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How much does an X crank weight ???

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Does any body know what the weight difference is between an X crank and an R crank, want a bit more snap from the X, have already made many mods and the bike will due a rod soon, should I change to an R crank?? Will it fit? :moon:

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dont know how much either crank weighs but both the crank and the flywheel on an X are heavier. The crank from the R is shorter on the clutch side(RS). Might try a lighter flywheel, maybe install the R flywheel on the bike.

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flywheel, if you tried to fir a R crank (if possible) you'd lose the e start capability, might as well just sell and buy a R at that point.

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_DSC2313.jpg

I had an extra one that I just got replaced when installing a big bore kit. Looks like about 5.5 pounds. This is an 06 X crank.

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Thats great, just need the weight of an R crank now. Not sure why it means the electric start will not work as the starter runs off the clutch!

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Thats great, just need the weight of an R crank now. Not sure why it means the electric start will not work as the starter runs off the clutch!

The starter clutch assembly is located on the RS of the crank. Can I ask why your interested in the weight of the crank?

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The starter clutch assembly is located on the RS of the crank. Can I ask why your interested in the weight of the crank?

I want the engine revs to pick up and slow down down quicker, I am sure it is possible to fit the R crank to the X as I know somebody in the UK that has done it without a problem.

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I'm pretty sure it will not work. The strokes are different.

The R- 76.8mm x 53.8mm

The X- 78.0mm x 52.2mm

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I'm pretty sure it will not work. The strokes are different.

The R- 76.8mm x 53.8mm

The X- 78.0mm x 52.2mm

I am sure that on the 08 models the bore and stroke is the same on the X and the R 78.0mm x 52.2mm.

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The difference in crank weights is located at the axis, not the throws, so has very minimal effect on the centrifugal force. Seat of pants you'd feel nothing.

You can use a R flywheel on the X, 3-4 oz lighter, you'd feel it. BUT your charging and lighting would be reduced. You can't really go the other way X flywheel on a R, the addition magnets for lighting plays games with the ignition.

Trailtech or Selthy might make you a light lighting flywheel, or lighten and rebalance your stocker.

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Yeah it would be noticeable, I think there would be more than a 3-4 oz difference in weight. The outer intertia ring on the x flywheel is a big piece of iron, the r flywheel doesnt have this. Although I havent tried it, the best of both worlds would probably be to machine some of it off, not all of it. Still shouldnt be too expensive to pick up a used r flywheel and give it a try to see how it works for you.

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Gday mate just wondering if you went ahead with the r crank in the x. I recently bought a 04 crf 250x of a mate for cheap as it has done the bottom end. Was hoping to put a R crank in it. Any ideas?

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Given the differences noted previously, you'd almost certainly be better off having a competent engine builder lighten and rebalance your x crank and reduce the flywheel inertia.

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