How to determine the correct sprockets and chain when converting

Why change to 530 chain?

Two main reason:
Cost savings - the 530 chain tends to work out about $10-$15 cheaper.
Weight saving - this is less mass the engine has to drive - and this tied directly with HP to the rear wheel.

A third reason is chain options - you can get more colors of 530 chain, and more variety of O Ring types.

In converting, it is fairly easy to calc the 530 sprocket sizes (see below) - but then you need to match against the availability of sprockets. If you want custom sprockets, Sprocket Specialists can make just about any size rear sprocket in aluminum - the caution here is cost and wait - depending on the time of year, you can wait 3-4 weeks for a custom sprocket, and may pay $10-$15 or more over the cost of a steel sprocket.

630 chain is 3/4" pitch (or think of it as 6/8"), 530 chain is 5/8" pitch - so the simple conversion in teeth is divide the 630 sprocket teeth count by 5 and multiply by 6.

630 15 tooth front becomes a 530 18 tooth sprocket.
630 35 tooth rear becomes a 530 42 tooth sprocket.
92 link rear chain becomes 110.4 links (rounded to 110).

The sprockets are the same diameter as before, just with more (but smaller) teeth.

Often you end up with fractions of teeth - these you have to round up or down - the key here is to calculate a ratio close to the ratio you require...

Click to read more on calculating sprocket sizes

To be able to easily convert from 630 to 530, you have to find sprockets with the same mount attributes.

For the rear sprockets, this means having the same center size and bolt spacing.  The following two sprockets have the same 80mm hole spacing, bolt centers 104mm apart and bolt holes 10.5mm in diameter.

For the front sprockets, the center spline size and teeth count must match to be able to swap the sprockets - the Z=13 shows the spline count and the 25mm & 21.6mm show the diameter and depth of the teeth.

Sprocket spacing is important too - on the two front sprockets above, you will see the 630 version has a slight boss (raised area) to the inside - to be able to switch to the 530 equivalent sprocket, spacers must be added to give enough clearance between the chain and the engine cases.  We sell spacers from both sprocket specialists and JT Sprockets - the JT sprockets spacer is 6mm, the Sprocket Specialists version is 1.5mm.

JT Sprockets has an excellent reference - click on their link below.  This shows the attributes for each sprocket - and from this you can look at other bikes sprockets and be comfortable the sprocket will fit.
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