*PICS* of Machined SRX Rotor! Sweet!

Yep, it's all good!! :WayCool:

I've spent a load of cash trying to make my 440 lighter and more efficient trail sled. Boss seat, BR Tech plastic hood (5lb?) lighter silencer only saved me 3lbs, oil injection yanked out including oil tank, lighter air box, lighter motor mounts and that SLP wave rotor... crap I don't remember it all now but there is more and some things I've done have added weight. I'll weigh it one day and probably fall over finding out I didn't gain what I hoped for that money spent, but it will still be a gain regardless and I'm sure I will feel it.

This is a great site, lots of good, helpful folks here and I've enjoyed every minute I've spent here. I only wanted to clarify I wasn't trying to be a knob because currently I ride a Cat and it does show in my info there. Didn't want anyone thinking I was here to stir it up.
 

The intended reason for a drilled or wave rotor is improved braking performance. The weight reduction is a secondary benefit.

The holes in the rotor should be sharp edged -no chamfered edge. After drilling the rotor, I did no deburring at all. Installed the rotor and ran the sled with the rear suspended and held a flat knife sharpening stone against the rotor while it rotated. Could also be done in a lathe, but I don't have one.

As Jeff is saying, the diameter at which the weight is removed will change the effect of the weight reduction. RPM will also have an influence. It will not be that there is a flat 1 lb to 10 lb gain. It may be 1 to 10, but it may be 1 to 3 -or 1 to 17 .... every different item and reduction is going to have a different effect. If you removed 1 lb from the hub of a wheel it would have much less of an effect as removing 1 lb from the outer diameter.
 
guys not sure if this makes sense or not but wouldnt a good example be adding or removing wheight to a crankshaft.. go lighter and the engine revs up quicker go heavier and it revs slower must have same effect on any rotating mass
just wondering
Pat
 
Jeff H said:
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.




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.




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.



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.



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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Jeff is absolutely right with his train of thought, as is Junior. Rotational inertia (and therfore the force required to rotate an object about an axis) is proportional to the mass, and proportional to the square of the distance that mass is from the center of rotation. They are exactly right with their explanation of why taking say 2 lbs from a track will have more effect than 2 lbs from a 2cm diameter rotating shaft. It is because of the variable of where the mass is located relative to the rotational axis. 1lb rotating mass = 10 lbs stationary mass is a WAY simplified statement as someone already said. This may be what somebody found to be some type of "average" effect to make a correlation between the static and rotating mass, but it definately is no hard and fast law of physics. Virtually every different mass/rotation system will have a different ratio of effect on the force to put the system into motion. But also at the end of it all, Don is right with his statement that no matter how you calculate it, subtracting mass is going to increase the acceleration of the system, and therefore make the sled quicker and faster on an absolute scale.
 
Wow!

I am not an engineer or physics guy, but you just toally blew my mind.

In any case, I like the CB guys and they will be tweaking the "s" out of my '02 SRX this Fall.

BigMan76
 
did you guys notice any stronger or more positive breaking with this rotor? want to upgrade my brakes for more feel and better breaking, any thought besides this rotor? still excited to order my sway bar from you guys after the wedding (2 weeks away!!!) thanks!
 
03viperguy said:
did you guys notice any stronger or more positive breaking with this rotor? want to upgrade my brakes for more feel and better breaking, any thought besides this rotor? still excited to order my sway bar from you guys after the wedding (2 weeks away!!!) thanks!
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if you really work the brakes hard enough to induce fade, then yes it will help by giving some of the gases an escape path instead of keeping the pad from the rotor. normal riding, i doubt you will feel any difference.
 
To make this worth your while at least start with the lightest brake rotor available which is the viper unit/srx01-02 rotor, this is the lightest one yamaha offered and will interchange on any proaction 2 stroke sled back to 97.
 
mrviper700 said:
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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This is why I love Don. Love to see guys challenge him (sorry Don). Every Forum/Blog has a guy who is the smartest guy they know and will challenge the resident guru. Love it!!
 
SRX_700 said:
This is why I love Don. Love to see guys challenge him (sorry Don). Every Forum/Blog has a guy who is the smartest guy they know and will challenge the resident guru. Love it!!
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Holy old thread batman.......... I am certainly not the smartest person, I just work on these things everyday and have put a few together 1 or 2 over the years that keep up with the local traffic.... :dunno:

back to the question, Get a hold of srx2000, they did a nice job on that rotor.Sure they can hook ya right up with one.
start off with a 2001-02 srx or any year viper rotor(same) and put on a aluminum brake hub and you should have a pretty light unit there.
 
They've done a ton of work for me; just was bored at work and reviewing old threads that I had favorited; somehow had forgotten about this one (and I had my SRX just at CB for a few weeks of storage while we rearranged our warehouse shop area too (doh!)
 
mrviper700 said:
Holy old thread batman.......... I am certainly not the smartest person, I just work on these things everyday and have put a few together 1 or 2 over the years that keep up with the local traffic.... :dunno:

back to the question, Get a hold of srx2000, they did a nice job on that rotor.Sure they can hook ya right up with one.
start off with a 2001-02 srx or any year viper rotor(same) and put on a aluminum brake hub and you should have a pretty light unit there.
Click to expand...


So 01-02 had a aluminum hub right. If so how much lighter? Actually I am looking for a wave hub and rotor for my prostock.
 
no, later srx/vipers had a steel everything. the section center section has way less material in it as well as less unused disc material where the pad touches. If you wanted to run a stock rotor, the lightest you could get is this one, then buy the aluminum hub to bolt it to. Then if you wanted to lighten it more, you could have it drilled. Though I doubt all of it together would come close to being as light as a wave. for trail riding, it is a big wast of time, don't bother. you would see no gain. if your drag racing, that is where you see differences in acceleration by dropping spinning weight. The further from center the mass lost, the bigger the gain. Also is the speed of what is being spun. the brake is accelerated to roughly twice the speed of the drive shaft so losing two pounds from the brake disc is a greater gain than losing two pounds on the drive shaft. Lightening the secondary is another great area. For drags, remove the windage plates, for lake racing, keep them on or buy carbon ones. As I remember, they weigh 1/2 lb. There are some areas of the secondary that can be machined to remove weight as well. It is amazing how much you can remove when you try. from one year to the next, my viper lost over 5lbs of spinning weight, I think I gained 20lbs that year so not sure if I saw any real gains other than on a scale.
 
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