Best source for aftermarket sprockets?

[aum108]

Hi all,

Can someone please recommend a good NZ supplier of aftermarket sprockets?

I'm looking for a 41-tooth rear for my Yamaha XV250. So far, the only options are a JT via Amazon (!), NZD$67 including shipping, or a JT via eBay, NZD$65. I can't even find a retailer within NZ who can do a 41 tooth.

With both Amazon and eBay, the sprocket price is ok but the shipping costs more than the sprocket. So it would be a relief to find a good supplier within NZ.

Cheers in advance
Dave

[FJRider]

What size will it replace ...???

[aum108]

What size will it replace ...???

Current sprocket is OEM - 45t.

I've already replaced the 16t front with a 17t, great result

I built a spreadsheet for calculating the RPM/speed relationships for all gears for different sprocket configurations, and for my needs, the 17/41 configuration comes out best. It makes the new 4th gear a tad more torquey than the old 5th gear, and the new 5th gear becomes a true overdrive.

But do you think I can find a 41t for XV250 in NZ?
I'd be quicker at persuading ACC to drop their bike license levy to $100/year.

D

[FJRider]

Be wary of going further ... otherwise reving the nuts off it in 4th, will be the only way to go anywhere in anything other than ... down hill, tail wind, and sail up ....

Five (useable) gears are better than only four.

[aum108]

Be wary of going further ... otherwise reving the nuts off it in 4th, will be the only way to go anywhere in anything other than ... down hill, tail wind, and sail up ....

Five (useable) gears are better than only four.

That's what intuition and common sense would suggest, based on the little Virago's humble 250cc heart.

But scores of people on viragotechforum.com have had great experiences with it, and find they can even accelerate up moderate hills in (the overdrive) 5th at 120km/h. The factory gearing is chosen for absolute beginners - 1st gear is almost totally useless, and set up to reduce risk of stalling. But at 16kW, with a good low-mid torque, the Virago 250 seems to cope well with taller gearing.

Cheers
D

[FJRider]

Let us know how it goes ...

[aum108]

Found a JT Sprocket on eBay with a $15 freight option, cheaper than the local 39T and 40T sprockets

Taller gearing here we come!

[dogsnbikes]

Glad you found one but did you consider getting a Blank sprocket???

[aum108]

Glad you found one but did you consider getting a Blank sprocket???

How much are blanks?
I'm a bit short of CNC milling gear at home. Are there any workshops in Hamilton that can do the machining? How much would a workshop typically charge?

You've got me wondering whether I should get the new sprocket measured when it arrives, so I can get new replacement ones machined in the future when I need them.

[Madness]

I built a spreadsheet for calculating the RPM/speed relationships for all gears for different sprocket configurations

I hope you didn't spend long putting that together... http://www.gearingcommander.com/

[dogsnbikes]

How much are blanks?
I'm a bit short of CNC milling gear at home. Are there any workshops in Hamilton that can do the machining? How much would a workshop typically charge?

You've got me wondering whether I should get the new sprocket measured when it arrives, so I can get new replacement ones machined in the future when I need them.

Will depend on your friendly local engineering firm as all they will need to do is machine out the centre and put in the stud holes to match your wheel,

I got one for the CBR400 as I change the rear wheel from 18" to 17" of a 250 and couldn't match up a front and rear sproket in the same pitch so used a blank in the matching pitch too the front

think it cost me $30 for a sprocket and $25 donation to a local engineer

[aum108]

think it cost me $30 for a sprocket and $25 donation to a local engineer

Intriguing idea. I've got a couple of engineering workshops just a couple of km away in Hamilton North.

So when buying a blank I guess one would ask for something like "41 tooth blank for a 520 chain"?

Who would you recommend as a blank supplier?

[dogsnbikes]

Talk too your local bike shop parts person they will sort you out...and yeah thats what your looking for in the sprocket

[Murray]

Try Cycletreads in Auckland they have a lot of JT sprockets and I got a new sprocket through them at a pretty reasonable price

[aum108]

Will depend on your friendly local engineering firm as all they will need to do is machine out the centre and put in the stud holes to match your wheel

What form of input did the engineer need? CAD files? Or a JPEG of the sprocket with the stud holes?
Even half a mm out, and the sprocket would contribute some interesting noises and vibrations to the riding experience.