So my swingarm is at a buddies shop who is adding three inches to it, but it is taking longer than expected. My problem is I need to know in advance of getting it back, how many links I'll need to have for the new chain and rear sprocket.
I'm leaving for a trip on the 27th.
The particulars: switched from a stock sprocket (45t I think) to a 50t. Adding 3" so figure 5 teeth and 6 inches more swing arm.
Any ideas, I have a chain breaker and master link pliers.
Unless you're an astrphysicist I know of no way to reliably calculate for so many variables in advance.
My advice would be to get at least a foot of extra chain and when the time comes shove your axle as far forward as possible while still falling on even links, cut the chain and run 2 masters for your trip, if you're that pressed. Cut the chain as short as possible while still allowing enough slack to be in adjustment at the lowest possible position on the snails.
The longer swingarm will mean shorter practical chain life. Not because the chain will wear faster, but because you're introdicing more wear points, so the overall length will be excede the adjusters quicker. Despit the longer swingarm you still have only the same range of adjustment the stock swingarm.
To illustrate this, let's say you have a chain of 100 pins (wear points), and each pin wears 1/100" over say 2,000 miles. Total stretch is 1 inch.
A 150 pin chain would then stretch 1.5 inches in the same number of miles. This is an exagerated example, but in your case you're adding 16-20 pins, assuming 8-10 inches of chain.
So keep it short as possible initially, so you get the most range of future adjustment that you can.
I can explain it to you, but I can't understand it for you.
Powdercoated '87 frame, extended swingarm, YZ fork legs, ATV tire, 14/55, XT350 tank, spliced quick-release seat, disc brake conversion, beeg headlight, beeger rack, Lizrdcooler, Lizrdventz and bunch of other stuff all covered in invisible ink.
Thanks for replys. Sorry for the confusion, I must have gone up to a 55 tooth, I ordered five teeth above standard.