NC30 - Front Sprocket - how small is too small

[999Gomerz]

Hi Everyone,

I am looking to cary a bunch of sprocket combinatons so I can change gearing.

I have the the following rears:

1 * 38
2 * 39
2 * 40
2 * 41

The gearing that I need to use is I think between 14/40 and 14/43.

My question is if I can use a 13t front sprocket and if it will foul on anything and cause issues as it would be far easier for me to get one 13t sprocket than a few more rears.

The bike is running a 2006 GSXR shock and thus is a bit longer than normal incase this causes issues with hitting top swinarm guide or frame area below the bottom section of the chain.

Cheers,

[dougie conacher]

Hi Threre
sorry for hijacking this thread,l posted a thread about using gsxr shock on a nc30 most of the replys said it would be to soft how do you find lt, plus what weight are you
thanks in advance
dougie

[Jashdown]

^ Obviously you need to change the spring rate on the GSXR shock, and the valving if you're serious enough. I have a 600RR shock, and I've just changed the Spring rate from a 650lb spring to an 875lb spring to suit my weight on the RVF. $140 for a fully adjustable shock suited to my weight on the RVF, as opposed to $500 for a Hagon shock or something.

In relation to the actual thread, I wouldn't go with a 13t front sprocket. I've heard rumours of it fouling on the swingarm. Also, a sprocket that size will wear out a lot faster than the 14t sprocket, it will also wear the chain a lot faster and most likely the transmission too.

Why do you need so many combinations? There aren't that many track around Melbourne. Just buy a 42t rear sprocket.

[999Gomerz]

Dougie: The shock is great, but it has been revalved and has a 16 spring on it.

Jash - What I was getting at is that I already have a bunch of sprockets to fill a range using 13 and 14 T front sprockets. And rather than buy a bunch more it would have been easier to get one 13t front. But I will get more to use 39-43 with 14 and 15 fronts. I belive you need to change front and rear sprockts together or change to different chains becuase unfortunately with SSSA bikes when you alter the front or rear sprocket in isolation you will change the swingarm length and ride height and consequently the weight distribution, shock ratio, rear ride height, swingarm angle, steering head angle, COG will all be altered.

[Jashdown]

Changing the sprockets has no effect what-so-ever on the bikes geometry. The only thing that affects it is the adjustment of the chain tension at the rear hub. And that adjustment is so small you will barely notice it unless you know a lot about what you're doing.

They say it's bad to mis-match chains and sprockets, but I daresay you don't have 10 different chains to use on all the combinations, so it won't be a problem to change a sprocket and leave the chain and other sprocket alone.. If all the parts are relatively new, then there isn't really much of a problem, and if you change the sprockets regularly, then they will all wear at around the same rate, give or take a couple of hundred km's.

[lukemillar]

Changing the sprockets has no effect what-so-ever on the bikes geometry.

I'm pretty sure that is incorrect. Have look here:

http://www.sportrider.com/tech/146_0404 ... index.html

[999Gomerz]

Changing the sprockets has no effect what-so-ever on the bikes geometry. The only thing that affects it is the adjustment of the chain tension at the rear hub. And that adjustment is so small you will barely notice it unless you know a lot about what you're doing.

They say it's bad to mis-match chains and sprockets, but I daresay you don't have 10 different chains to use on all the combinations, so it won't be a problem to change a sprocket and leave the chain and other sprocket alone.. If all the parts are relatively new, then there isn't really much of a problem, and if you change the sprockets regularly, then they will all wear at around the same rate, give or take a couple of hundred km's.

I have to disagree mate, when you change sprockets but keep the same chain you need to adjust the chain tension. On a SSSA bike this will also effect rideheight because of the eccentric hub adjuster. The ride height difference betweeen the hub at 6 O'clock position and the 3 O'clock position is about 20mm, if you continue up to the 12 O'CLock position the difference will be up to 40mm which is massive. So by having a series of sprockets you can adjust ride height independant of gearing or adjust gearing independant of ride height.

[Jashdown]

Changing the sprockets has no effect what-so-ever on the bikes geometry.

I'm pretty sure that is incorrect. Have look here:

http://www.sportrider.com/tech/146_0404 ... index.html

The RVF does not have enough power to lift the front wheel coming out of a corner on the gas, so changing sprockets on the RVF is going to have a negligible effect on the bikes geometry, it will only affect acceleration.

999gomerz - Not sure what you're doing, but when I adjust the hub, my ride height does not come near 20mm in ride height change.

Anyway, it's your decision. You would be better off buying a 13t front sprocket, instead of bigger rear sprockets, otherwise you will need another chain.

[porndoguk]

Changing the sprockets has no effect what-so-ever on the bikes geometry.

I'm pretty sure that is incorrect. Have look here:

http://www.sportrider.com/tech/146_0404 ... index.html

The RVF does not have enough power to lift the front wheel coming out of a corner on the gas, so changing sprockets on the RVF is going to have a negligible effect on the bikes geometry, it will only affect acceleration.

999gomerz - Not sure what you're doing, but when I adjust the hub, my ride height does not come near 20mm in ride height change.

Anyway, it's your decision. You would be better off buying a 13t front sprocket, instead of bigger rear sprockets, otherwise you will need another chain.

what hes saying theres about 20mm in total adjustment between each side of the hub,

you can reverse rotate the hub so you have more clearance or less.