Chain weights & custom chainrings

[Pancakes]

Ok so I'm coming up due for a new final drive. Have worn out the first chain and the sprocket & ring were ok so being me I chucked on a cheap as chain off some little importer (and after leaning not to use the clip joiner and being rescued in the middle of the night by Frosty) it has been sweet. The std chain was crap and this one is too.

As far as I understand (and I don't know where I got this from so it's probably wrong) the chains are all the same or a minimum strength for their rating? Mine is a 520 so should be as strong as other 520's but maybe heavier or softer/less accurate machining/tolerances etc than a better on but pretty common eh? My bike has jack all power so anything I do to it really needs to reduce unsprung and rotating weight. Chains are fricken heavy and get accellerated/decelerated quickly. I want to go up 2 teeth on the back and don't think this will cost any more cos there aren't (or weren't last time I checked) OEM 'rings in NZ for Hyo's, they are being made here. 2 teeth should take me from 7500 RPM @ 100K's to 7825 RPM @ 100K's which I recon I should notice without it buzzing too much. These bikes can go up to 150 but take space to get there. They really only do 130 quick enough so I thinb this should give me the same (real world) top speed, just get there faster.

Sheesh, getting there.

The question is are there reasonably priced (low power bike so it will last so I would pay an ok amount for one) light chains. The Hyo's rear suspension seems (to me) to be affected lots but chain tension. If it's too tight (even if the book says it's ok) it seems to load the rear shock and the centifugal force of the chain at higher speeds is giving a simalar feel to a too tight chain.

Also... any KB'ers or reliable people making light sprockets? 47 - 48 T?

Thanks tons in advance. Brian.

[Squiggles]

http://www.quality-cycle.com/truth_about_motorcycle_chains.htm

is an interesting read, i wont put real cheap chains on, dont plan on chucking one off and locking the rear/braking the casings mid corner....

how much does the chain tighten with you sitting on the bike (as opposed to setting it with you off it)? the tl squats a bit under acceleration and my understanding is the chain gets tighter when this happens. Quite possibly its overtight with you on it?

[Pancakes]

This is the pic from the manual that shows what the sag should be without the rider on. I set mine to 40 - 45mm using the same measuring points. Less than 40mm and it has the definite feeling that it loads on bumps and also on compression on hard corners (not that cool!). More than 50mm and there is too much slack and it chatters on the swingarm which obviously isn't good either. I just check it lots (twice a week, probably as much as I would check a chain visually anyway) and adjust if needed. Even if it's just a little bit.

The amount of compression needed to get the bottom out feeling is less at speed and I assume that the top chain line would be more curved at higher speeds due to the weight of the chain pulling out more and taking up more slack. I'm not heavy <75Kg's and the rear is firm enough to start moving but has ok range once it's going. I can lift the front on launches but the lack of power means it doesn't squat like a TL would.

I actually ballanced on the pillion seat and bounced/pulled the shock down while watching the chain to see if it tightened up when I first noticed the odd action. Was hard to get it really compressed with my back shed method though!

[Max Preload]

How much does the chain tighten with you sitting on the bike (as opposed to setting it with you off it)? the tl squats a bit under acceleration and my understanding is the chain gets tighter when this happens. Quite possibly its overtight with you on it?

It also 'tightens' with a pillion. It's the geometry - the front sprocket is forward of the swingarm pivot, which is what the rear sprocket swings around so the centre distance of the sprockets changes. The chain is at it's tightest when the line between the centres of the output shaft, swingarm pivot and rear axle is straight. But because it's affected by ratio of distances and suspension travel it's much less pronounced on a road bike over say a MX'er.

One way to overcome this tightening is to simply put the swingarm pivot central to the output shaft - but it's expensive to do so and makes it the bike wider.

[Max Preload]

This is the pic from the manual that shows what the sag should be without the rider on. I set mine to 40 - 45mm using the same measuring points. Less than 40mm and it has the definite feeling that it loads on bumps and also on compression on hard corners (not that cool!).

That is excessive but I seem to remember the Hyosung's have a lot of ground clearance and their swingarms at quite an acute angle.