I have finished rebuilding my front & rear hubs, new bearings ect and now want to take them to Buchanans for stainless spokes and excel shouldered alloy rims. My question is whitch size to use. I was just going to go with what the Manuel mine came with (WM1.9) I suppose this is what they call a WM2? but have heard some people talking about there WM3 rims. What works best? What is the diffrance? Also they asked if I want them use the "heavy duty" spokes in the rear. Any advice on what to due front & rear please? I don't want to spend this $ and regret not making the right choose of something in a month. Thanks.
Alloy rims, WM2 or WM3 ??????
- Thread starter gtsun
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gtsun said:
"WM1.9" means nothing as far as I know? The factory manuals normally quote the rim size as: "WM2 - 19" front & rear.
A WM2 rim has an internal width of 1.85 inches, and a WM3 is 2.15 inches internal width.
http://www.central-wheel.co.uk/rims/eng ... e_rim.html
This tires/rim debate is somewhat like oil preferences. I think it best to decide what tire(s) you want to run and this will dictate rim diameter and rim width. I, personally, would opt for a WM3 x19 front and a WM4 x 18 rear. I prefer the more modern tire choices available. With a 19 inch rear rim you are somewhat limited.
+1 to your +1 (=+2 so far) I put a WM3-19 on the front of my Fastback and a WM4-18 on the back, I think the front tire is a 90-90-19 and the back a 120-85-18. On my café racer, both rims are 18", the front is a WM3 and the back is a WM4, the front tire is a 90-90-18 and the back is a 110-90-18.Coco said:
Jean
Well I'm going to have to give this some thought. It's very tempting to go with wider modern wider rims/tires. Guess I should have thought of this before buying a new set of Avon 100/90/19's but I'll use the on another bike!! Any way at that time I was going to just re-lace my stock rims. Anyone have opinions on using a WM2 x 19 front and WM3 x 19 or 18 rear?"does anyone have a opinion" That was a silly question to bike guys...
I have thousands of miles on my combination and personally, I think it makes more sense than some other options. Firstly, if you look at Avon's website, the recommended rim size for 100/90 19 Roadriders is 2.5", even though they recommend the tyre for the standard 1.85" rims. I went to 2.5" non-shouldered Morad aluminium rims at both ends for my 850. If you look at a Roadrider on a standard rim and check the profile, you will notice that in order to use all of the available tread to the edge of the tyre, you'd be grinding the crankshaft to do so! In other words, you simply cannot use the available tread. By fitting a wider rim, what you are doing is flattening the profile so that more rubber is on the road at any lean angle. With the Roadrider fitted, it was about 1/2" wider than the same tyre fitted on a standard rim. Believe it or not, I had to reverse the right lower shock mounting bolt in order for this combination to fit. With the front tyre fitted on my 2.5" rim, it simply wouldn't fit between the mudguard stays. I had to buy four button headed capscrews to replace the mudguard mounting bolts in order to get the tyre to fit! When my rear tyre wears out now, I fit the front tyre to the rear rim and the new one goes onto the front. You never have to replace two tyres at once and tyre life is pretty good because it gets a workout on front and rear. I like the idea of using the same tyre front and rear because the profiles are exactly the same and there are no times when a mismatch can affect the feel of the bike at any lean angle. The bike is very stable and feels very planted on the road.
The wider rims also get rid of what I call the "Mr Moped" look with those skinny little rims. Looks good (if I give the old girl a wash I'll even post some pics today). I think too many people think that Bigger is better ( been trying to convince the wife otherwise for 26 years!) but if you grab a few tyres and check out profiles you'll see the folly. A wider tyre does not necessarily mean greater lean angles.
My mate's Suzuki Boulevarde (Ugh! A hideous creation) has an 8 inch rim with a 240 section 18 inch tyre but nearly all his tread is on the road while the bike is on the side stand!! Have a look at one and you'll see what I mean. The Norton eats it through the corners because he just can't match the lean angles.
The fact that you have a wider choice of tyres is irrelevant to me as the Avons are a superb tyre and I have no complaints whatsoever.
Think skinny!!!!
The wider rims also get rid of what I call the "Mr Moped" look with those skinny little rims. Looks good (if I give the old girl a wash I'll even post some pics today). I think too many people think that Bigger is better ( been trying to convince the wife otherwise for 26 years!) but if you grab a few tyres and check out profiles you'll see the folly. A wider tyre does not necessarily mean greater lean angles.
My mate's Suzuki Boulevarde (Ugh! A hideous creation) has an 8 inch rim with a 240 section 18 inch tyre but nearly all his tread is on the road while the bike is on the side stand!! Have a look at one and you'll see what I mean. The Norton eats it through the corners because he just can't match the lean angles.
The fact that you have a wider choice of tyres is irrelevant to me as the Avons are a superb tyre and I have no complaints whatsoever.
Think skinny!!!!
gtsun said:
This is the setup that I'm going with, I think Commandos do better with identical tires and wheels.
Easily the best handling bike I've ever ridden was my 1973 850 with 4.10 X 19 Avon Roadrunners
front and rear. The front to rear tire swap is something that I had not thought of before, but it sure
sounds good to me.
Unclviny
gtsun said:
As different systems to measure rim widths are used, I'm not sure that 2.5" rims are WM3s, but, yes, it works a treat, and, not having measured it, I would think that the rolling diameter would be so close to stock that it wouldn't matter. I certainly did not notice any difference in my revs/speedo ratio when I fitted the wider rims. Anyway, your Smiths instruments can be calibrated simply (by owner) anyway, so, not a problem.
Another thing to contemplate, lovers of wider tyres on narrower rims. Your tyre height, and hence, rolling diameter may be greater, upping your gearing slightly, but, answer this question......
Does a 120 section tyre on a 2.15" rim put more rubber on the road than a 100 section tyre on a 2.5" rim?
Thinking about it, WM3 I think is 2.15"? Somebody will chime in with an accurate answer.
Think you'll find the latter as the tyre is not squeezed into as small a diameter. Putting a large section tyre on a small rim makes the profile more rounded and you'll wonder why you have huge 'chicken strips' that never get used. I have new AM26, 110 x 18 on a WM3 (2.15) rim and a 90 x 19 on the front WM3. When I look at the amount of rubber in use and that strip of virgin rubber either side I worked out I'd have to be over at 60+ degrees to get on the tyre edge which ain't going to happen. I should be using a WM4 with that rear. The front on the other hand is within a few mill of using the whole treaded area.
I'm rather with Fullauto on the use of slightly wider rims with narrower tyres than a 120. I didn't quite have the confidence to got the whole way and have a 110/90 18 on a 2.5 rear (with a 100/90 18 on a 2.15 at the front) Dropping the front like this helps quicken the steering a bit (and I don't miss the ground clearance).
On one bike I built in the seventies, I had 19" WM2 alloy rims onto which I put K81 with a 3.6 cross section, it looked cool with smaller tires front and back. It would be nice to build the next one with 20" or 21" wheels if the whole bike looked spindly (small gas tank, oil in frame...)
Jean
This is the exact same frame I am using on my café (see cafe-racer-all-finished-t4710.html )
Oh and please ignore the guy in the background, I was young and foolish then, quite a diffirence from now where I am now old and foolish :lol:
Jean
This is the exact same frame I am using on my café (see cafe-racer-all-finished-t4710.html )
Oh and please ignore the guy in the background, I was young and foolish then, quite a diffirence from now where I am now old and foolish :lol:
I wouldn't go any bigger than WM2 front and WM3 rear.
Anything more isn't going to get you any performance improvement you'll just add extra weight and slow the steering down.
Don't forget a Commando in standard trim is putting out under 50hp you don't need a lot of tyre to cope with that, check out what bikes with equivalent power are wearing.
Anything more isn't going to get you any performance improvement you'll just add extra weight and slow the steering down.
Don't forget a Commando in standard trim is putting out under 50hp you don't need a lot of tyre to cope with that, check out what bikes with equivalent power are wearing.
I'm unconvinced about not achieving improved performance from wider rims. There is something a little odd about Norton's use of 1.85 rims front and rear, certainly once they were fitting them with 4.10 tyres. In fact, a 4.10 tyre falls outside of the permitted sizes for a WM2 rim.
Avons older recommendations are that the 1.85" WM2 was best suited to tyres of 2.75, 3.00, 3.10 and 80/90. The recommended rim for even a 90/90 is the 2.15" WM3 and a 4.10 or 100/90 should be fitted to a 2.50 for best tyre performance. This is independent of any discussion of the benefits of running a wider tyre.
Bearing in mind that most of us who replace rims change to alloy, then I'm not sure that the unsprung weight argument holds, especially if the diameter is 1" smaller.
The Commando doesn't need wide tyres but I see no reason not to fit the rim width that the tyre manufacturers recommend for the standard tyres.
Avons older recommendations are that the 1.85" WM2 was best suited to tyres of 2.75, 3.00, 3.10 and 80/90. The recommended rim for even a 90/90 is the 2.15" WM3 and a 4.10 or 100/90 should be fitted to a 2.50 for best tyre performance. This is independent of any discussion of the benefits of running a wider tyre.
Bearing in mind that most of us who replace rims change to alloy, then I'm not sure that the unsprung weight argument holds, especially if the diameter is 1" smaller.
The Commando doesn't need wide tyres but I see no reason not to fit the rim width that the tyre manufacturers recommend for the standard tyres.
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