Rear tire fitment to 1970 Commando S

I want to lace up new rims this Winter and replace (virtually unused) 30 year old K-81s on my 1970 Commando S. From other threads, I think I'll buy Avon roadriders (AM26), and stick with 90/90- 19" on front. My question is, will a 110/90 -18" (wm-3) fit on the rear and clear the chain guard? Otherwise I will use the 100/90 - 19" (on a wm-3).

Thanks
ted

Ted , I have two AM26 rubbers sitting beside me to kiss the old rubber goodbye and thanks for their previous service too. From all the research I have done these are matched 19 inch and rightfully as it should be for a Norton. Many will disagree,we shall see come spring.

Ted Lang said:

I want to lace up new rims this Winter and replace (virtually unused) 30 year old K-81s on my 1970 Commando S. From other threads, I think I'll buy Avon roadriders (AM26), and stick with 90/90- 19" on front. My question is, will a 110/90 -18" (wm-3) fit on the rear and clear the chain guard? Otherwise I will use the 100/90 - 19" (on a wm-3).

Thanks
ted

Click to expand...

110 tyre is 5 mm wider each side from 100, if you have more than 5mm when measuring with old 100 tyre inserted then yes it will fit!

I'm running a 120/90-18 on a WM-4 with no clearance problems. Stock chain guard, btw.

JimC -- What year/model is your Commando? I understand the earlier models like my 1970 had less clearance. My chainguard is the type that is all chrome and rounded down around the rear sprocket. Not the one that runs straight back and stops abruptly, with a black portion that drops over the sprocket. (The biggest front tire I can use is equivalent to a 3.6x19 Dunlop K81, which is the current ancient tire, but that size is fine with me up front)

Thanks

The most miles I've put on Commando was '72 Combat fitted with front WM2/110 tire and rear WM3-120 tire. Tight to work the 120 into the swing arm but once in it worked fine. Could feel its added mass a bit but more throttle over came that and mileage was distintly better for a daily commuter on hwy and rough stuff. For just larks here and there in good conditions the narrower tires are easier-lighter to maneuver and respond to throttle. If chain clears guard then 120 should too. Early front fenders may limit to 100 front but my 2 Combats both have run 110 up front fine.

Torontonian said:

Ted , I have two AM26 rubbers sitting beside me to kiss the old rubber goodbye and thanks for their previous service too. From all the research I have done these are matched 19 inch and rightfully as it should be for a Norton. Many will disagree,we shall see come spring.

Click to expand...

I'm with you. 18 inch rims do nothing for handling or grip and actually make some Commando handling traits worse. Stick with 19s.

Hello everybody,
I am a new member on this great forum (not so new but no question yet - only see and learn until now). My english is not very good -sory for that. I have a rear tire dilemna for 1970 Roadster. I just bought 3,6 Dunlop TT100 K81 R19 front and 4,1 rear. Now I noticed that another TT100 exist - 100/90 TT100 GP R19 (4,0). Do You thing it is better to rear wheel? Or it is not good combine it with normal 3,6 TT100 in front? Somebody know about difference between TT100 and TT100 GP? Pictures seems the same..Thanks

Running Avon Roadrider 110/90V18 on the rear with Akront WM-3 rim no problem. Been using 100/90V19 old Avon Super Venom with Akront WM-3 on the front for a too long time but going to another Roadrider 90/90V19 as soon as it gets here (Monday).

Should be OK with the rear clearance. I had a 120/80V18 on there at one time and it just fit.

Eek - just realized you have 1970 so maybe not applicable. Mine's a '72.

Russ

Original fitment on 69/70 was 3.00-19 ribbed front and 3.50-19 rear. But you may want more modern tyres than what's available in that size. I'm using an Avon SpeedmasterII front ribbed and a 410-19 Avon Roadrunner rear, but there are plenty of better tyres available. I was going for original look.

Dave
69S

My commando is 1970 with the old one frame witk center stand on main frame. Now I have both 100/90 Avon roadrunners. Front about 90%, rear KO..terrible combination..looks very bad when front rear is bigger. It is the only Commando I drowe ever and I thing It is too hard to "put it down" to bends than it should be. So I wanted to try smaller in front and bigger to rear. My good friend recommened dunlop TT100. He has this 3,6 and 4,1 on his 69 fastback and he is very happy with it..so I bought it. A short while after it I found a TT100 GP by chance. Before that I was finding according to K81 index, so I did not found this. I thing it will be Ok with 3,6 and 4,1..but maybe the next rear will be 100/90 TT 100 GP.. Thanks

I have an 18" WM-3 rim on the back of my '70 Commando. Every tire that I have mounted back there would rub on the chain guard until I pressed a little channel in the guard. If you are not at all fussy about alignment, you can make it work, sort of.

Greg