Chromaphase
True Classic
Its always cool to hear these stories
New Alloy Wheels or Old Magnesium ?
- Thread starter Chromaphase
- Start date
Steve Thomas
True Classic
No. Most you see are modern aluminum copies. And at least 30% heavier.
Ulix
True Classic
Hi Eric,
Yes, I used those carbs on my hot 1300, then 1600. just sold them recently, since I am running 42s (bought from Carl!) on the 1900. Still in the same yellow 74 I bought in Seattle almost 30 years ago.
Ralf‘s X has pretty basic suspension actually.
The standard progressive lowering springs that „everyone“ is using on the street with some good shocks, strut housings lowered. Addco swaybar makes a big difference.
But the Nordschleife really like a softer suspension setup, so it is a good match.
The game changer are the tires. Toyo 888R or Nankang in 185/60. Absolutely transform the car on track.
Rupunzell
Bernice Loui
Spring & damper rates are road surface dependent. If the "ring" is bumpy, there is a significant advantage to set up the chassis/suspension with moderate spring and damper rates as this allows the tires to stay in contact with the road's bumpy surface. This is where matching damper rates to the spring rates is really important.. Notable here is just how excellent the stock exxe chassis/suspension was designed and set up.
Note the bold text regarding tire choice.. This is why if you're interested in traction and control tires are IT. Tires are the only contact surface between moto/driver and road surface, the traction/grip offered by the tires puts an absolute limit of ALL aspects of moto performance. Once tire selection has been made, pick a proper wheel to support it that meets the needs of the exxe suspension/chassis.
While on the topic of tires, there was a time when 24 Hours of LeMons could be considered the Dunlop Direzza cup series as that was the tire with a DOT180 rating (mandated by LeMons rules and the only thing that limits track lap times of many LeMons racers). Spent many hours yaking with Dave Coleman
Dave Coleman’s Winding Road Home | Inside Mazda
“There was a period when my dad bought an RX-7,” Coleman recalled. “When people would ask what I wanted to do, I’d say I wanted to work at Mazda’s R&D.”
insidemazda.mazdausa.com
Team captain of eye sore racing about tires, chassis/suspension set up and tires like Dunlop Direzza and much more. Lots of really good memories here. Too many focus on straight line acceleration/power, but are blind to control/feel and traction of the moto and how absolutely important that is.
"Those four small patches of rubber on the road is the only things between you and St. Peter."
~Mark Donahue.
Bernice
Chromaphase
True Classic
I see, interesting... could you direct me on a post or something about this basic suspension setup ? Also I dont have much of budget and my suspension right now is pretty good I feel already. So I would like to know if there is a really a big step to go for this kind od suspension setup !Hi Eric,
Yes, I used those carbs on my hot 1300, then 1600. just sold them recently, since I am running 42s (bought from Carl!) on the 1900. Still in the same yellow 74 I bought in Seattle almost 30 years ago.
Ralf‘s X has pretty basic suspension actually.
The standard progressive lowering springs that „everyone“ is using on the street with some good shocks, strut housings lowered. Addco swaybar makes a big difference.
But the Nordschleife really like a softer suspension setup, so it is a good match.
The game changer are the tires. Toyo 888R or Nankang in 185/60. Absolutely transform the car on track.
Chromaphase
True Classic
Spring & damper rates are road surface dependent. If the "ring" is bumpy, there is a significant advantage to set up the chassis/suspension with moderate spring and damper rates as this allows the tires to stay in contact with the road's bumpy surface. This is where matching damper rates to the spring rates is really important.. Notable here is just how excellent the stock exxe chassis/suspension was designed and set up.
Note the bold text regarding tire choice.. This is why if you're interested in traction and control tires are IT. Tires are the only contact surface between moto/driver and road surface, the traction/grip offered by the tires puts an absolute limit of ALL aspects of moto performance. Once tire selection has been made, pick a proper wheel to support it that meets the needs of the exxe suspension/chassis.
While on the topic of tires, there was a time when 24 Hours of LeMons could be considered the Dunlop Direzza cup series as that was the tire with a DOT180 rating (mandated by LeMons rules and the only thing that limits track lap times of many LeMons racers). Spent many hours yaking with Dave Coleman
Dave Coleman’s Winding Road Home | Inside Mazda
“There was a period when my dad bought an RX-7,” Coleman recalled. “When people would ask what I wanted to do, I’d say I wanted to work at Mazda’s R&D.”insidemazda.mazdausa.com
Team captain of eye sore racing about tires, chassis/suspension set up and tires like Dunlop Direzza and much more. Lots of really good memories here. Too many focus on straight line acceleration/power, but are blind to control/feel and traction of the moto and how absolutely important that is.
"Those four small patches of rubber on the road is the only things between you and St. Peter."
~Mark Donahue.
Bernice
I see, interesting to learn about all that...
So guys I just checked and... apparently my cromodora uno turbo have a ET of 47mm !
So for sure I have huge fat spacer on my X (havent taken off the wheel yet since I bought it)
So Im thinking going to the Cromodora CD30 route, and getting ride of the spacer... this would reduce weight by at least 3kg by wheel...
I think this would be huge to be honest !
However anyone would have soem idea about the original CD30 ? I mean, anyone here heard about these CD cracking or else ?
I have seen on another forum I can X-ray the wheel to see for cracks...
Steve Thomas
True Classic
If you are talking genuine OEM magnesium Cromodora, the there are multiple issues with heavy use. Magnesium, like aluminum, always fatigues plus magnesium also ages [degrades] and suffers from multiple types of corrosion. Any original magnesium wheel is a risk. If you want the CD30 look, there are modern aluminum copies. At a guess they will be lighter than your Uno turbo wheels anyway.
kmead
Old enough to know better
One of the things you see most often on magnesium rims is corrosion at the wheel centric hub area on the back side of the rim. The hub sacrifices the magnesium alloy (it is why hot water heaters use a magnesium anode to minimize corrosion of the steel tank).
That particular rim has a fairly thick edge to the rim so you don’t see the edges of the rim cracked off like you see on many other magnesium rims. I personally have never seen one cracked at all, what I have see is hub corrosion.
Like all things, buy the best ones you can find.
A search of this site and the internet in general will turn up multiple threads and articles on magnesium wheel refinishing and corrosion protection. There seems to be several methods using a disparate set of materials, but simply sanding and painting is highly not recommended. I have no automotive wheel experience but I do have 42 years of spacecraft and launch vehicle experience with magnesium and corrosion prevention is paramount.
Ulix
True Classic
No, the old CD30 is not prone to cracking, just corrosion, as mentioned above.
In theory, the old CD30s are supposed to be run with tubes in the tires, because they don't have a hump. Some Germans get hung up on that.
In terms of supension "setup", the message is that you don't need a lot.
Make sure your shocks are in good working order and the suspension rubbers are in good shape.
Even a stock X handles great and the ride quality is supreme with stock springs.
If you want to go faster and feel safer on turn-in, get a swaybar (there is only one type available).
After that, you can install lowering springs.
But my feeling is, if your haven't even removed your wheels yet, you should spend your time and money on a maintenance program, getting the car to perfect working order, before your jump into mods.
In theory, the old CD30s are supposed to be run with tubes in the tires, because they don't have a hump. Some Germans get hung up on that.
In terms of supension "setup", the message is that you don't need a lot.
Make sure your shocks are in good working order and the suspension rubbers are in good shape.
Even a stock X handles great and the ride quality is supreme with stock springs.
If you want to go faster and feel safer on turn-in, get a swaybar (there is only one type available).
After that, you can install lowering springs.
But my feeling is, if your haven't even removed your wheels yet, you should spend your time and money on a maintenance program, getting the car to perfect working order, before your jump into mods.
Lowtechprime
Retro Grouch
Those companies have mostly gone away who would x-ray a wheel for you, in California anyway... The only place I could find that would do it at all was a non destructive science test lab, but they wanted around $1,000....
Chromaphase
True Classic
Hi, thanks for the tips !
So do you mean I cannot put modern tire on the original CD30 ?
Yeah I have been working on my X for over a year, and finally everything is working real good, its for this I want to prepare it for some trackday and a bit of regularity rally.
I wont be crazy with it coz of my budget anyway, wont take big risk etc...
I took it for a mountain pass ride uphill / downhill and it feels all pretty good... my stock suspension is pretty good so I will let it as is for now thanks !
Chromaphase
True Classic
Guys, some photos of the one I wanna buy.
I just wish some very light wheel, if its to buy alloy then i would just buy Superlite one because they are half price of the CD30 alloy and look good as well.
These one are at 750 euros (kind of the same price of the CD30 Alloy) and they are in perfect condition.
Should I ask the vendor the contact of the one that repainted it ? So I can ask the method and be sure it has been done properly ? What would you do ?
I just wish some very light wheel, if its to buy alloy then i would just buy Superlite one because they are half price of the CD30 alloy and look good as well.
These one are at 750 euros (kind of the same price of the CD30 Alloy) and they are in perfect condition.
Should I ask the vendor the contact of the one that repainted it ? So I can ask the method and be sure it has been done properly ? What would you do ?
Chromaphase
True Classic
Ok Nevermind I read everywhere shouldnt use old magnesium wheels for any kind of racing...
I should go alloy even if its a bit heavier... ;(
I should go alloy even if its a bit heavier... ;(
Cut and paste because I’m old and lazy:
These magnesium wheels can be inspected by the Eddy Current method. Liquid penetrant inspection could be performed, but all of the corrosion on the surface would have to be chemically removed first (eched). Liquid penetrant can only be applied to a absolutely clean surface. Ultrasonic inspection is good for internal problems, but magnesuim generally produces surface defects first. Plus ultrasonic NDI is relatively expensive.
These magnesium wheels can be inspected by the Eddy Current method. Liquid penetrant inspection could be performed, but all of the corrosion on the surface would have to be chemically removed first (eched). Liquid penetrant can only be applied to a absolutely clean surface. Ultrasonic inspection is good for internal problems, but magnesuim generally produces surface defects first. Plus ultrasonic NDI is relatively expensive.
Chromaphase
True Classic
humm Im reading as well that if the car is stored outside, its even worse for the mag wheel in the long run, My X sleeps outside so I think I should avoid mag wheels...
Unfortunatly I cannot afford to buy them then X ray them or do other tests. Its too risky financially. However I will ask the vendor about the repaint process old these mag wheels and share here with you if I get it !
Steve Thomas
True Classic
That main surface [that sits against the disc/hub ] looks very corrosion pitted beneath the paint. Compare it to the inside of the spokes.
Chromaphase
True Classic
Thanks Steve,
Now I can see it, its very clear indeed,
Thanks for your feedback, gonna go for the CD30 replica gold, even if its pricier than the superlite, I like the vintage look more !
Steve Thomas
True Classic
Nice!
Good call on this. I think there is something hiding under the very heavy paint.