520 chain conversions and aluminum sprockets

[Frank B]

Haven't had either one on any of my bikes but thinking about it for my RD400.
Is it worth it? Lighter chain, lighter sprocket, but can it make a difference on a stock-ish bike? I'm not running a wider tire so I don't need extra clearance

[pdxjim]

If you need a new chain/sprox, then going 520 is a good idea, but I wouldn't do it just to do it.

[Frank B]

Oh I need them, definitely a chain and rear sprocket. Front was changed in the past with a 16t.

[oxford]

I would suggest if you do go with an aluminum sprocket to get a good quality one and it will last a long time.  I got mine from PBI.

[pdxjim]

Yep.  Running a PBI 520 conversion on my KH400.

They are right down the road from me, so I got a tour of the factory and some swag when I went to pick em up.

[e30 gangsta]

520 is the way to go, although I have a 530 on mine because the kit was cheap lol.

[Economy Cycle John]

The 520 set up will save about 3lbs of unsprung weight. We do them with the rear aluminum sprocket hard annodized, lasts much longer. Also you need to shim the 400's when you go to 520. We have a kit for that as well.

520 Kit
https://www.economycycle.com/shop/yamaha-rd250350400r5ds6ds7-parts/520-chainsprocket-conversion-kit-for-rd250350400/

Shim kit for the 400
https://www.economycycle.com/shop/yamaha-rd250350400r5ds6ds7-parts/rd400-all-520-conversion-shim-kit/

[Frank B]

Thanks
So both the 400 sprockets need to be shimmed? Even though the listing for the front sprocket says it has the correct offset?

[Jspooner]

Thanks
So both the 400 sprockets need to be shimmed? Even though the listing for the front sprocket says it has the correct offset?

You don't shim it because of offset. The shim is on the front side so that the counter shaft nut will tighten all the way. The rear is also shimmed on the front side so that there is no slop between the sprocket and the original shim and cir-clip.

[Frank B]

Clears it up, thanks! 

I've always just used stock replacement, other than just a tooth less on the front.

[Gill]

If I remember it right, for 350 you can use 02 front sprocket special washers in case you are using 520 chain and for rear you are good to go as it is with aluminum sprocket.

[Organicjedi]

Science has proven more rear wheel HP with a 520 chain.

https://www.superstreetbike.com/does-520-chain-conversion-increase-horsepower-mythbusters#page-3

[m in sc]

yup. 520 is the way to go. If i could have swapped to 428 on the lightweight i would have, but the chains cant handle the HP. weight savings would have been fantastic.

On a side not, if you do wheel conversions, the offset ft sprockets get limited with some splines. just .02

[bizzcb1100f]

I bought a set of 520 sprockets from economy cycle, rear was hard anodized aluminum, after close to 4k miles it seems to be holding up well.

[Dvsrd]

I bought a set of 520 sprockets from economy cycle, rear was hard anodized aluminum, after close to 4k miles it seems to be holding up well.

I have been using anodized 520 rear sprockets on my 680 kitted Ducati 600, which is pretty hard on chains and sprockets. They generally last a bit over 9000 miles/ around 15000 km. And I tend to let the desmo roar whenever possible