Putting UFO wheels on a diet.

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Sharky

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I've always hated the weight of the Maxdaddy wheels from UFO.
I had no idea how heavy they were until they arrived.
So, to date I've tracked down (with help from Sean) the supplier of the roto forged blanks and the company that machined them.
I've also found a company local to me in Brisbane that buys in same blanks to make harley wheels.
I want to keep the style so I'm thinking about getting the spokes machined out as per my pic and the main flat part reduced in thickness.
I've done the maths on weight/cm cubed and I reckon there's easily a couple of kilos per wheel that can go.
Thoughts O wise monkeys ?
 

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Traumahawk

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I've always hated the weight of the Maxdaddy wheels from UFO.
I had no idea how heavy they were until they arrived.
So, to date I've tracked down (with help from Sean) the supplier of the roto forged blanks and the company that machined them.
I've also found a company local to me in Brisbane that buys in same blanks to make harley wheels.
I want to keep the style so I'm thinking about getting the spokes machined out as per my pic and the main flat part reduced in thickness.
I've done the maths on weight/cm cubed and I reckon there's easily a couple of kilos per wheel that can go.
Thoughts O wise monkeys ?
I agree. I have the RC version of a Maxdaddy rear wheel( actually the company that MADE the maxdaddy), and shipped to my door, it was 44 lbs. Sean thinks I'm actually loosing about 4 hp. Face it, it all comes down to sprung vs unsprung weight.
 

PMaxx

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My only words of caution would be to not go too aggressive with the width of those machined areas. You don't want the resulting spokes to be too thin and not be strong enough to take a good hit from a pot hole.
 

Sharky

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Question.....
As the cast,stock wheels are what...8-10mm on the spokes...any reason not to go that think in my roto forged maxdaddy's ??
 

Vinmax

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I agree. I have the RC version of a Maxdaddy rear wheel( actually the company that MADE the maxdaddy), and shipped to my door, it was 44 lbs. Sean thinks I'm actually loosing about 4 hp. Face it, it all comes down to sprung vs unsprung weight.
Hi Traumahawk,
Yep, unsprung weight is bad. Actually sprung weight is bad also. Most extra weight is bad! But unsprung weight mostly affects handling and has no bearing on the HP that's making it's way from the engine to the rear wheel and onto the road.

Unsprung weight means the weight that is carried that is 'under' the springs. Hence the 'unsprung' terminology. What happens with unsprung weight is that the heavy mass has no springs/shock absorbing mechanism to control it. Therefore, it's a harder mass to control regarding handling.

When most weight is carried above the spring/shock absorbing mechanisms, then it's called 'spung' weight, and is positively controlled. So you want most weight 'above' the springs/shocks for better handling.

Now............ when it comes to HP, you want to refer to static mass vs rotating mass.
BOTH are badddddddddd!!!! But here's the kicker;
Static mass is actually easier to get moving. Rotating mass is harder, as you not only have to carry it, but you have to get it spinning (like getting a heavy merry-go-round moving.

Rotating mass is also harder to stop then static mass. So rotating mass will adversely affect acceleration as well as stopping. PLUS, you still have to carry it around.

Rotating mass (or sometimes called Dynamic mass), is the worst way to carry extra weight.

Depending on how far to the outside circumference the rotating mass is carried, it can calculate out to a pound of rotating mass is equal to 4 pounds of static.
So in other words, if you had to carry an extra 1lb around with you, you'd be better off carrying it on the seat behind you and not on the rotating wheels.

To sum it all up;
1) Unsprung and sprung weight is all bad
2) Unsprung and sprung weight will BOTH negatively affect handling.
3) BUT, sprung weight is the better way to carry the weight (above the springs/shocks so that it can be controlled properly and keep the tires in contact with the road surface).
4) Static and rotating weight: BOTH bad!
5) But, if you have to carry weight around, keep it non-rotating. By eliminating as much unnecessary rotating weight (especially on the wheels/brakes/tires), then you get to use more of the HP that the motor is generating, as opposed to wasting this energy trying to get that heavy merry-go-round to spin.

Yes,,,,,,,,,,,,,,,,, a heavy wheel/tire combo will help eat-up some of the HP you're making. And it will also make braking less effective.

Here's a very good article defining some of the terminology much better than I attempted to do;
http://victorylibrary.com/mopar/sprung-c.htm

And a quick question/answer from the bicycle folks asking a Dept. of Physics about rotating weight on wheels;
http://van.physics.illinois.edu/qa/listing.php?id=7559



Vinnie
 

Traumahawk

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Hi Traumahawk,
Yep, unsprung weight is bad. Actually sprung weight is bad also. Most extra weight is bad! But unsprung weight mostly affects handling and has no bearing on the HP that's making it's way from the engine to the rear wheel and onto the road.

Unsprung weight means the weight that is carried that is 'under' the springs. Hence the 'unsprung' terminology. What happens with unsprung weight is that the heavy mass has no springs/shock absorbing mechanism to control it. Therefore, it's a harder mass to control regarding handling.

When most weight is carried above the spring/shock absorbing mechanisms, then it's called 'spung' weight, and is positively controlled. So you want most weight 'above' the springs/shocks for better handling.

Now............ when it comes to HP, you want to refer to static mass vs rotating mass.
BOTH are badddddddddd!!!! But here's the kicker;
Static mass is actually easier to get moving. Rotating mass is harder, as you not only have to carry it, but you have to get it spinning (like getting a heavy merry-go-round moving.

Rotating mass is also harder to stop then static mass. So rotating mass will adversely affect acceleration as well as stopping. PLUS, you still have to carry it around.

Rotating mass (or sometimes called Dynamic mass), is the worst way to carry extra weight.

Depending on how far to the outside circumference the rotating mass is carried, it can calculate out to a pound of rotating mass is equal to 4 pounds of static.
So in other words, if you had to carry an extra 1lb around with you, you'd be better off carrying it on the seat behind you and not on the rotating wheels.

To sum it all up;
1) Unsprung and sprung weight is all bad
2) Unsprung and sprung weight will BOTH negatively affect handling.
3) BUT, sprung weight is the better way to carry the weight (above the springs/shocks so that it can be controlled properly and keep the tires in contact with the road surface).
4) Static and rotating weight: BOTH bad!
5) But, if you have to carry weight around, keep it non-rotating. By eliminating as much unnecessary rotating weight (especially on the wheels/brakes/tires), then you get to use more of the HP that the motor is generating, as opposed to wasting this energy trying to get that heavy merry-go-round to spin.

Yes,,,,,,,,,,,,,,,,, a heavy wheel/tire combo will help eat-up some of the HP you're making. And it will also make braking less effective.

Here's a very good article defining some of the terminology much better than I attempted to do;
http://victorylibrary.com/mopar/sprung-c.htm

And a quick question/answer from the bicycle folks asking a Dept. of Physics about rotating weight on wheels;
http://van.physics.illinois.edu/qa/listing.php?id=7559



Vinnie
Thats a very good explanation. I am looking up those links that you posted. Here's one thing that i did to improve braking, on the rear wheel. An aftermarket wave rotor (I have them on the front too, i like everything to match) also HH pads on the stock caliper. Eventually I plan on a 6 pot caliper on the rear, like I have on the front.
 

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Vinmax

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That's a nice looking brake setup on the rear. I did EBC Superlights on my front and want to get a floating disk eventually on the rear like you have.
Looks great.

Vinnie
 

Traumahawk

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That's a nice looking brake setup on the rear. I did EBC Superlights on my front and want to get a floating disk eventually on the rear like you have.
Looks great.

Vinnie
Thanks. Its worlds apart from where it was stock. One night I had to panic stock, and locked up the brakes TWICE, before I got it shut down, and then and there, I wanted to upgrade the brakes.
 

MaxMidnight

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Adding to Mr Vinmax's post, we should also note that the wheel are also a pair of rater large gyroscopes.

This has a significant benefit to all single tracked machines - they stop them falling over when moving.
As the rider senses that the machine is falling over to the left they will steer to the left and gyroscopic precession will act at right angles to the spinning wheels and move the bike over to the right.
These movements are so small and subtle that we don't even notice we are doing them.
Anyone who has experienced the 'joy' of teaching someone to ride a bicycle will notice that initially the riders steering input when (say) falling to the left is too much so they immediately fall to the right. Only when they learn to moderate the input do they start to balance.

However, the larger the rotating mass the greater the input required from the rider to turn the machine.
This is another benefit of a lighter wheel/ tyre combination.

Those who follow Moto GP will have noticed that Yamaha (and others) have the engine rotating masses turning in the opposite direction to that of the wheel to offset some of the gyroscopic effect of the wheels.

So to surmise, lighter wheels not only give the suspension an easier time, allow faster acceleration and retardation but also make the machine easier to steer.
 

Sharky

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So yes..we all agree light good heavy bad.
My ufo's are 18mm thick...stocks are 8-10mm.
As the ufo wheels are roto forged surely they could go as thin as cast wheels with no loss of strength? ?
 

Sharky

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I'm talking to an aussie wheel maker that works with the same blanks.
Gonna be away in the uk for a week visiting parents (and picking up loads of bike parts).
I'll be seeing the wheel man when I get back.
 

Traumahawk

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I'm talking to an aussie wheel maker that works with the same blanks.
Gonna be away in the uk for a week visiting parents (and picking up loads of bike parts).
I'll be seeing the wheel man when I get back.
Have a safe trip, and let us know how it turns out with the wheel.
 

wildweasel_pt

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I would prefer to cut longitudinally rather than on the sides. Having a thin wall will decrease side load resistance I would just cut smaller spokes and match the rear
 

Fire-medic

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I interpret that to mean, "cut a pattern concentric to the hub/axle, in the shape/form of the OEM wheel cutouts, removing more material, but don't thin the web (the remaining material after cutting the holes) too."

I would prefer to cut longitudinally rather than on the sides. Having a thin wall will decrease side load resistance I would just cut smaller spokes and match the rear
 

wildweasel_pt

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The stock spokes are wide looking from the side. Making them narrower would shed weight without compromising the side resistance
 
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