lightened flywheel??

[benny hedges]

having done this on other bikes with nice results, ive just bought another off ebay...
last one i bought the guy i gave it to for turning made a right pigs ear of it and made it look like a metal egg
bike would've ridden like a rampant rabbit...

the idea is to give better pick up and it does work... as long as it's still balanced, so the question is, is there an optimum weight for the flywheel and is it possible to remove so much metal that the genny doesn't work proper?

i'll be turning this one down myself lol

[Phil-VTwin]

Have a word with Steve at http://www.vibrationfree.co.uk/ removing metal from a crank is certainaly not something i would attempt myself

[benny hedges]

Have a word with Steve at http://www.vibrationfree.co.uk/ removing metal from a crank is certainaly not something i would attempt myself

why not lol??? where's your sense of adventure???
all i'm doing is taking 6-8mm off, losing nearly a kilo off the flywheel, makes it rev like a cr lol
i'm sure someone else here has done the same, it's either the canadian modding chap or rama?

i boast to being pretty pro on the lathe & miller and if i crouton it up no biggy as it's a spare one.
the last one i gave to a m8 and he didn't mount it proper, but i found a motor shaft with the same diameter and it should bolt up good & proper - easy.
i don't mean grinding the crank counterweights btw, just the flywheel behind the timing cover.

2 strokes??? used to do the cranks all the time - learnt to port & mod off karting king terry shepperd, author of many books on 2 stroke tuning and the man behind champions, he ported my peds and it went from there.... little things like packing the balancing holes with winecorks full of 2 stroke oil to raise primary compression, weigh the corks and drill out the same amount of metal till it spins free...
when i did it they still shook themselves to bits but what a buzz!!!

[tony.mon]

Check out the "time for stage 1" thread on Superhawks forum, a guy called Flo2Supahawk996 has some useful info, and Mikstr has some experience, too.

[Phil-VTwin]

Ahhhhh right, flywheel, gotcha, for some reason I was thinking crankshaft lol

Let us know how you get on

[benny hedges]

looked at that thread tony - seems there's some good talent there...
i noticed mikstr & rama's posts on there and yes they do run lightened flywheels - so if they read this i'd appreciate their comments before i start taking metal off.

agree with rama, i don't mind removing the timing marks as i have a standard one to use if i need to set / check the timing - but i am concerned about taking off so much metal that the genny won't work...

seems one guy took off 5.4lbs - that would rev up ace!
another concern is if it would lose the characteristic v twin grunt???
i don't want it to end up just revvy like a il4, but tbh i don't see how lightening the flywheel can take away the torque, should just make it come on faster and hit the redline sooner, especially wiht the advancer?

might give roger a call

btw while i was reading various posts i came across this -----> http://cgi.ebay.com/ebaymotors/JE-PISTO ... enameZWD1V

looks like i might have to sell my cbx to fund all this lol if i decide to take it all the way, cams, pistons etc...
also had really good results before polishing the carb bores... very easy to do and makes a big difference - like fitting a bigger carb!

[mik_str]

Hey, the "canadian modding chap here"

I am undeed running alightened flywheel and have been for abour four years now. Mine was machined by Roger D (bout it on eBay UK and had it shipped directely to Sir Roger). He took care to have it balanced for me too. While not cheap (postage is what killed me), I know it was well done. AS for the gains, the engine spools up noticeably quicker and I have no intention of going back to the stock (heavy) unit.

Give Roger a call, he can either machine it for you or give you the precise specs needed to do it right.

[tony.mon]

My cams are being re-profiled for about £100 all in, but we'll have to see what (if any) difference it makes before offering the details out.

It's a lot cheaper than buying a decent set, so as long as I get anywhere near the same power gain I'll be happy enough.

[benny hedges]

Hey, the "canadian modding chap here"

I am undeed running alightened flywheel and have been for abour four years now. Mine was machined by Roger D (bout it on eBay UK and had it shipped directely to Sir Roger). He took care to have it balanced for me too. While not cheap (postage is what killed me), I know it was well done. AS for the gains, the engine spools up noticeably quicker and I have no intention of going back to the stock (heavy) unit.

Give Roger a call, he can either machine it for you or give you the precise specs needed to do it right.

cheers mik lol, could not for the life of me remember your name!
i work in lancaster a few days a week so might call in and have a word with rd, and also while i'm there book the dyno next door!
got access to a good machine shop so will probably turn it myself, just wanted to know optimum weights etc - expecting the results you say

[benny hedges]

cams .

cams will have to wait for now - i'll be doing them same time as hc pistons so might buy the lot as a kit....
still pondering whether to buy another engine to mod or use the one i have now.
i'd rather get the spare one but means i'll have to sell a bike

[benny hedges]

2 replacement flywheels turned up today - off they go for turning down!
if i end up with one surplus to requirements i'll put it up on here

[benny hedges]

spoke to roger from revolution and he said he'd mail me his drawings to get this done - he just uses a local firm.
as i'm in the area i'll probably use the same firm seeing as they've done the job before.
he posted the specs on superhawk.com so with his permission i'll post them here for future reference
http://users.fdn.com/~dward/SuperHawk/V ... heel-1.pdf

looking at cutting it down by 25mm and removing 15 - 18mm off the diameter, then balancing

should be over 2kg lighter!

[benny hedges]

took a while to get this back as the guy was doing it for nawt boxed him off a few £ like.
same bloke who does all the machining work for roger - rides a r6 as well, after going a bit mad on an r1 and deciding to tone it down a bit

this is the drawing from rogerD ----

when i measured my 2 spare flywheels, both were already smaller than the finished dimensions shown on the drawing, so i modded it a bit more....told him to take off as much metal as possible without losing the magnets, and just keep the mounts for the starter gear.
plan is to see what this runs like, and if i feel i want to take it further, the guy will dish out the middle, basically milling a semicircle of steel & magnet out from opposite sides.

this is an original flywheel with gear removed...


and the one i picked up today

i'll weigh it in a bit and compare it with my original one - if i can get the fker off lol!
in the workshop it felt a LOT lighter than the other one, at least 1.5 kilo lighter i'd say.

not a clue what effect i'll get off this, but it should pick up even quicker
obviously concerned about dishing the magnet out as that will definately affect the way the genny works - i'll see if i like this first - don't want to end up with an unrideable bike!
there's probably some complicated mathematics to work out the revolving mass and inertia of a flywheel but tbh butt dyno will tell!

[seb421]

good luck mate, I read a while ago that guy on here with the storm with sp2 plastics on and red triple clamps had done his, try ask him for advise?

good luck hope it gives the desired result.

[benny hedges]

well got the old one off - it does come off with a m22 bolt, once id got the fkin 17mm out lol! what a pig that was!

weighed em both -
original = 3.325kg or 7.33lb outer diameter 143mm, plate diameter 154, height 63.5mm
new = 2.075kg or 4.57lb outer diameter 135mm, plate diameter 128, height 62mm
that diameter and height is like the bare butt minimum without exposing the magnets inside or going into the mount for the starter gear, so the only further weight reduction would have to be by dishing the middle, milling into the sides.

the difference in weight is 1.250kg or 2.76lb
doesn't sound too radical tbh - not exactly sure what that means in terms of revolving mass & inertia but i'm sure it will make a noticeable difference.
probably shake the fkin thing apart lol

i saw someone on superhawk.com post how they made the flywheel 8lb lighter
that's amazing - did they make a new one out of helium?
and did the genny still work?

so i now have the choice of get my head around this - http://www.freestudy.co.uk/dynamics/mom ... nertia.pdf

and this
http://www.mugul.com/buhler/spg1.pdf

or use this calculator
http://www.botlanta.org/converters/dale ... wheel.html

works out the original flywheel at 5000rpm makes a centrifugal force of 7256.207951060205kg

while the lightened flywheel at 5k makes a centrifugal force of 3713.531989289742kg
so the lighter one, depending on the revs, at mid rpm spins with more or less half the inertia of the original, for such a small shaving off the weight.

but you still wouldn't want to get your baldrocks caught in that lol