying them off him and now he's starting to sell a few. However, before i had my wheels rebuilt with alloy rims, I did a bit of research and found that they were made for 2.5 inch rims with 2.75 and 2.15 being the alternatives. Then, when you look at suitable tyres for Commandos, Avon recommend the same tyre for our skinny 1.85 inch rims as well. This is what I was using before the wheel rebuild but with the Roadriders, the steering and stability were much improved over the standard rims. Where some Commandos steer like trucks with some tyres, the steering on mine is exemplary with no issues right up to top whack. I do have Ikon shocks on the rear which are brilliant, giving excellent handling with good comfort on the rough, but my slightly leaking forks have never been touched. Just waiting for some cash for the Lansdowne conversion.

If you run 100/90 tyres on standard rims, have a look at how much lean you require to use all the tread. Correct, half your crankshaft will be gone before you get to that point. I know TT100s are cheaper. Big deal. Skunk meat's cheaper than beef. Which one would you rather eat.

Please, somebody out there, fit a pair of alloy 2.5 inch rims and 100/90 Roadriders on your Norton. You will become a believer.

If the 4.1 tires were standard on the Commando on wm2 rims, is it bad to run am26's on wm2's when the width is no more and maybe a bit less than the Dunlops? Supposedly Avon recommends wm3's as a minimum for am26 100/90's.

Fullauto I take note of your comments and may someday try that on Peel. Tire traction area and pressure sure play against each other in isolastic C'do's. Same size tire also allows front to rear rotation for extra economy.

As too the tire per rim fit essentially anything you can spoon on and fit on bike is pretty much all in same ball park handling and safety wise. Some fits give a bit more tire pinch rounder profile than others is all. Peel has WM3 fitted with a 130 tire - just at limit of acceptable I read. Getting more technical the only danger is side walls warm more if pinched together more, but not likely an issue unless under aired and over loaded doing the ton for a tank of gas.

Ya know Steve, for once I disagree with you. Doesn't matter what width tyre you can fit on a rim. Because of the mushrooming effect that a wide tyre on a skinny rim gives you, it will put less rubber on the road at any lean angle and upright than a narrower tyre made for that rim size. It can also upset the handling due to the unnatural profile, especially when the tyres aren't matched front to rear. like in the seventies and early eighties when 130 section tyres were fitted to 2.5 inch rims. Not good. "Looked better" to some but a price was paid in steering and stability.

It's one thing that recurs in these tyre threads. People go for the 18 inch rims and wide tyres because they look great, in their opinion. You're better off spending the money on bling and putting the right tyres on what you've got. As far as steering precision, handling, and grip are concerned anyway. If those things aren't a concern then put on whatever you want. The reasoning is exactly the same as the current people who fit the huge rims and 360 section tyres on their "cruisers". It's all about the looks. Ask anybody who has ridden one and see what they say.

I was talking to Matt Rambow this morning and I urged him, and before now to set up a pair of wheels this way and try them with Avon Roadriders. I can almost guarantee that if he does so, then that will be the new setup on all CNW Nortons. A big call, but I believe it to be true.

As I've said before, when my rear tyre wears out, I fit the new tyre to the front and put the barely worn front onto the rear. I hadn't done this for the last three rears and the front wore to the point where I could feel that the handling had deteriorated somewhat. With new tyres front and rear handling was restored to it's former quality.

The whole 18" rear thing came about because it looked for a while as if manufacturers were going to phase out the 19's completely, turned out to not be the case.

If I was going round again I'd stick to 19's front and rear.

This is what my '68 P!! ran before I got it. In both our rim sizes
http://showandgo.blogspot.com/2010/06/n ... slick.html