Hey All,
I'Ve collected all the bits to do a 520 -1 chain conversion, and a rear stand. Now all I need is a decent day to put it all on, damn winter weather! I have two questions:

1. Which way does they -1 front affect the speedo ( I know their off about 10% for the factory)
2. Is the 110 link chain I got gonna e long enough?

 

There's been a few posts discussing the speedo error and other stuff about sprockets. Go check out this post...it has some other users info on all that ----->Click Me! As far as the chain being long enough, I know the stock one should be long enough if you're just doing a -1, but I don't know the stock link count off the top of my head. Hope that helps!

 

Removing a tooth from the front sprocket makes the sprocket smaller, meaning it will have more revolutions per engine revolution than before. Say for example a stock sprocket revolves 1000 times in a half mile. If you remove a tooth that sprocket has to revolve 1200 times to cover the same half mile. Why is this bad? For one your speedometer will always read high of your actual speed. But even worse your odometer will always read more miles than you've actually ridden. This isn't so bad if you plan on keeping your bike forever, but when you try to sell it might be hard to convince someone that your actual miles is 10-20% less than what's actually on the odometer.

 

Your odometer will only be 6.25% off. So at a true 10,000 miles your odometer will say 10,625. Speedo will be off by the same as well. Really not that big of a difference. Just say, "Its about 625 miles off the actually miles" Or dont say anything and sell it as 10625, I dont think your gonna lose much money because of 625 extra miles on the odometer. And yeah the speedo is off from the factory too by some amount, I wouldnt say 10% unless you are going really fast. There is no way its off 10% at slower speeds. Just go as fast as the other cars around you or keep your indicated speed just a little bit (2-4mph) over the posted limit and youll be fine. There is a plus side though. Now if a cop pulls you over and asks how fast you were going, you can honestly say that you don't know. It might hold up in court too, maybe the judge will give you an order to fix the speedo on your bike and drop the ticket.

 

Get a speedohealer, it's worth the money and takes a few seconds to reprogram any time you change your gearing.

I did -1, -1/+1 and -1/+2 without having to change the stock chain, they all fit.

Speedo healer is needed though. My bike was on a dyno and the speedo was reading 162mph while the Dyno read 139mph. That's a huge difference!

 

Squire, is it woth getting the speedo healer EXT or is the original fine? The reason I ask is I tried ordering the EXT and is on backorder... I need something though cause I also did the -1/+2. Was considering the yellowbox??

 

I have not tried the EXT, I got the regular one and it works great. The hardest part of the install is getting your damned hand down behind the tank to connect the thing. After that, go to the website, plug in your stock gearing and then type in the change you made, and it prints directions that take 45 seconds to key in and recalibrate the speedo/odo.

Very good investment.

 

Squire, I got the speedohealer, however, I cannot find the speed sensor? How do I get to it? Do I have to completely remove the tank? Please advise. Thanks.

 

It is a bitch to get to it, so find someone with small hands to make it easier. It is located under the tank, behind the engine and way in front of the rear shock, sort of above the transmission.

I wish that I had thought to take a picture at the time, but you have to remove the tank, or at least lift it enough to snake your arm down in there and hopefully you have good dexterity.