Flywheel ????

I have a 2008 CRF450r and I am a novice rider that likes to MX and Hare Scramble a little, can you tell what is the best weight flywheel that I should consider and do I have to complete any other modifications to my bike if I decide to increase the flywheel wt.???



The best weight is the one that does what you want it to do. What do you want to change about the engine?

If you want only to make it slightly "smoother" (tone down the snap) but no other noticeable differences, then you want a light flywheel (+5oz).

A 7-9 oz flywheel will be similar to stock, like the +5, but slightly less prone to stalling as well.

A 9-11 oz flywheel will slow down the off idle snap, and make it a good deal less prone to stalling.

If you want it to grunt like a diesel and not stall at all, then use the heaviest flywheel (+13 oz). It will feel pretty slow revving right off idle, but will pick up after 1/3 throttle.

I have a off-the-showroom-floor 07 and I will put a flywheel from an 02-03 on to take away just a tad bit of the snap (I think it's +4 oz ) until my arms get used to it. Then I'll go back to stock for MX.

I had an 11oz on my 04CRF and when riding back-to-back with and without it, it really smoothed out the low end and made it easy to ride. I rode it like that for about 1.5 years. But I got better and faster and ultimately I decided it was too much flywheel for MX.

If you aren't sure what you want, then go for the 9 or 11. Either way you'll be able to sell it pretty easily.

For any flywheel 11 oz or smaller, no mods are necessary. Just go to trail tech's web site and buy it, the puller, and the gasket (or buy it all from TT).

Thanks for the reply very thorough and helpful information.



Romans 10:9

Just remember 18oz is stock weight.

The heaviest Trail Tech flywheel is +17oz (35oz total) and requires grinding the case just a bit to fit.

I use a +15oz (33oz total) and love it off-road. I never ride track.

Unlike skthom2320 I think the bike still revs great with a 35oz flywheel, and I could not imagine Ohio woods with a smaller weight.

If you ride more track, go lighter. But off-road, nothing you can buy will be too heavy. Scott Summers used to weld a man-hole cover on his :busted:.

More info here...

Enjoy :thumbsup:.

Yep my bad. I was going off memory. I was thinking that the heaviest *without* grinding was the 13 oz.

As far as the "revving" there is no question that the CRF revs just fine and you hardly notice after 1/3 throttle with or without. But riding bikes back-to-back with and without a flywheel it is very obvious that the "snap" or off-idle rev is different. And it scales, for me anyway, like I described. Barely noticeable to tractor-like!

On my 2007 the 15oz trailtech is excellent. I originally thought it would be too much but it gives the bike nice midrange grunt that is great for single track and outdoor moto. It takes away most of the stalling. I think the 17oz comes with a case spacer. Cam.

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