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Some good advice on flywheel lightening on this thread:

http://www.triumphrat.net/air-coole...447-lightening-the-crank-or-the-flywheel.html

This company reckons on reducing its weight by 42%, from 4 kg to 2.8k:

http://www.classicbike-raisch.de/tr...ing-vergaser-modelle/318/polrad-abdrehen?c=22

A Google translation from the German:

Flywheel weight optimization. We turn from your supplied flywheel and lighten it to only 2.8 KG. The original is a good 4 KG. That's a whopping 42% more. This results in a much easier revving of the engine, what you really feel immediately the throttle. A completely new engine dynamics! The theoretical loss of a poorer runout at the bottom are really negligible, since you do not actually feel it. The flywheel is balanced and ready for installation perfectly incl. New seal supplied.
 

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Lighter is not always better

I am in the middle of changing my side covers.
While I have the motor apart should I install a new clutch? My bike currently has 30K miles on it.
I am also considering sending the fly wheel out to be lightened. Any thoughts on this?
Mr. Jhtjon,

Unless your clutch is slipping or grabbing because of friction plate wear, then NO, you don't need to mess with the clutch. In theory it should last 3 to 4 times that millage.

IMHO I would leave the fly wheel alone. Especially if you do a lot of slow riding. The reciprocating mass is there to smooth out the engine pulses and enable the engine to maintain a normal idle. I think you would find the disadvantages far outweigh the advantages.
If you are drag racing all the time, well maybe?

There are far better ways to spend your time and money on the scoot.

Namaste,
Charles
 

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Discussion Starter · #4 ·
The bike gets a lot of agressive backroad riding the occasional track day. As far as the clutch goes I'm more inclined to drop one in, as the plans call for carbs and possible big bore are in the future.

Is the Barnett the one to get or something else.
 

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As Endoscopy says, you'd probably be better off spending money on e.g. front suspension and brake upgrades first (I see you've addressed the rear suspension).

Having the flywheel lightened is, in my opinion, only worthwhile if you've also done (or are intending to do) a *lot* of other major engine mods (big-bore, cams, valves, flat-slide carbs) <- some of these (TPUSA stroker cranks, SportEvolution 1100) require that the engine be dismantled to below the sub-atomic particle level, so it might be better to leave the flywheel alone until then? In any event, the stock clutch is man enough for everything up to 904cc so I'd leave it as it is, though it might benefit from stronger (Barnett or EBC) springs.

FWIW my flywheel's been lightened down to 2.25Kg - the only downside is that the 1.6-1.8K rpm tickover means lots of clutch-slipping in slow traffic (which is basically non-existent in Finland anyway...)

Tim
 

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If your in that far you may want to consider a TTP Safe-Start if that portion isn't already reinforced from the factory... I think Triumph started reinforcing that portion in later year cases. I'd leave the clutch alone for now and go with better springs.

Save the FW Lightening for when/if you go big bore.

YMMV
 
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