Alloy rims worth it?

Yorkie · Apr 23, 2018

I am in the process of building a Sunday afternoon rider (no track time just putting around the backroads) and I need to have the wheels rebuilt. I’m debating using either alloy rims or chromed steel and wondered if I would feel the difference in unsprung mass? I was thinking I would stay with 19”diameter rims but maybe WM3 width. Thoughts on steel be aluminum?

1up3down · Apr 23, 2018

probably not worth it for weekend riding, but I sent my hubs to Buchanan's in California and they built beautiful shouldered type rims around them to accept modern tires, 19 front, 18 rear, it was around $1000 total some 10 years ago

Fullauto · Apr 23, 2018

Yes. You will feel the difference with the improved handling and quicker response. If you want everything that is to be had, go to WM4 alloy rims (2.5 inch) and use Avon Roadriders in 100/90 x 19 which is the correct size rim for these tyres. You won't regret it.

ashman · Apr 23, 2018

Alloy rims are the go and they do make a differents to the handling, I put alloy rims on my Norton when I first converted it to the Featherbed frame in 1980 Akont rims and they look as good as the day I put them on over 37 years ago my orginal chrome rims started to peel the chrome after a year or so and one rim was replace on warranty the other lifted after the warranty ran out so that was a big factor in going alloy, plus they are better rims.

Ashley

Mr. Rick · Apr 23, 2018

No experience in comparing the steel vs alloy. But looking back,after rebuilding my wheels several years ago using the stock steel rims, I wish I had gone to Buchanan's for the Excel WM3's or maybe WM3 front and WM4 rear. The stock rims are sturdy, yes, but quite heavy.

850commando · Apr 23, 2018

consider that rust never sleeps, if you go chrome steel rims, They will rust....

JimC · Apr 24, 2018

Easy choice. Alloy, WM-3 x 19 front, WM-4 x 18 rear. Since you state you need to rebuild the wheels I assume this means new rims. If so, why even consider steel?

JimC · Apr 24, 2018

From what I’ve read, 19” front and rear wheels was not a design decision. It was a manufacturing and inventory decision, dispelling the myth that Commandos were designed to have 19”, front and rear.

kommando · Apr 24, 2018

If you research the tyres of the time the only tyres capable of the high speeds and loading of the Commando and the Trident were 19 inch, 18 inch could not handle it. This is the reason for the 19 rims front and rear, the tyre technology has now moved on and the restriction forgotten.

Fullauto · Apr 24, 2018

JimC said:
From what I’ve read, 19” front and rear wheels was not a design decision. It was a manufacturing and inventory decision, dispelling the myth that Commandos were designed to have 19”, front and rear.

Ride my bike and you realise that it is no myth. With your rims, you will not get the best out of your bike. With WM4 rims and 100/90 x 19 Avon Roadriders at both ends, you will realise finally what a good handling Commando is. Anything else is a compromise.

JimC · Apr 24, 2018

kommando said:
If you research the tyres of the time the only tyres capable of the high speeds and loading of the Commando and the Trident were 19 inch, 18 inch could not handle it. This is the reason for the 19 rims front and rear, the tyre technology has now moved on and the restriction forgotten.

The 1969 Honda CB750 was certainly as fast as a Commando and heavier, it came with 18” rears.

ntst8 · Apr 24, 2018

Do you change your own tyres - steel rims are much more forgiving of an amateur swinging on tyre levers. Being somewhat ham fisted that makes it a deciding factor for me.

Danno · Apr 24, 2018

kommando said:
If you research the tyres of the time the only tyres capable of the high speeds and loading of the Commando and the Trident were 19 inch, 18 inch could not handle it. This is the reason for the 19 rims front and rear, the tyre technology has now moved on and the restriction forgotten.

This. Dunlop K81s were called "TT100" for being the first tire to lap the IOM at 100mph. They were only made in 19" at first.

Danno · Apr 24, 2018

And if you're having the wheels re-spoked, definitely go with alloy, unless you're doing a correct restoration. When the SS clone got it's alloy wheels years ago, I remember what an amazing difference it made in ease of handling and steering response. Later, when good 18" tires became commonplace, I swapped the rear 19" for an 18" to have a better selection of rubber. Losing unsprung weight is the best thing you can do to improve a bike's handling.

kommando · Apr 24, 2018

The standard big bike rear tire at the time was 4.00-18, but road racers still used 3.50-19. These were the same rolling diameter, but the slimmer carcass of the 3.50-19 ran cooler. (The biggest problem with racing tyres is usually operating temperature rather than traction- of course, traction fades as a tire overheats). In the 1960s even a hard ridden street bike could stress a good quality 4.00-18 to the point of disintegration. The lighter weight of the 3.50-19 was also advantageous- heavy wheels and tyres are flywheels and gyroscopes that make a bike hard to accelerate and maneuver.

http://www.nocnsw.org.au/technical/tyres-norton-commando

That was in the context of the UK tyre manufacturers talking to the UK motorcycle industry, what the Japanese tyre manufacturers told the Japanese motorcycle industry may have been different, at the time and well into the 80's most UK riders of Japanese bikes changed to European tyres at the first opportunity.

JimC · Apr 24, 2018

Now we can add the Great Rim Debate to the ever growing list of subjective criteria.

Unless put to the track, the 19”versus 18” rear wheel comparison is basically a personal choice. My experience did not show a wit of difference, other than the much longer tire life with the greater choice of available 18” tires.

NortonMKIIA850 · Apr 24, 2018

kommando said:
[snip]... well into the 80's most UK riders of Japanese bikes changed to European tyres at the first opportunity.

In the late seventies a friend of mine coined the slogan 'Have a drama on a Yokohama!' And I was one of those who dumped Japanese tyres asap and switched to Dunlop or Avon mainly, although I remember using Metzelers too. Things have changed though, and Japanese tyres that I've ridden on in the 2000s were fine, they just wore out quickly – even that won't have beeen their fault though, it'll have been mine for thrashing the bike! Which wasn't my Norton.

Back to the topic, though, my 850 had Akront shoulderless ally rims fitted when I bought it 21 years ago, they're still good and polish up beautifully. They're also still unmarked despite me having changed the tyres or fixed punctures myself on numerous occasions – but then I've always used my set of nylon rim protectors when levering, they're still good too after about 30 years. I suppose all I'm really saying is don't be afraid of ally rims.

o0norton0o · Apr 24, 2018

Fullauto said:
Yes. You will feel the difference with the improved handling and quicker response.

A fatter front tire gives up some of it's quicker responsiveness in favor of the larger contact area it presents to the road when the bike is leaned over. You have better grip in the corners on the fatter tire because it has more surface area in contact with the road , but the fatter tire doesn't respond to imput quicker than the narrower tire.

I'm just talking about physics here. I'm not saying narrow tires are a "better" choice, only that they actually respond quicker. (which is why poor handling cruisers sometimes mount a tall, narrow tire up front to give more responsive handling to a bike that isn't designed to handle, but go straight down the hiway)

As far as the original question goes; IF you need tires AND rims too, go with the alum rims. I would go with a slightly narrower front for quicker handling WM3, and go with an 18 rear WM4 and mount the appropriate Avon roadriders... That's my OPINION... and opinions vary...

Fast Eddie · Apr 24, 2018

Regarding 18 or 19 inch, as I’ve said many times before, if you choose the right combo of Roadriders you get a 19 front and an 18 rear with exactly the same rolling radius. But you get a rear that has slightly more cushioning, a bigger contact patch, and importantly, a proper rear tyre tread depth.

Regarding alloy or steel, IMHO I don’t seem to be able to tell much difference when I ride a steel or alloy rimmed bike. Maybe my ass is just too insensitive?

Nevertheless, with one exception, I have only ever had alloy rims when I’ve had wheels built. They’re lighter, they look cool, they never rust.

Unless you’re building a conkers job, I can’t see why you’d even consider steel over alloy personally.

Fullauto · Apr 24, 2018

o0norton0o said:
A fatter front tire gives up some of it's quicker responsiveness in favor of the larger contact area it presents to the road when the bike is leaned over. You have better grip in the corners on the fatter tire because it has more surface area in contact with the road , but the fatter tire doesn't respond to imput quicker than the narrower tire.

I'm just talking about physics here. I'm not saying narrow tires are a "better" choice, only that they actually respond quicker. (which is why poor handling cruisers sometimes mount a tall, narrow tire up front to give more responsive handling to a bike that isn't designed to handle, but go straight down the hiway)

As far as the original question goes; IF you need tires AND rims too, go with the alum rims. I would go with a slightly narrower front for quicker handling WM3, and go with an 18 rear WM4 and mount the appropriate Avon roadriders... That's my OPINION... and opinions vary...

That's great theory, but you have to remember that 99% of the people here using Avon Roadriders ARE ON COMPROMISED RIM/TYRE COMBINATIONS! I use 100/90s at both ends and my steering is light and precise. That would be because my tyres are mounted on rims of the correct size. I still maintain that most people have this discussion and then fit "what looks cool".

Jesus wept.

Alloy rims worth it?

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