How big of rear tire fits commando? (2010)
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I would not go bigger on the rear than 4.10 x 19. (and there ain't much room between the insides of the swing arm and chainguard) I still prefer the Dunlop K81 TT100. I use a K81 GP 3.90 x 19 on the front as its a stickier compound. The stock 4.10 front I found a bit heavy on the steering. Basic rule is stay with the same combination front and rear such as the Avon AM26 products. If you mix different types you can risk upsetting the handling.
Mick
Mick
Welcome to the forum!
pbmw has it right, the stock WM-2 rims on the Norton won't take advantage of wide tires.
Remember that it's not how much you can fit in there, it's about how much you can keep in contact with the road. Those skinny 1.85" rims will turn too much of a wide tire tread into sidewall, that you can't use at any remotely sane lean angles. If you absolutely, positively, have to have a fatter tire, get a wider rim first.
Do a search for tyre / tire sizes, and another for 'rim sizes' , lots of good information that could keep you here most of the night.
pbmw has it right, the stock WM-2 rims on the Norton won't take advantage of wide tires.
Remember that it's not how much you can fit in there, it's about how much you can keep in contact with the road. Those skinny 1.85" rims will turn too much of a wide tire tread into sidewall, that you can't use at any remotely sane lean angles. If you absolutely, positively, have to have a fatter tire, get a wider rim first.
Do a search for tyre / tire sizes, and another for 'rim sizes' , lots of good information that could keep you here most of the night.
I've been running 130/90-18's (roughly 5.10 inch) on WM3 rims for about twenty years. There's enough room for the chain and swingarm (you might have to notch the chainguard)--and you need to keep things straight. The tires are about 7-8% taller than TT100's and last forever--one Cheng Shin with minimal grooves went over twenty thousand miles. The big tire absorbs all the Isolastic vibrato with aplomb--rated for 700 lbs or so--and gently stops the bike: I rarely use the front disc around town.
My rear TT100 would have visible wear after every summer afternoon outing when I was going through a tank of gas a day--and a tire every other month. I keep a 19-inch TT100 back tire for quick changes when I get a flat on the road (the big tires need inflating after you squeeze them past the paddles). No doubt the handling is diminished somewhat--the back end feels a little nervous with the smaller tire--but I find myself swapping the bigger tire back within a day or two.
Tim Kraakevik
kraakevik@voyager.net
My rear TT100 would have visible wear after every summer afternoon outing when I was going through a tank of gas a day--and a tire every other month. I keep a 19-inch TT100 back tire for quick changes when I get a flat on the road (the big tires need inflating after you squeeze them past the paddles). No doubt the handling is diminished somewhat--the back end feels a little nervous with the smaller tire--but I find myself swapping the bigger tire back within a day or two.
Tim Kraakevik
kraakevik@voyager.net
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I tried an avon 120 on my 18" rim, this made it impossible to get a proper wheel alignment, I now use an avon 110, it is only a few mm of the chain guard but does allow a good wheel aligment.
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I had (by previous owner) a 120/18 on the rear and a 100/18 on the front. As noted above, I couldn't really get the rear to align properly without rubbing so it was never properly aligned though a lot of miles was put on it with no obvious problems as far as handling was concerned. Recently , as part of my conversion from Roadster to Fastback, I removed the 18" wheels and put new oem 19" wheels/Avon 4.10x19 tires back on the bike. I much prefer them though I'm sure the rear will wear out relatively rapidly compared to that 120x18.
One thing I've noticed about tires is that one mfg 160 tire may well be narrower than another. I use a lot of 160/17's on my motard. Pirrelli's are narrower than just about everything else. I have a suspicion this is true in the smaller sizes also.
But I still wouldn't go any larger than a 100/90 on the rear. I like the faster handleing of the smaler tire.
But I still wouldn't go any larger than a 100/90 on the rear. I like the faster handleing of the smaler tire.
MexicoMike said:
mike
If you like the switch to 19s' and K81s' next time try the Avon AM26's in 100/90 rear and 90/90 front. much better handling tyre does not track grooves like the K81s' and out lasts them by a little plus the smaller front quickens up the steering even more
concours
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SteveA
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As shown in the above chart, they don't keep specs secret, but you have to look in detail to see what you will get when fitted to a wheel.
The other thing is that they will only publish the dimensions when fitted to the rim they recommend for the tyres.
Look at the chart for the 100/90 109 mm wide.....on a MT2.50 rim, but....measure it on a 2.15 (WM3) rim then you are more likely to measure nearer to the 100 mm!
If your Commando is on WM2 front and WM3 rear, then you really would be advised to use 90/90 front and 100/90 rear.
Remember, an original rear was also WM2 like the front, so by most standards the 4.10s were too big for the fitted rims!
The other thing is that they will only publish the dimensions when fitted to the rim they recommend for the tyres.
Look at the chart for the 100/90 109 mm wide.....on a MT2.50 rim, but....measure it on a 2.15 (WM3) rim then you are more likely to measure nearer to the 100 mm!
If your Commando is on WM2 front and WM3 rear, then you really would be advised to use 90/90 front and 100/90 rear.
Remember, an original rear was also WM2 like the front, so by most standards the 4.10s were too big for the fitted rims!
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Avon is the only tire manufacturer that i can tell that publishes that info. I'm asking about the Conti's and specifically the 120/90s. No offense, but if you don't have that tire, you're not answering my questions
Also interested in feedback on 120/90 BT46s
Also interested in feedback on 120/90 BT46s
SteveA
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No offence, but you chose to use a 12 year old thread....the opening question of which was:
'Can someone tell me the size of the widest 19 inch tire that will fit on a 1973 stock 850 commando? Thanks in advance!'
Actually, looking deeper into it I would also like detailed dimensions for the Conti Classic Attack race tyre in 120/90 x 18, I have a 3.2" rear rim and use a 130/70 x 18 rear Heidenau, which I like but is not suitable for really hot conditions.
The difficulty is not the specific width, but where the widest point of the tyre is with regard to the wheel spindle, 120 may be narrower at max width, but if that width is nearer to the swinging arm spindle there is less room due to taper! This probably has more effect on my Rickman swinging arm with fixed distance between spindles than it does on a Commando swinging arm with slots!
I think Time Warps comment regarding rim width is very relevant to your situation.
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SteveA
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Why do you say that? A 90/90 works perfectly with a single disc on a race circuit, several of us have evidence of that.
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I wish I could help but I have that tyre in 100/90/19 both ends.
Hopefully you will get an answer but the installed width would depend on the rim width to some extent and that Continental in a 120 would probably suit a 2.5 + inch rim or it would be a waste of money to some extent.
#
My tyre shop rates the BT46 as a better option over the radial Classic Attack (and they sold them to me) , if I ever wear them out I will consider two BT46 fronts in 100/90/19.
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I've said it 37 times but obviously 38 is required. !00/90 Roadriders on 2.5 inch rims is the absolute best combination. When the rear wears out, put the front on the rear and the new one on the front. Great handlng, stopping and extended tyre life. No compromises this way.
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What part of Continental Classic Attack 120/90/18 was missed.
I can not comment on the 120/90/18 Classic Attack radial but if I was to fit an 18 inch rear rim (unlikely) I would now consider the Bridgestone BT 46 in a 19 front / 18 rear combination over the Classic Attack in any size based on the resent information.
Tom U I hope you actually get someone with a 120/90/19 Classic Attack on the rear to post.
I can't see it being any different fit wise to the antiquated Avon's though.
#
When that time comes I will ask their advice sticking to 19's both ends regarding a 100/90/19 BT46 reversed on the rear wheel.
One problem with the 19 inch Classic Attack is even though they come in a front and rear dedicated fitment the thread depth is the same almost like the rear is a front with reversed arrow (Are they different internally being a radial is unknown, that might include the not imported here 110/85/19 rear also)
Mileage reports on the CA 19's is not inspiring but the 120/18 rear might be different (more thread depth) and most likely sold in higher numbers being popular in racing circles also.
I can not comment on the 120/90/18 Classic Attack radial but if I was to fit an 18 inch rear rim (unlikely) I would now consider the Bridgestone BT 46 in a 19 front / 18 rear combination over the Classic Attack in any size based on the resent information.
Tom U I hope you actually get someone with a 120/90/19 Classic Attack on the rear to post.
I can't see it being any different fit wise to the antiquated Avon's though.
#
When that time comes I will ask their advice sticking to 19's both ends regarding a 100/90/19 BT46 reversed on the rear wheel.
One problem with the 19 inch Classic Attack is even though they come in a front and rear dedicated fitment the thread depth is the same almost like the rear is a front with reversed arrow (Are they different internally being a radial is unknown, that might include the not imported here 110/85/19 rear also)
Mileage reports on the CA 19's is not inspiring but the 120/18 rear might be different (more thread depth) and most likely sold in higher numbers being popular in racing circles also.
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concours
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Nice idea, but I'll be damned if I'll waste time swapping tires twice. Over my shoulder....I've said it 37 times but obviously 38 is required. !00/90 Roadriders on 2.5 inch rims is the absolute best combination. When the rear wears out, put the front on the rear and the new one on the front. Great handlng, stopping and extended tyre life. No compromises this way.
