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Discussion Starter · #1 ·
Not quite tires/tyres but rims.
moved discussion from:
http://www.ninjah2.org/forum/ninja-h2-h2r-build-area/18786-envied-h2-build-log-21.html
...so not to drag the great Envied thread off-topic.





I love the thicker spokes but can't get pictures out of my head of carbon wheels tearing the centres out. I think our local roads have way too many random pot-holes to be confident enough to run carbon but on the track you should only see performance gains.

I put over 30,000km's on my BST wheels, with probably 400+ passes in the 1/4 mile with my zx10r. I live in Canada where winter ruins the roads and never had a single issue with them.

The bikes destroying them at the track are 500-600+whp, and even that is a rarity. I have seen magnesium wheels get damaged very easily, and they are standard on a few bikes.
Truely awesome you have not had a problem and I sincerely hope you never do but it's certainly not only 500hp monsters that have had problems, the Internet is littered with stories about sub 200hp track bikes doing this on good race surfaces.

...and magnesium isn't much of a comparison. They have stopped using mag rims in World Superbike (WSBK) and in many other competitions too. In our local LSR rules they "don't recommend" (whatever that really means).

"Magnesium wheels are not recommended and, if used, shall have an initial Zyglo certificate and stamp available. Zyglo inspections made with tires mounted are accepted. Wheels are to be re-inspected if any adverse condition arises." -- 2017 Rule Book Dry Lakes Racers Australia

Brembo make some of the best magnesium rims in the world under the Marchesini brand, you need deep pockets and I'm pretty sure the MotoGP guys just toss them away nearly as often as they change tyres.

I'm pretty sure that both MotoGP and WSBK both stopped the use of carbon rims a few years ago, not to say they won't come back at some point.

Carbon wheels look amazing and I understand the performance advantage of something the will turn-in faster with less gyro and accelerate faster with less rotational mass... but as mentioned, the exploded pictures that everyone likes to share when there is a failure give me a twitch.

Some of these pictures are getting quite old and I'm sure the companies and their technology is in constant development too as they don't want any failures, ever. I get that.

I live near Carbon Revolution and have watched their progress over the last 10 years. They have come a long way in that time and produce some of the world's best wheels now. It's their wheels you can get optioned on a Shelby Mustang (at a price!).
They are even using ceramic coating (think space shuttle tiles) on the insides of the rims to protect from brake heat and their rims are forged under very high pressures, not laid out in molds.

I wonder if any of the bike rim manufacturers are going to anything like this level of research, development and production values?
...or are they just knocking out carbon rims and letting the owners test them?
 

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Could some of you guys post pictures of the rims you have seen that failed? I would google them but this Iraq internet only lets me look at certain things.
 

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Ayjayef, the fastest and most powerful bikes on the planet still use carbon wheels to this day, running 6 second 1/4 mile passes at over 225mph, and have been 311mph on a Turbo Hayabusa. I do understand there has been failures, but who is to say what actually caused the problem. Was it because the rim failed? Was the rim in a crash before hand? Improper installation? etc etc. I have had carbon rims on two separate bikes now with no signs of a problem.

Years back at a bike show, a dealer had a BST rim, literally all weekend this bare rim was thrown in the air and landed on the concrete floor probably 100+ times, and it never cracked or broke lol.

Brocks performance released a statement in regards to what to look for if a failure is possible. I mean if you smacked a pot hole and damaged your rim, would you try to fix and or replace it? Or would you continue to use it. Problem is some people are stubborn and wont spend the money to replace what might have been damaged already, then when a failure occurs they leave that piece of information out and blame the company.
 

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Not quite tires/tyres but rims.
moved discussion from:
http://www.ninjah2.org/forum/ninja-h2-h2r-build-area/18786-envied-h2-build-log-21.html
...so not to drag the great Envied thread off-topic.










Truely awesome you have not had a problem and I sincerely hope you never do but it's certainly not only 500hp monsters that have had problems, the Internet is littered with stories about sub 200hp track bikes doing this on good race surfaces.

...and magnesium isn't much of a comparison. They have stopped using mag rims in World Superbike (WSBK) and in many other competitions too. In our local LSR rules they "don't recommend" (whatever that really means).

"Magnesium wheels are not recommended and, if used, shall have an initial Zyglo certificate and stamp available. Zyglo inspections made with tires mounted are accepted. Wheels are to be re-inspected if any adverse condition arises." -- 2017 Rule Book Dry Lakes Racers Australia

Brembo make some of the best magnesium rims in the world under the Marchesini brand, you need deep pockets and I'm pretty sure the MotoGP guys just toss them away nearly as often as they change tyres.

I'm pretty sure that both MotoGP and WSBK both stopped the use of carbon rims a few years ago, not to say they won't come back at some point.

Carbon wheels look amazing and I understand the performance advantage of something the will turn-in faster with less gyro and accelerate faster with less rotational mass... but as mentioned, the exploded pictures that everyone likes to share when there is a failure give me a twitch.

Some of these pictures are getting quite old and I'm sure the companies and their technology is in constant development too as they don't want any failures, ever. I get that.

I live near Carbon Revolution and have watched their progress over the last 10 years. They have come a long way in that time and produce some of the world's best wheels now. It's their wheels you can get optioned on a Shelby Mustang (at a price!).
They are even using ceramic coating (think space shuttle tiles) on the insides of the rims to protect from brake heat and their rims are forged under very high pressures, not laid out in molds.

I wonder if any of the bike rim manufacturers are going to anything like this level of research, development and production values?
...or are they just knocking out carbon rims and letting the owners test them?
Carbon Revolution uses
to construct their wheels - so does Rotobox. Rotobox also has all for their wheels independently tested, to verify their in-house testing.

The carbon fiber motorcycle wheels of today are vastly improved from just 5 or so years ago, not only in design, but in material advancements.

Some people prefer the 'security' of a metal wheel...



I am (personally) not one of those people.

Brock
Brocks Performance
 

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A prohibition in racing doesn't necessarily mean there is a technical problem with whatever they are prohibiting. It can be for cost containment as much as for anything else.

I have magnesium rims on my race bike. Carbon fiber is not allowed ... and it's simply because in the vintage racing class that the bike is eligible for, the rulebook doesn't allow it because in the time period that the bike was originally built and was originally raced in, carbon fiber rims didn't exist but magnesium rims did. Back in 1989 (cutoff year for the class) someone could have rung up Dymag and had them make the same rims back then that I have now.

Magnesium will corrode very quickly if unprotected, and if involved in a fire, it will burn and can make the fire near impossible to put out until it burns up. You can't put out a magnesium fire with water. Those are potential rationales for disallowing magnesium rims. So, I am careful with who changes my tires, and I certainly don't do it myself with hand tools, and I don't roll the rims around on a concrete floor without tires on them (I saw someone do that to a Marchesini wheel and cringed!), and I don't run the bike over curbs or through potholes, and I pay attention to the tire pressure. And try not to set stuff on fire.

If you have an expensive set of wheels, you have to take care of them and be careful with them no matter what they're made of. With that in mind, I wouldn't be concerned about wheels from one of the known-good reputable manufacturers, and I would include BST, Rotobox, Marchesini, and Dymag as known reputable wheel manufacturers. I'm probably forgetting some. Generic no-name copycat made in C***a ... no thanks.

Can you break a wheel from one of those manufacturers? Sure. Everything has limits to what it can withstand. I've seen a stock front wheel on a GSXR break in a crash on the street ... the bike slid into a curb. (Lots of other stuff got broken besides the wheels. Rider - who was running from the cops - was more or less ok although obviously in a heap of trouble.) I put a massive dent in a car wheel by hitting a big rock.
 

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I think the racing ban is a homologation issue. I also had magnesium Marchesini wheels on my old Hayabusa. Strangely these are ok for racing. What a lot of people forget is that magnesium is very reactive and needs crack testing and chromite coating every couple of years. Chip the paint off one and the metal quickly turns to powdery oxide. In terms of longevity and robustness the carbon wheel is a better product.
There are production bikes with magnesium wheels, the R1 for example, I don't know what extra advice Yamaha is giving R1 owners but if they aren't then they should.
 

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Discussion Starter · #9 ·
Some people prefer the 'security' of a metal wheel...
I am (personally) not one of those people.
Looks like a stock ZX14 rim on an extended swingarm bike with a sticky track tyre on it... all sorts of potential abuse and made worse if those custom colours were powder coated and oven baked by Jim-Bob's paint down the street.

There is no shortage of smashed-up alloy cast rims at any wreckers (breakers) but most of those came to a sudden stop against a non-movable object. There are just as many "D" shaped rims after an accident but it's pretty rare to see them break the centres out like the picture above.

I get that there are good and bad in all designs and materials and depending on its use (and abuse) but in all the things that have ever happened to me on a motorcycle, total rim collapse isn't one of them.


As requested by Envied...









...and while not a bike rim, this hybrid rim is interesting. Carbon rim okay, alloy spokes destroyed... but still holding (bolted?) to the carbon okay.



I'm not really trying to start a religious war for or against carbon, as mentioned I personally get a twitch when I see these (mostly old) images and was curious what the board consensus was.

I really do like the look of these new Rotobox "heavy spoke" and with a few early failures I'm sure BST have upped their game in design too.
 

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CF rims are awesome, I love mine.
just don't hit anything cause they won't survive the impact.



 

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Crashing is certainly hard on wheels, as well many other items.

It's common for us to receive e-mails these days, thanking us for a carbon wheel keeping the rider upright after a mishap. Unlike a metal wheel, carbon will flex when it comes in contact with an object, road debris, exceptionally deep potholes etc.

Here is a video of a BST impact test:


This is a video of one of the impact tests that BST performs in house to pre-test before US DOT and German TÜV certification. This is a stock/standard BST rear wheel. BST Engineers performed 16 consecutive impact tests on the same wheel, with increasing weights. This Video of Test 15 shows 490 kgs (1080 pounds) dropping onto the wheel, using a steel V point at the impact location. You can see the wheel flex, but the tire still holds air.





This is a metal wheel after that same test was attempted.




FYI: The motorcycle world has been a bit slow to embrace carbon fiber, but the rest of the world relies on it's incredible strength to weight ratio. Brocks Performance: Trusted Strength: BST Carbon Fiber Wheels


That said, it is happening. Many OEM's have now begun to offer carbon fiber wheels. Ducati, BMW, Norton as well as a host of smaller companies like Confederate and Arch motorcycles.
Brocks Performance: Carbon Fiber - Moving Faster Than Ever


Brock
Brocks Performance
 

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"carbon will flex"...that's the one problem I had with my 14r.No amount of suspension tuning would stop the shimmying at over 130 leaned in.Great wheels,but on a heavier bike,perhaps not the best choice for higher speed cornering.Tires were inflated to factory specs.Quality Pirrelli's.Good tread.Smooth road surfaces.When I bought mine a few years ago,I didn't realize there were two models of BST wheels that could go on my bike.Apparently I bought the 'lighter' model.This could explain what was happening with my ride.???
 

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"carbon will flex"...that's the one problem I had with my 14r.No amount of suspension tuning would stop the shimmying at over 130 leaned in.Great wheels,but on a heavier bike,perhaps not the best choice for higher speed cornering.Tires were inflated to factory specs.Quality Pirrelli's.Good tread.Smooth road surfaces.When I bought mine a few years ago,I didn't realize there were two models of BST wheels that could go on my bike.Apparently I bought the 'lighter' model.This could explain what was happening with my ride.???
Not sure what's up there? I have had no issues of that nature on my personal 14. Granted, I don't do much high speed cornering on it...but it occasionally gets a workout. It did install an Ohlins steering damper, because land speed rules mandated - not because of any type of poor handling. It got 'tightened up' for high speed use. My guess is your issue is more vehicle choice, than wheel flex... that extra wheelbase on the 14 makes for a stable ride, but they don't see much road course use.

BST and Rotobox both have boatloads of H2 riders (not a light bike) cornering at much faster speeds with no similar complaints? Maybe some of them can comment?


Brock
Brocks Performance
 

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Yeah...agree on the H2's.Probably no issue.Performance of those carbon wheels on an H2 is probably more noticeable.I would think so.The 14 can be a big bastid;)I also installed(already had)a very good damper on the front.
The steering damper on the H2 is VERY good.I love mine.

I went back to my stock rims...bike was grippy and smooth at all speed ranges.
 

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Yeah...agree on the H2's.Probably no issue.Performance of those carbon wheels on an H2 is probably more noticeable.I would think so.The 14 can be a big bastid;)I also installed(already had)a very good damper on the front.
The steering damper on the H2 is VERY good.I love mine.

I went back to my stock rims...bike was grippy and smooth at all speed ranges.
Sorry to disagree but the stock Ohlins damper on the H2, which appears to be the same as the one on my 2016 zx10r is complete garbage!

On both bikes i have encountered huge tank slappers, lock to lock and then you have to pull the front brake lever numerous times to get the caliper pistons back to where they should be...... very scary at speed!

I have replaced them with the quality manual Ohlins damper and usually have it at about stiffness 15 - 17 out of 20.
 

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Changing the weight or moment of inertia of a wheel will change the natural frequencies of chassis oscillation (be it "shake" or "wobble" or "weave"). All motorcycles have these vibration frequencies. The OEM design hopefully puts these frequencies outside of the normal operating range and/or arranges them so that they don't coincide in a way that amplifies them. If you change something on the bike, which changes these frequencies, they could get further out of the operating range, or they could come back into the operating range, or they could now coincide with some other vibration which now sets it going. This is REALLY complicated to analyse.

My race bike gets a front-end chatter in one particular long right-hand 4th-gear corner if I try to run the front tire pressure at the pressure that the tire guy wants me to use. The fix is to run it 2 psi higher. Gotta do what ya gotta do.
 

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Sorry to disagree but the stock Ohlins damper on the H2, which appears to be the same as the one on my 2016 zx10r is complete garbage!

On both bikes i have encountered huge tank slappers, lock to lock and then you have to pull the front brake lever numerous times to get the caliper pistons back to where they should be...... very scary at speed!

I have replaced them with the quality manual Ohlins damper and usually have it at about stiffness 15 - 17 out of 20.
I am assuming this is from track racing? I never had a tank slapper on my gen4, or on the H2.
 

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"On both bikes i have encountered huge tank slappers, lock to lock and then you have to pull the front brake lever numerous times to get the caliper pistons back to where they should be...... very scary at speed! "...so did you figure out what was causing the slapper?I'd definitely want to know so I didn't repeat it.

"I am assuming this is from track racing? I never had a tank slapper on my gen4, or on the H2."

...same here.I've rolled over some pretty iffy surfaces at big speed...well into the triple digits,and never had the frontend get even one bit squirrely.Had that damper not been on there,I'm convinced she would have got outta shape real fast.Leaned in mind you.
 

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Crashing is certainly hard on wheels, as well many other items.

It's common for us to receive e-mails these days, thanking us for a carbon wheel keeping the rider upright after a mishap. Unlike a metal wheel, carbon will flex when it comes in contact with an object, road debris, exceptionally deep potholes etc.

Here is a video of a BST impact test:

http://www.youtube.com/watch?v=LyTNFK8P8LQ

This is a video of one of the impact tests that BST performs in house to pre-test before US DOT and German TÜV certification. This is a stock/standard BST rear wheel. BST Engineers performed 16 consecutive impact tests on the same wheel, with increasing weights. This Video of Test 15 shows 490 kgs (1080 pounds) dropping onto the wheel, using a steel V point at the impact location. You can see the wheel flex, but the tire still holds air.





This is a metal wheel after that same test was attempted.




FYI: The motorcycle world has been a bit slow to embrace carbon fiber, but the rest of the world relies on it's incredible strength to weight ratio. Brocks Performance: Trusted Strength: BST Carbon Fiber Wheels


That said, it is happening. Many OEM's have now begun to offer carbon fiber wheels. Ducati, BMW, Norton as well as a host of smaller companies like Confederate and Arch motorcycles.
Brocks Performance: Carbon Fiber - Moving Faster Than Ever


Brock
Brocks Performance
Not to thread jack your post Brock, but that "metal" rim in your pic is a Cast Magnesium Marvic which is probably old and brittle based on the pic. An aged cast magnesium rim will not hold up to any real stress test. You know I love you bro, but I had to chime in with that. :D

A carbon fiber wheel is stronger and safer than a cast magnesium wheel past its warranty period. Just fact.

Well built carbon is in fact strong but ultimately it won't provide the same safety net as an aluminum wheel (forged or cast).

In all fairness, I read the carbon wheel data page on your site and it does seem that Carbon wheels have come a long way from just 10 years ago. Manufacturing processes and quality control look to have improved dramatically.

......I'm not sure I'm ready for a set tho. Maybe one day. ;)
 

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I am assuming this is from track racing? I never had a tank slapper on my gen4, or on the H2.
This was street riding the 2016 zx10r and H2 and they are the ONLY bikes this has ever happened on in 42 years of riding many bikes on the same roads, under the same conditions !

I think it has to do with the Kawasaki geometry as no such issues on BMW s1000rr (10, 12), Gsxr1000's (01, 05), R1's(99), Busa's (99, 00), CBR900rr (93), YZF1000 (89), plus many more.
 
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