Honda Dio - clutch centre spring question (1st post)

[W/C]

Since the belt is not dropping all the way down or prob not more then half way means the transition is not a broad as it is supposed to be
low range - belt low in front , high in back

W/C, can you explain this one a bit more? I still don't fully get it. If my belt wasn't dropping all the way down, wouldn't that mean I stayed in the low range for longer? Or am I missing something? Thanks for putting up with all my dumb questions, BTW.

Only dumb questions are the ones not asked.
Because your belt may not be riding as low as if it was a stock belt in the rear drive,your actually starting off in a higher gear, and to compensate you ran lighter weights to get the revs up? Hope that helps
It may be your center spring is weak, but I seen 100+ cc strokers run stock center spring.

[wedgepilot]

I have already installed an upgraded contra spring once on my bike already (1000rpm) and once on a friends hyosung rally.

Did you try the upgraded spring before or after the bore upgrade? I'm just wondering how a 50cc would be with a 10% stiffer center spring.

The tacho looks cool, btw, I'll have to look into getting one of those once I get my gearing sorted.

[jeremydde]

I have already installed an upgraded contra spring once on my bike already (1000rpm) and once on a friends hyosung rally.

Did you try the upgraded spring before or after the bore upgrade? I'm just wondering how a 50cc would be with a 10% stiffer center spring.

The tacho looks cool, btw, I'll have to look into getting one of those once I get my gearing sorted.

I did the spring after the bore upgrade. My friend has a 15% stiffer one on his stock bore Hyosung Rally and it gets stuck in too low of a gear so we are experimenting with heavier roller weights to compensate.

[W/C]

If you need more stall, then stroger clutch springs or a lighter clutch,center spring is just used to keep the belt from slipping.
Dont run a heavy spring unless you need that style for drag racing.
RUn the stock belt and switch the boss back to stock, you can still run the zx pulley-even though it's the same thing as a stock other then angle and or weight, the outer drive for zx is different, typically a steeper angle and slight larger overall dia

[wedgepilot]

Having looked into it, the only uprated center spring I can find is 20% stiffer, which is too much I reckon.

I think I'll try to find a slightly shorter/narrower belt than the one I have, but not as small as the stock one. That would change the gearing too much - my poor engine would be screaming its head off down the highway!

jeremydde - I'll be interested to hear how your spring upgrade goes though, and also what the result is with your friend's Hyosung.

[wedgepilot]

A quick update on this one. I've never put grease on my roller weights before, so as an experiment, I added a little light lithium based grease to each roller.

Now I'm not sure exactly why, but it's had the effect of keeping me in the lower range for longer, which is exactly what i wanted! I now hit 'top gear' around 60kph, which is just where I want it. Also, if close then re-open the throttle, I'm straight back in the power band, whereas before I would have been stuck in 'top gear'.

The engine sounds a lot quieter too.

I'm sure someone smarter than me can explain the science behind this...

[jeremydde]

My order from vt cycles arrived. I installed a Kuka 1500 RPM center torque spring and my dead spot has vanished. The tach stays at 7400rpm the entire range of the variator until top speed is reached. My top speed has decreased slightly, although it is almost negligable.

[wedgepilot]

Sweet - glad you got it sorted

My grease solution seems to be working well too, after a few weeks of riding. I've still no idea *why* though