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if i do a +2 in the rear do i need a speedohealer. is it going to be out that much
cant decide between a +2 in the rear or a -1 in the front. thanks
 

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cowboygsxr said:
if i do a +2 in the rear do i need a speedohealer. is it going to be out that much cant decide between a +2 in the rear or a -1 in the front. thanks
Doesn't matter which end you change, the effect on the speedo is going to be equivalent to the overall ratio regardless.

If you're talking a 17f/42r stock gear, the ratio is 2.47:1. If you go to 17f/44r, the ratio becomes 2.59:1. The difference is about 5%, which is what you'd see on your speedo - it would read 2.5 mph fast at 50mph. "Out that much" is a call you have to make yourself.

As far as the sprocket change is concerned, the only pro I've heard for going small in the front is a minor weight loss. The negatives are significantly greater chain wear, and potential chain guide rubbing/destroying. I believe MOST people go smaller in front in cases where they are unwilling to replace the chain if needed when upsizing the rear.

If I am buying new sprockets/chain all at once I'd never go down in front. Might do it to check if I'd be happy with a gearing change, but then I'd accomplish it with a new rear sprocket at the next chain change.

KeS
 

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cowboygsxr said:
if i do a +2 in the rear do i need a speedohealer. is it going to be out that much
cant decide between a +2 in the rear or a -1 in the front. thanks
approximately 10mph off with -1 in front and factory speedo error. Speedohealers are awesome and cheap. Motomummy sells them for less than 100 otd including shipping. Well worth the money imo.
 

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I went down 1 in the front and got a speedo healer, works great and was super simple to install.

And as far as "significantly" more wear on the chain... I don't think it will hurt to go from a 17 tooth to a 16 tooth. You are not creating that much tighter wrap around the sprocket, that is what causes "significantly" more wear. If you went to say a 15 or a 14 you would definitely see a difference in chain wear. I don't think I will get a whole lot less mileage with the 16 tooth front.
 

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gsxr6racer said:
I went down 1 in the front and got a speedo healer, works great and was super simple to install.

And as far as "significantly" more wear on the chain... I don't think it will hurt to go from a 17 tooth to a 16 tooth. You are not creating that much tighter wrap around the sprocket, that is what causes "significantly" more wear. If you went to say a 15 or a 14 you would definitely see a difference in chain wear. I don't think I will get a whole lot less mileage with the 16 tooth front.
+1 wear will not be substantial until you get down to a 14, because the chain wraps too tightly. 15 is fine even. But since the 750 is stock 17, 16 is perfect. If you're changing the chain then do both, if not, just change the front, its cheaper.

I am -1+1, but I may go +2 once I figure out the gearing for my tracks
 

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spcmedic said:
approximately 10mph off with -1 in front and factory speedo error. Speedohealers are awesome and cheap. Motomummy sells them for less than 100 otd including shipping. Well worth the money imo.
+1 on the Speedohealer from Corey.

My speedo was 7.9% fast with the stock gearing. Kevin Stephens noted that you would be off by another 5% with your proposed gearing, for a total of 13%. Probably good for bench racing but ...
 

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i guess i'm a squid when it comes to all of this +1 -2 stuff... can someone just explain to me what u guys are talking about? I'm sorry i tried searching for this stuff but it's not taht easy to get the right topic at times. Anyone that wants to PM to explain the benefit of +1 or -2 in the front and rear I would greatly appreciate it. With winter here I definitely will have more time to work on my bike. THx
 

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-1+2 means that you go down 1 tooth on the front sprocket and up 2 teeth on the rear sprocket. that will give it more torque, feel stronger at the expense of top speed. +1-2 would be the opposite. up 1 in the front and down 2 in the rear. thats for more top end but the bikes do not have enough power if with that tall of a gearing to use it. needless to say, i hope that helps. personally , you better of stock gearing if you want every bit of mph. but -1(down one) kinda gives you a taste of both worlds

ron
 

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Someone said that it was simple to install the speedo healer, which may be true but from there website it looks like you need a math degree to callibrate it. I went down 1 in the front and would like to get my speedo accurate. So can anyone talk about how difficult it is to callibrate. Also, while we are on the subject of sprockets what is the best combo. My buddy has a 929RR with a -1+2 and a 520 chain, and he said that is the way to go. Is this true?
 

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GIX750 said:
Any of the advertisers sell just the front sprocket?
BTW...how difficult is it to replace?
Do I need any special tools?

Thanks
Talk to Corey at Motomummy.com he is a site sponser and runs an absolutely awesome business. Prices are the best and shipping is super fast and free! the -1 front sprocket is 29.00 from him.
 

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XAC750 said:
Someone said that it was simple to install the speedo healer, which may be true but from there website it looks like you need a math degree to callibrate it. I went down 1 in the front and would like to get my speedo accurate. So can anyone talk about how difficult it is to callibrate. Also, while we are on the subject of sprockets what is the best combo. My buddy has a 929RR with a -1+2 and a 520 chain, and he said that is the way to go. Is this true?
Couldn't be any easier. Pace a car at 50mph and look at your speedo. Enter the two numbers in the website and it generates directions.:cheers
 

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XAC750 said:
Someone said that it was simple to install the speedo healer, which may be true but from there website it looks like you need a math degree to callibrate it. I went down 1 in the front and would like to get my speedo accurate. So can anyone talk about how difficult it is to callibrate. Also, while we are on the subject of sprockets what is the best combo. My buddy has a 929RR with a -1+2 and a 520 chain, and he said that is the way to go. Is this true?
The speedo healer website has a calculator for figuring out exactly what you should program your healer to. And programming was not hard at all, just takes a little bit of time and small fingers to flip the switches on the box itself. I was concerned with that as well before I got mine and it was way easier than I thought it would be.
 
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