Carbon Fiber Wheel Update

Vernon240 said:

Yep, 2.85kg / 6.28lb for the front, and 4.19Kg / 9.24lb rear. Excited to try it out!

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Thank you! Very awesome.

It’s not just the amount of weight, it’s where the weight reduction is from ie mainly the rim and outer diameter of the wheel, hence (hopefully) big effect on gyroscopic forces…

Vernon240 said:

Yep, 2.85kg / 6.28lb for the front, and 4.19Kg / 9.24lb rear. Excited to try it out!

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Tremendous improvement!
Should have very noticeable effect on turn-in, and suspension control.

Good to compare complete finished weights like that. Usually weights are given in some state of undress so it's difficult to know what the numbers mean.
A bit like the "dry weight" and "wet weight" given for bikes.
As one reviewer said, " I've not been able to figure a way to ride the bike in its dry weight state, so I've weighed it ready to ride instead"


Glen

worntorn said:

As one reviewer said, " I've not been able to figure a way to ride the bike in its dry weight state, ..."

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That would be in the EFI "Down hill" rider mode.

Fast Eddie said:

It’s not just the amount of weight, it’s where the weight reduction is from ie mainly the rim and outer diameter of the wheel, hence (hopefully) big effect on gyroscopic forces…

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Exactly! Not only unsprung, but also rotating mass. They say that 1 unit of unsprung rotating mass is equivalent to 4 units of fixed sprung mass. Thus, your 15.5 lbs of weight loss to wheels is approximately an equivalent to removing 62 lbs of weight off the frame. Can't wait to read your ride report. Now how do I convince the wife I need new $4000 wheels??!??

italia said:

Now how do I convince the wife I need new $4000 wheels??!??

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Just do it!
"It's easier to ask forgiveness than permission."
Grovel a bit before SWMBO, then you'll have your wheels.

BritTwit said:

Just do it!
"It's easier to ask forgiveness than permission."
Grovel a bit before SWMBO, then you'll have your wheels.

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Yep, it's a tough one to justify. Luckily, I've just finished a long term car restoration and have a number of parts bought 15 years ago, or came off the car that were good, but not good enough to go back on, that now are very rare. Ebayed what I didn't want, bought what I did. All worked out, so overall hit to the coffers negligible. My man maths says they cost very little. My other half will say they cost what they cost, as I could have had that money in my account. True, but why think like that?

Lighter wheels will make it more economical. Using less fuel cuts carbon emissions into the atmosphere.

Plus, making those carbon wheels has captured a lot of carbon that is therefore not being released into the atmosphere.

So, basically, they make you and environmental hero.

If you can’t sell it to the Missus like that then you seriously need to work on your sales skills…

italia said:

Exactly! Not only unsprung, but also rotating mass. They say that 1 unit of unsprung rotating mass is equivalent to 4 units of fixed sprung mass. Thus, your 15.5 lbs of weight loss to wheels is approximately an equivalent to removing 62 lbs of weight off the frame. Can't wait to read your ride report. Now how do I convince the wife I need new $4000 wheels??!??

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You buy them for her obviously

This is about the only way we can ditch weight off our 961 without cutting up the rest of the bike. I’m ok not having 100 hp. I just wish we could lose 100 pounds off the bike.

I never thought of weighing the plastic vs aluminum tank. I know it’s not much of a difference but the carbon fiber vs spoked wheels sure are a nice weight savings and rotating mass / unsprung weight loss.

I've been looking at using abs plastic for some items on the 920.
The specific gravity for pigmented ABS is 1.07.
By comparison Aluminium is 2.5 to 2.7, Titanium is 4.5
and steels are around 8.
No wonder plastics are used for non-structural stuff on Sportbikes.
With ethanol in fuel, plastic is a bit tricky for tanks.


Glen

Voodooo said:

This is about the only way we can ditch weight off our 961 without cutting up the rest of the bike. I’m ok not having 100 hp. I just wish we could lose 100 pounds off the bike.

I never thought of weighing the plastic vs aluminum tank. I know it’s not much of a difference but the carbon fiber vs spoked wheels sure are a nice weight savings and rotating mass / unsprung weight loss.

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I'm not OK with not having 100hp, still want a supercharger!
But removing 100 lbs would be next to impossible.
The engine cases and frame are stout units so weight reduction will have to come from lightening the rest.

1. Light weight wheels - already mentioned
2. Aluminum swingarm
3. Hollow axles
3. Carbon fiber fuel tank
4. Carbon fiber tail
5. Carbon fiber primary cover
6. Carbon fiber rocker cover
7. Carbon fiber engine sprocket cover
8. Titanium exhaust
9. Put rider on diet

BritTwit said:

I'm not OK with not having 100hp, still want a supercharger!
But removing 100 lbs would be next to impossible.
The engine cases and frame are stout units so weight reduction will have to come from lightening the rest.

1. Light weight wheels - already mentioned
2. Aluminum swingarm
3. Hollow axles
3. Carbon fiber fuel tank
4. Carbon fiber tail
5. Carbon fiber primary cover
6. Carbon fiber rocker cover
7. Carbon fiber engine sprocket cover
8. Titanium exhaust
9. Put rider on diet

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Adding a supercharger isn’t gonna help reducing weight. Not to mention it’ll add heat, and how much would you expect the 961 to gain if you could even add a supercharger?
Doing all the weight loss you mentioned is do’able.
1) carbon wheels. Available
2) aluminum swing arm. Available for commando.
3) hollow axles, easy.
4) carbon fiber gas tank. Good luck.
5) carbon fiber tail. Easy if you have a dominator.
6) carbon fiber primary cover. Can be done
7) carbon fiber rocker cover. Can be done
8) carbon fiber sprocket cover. Can be done or removed.
9) titanium exhaust. Can be done.
10) good luck.

You forgot…..
Lithium battery if you don’t already have one. Carbon ceramic rotors, carbon handle bars, carbon rear sets.
Ditch the turn signals, ditch the head and tail light, ditch the plate holder, titanium bolts throughout the whole bike, lighter seat cushion on the commando, oh and ditch the starter.
Lighter chain, titanium rods, lighter pistons.

Or.
It would be easier and cheaper to run 1-2 gallons of less gas (1 gallon of gasoline weighs 6.3 pounds or 12.6 for 2 gallons) than to spend all that time and money on the carbon fiber tail, primary cover, rocker cover, sprocket cover and titanium exhaust.

The wheels would provide the best performance gain in weight savings, handling and braking.

Voodooo said:

It would be easier and cheaper to run 1-2 gallons of less gas (1 gallon of gasoline weighs 6.3 pounds or 12.6 for 2 gallons) than to spend all that time and money on the carbon fiber tail, primary cover, rocker cover, sprocket cover and titanium exhaust.

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Not doubt about it, rider weight and fuel usually get overlooked.

Given the demographics of this forum, I’d wager that reduction in rider weight has huge potential !

And fuel, I’ve often thought that whilst wet weight is a much better indicator of real life weight than dry, it still isn’t finite. A bike with a bigger tank gets penalised with the wet weight figure simply for having the option of carrying more fuel.

Given that on most bikes the fuel tank is high up, reducing fuel weight also has a greater effect on handling and performance than lightweight engine covers for example, as that weight is very central.

As a note, although I didn’t weigh them side by side, it was clear to me just by feel that the plastic 961 tank was heavier than the alloy one. That was no doubt due to the difference in thickness, the plastic tank is THICK.

There's always NOX..........

Even with the weight gain and benefits of CF wheels it's still going to be a bit of a haul round a track. The question is how much you want to destroy the 961's character to improve, what shall we call it, track performance? To me CF wheels detract from the CR appearance too much. You reach a point where if you want a track bike you buy a track bike - to that end I'm just getting a little zxr400 ready for some track sessions next year. Or you accept that there is always going to be someone faster than you so you work on getting the best from what you have.

The greatest improvements in bike performance are often made by making adjustments to the nut on the handlebars.......

Clive said:

There's always NOX..........

Even with the weight gain and benefits of CF wheels it's still going to be a bit of a haul round a track. The question is how much you want to destroy the 961's character to improve, what shall we call it, track performance? To me CF wheels detract from the CR appearance too much. You reach a point where if you want a track bike you buy a track bike - to that end I'm just getting a little zxr400 ready for some track sessions next year. Or you accept that there is always going to be someone faster than you so you work on getting the best from what you have.

The greatest improvements in bike performance are often made by making adjustments to the nut on the handlebars.......

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The reason I fitted carbon wheels were first for punctures.
Second , I hate cleaning spokes,it’s more boring than F1,
and thirdly the weight.
And boy does it make a difference.
Laying off the pies could save you a fortune in carbon fibre!

is that the self- locking nut to the right?

Well, finally they are on. I did not re tax the bike, so it will probably be a month or so before a proper test ride...but looks good so far:










I must trim that tie wrap!

Looks the bollox !