*PICS* of Machined SRX Rotor! Sweet!

2ooosrx

2ooosrx

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Oct 2, 2004
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Gurnee, Illinois
Website
www.cbperformanceparts.com
Hey guys, Fresh out of the CNC is my "New" rotor. This thing is absolutely sweet now and I will fill you in with the facts. Okay, before I machined anything on this rotor, it weighed in at 4.479 pounds stock. After a little programming on the CNC and waiting for the cuts, the rotor was finished. Now as you can see in the pictures, the rotor looks much better IMO and it now weighs in at.... Well look at the picture and it will tell you. The weight loss of the rotor comes in at .561 Pounds which I did not think it would take out that much. Anybody who is interested at all in having this done to your rotor, send it in to us and it will be $99. Let me hear what you think!
 

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if ya start with a 2001 brake rotor would be lighter yet, and now add a bender aluminum brake hub for a 2lb weight reduction! the stock cast center hub is very heavy.
 
well each pound of rotaing weight is equal to 10lbs of staionary weight. So if you can remove 2lbs here thats like taking 20lbs off the sled, I guess I will say yes, but its not the same as say adding 15hp to a sled, that ,you can feel alot more if you took advantage of clutching to apply the extra 15hp that is.
 
Thanks Don, it makes sense. I am running out of trailable 15hp increases since your porting is already done. Hey Bruce, any plans on making your own aluminum brake rotor? I know you're already a Bender dealer, but just wondering.
 
We may make the aluminum hub shortly however, we will not make an aluminum rotor. LOL We tried that back in the 70's just for fun with our drag sleds and it worked great...until you hit the brake. First time we touched the brake, the track locked up. lol
 
2ooosrx said:
We may make the aluminum hub shortly however, we will not make an aluminum rotor. LOL We tried that back in the 70's just for fun with our drag sleds and it worked great...until you hit the brake. First time we touched the brake, the track locked up. lol
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Yes aluminum is very soft I can just imagine how much the pad gripped the rotor I bet that was fun, did it tear up the jack shaft?
 
How much of a factor is diameter in this equation? Taking 2lbs out is still taking 2lbs out of the big picture, which is good as long as it's part of total weight reduction package aimed at shedding weight altogether. I'm not convinced it is like removing 10lbs of stationary mass though....not at that diameter. I don't think there is a damn thing to be gained in rotational circumstances with lightweight shafts either, but still....losing a few pounds anywhere is good as long as structural integrity is there.

I just installed a SLP wave rotor on my sled and I don't think I'll "feel" a damn thing from it in terms of power to the track gained from rotational mass reduction. It is just part of a weight loss package thrown at the whole sled as far as I'm concerned. I could be wrong, but the diameter question lingers in my mind.
 
JeffH, take a cement block and tie it to a rope 4 inch long and swing it around your head, now take a 1/2 cement block to the same 4 inch rope and see if its not easier to swing, you didnt change the diameter, just the weight.....

Anytime you reduce rotating weight, that weight is multiplied when its rotating, say a studded track versus a non studded track, great big differance there, the differance in topspeed acheived will be very large!!

Same thing here, anytime you can reduce rotating weight it makes the machine easier to get up to speed faster. Thats why they make titanium shafts and aluminum drive gears,lightweight brake rotors, lightweight carpet tracks for speed runs, etc.

the rotating weight is true, your entitled to your own, this is fact. 1lb of rotating weight is equivalint to 10lbs stationary mass replacement.
 
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I Agree with Mrviper 100% and always have noticed the difference in rotating weight over stationary. The belt drive we are throwing on my sled is going to be huge savings. When finished, the belt drive alone will be 2-3 pounds lighter then stock (gears and belt are .7 pounds lighter then stock gears and chain). We are also going to use a aluminum drive axel to go with the belt drive and run a spline through the entire lower gear to hold up. We may tinker next year with a titanium jackshaft. Rotating mass is HUGE!!
 
mrviper700 said:
JeffH, take a cement block and tie it to a rope 4 inch long and swing it around your head, now take a 1/2 cement block to the same 4 inch rope and see if its not easier to swing, you didnt change the diameter, just the weight......
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Huh? Thats not the same dude. A brake rotor is a uniform rotating object. There is no centrifugal force involved unless its fit on the shaft is sloppy and if thats the case you got other problems. A shaft is the same thing. Ok, none of this really matters though, and it's not important in our quest here. I'm not trying to be a jerk and argue, don't take me wrong on this. It's just there is a world of difference with centrifugal force rotation.


mrviper700 said:
Anytime you reduce rotating weight, that weight is multiplied when its rotating, say a studded track versus a non studded track, great big differance there, the differance in topspeed acheived will be very large!!.
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I don't doubt the example of a track, and the result will likely be bigger per lb reduction then equivalent reduction to a brake hub or jack shaft. Thats what I'm saying. I don't think we can blanket statement everything that spins on our sleds. If you tried to apply the exact same equation to a rotating track as a rotating jackshaft I don't think it would work out to the same result. A track will have a centrigual effect to it also, they "balloon" as you speed up right??. Studs only compound that effect. So many people think studs are directly correlated to speed but if you consider all angles on them it's not the real case. They have detrimental effects on speed. They are kick-*** for slowing down though!!! hey we all need the traction but we lose a little bit right along with that, right?

Going further, like stated before the rotor is a uniform object ( it damn well better be). It's weight is not multiplying with rotation because on a 180 deg axis there is a canceling force of the weight. The concept of of the correlation between rotating mass and it's equivalancy to static mass comes from the fact that if you lighten the rotating mass it's easier to spin or takes less hp to do it. It has nothing to do with the weight multiplying in rotation unless you are discussing centrifugal aspects...and thats not our case with a fixed brake hub or rotor. Although it can be with our track. See, there is a LOT more variables involved then a blanket marketing statement will show. Seriously, pose this quest to a full on mathematician and you'll have a different answer I bet. In fact, how does he factor in bearing efficiency loss etc for any given application. A bad bearing is going to make that shaft harder to turn. LOTS of variables involved and I'm just blowing stuff off the top of my head here.


mrviper700 said:
Same thing here, anytime you can reduce rotating weight it makes the machine easier to get up to speed faster.
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I agree with that, it has an effect but it's not a proportionate deal in all rotating parts. Diameter and Mass both are involved or you will have a one sided equation. I'm just saying there is more to it then just mass.

mrviper700 said:
Thats why they make titanium shafts and aluminum drive gears,lightweight brake rotors, lightweight carpet tracks for speed runs, etc..
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I don't doubt this. I'm not saying it makes ZERO difference but I am saying that a jackshaft won't have the same effect on static mass reduction/equivalancy as say... a track will. A 2lb reduction to a track is not going to be the same as a 2 lb reduction to a brake hub/rotor.

mrviper700 said:
the rotating weight is true, your entitled to your own, this is fact. 1lb of rotating weight is equivalint to 10lbs stationary mass replacement.
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Hence our blanket statement...This is advertising or marketing ad hoc made to simplify the connection. It's not true in all cases. I would rather take 30lbs off my sled then add a 3lb lighter jackshaft. I don't think the results would be equivalent ala our blanket statement and I think the 30 lb lighter sled would kill it...especially if it was unsprung mass. How much of a track is unsprung weight?? Intersting huh? What does a reduction in rotating unsprung weight amount to in static weight equivalency?? Does the equation appear as the same for a simple uniform rotating object?

I am no expert on this and everything I just said could be wrong but I guess I'm just not the type to accept things at will because so and so said it is this way and only this way. The consumer is a gullible person. Sometimes simple concepts can be exaggerated because it's easy for the consumer to grasp....and they run with it. I'm not questioning anyone here or their knowledge, I'm just stating my position as to why I don't agree with all of it. I have a great interest in this because I've been on a quest to reduce the weight of my own sled and man it's expensive. Hell, I'm not even sure anymore of half of what I just said. It's an interesting topic though and it's giving me brain warp just thinking about it.
 
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Rotating efficiencies of items like brake rotors and axles can be improved by reducing the weight but it shows up mostly in the drivelines ability to accelerate.
 
Jeff H, you're 100% correct, diameter has a squared effect on the force necessary. this is why a track will make more difference than a jackshaft, and why the jackshafts have never sold well with anyone except the racers, still a reduction yes, but not nearly as effective as some of the larger pieces.

to do the quote feature properly, you need a square bracket when you open the feature, like [ Q U O T E ] <text here> [ / Q U O T E ] without all the spaces.

the blanket advertising statement of the 1:10 ratio is tricky at best. the difference in track hp on the machined rotor with a 1/2 lbs difference will be similar to the difference on the hub with a 2lbs difference because the diameter on the rotor is 2x as large, and diameter has a squared effect.
 
sxviper32 said:
...hehe, carbon fiber....
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CF doesn't really hold up to high temperatures well, there IS a carbon composite that works extremely well for braking, it's dynamic coefficient of friction actually increases as the temperature rises, meaning that it has "reverse fade" common in F1 cars and GP bikes, but as far as I know the technology is rediculously expensive (think upwards of $12K/rotor) and a very well kept secret, was first used for stopping bombers, to allow them to use shorter runways for landing.

tons of info on carbon brakes and there history on the net, just google it if you're looking for more.
 
Sorry about that Junior...got 'er fixed up now though. I guess I didn't get that other bracket when I copy/pasted it.

I have an affliction to Carbon Fiber. My YZ 250 has a load of GYT-R CF accessories on it. That stuff just gives me the willies ya know. So cool looking. So light. Stronger then ****. I want a CF tunnel for my sled, $1200+ and the dream comes true!!!

I think driveline efficiency is king. There is a lot one can do to improve this or ensure it's at it's best. One thing I've been wondering about is the efficiency loss involved in the chain and gears. My gears were 19/39 with a 70 pitch chain. For the heck of it, I've got 22/45 gears and 74 pitch chain in it now. My 45 tooth gear is a LOT lighter then my 39 was. I have not weighed the entire mess so I don't know about any weight differences, but that was not my concern in this quest. I figured the chain would roll easier with the larger diameter gears, making the entire mess more efficient. Anyone try this before or know anyone that has....any comments?? I'm not sure it will make any difference and the only way I could tell is to run both setups on a track Dyno I suppose. I'm guessing any advantage may be really small but figured I'd try it anyway. If nothing else the chain should last longer right??
 
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ok well lets use this example then: you put a torq meter on the end of your jackshaft, and it takes "x" amount of force to turn the shaft, now lighten up the componets on that shaft and it takes less force to turn that same shaft given all the other things stayed the same. Most of the force saved will be at the begining of the first revolution, as it took less power to turn the lighter objects on the same shaft. As far as it moving, it also will have a effect, I was trying to give you a lamen term example, but its called flywheel effect, the heavier the objects on the shaft, the more force it gains by simple momentum.

I have no ad claiming anything, nothing to be gained by myself. Someone asked I supplied a answer. You can divide this into that, add the lunar polarity effect, divide by the coefficent of nickel content in the shaft or whatever, but a lighter brake hub/rotor and along with jackshaft and driveshafts are faster, plain fact. Its proven all the time at the races. Can all this be used for a simple trail sled, well maybe not, but the benefit still applies within reason. Less weight is free power.

I didnt take it as you wanted to argue, this is a free country, everyone is entitled to thier own opinion. Nice job posting, I like to read good information, others view points. Sometimes here we have all kinds of engineers on here, yet, in real life they drive bread trucks. I work on sleds for a living, so my views,opinions is real world applied views. thats all.


As far as your gear chain combo's yep, the larger sprockets provide less drag then the smaller ones do, the chain isnt bending nearly as hard as it is with small sprockets. It goes along the ways of track drivers as well, when you go from simply 9 tooth stock drivers to 10 tooth drivers, it makes a huge differance in the way the track rotates, does not take nearly the force to turn it by hand as with the smaller drivers, chaincase is same thing, you can feel this when you dont have a track on the driveshaft and spin the secondary clutch by hand rotating the chain/geras,jackshaft/driveshaft assembly. I think this is that way with about anything, even clutching, thats why the sled will be faster in a given distance from point A to point B when its in 1:1 drive ratio, the belt doesnt bend as hard in either clutch. Like ya said, free up rolling resistance.
 
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