What do Wheels Weigh?

texasSlick · Oct 2, 2016

worntorn said:
illf8ed said:

. If road use is there any significant advantage of lighter wheels?

Click to expand...

Definitely.
Reduction of rotating, unsprung weight means improved handling, plus every 7 lbs=1 bhp.

Glen

Agree.

It should be obvious to all that weight reduction leads to increased acceleration, but in the case of a wheel, lighter means less rotational inertia in addition to less translational inertia, and that leads to increased acceleration as well.

Slick

lcrken · Oct 2, 2016

Of course the logical progression of lighter wheels would lead us to the Blackstonetek carbon fiber wheels, which are down to about 6.5 lbs with hubs and bearings in the 19" sizes. Conveniently, they are now available in 19" sizes from 2.15 to 3.0 widths, thanks to the flat track guys. Also in all sorts of 17" and some 18" sizes. The only drawback would be the price, about $2,000 each. The 17" ones that came with the Norton SE look pretty good, too. Not realistic for most of us, but still interesting to see the technology.

http://blackstonetek.com/carbon-fiber-w ... ack-wheel/

Ken

acotrel · Oct 2, 2016

It is possible to create the situation with a racing motorcycle where you can be all wound up and looking lovely and in the next instant be picking yourself up off the bitumen wondering how you got there. Any weight reduction is good for helping acceleration, however there ARE other considerations.

nickguzzi · Oct 3, 2016

Not on a Norton, but relevant to a previously asked question, I swopped the dual discs on the guzzi from the standard one piece cast iron discs to the Le Mans two piece type which had alloy centres. I was amazed by how much such a comparatively small change made - the braking surface part of the disc was nigh on identical.

As far as "shelf life" of magnesium parts is concerned, the technology is constantly evolving. http://www.magnesium-elektron.com/marke ... otorsports make lots of bits and you may recognise the name.
Somewhere on the site is an explanation of some metalurgical developments which extent product life and also advances in coatings and finishes which do likewise. Old parts, slung in the back of a leaky old shed since the 50's? Maybe not.
Many modern vehicles, and not just sporty ones, have a least a few magnesium parts for a diverse range of reasons.

lcrken · Oct 3, 2016

acotrel said:
It is possible to create the situation with a racing motorcycle where you can be all wound up and looking lovely and in the next instant be picking yourself up off the bitumen wondering how you got there. Any weight reduction is good for helping acceleration, however there ARE other considerations.

Try as I might, I can't see any negative handling impacts of using lighter wheels, only positives. In terms of durability for street use, however, I must admit to having some second thoughts about using 30+ year old magnesium racing wheels. I might reconsider that.

Ken

acotrel · Oct 3, 2016

A friend of mine recently took the crankcases of his 350 Manx to have the baked-on Castrol R removed. The guy he took them to vacu-blasted the grey-green conversion coating off. My friend nearly flipped, so kept the cases warm and dry and then we started looking for somebody who could restore the conversion coating. The original coating was the same as used during WW2 on Spitfires to a DTD spec. However we finally found a supplier to the aircraft industry who showed a bit of interest in the bike, so did the job for nothing as long as he could see the bike when it was rebuilt. The final colour of the cases was perfect
As far as light wheels are concerned, does a light wheel need the same damping and spring rate as a heavy one ? Perhaps if your handling is already stable and slow, if the lighter wheel quickens it, it feels better ?

nickguzzi · Oct 4, 2016

Damping is for controlling wheel motion. If the wheel weight is less then the forces required to control it should be less too.
It is very noticeable on cars going from the standard fredflintstones to half the weight mags and light tyres.

Rohan · Oct 4, 2016

nickguzzi said:
Damping is for controlling wheel motion. If the wheel weight is less then the forces required to control it should be less too.
It is very noticeable on cars going from the standard fredflintstones to half the weight mags and light tyres.

Mmmmm, its half and half here ?, the spring and damping rates also reflect (and control) the weight of the vehicle and rider.
Although there is a fair bit of the tail that wags the dog thrown in there...

Bernhard · Oct 4, 2016

mag will reacts differently to salt than alloy salt that attacks it will turn it into powder :!: :shock:

lcrken · Oct 4, 2016

Rohan said:
nickguzzi said:

Damping is for controlling wheel motion. If the wheel weight is less then the forces required to control it should be less too.
It is very noticeable on cars going from the standard fredflintstones to half the weight mags and light tyres.

Click to expand...

Mmmmm, its half and half here ?, the spring and damping rates also reflect (and control) the weight of the vehicle and rider.
Although there is a fair bit of the tail that wags the dog thrown in there...

Both correct, of course. I just expect to adjust the setup as required for any significant changes I make to a bike. I don't see that as a reason not to make changes. I'm not proposing that anyone really needs to change the wheels on their Nortons. But there is a pretty good subset of listers here who like to modify their bikes, so I'm posting stuff that I think might be of interest to them. Inquiring minds want to know.

In responses to a post on another thread, I think I'll try to also include some other related weights here, like disks, sprockets, and tires. So far I've just included weights for wheels with bearings and spacers. It would be entertaining to be able to compare various combinations too.

Ken

acotrel · Oct 4, 2016

As a kid I made the mistake of compensating too much for a bad bike, and I learned a lot of hard lessons. It probably doesn't matter much what changes you make within reason, you always adjust your riding to suit the bike. The crunch comes in road racing when another rider goes around you so fast that you look stupid. If you fit lighter wheels to your bike, you probably need to adjust the suspension to either restore or improve the handling. A good race bike is not simply the sum total of it's component parts, a lot depends on the fine tuning. With road bikes you get away with a lot more because the way you ride them is rarely extreme.

Rohan · Oct 4, 2016

lcrken said:
In responses to a post on another thread, I think I'll try to also include some other related weights here, like disks, sprockets, and tires. So far I've just included weights for wheels with bearings and spacers. It would be entertaining to be able to compare various combinations too.

Yes I wondered a bit why you didn't just weigh the wheels whole, and ready to go.

I'm always stunned when I pick up the complete back wheel for an early plunger framed dommie,
it feels like it must be 25 or 30 lbs. ! (steel hub, steel spokes heavy axle iron brake drum)
And I was surprised at the other end of the scale picking up someones front wheel for an early 7R Ajay,
it was a real featherweight (magnesium hub, alloy rim, magnesium brake)

lcrken · Oct 4, 2016

Rohan said:
lcrken said:

In responses to a post on another thread, I think I'll try to also include some other related weights here, like disks, sprockets, and tires. So far I've just included weights for wheels with bearings and spacers. It would be entertaining to be able to compare various combinations too.

Click to expand...

Yes I wondered a bit why you didn't just weigh the wheels whole, and ready to go.

Mostly so I could have a way to compare various combinations. The different tires and brake bits that one can choose from vary a lot in weight. At least this way I can compare the basic wheel weights. Also, some of the wheels I have don't have any particular brake system fitted, so I would have had to try to find something appropriate to add. Just didn't seem right to try fitting a stock Norton disk to a light weight mag wheel. In any case, if I can compile some data on the other bits, that will probably help.

Ken

lcrken · Oct 4, 2016

These are the wheels I just bought from lister Edgarr. He thought they were Performance Machine, but they are actually Morris cast aluminum, with a 2.15x19 front and 2.50x18 rear. They are approved for tubeless tires. The rear brake setup was from Performance Machine, and I think that's why he thought the wheels were too. They have the Morris M logo cast into the rim.

The front weighs 12 lbs. 12 oz, and the rear is 15 lbs 4.6 oz. The front is slightly heavier than the one I posted earlier. These are 5 and 6 bolt pattern, not specifically meant for Nortons and Triumphs, and the earlier one is a 4 bolt pattern that takes stock Norton and Triumph disks.

Ken

worntorn · Oct 4, 2016

It's looking like a stock set up but with rims changed to Morad ( Akront) is a fairly light option.
I suspect the MK3 rear cush hub and sprocket mount is also not bad for weight, given that it gives you QD and a proper cush drive in the deal.
Without going to the cost of Magnesium or Carbon Fibre, is there a lighter option? Borrani was mentioned as lighter. Are these durable enough for street potholes?
Buchanan's Sun aluminium rims are very well made, but almost as heavy as the stock chromed steel.

acotrel · Oct 5, 2016

If I had a set of mag wheels I would use them - anything which saves weight is good unless it creates a problem. My shed is not warm and dry in winter, so mag wheels are probably not so good. I had them on my TZ350G - they had more problems than just corrosion. The holes where the sprockets and discs were held on were pretty buggered. I think the guy who had the bike before me didn't know how to tighten a bolt or a nut. I sold the bike to buy the 6 speed box for the Seeley - it would have needed a session of fitting helicoils before it could be raced. It had too many stupid little problems for my liking.

lcrken · Oct 5, 2016

worntorn said:
It's looking like a stock set up but with rims changed to Morad ( Akront) is a fairly light option.
I suspect the MK3 rear cush hub and sprocket mount is also not bad for weight, given that it gives you QD and a proper cush drive in the deal.
Without going to the cost of Magnesium or Carbon Fibre, is there a lighter option? Borrani was mentioned as lighter. Are these durable enough for street potholes?
Buchanan's Sun aluminium rims are very well made, but almost as heavy as the stock chromed steel.

You might be right about the front. Not so sure about the rear. That MKIII rear is pretty heavy. I'll try to get some weights posted on it soon, and we'll see how it compares. For the front, I ran a Norvil hub with alloy rim and lightened Norvil disk on my featherbed racer for a long time, and I think it is significantly lighter than the stock Commando wheel. I haven't weighed it yet, because it still has the tire mounted, but I'll do so and post the result. I ran a Barnes QD hub on the rear with alloy rim, and I'm sure it was quite a bit lighter than stock, but didn't have a cush drive. I'll post some info on that one too.

Ken

lcrken · Oct 14, 2016

Stock MKIII 1.85x19" rear wheel with disk but no sprocket - 20 lbs 14.4 oz.
Stock MKIII 1.85x19" rear wheel without disk or sprocket - 15 lbs. 10 oz.
Stock disk - 5 lbs. 4.4 oz.

Ken

worntorn · Oct 14, 2016

So the MK3 rear wheel is similar in weight to the Morris Cast aluminium and gives you cush plus quick detach. Not bad.
With an alloy rim laced in and drilled disc, the MK 3 wheel would be a couple of pounds lighter than the Morris cast aluminium.
Thanks for posting this Ken, it's good info to log away.

Glen

Fast Eddie · Oct 15, 2016

Great thread Ken.

I don't think I've ever measured a wheel, and I'm really surprised at how heavy they are. All of them.

No wonder that carbon fibre wheel's are all the rage on modern bikes!

What do Wheels Weigh?

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