flywheel lightening

[PEPwalshZ440]

Hey everyone,
just to let all of you people know who were wondering about flywheel lightening, duncan racing does it for $75!!

[sparky450AR]

This creates higher and faster revving, but does it have a negative affect on torque?

[Toadz400]

Originally posted by sparky450AR
This creates higher and faster revving, but does it have a negative affect on torque?

I'm wondering about that too, because you lose the ability to lug around at low speeds so wouldn't you think it would take away torque too because of the lost weight?

[PEPwalshZ440]

i'm not positive but i don't think it does, i'm gettin it done soon i think. That and an ignition.

[#1speedbump]

the only concern I would have would be that this would increase the easiness of stalling the motor. Duncan could probably tell you how it effects the torque

[dn1911]

i've done alittle reaserch on the whole flywheel thing, because i would like to add weight to mine.

if you lighten the flywheel it will rev faster and help with acceleration, but you loose some of you internal eninge enertia. making it easier to stall out. now if you ride mostly sand and maybe MX this might work for you but on this bikw i think heavier makes the most sense.

if you go heavier then gain a large amount of lugging ability great for tight woods. they also say it smooths up powder delivery and increase traction at take off by reducing wheel spin.

here are a couple of good sites for flywheel related questions. now neither have something ready for the R i was told a month on R&D, but that was about 3 weeks ago. i'de give them a call to see how there doin.
trail tech (http://www.trailtech.net/flywheel.htm)
steahly flywheels (http://www.steahlyoffroad.com/about_steahly.shtml)

[sparky450AR]

Originally posted by dn1911
i've done alittle reaserch on the whole flywheel thing, because i would like to add weight to mine.

if you lighten the flywheel it will rev faster and help with acceleration, but you loose some of you internal eninge enertia. making it easier to stall out. now if you ride mostly sand and maybe MX this might work for you but on this bikw i think heavier makes the most sense.

if you go heavier then gain a large amount of lugging ability great for tight woods. they also say it smooths up powder delivery and increase traction at take off by reducing wheel spin.

here are a couple of good sites for flywheel related questions. now neither have something ready for the R i was told a month on R&D, but that was about 3 weeks ago. i'de give them a call to see how there doin.
trail tech (http://www.trailtech.net/flywheel.htm)
steahly flywheels (http://www.steahlyoffroad.com/about_steahly.shtml)

Thanks for the info DN! Trail tech says a heavier flywheel will idle better, and the bike will be harder to stall. The only way I can think of it being harder to stall is an increase in torque. You say if you lighten the flywheel, you lose internal engine inertia. Torque is what keeps that inertia going, and it seems to me since a heavier flywheel does the opposite of a lighter, make it harder to stall not easier then it creates torque. Remember torque isnt just wheel spin.

I'm learning here, so correct me if im way off.

[PEPwalshZ440]

thanks! i still wanna get it haha

[440ex kid]

How exactly do they lighten it? I have a few cnc machines in my garage and I think I could do this myself. Do they just machine some material off or what?

[PEPwalshZ440]

yea they pretty much just take some of it off

[FatBoy Racing]

hmm... seems to be a good case to get it lightened . . . also a pretty good case to go heavier . . . then again, leaving it stock is free and seems to be a pretty good mix between the two. For my 4 bux, my best mod for the flywheel is no mod. Who woulda thunk you could do well leavin' sumthin alone?

Thannks for the info guys!

[trailtech]

Here are few tips on flywheel weight:

For the TRX450, if you ride woods or race GNCC, think about a heavier flywheel. If you ride sand/drag race AND do not currently have a problem with rough idle or stalling, then think about a lighter flywheel.

Flywheels give the motor rotational inertia. Bigger flywheel = more rotational inertia. If you go too low on rotaional inertia, the motor will stall easy, idle rough and in some cases (like the CRF450) it will pop and backfire thru the carburator at low rpm. Some of this can be corrected with jetting but in the limit, jetting will not replace the inertia the flywheel provides.

In either case, the best flywheel is a one piece, dynamically balanced flywheel. Bolt on weights throw off your balance.


Regarding shaving the TRX450 flywheel, it is a bad idea. If you pull material from the back face, you cut thru asymetric holes and this WILL throw your flywheel out of balance - VERY BAD IDEA.

If you have a dynamic balance machine, then this can be corrected but you should ask the person who is doing you flywheel is they have dynamic balancer before you let them cut on your flywheel. If the answer is no, call someone else.

If you cut from the OD where there are no asymetric holes, you are working ona face that is already less than 1/8" thick - there is a risk that your flywheel might come apart.

By the way, we are not done with the TRX flywheel. We dynamically balance our flywheels because we have seen the results of unbalanced flywheels - in some cases, it will cost you a motor.

[sparky450AR]

Originally posted by FatBoy Racing
hmm... seems to be a good case to get it lightened . . . also a pretty good case to go heavier . . . then again, leaving it stock is free and seems to be a pretty good mix between the two. For my 4 bux, my best mod for the flywheel is no mod. Who woulda thunk you could do well leavin' sumthin alone?

Thannks for the info guys!

I agree, i do every type of riding imaginable, so mine will stay stock. But theres nothing wrong with learning about it!

[PEPwalshZ440]

duncan when they do this they rebalance it, they wouldn't send you something that would mess up your engine. I ride only MX so this would benefit me having less flywheel mass.
Mike

[dn1911]

hey trailtech when can we expect those flywheels to be ready? i want one for mine.

[PEPwalshZ440]

Originally posted by dn1911
hey trailtech when can we expect those flywheels to be ready? i want one for mine.
me too!

[bigz-71]

i lightened my fly wheel on my 400ex, and it did fine. i will probably do the same for my R.

[fx1]

I have both +4oz and a -4oz flywheel from trailtech For my YFZ great quality product and custumer services

the +4oz I use is for winter trail ridding it give better traction and smoother acceleration and it's hardier to stall at low rpm

The -4oz it rev to the moon in heart beat very much snapier,hard acceleration,great for sand pit/dune and everything who dosn't need extreem low rpm I prefer this one by the way :D

[dn1911]

quote:
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Originally posted by dn1911
hey trailtech when can we expect those flywheels to be ready? i want one for mine.
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me too!

any ideas yet?

[trailtech]

We are testing them now. It is hard to promise an exact date - assuming no problems, we will be done in three weeks.