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Hey guys, just wanted to get some opinions on doing the 520 conversion. I'm not planning to put the RC on the track that often, so is there any real benefit of doing the conversion? I plan to get a dedicated track bike.


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Lighter weight where it counts. With aluminum sprocket it save a fair bit but aluminum wears faster. Just stay on top of chain adjusting, lubing and cleaning. I have had my Driven 520 quick acceleration kit on for 2k without issue

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I just replaced my 520 set. I got a DID and alum rear AFAM and Driven steel front. 15/42. It's an exact replacement for the last set that I got somewhere around 20,000 miles from.
This set-up is about 2-1/2 lbs. lighter than the steel 530 OEM. And that's rotational mass.
Definitely keep up on your chain slack and lube, but I wouldn't ever switch back to OEM for street use. I have no idea about track.
 

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If the 520 kit is a high quality kit it will generally outlast most OEM 525 or 530 chains if properly maintained. That's more of a by-product though of simply having a superior product installed as the main goal is weight savings. A typical 520 conversion from a 530 kit with an OEM steel rear sprocket usually saves about 4lbs of rotational mass which is quite a bit.
 

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If the 520 kit is a high quality kit it will generally outlast most OEM 525 or 530 chains if properly maintained. That's more of a by-product though of simply having a superior product installed as the main goal is weight savings. A typical 520 conversion from a 530 kit with an OEM steel rear sprocket usually saves about 4lbs of rotational mass which is quite a bit.
I gotta ask you if you weighed them to actually see the difference. I contend that there's about 2-1/2 lbs difference over a stock steel 530 set. Not 4.
I weighed my old set, it was about 4-1/2 lbs. Anyone know what a stock set weighs?
 

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I do believe that rotational mass is a different thing then stationary mass.....meaning something weighing 2 pounds weighs more when it's spinning ???
Correct me if I am wrong.....
 

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I would guess that using the alum sprocket would help the bike handle better because of the lower weight on the swingarm. But I'm just theorizing....
 

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I do believe that rotational mass is a different thing then stationary mass.....meaning something weighing 2 pounds weighs more when it's spinning ???
Correct me if I am wrong.....
It's a matter of physics, centrifugal force and all that shite I know soooo little about:eek:
The weight is the same, but it has different effects, see below.

Gyroscopic Precession
Gyroscopic precession is what happens when you are trying to flick the bike side to side and the wheels (since they are spinning) will resist the change in lean angle of the bike. The easiest demonstration on this is what every kid did at the local science museum: stand on a pedestal that is free to rotate, hold a bicycle wheel by the axle and have someone spin it. You can hold the wheel upright, but when you try and lean it over, it resists this motion and it will require much more force than the if the wheel is stopped. The pedestal you are standing on starts to spin because of this.

I would guess that using the alum sprocket would help the bike handle better because of the lower weight on the swingarm. But I'm just theorizing....
Yes, the lower the unsprung weight the easier it is for your suspension to react to changes in the road surface. Of course every ounce counts, but I wouldn't ever run an aluminum sprocket because the difference isn't really worth the increased wear. Unsprung weight consists of everything past the shock/fork spring (including part of the suspension itself). So that means the swingarm, wheel, rotors, calipers, pads, fluids, bolts. All kinds of stuff that adds up to way more than you would think.

The difference in weight between an aluminum vs. steel sprocket is so minimal that I would be willing to bet that nobody this side of motogp would be able to tell the difference in handling.

The place where you can really make a difference with weight is the wheel rim. This is why wheels like BST's can drastically change the handling of a motorcycle. This is because of the fact that the further the weight is from the axis of rotation (the axle in this case), the more effect it has on the moment of inertia of the wheel. And it is exponential when referring to the distance from the axis. Look at the left side below:




So if you were to take 200 grams off the sprocket (say 50mm from the axis) it would relate to less weight off the rim (at say 200mm from the axis).
I = moment of inertia, M = mass, R = radius or distance from the axis of rotation.
If I=M*R^2 (the R^2 means R squared), then
for the sprocket I=0.2kg*(0.05m^2) = 0.0005kg*m^2
for the wheel: I=0.2kg*(0.20m^2) = 0.008kg*m^2

In order to have the same change on interia as removing 200g off the rim of the wheel, the sprocket would have to remove much more, found by rearranging I=M*R^2 to M = I/(R^2) Using the I for the wheel found above, and the R for the sprocket, we can find the Mass, M required to get the same effect on inertia. So M = (0.008kg*m^2)/(0.05m^2) = 3.2kg. So we have 0.2kg removed from the wheel rim, or 3.2kg removed from the sprocket. That is 16 times the weight to get the same effect.
 

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I run a (well cleaned & maintained) 530 RK chain. Done about 15,000 miles so far, they're still OK.
Despite the calculations and weight differences, on a road bike there is no discernible gain in performance going to a 520. The is a bit less chain life & strength as a result though. Why reduce strength when there is no gain for the way the bike is used?
I'll be fitting a 530 again next time around.
 

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I run a (well cleaned & maintained) 530 RK chain. Done about 15,000 miles so far, they're still OK.
Despite the calculations and weight differences, on a road bike there is no discernible gain in performance going to a 520. The is a bit less chain life & strength as a result though. Why reduce strength when there is no gain for the way the bike is used?
I'll be fitting a 530 again next time around.
While you are probably correct about the discernible performance gain, that will vary from person to person. Another thing to think about is that not all 530 chains are the equal. A quality 520 chain will outlast a cheap 530 chain. The best thing to compare is tensile strength.

My main reason for going with a 520 was cost. I got a great deal on a 520 kit with A D.I.D. ERV3 with sprockets for $130. The normal prices on 520 chains are also lower when compared to a 530 of the same strength.
 

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While you are probably correct about the discernible performance gain, that will vary from person to person. Another thing to think about is that not all 530 chains are the equal. A quality 520 chain will outlast a cheap 530 chain. The best thing to compare is tensile strength.

My main reason for going with a 520 was cost. I got a great deal on a 520 kit with A D.I.D. ERV3 with sprockets for $130. The normal prices on 520 chains are also lower when compared to a 530 of the same strength.
I doubt anybody rides at the limit on the road enough, to honestly feel a difference between 520/530, really. Like for like, I'll just go for the best 530 chain. To me it would be false economy to have a cheaper but weaker / less durable chain. Not saying everybody should consider the same, that's totally up to the individual, but Honda put on a 530 on a road bike for a (good) reason.
 

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You know there's no difference in strength between a 520 and 530 chain right?
The pins that hold all the links together are the exact same diameter and tensile strength. The plates are exactly the same. Everything about a 520 is identical to a 530 in terms of strength and performance.
 
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