Optimal sprocket option

[NoisyDante]

At the risk of beating a dead horse I wanted to try and get a clearer answer to the gearing question as it pertains to me.

I've been riding with a 14t front sprocket, previous owner put it on, and I can only assume he did not change the stock rear sprocket, which for my '07 695 I believe it is a 42t.

If I stayed with the 14t sprocket would I benefit from going to a larger rear sprocket as well?

[ngk12]

i was told that every 3 tooth increase to the rear sprocket is equal to  going down 1 tooth in the front. so, if you increase the rear enough it would be similar to dropping down to a 13 tooth in front... if you want more bottom end power that would be one way to go.

[Raux]

you've got to look at what kind of riding you're doing.

where are you cruising at, rpm-wise?

are you having issues down low in the rpm-range? if so, maybe you have other issues than gearing

are you trying to stunt?

realise that you get about a 500rpm increase for each tooth down in the front or the 3-tooth increase in the rear.

so if you are cruising at 4k at 55mph then you will be cruising at 4.5k at 55mph.

[Howie]

This reminds me of a high school classmate.  He had a plain Jane 6 cylinder Chevy, '55 or '56.  He installed a 5.88 differential and would challenge people with muscle cars and hot rods to a one block drag race for money.  He made a lot of money with that car until people caught on.  The only problem was he couldn't break 50 MPH on the highway.

Figure it this way.  each one tooth increase in your rear sprocket will reduce your RPM by about 250 RPM and a one tooth decrease in the front will lower your RPM by about 750 RPM.

If you want to be more accurate you can use this plug in. 
http://www.gearingcommander.com

[evocarti]

At the risk of beating a dead horse I wanted to try and get a clearer answer to the gearing question as it pertains to me.

I've been riding with a 14t front sprocket, previous owner put it on, and I can only assume he did not change the stock rear sprocket, which for my '07 695 I believe it is a 42t.

If I stayed with the 14t sprocket would I benefit from going to a larger rear sprocket as well?

Leave it, unless you're unhappy with the performance. If you want more top end, add a tooth or two to the back. If you want more grunt, drop one or two.

[64duc]

Leave it, unless you're unhappy with the performance. If you want more top end, add a tooth or two to the back. If you want more grunt, drop one or two.

  You have it backwards. Add a tooth at the rear for more grunt, remove for more top speed. At least until the engine can not overcome increased wind resistance at higher speeds.

[duccarlos]

Most people prefer to go 1 down in the front because it's an easy and cheap mod. For the same performance gain you can go 2 up in the back and it's supposed to be better for the chain.

[stopintime]

Figure it this way.  each one tooth increase in your rear sprocket will reduce your RPM by about 250 RPM and a one tooth decrease in the front will lower your RPM by about 750 RPM.

.............

realise that you get about a 500rpm increase for each tooth down in the front or the 3-tooth increase in the rear.

so if you are cruising at 4k at 55mph then you will be cruising at 4.5k at 55mph.

Most people prefer to go 1 down in the front because it's an easy and cheap mod. For the same performance gain you can go 2 up in the back and it's supposed to be better for the chain.

From 15 to 14 front increases RPM by 1/15 = 6.67% at any rev count (for example from 4,000 to 4,266 revs)
From (stock 695) 42 to 45 rear increases RPM by 3/42 = 7.14% at any rev count. (for example from 4,000 to 4,286 revs)

[NoisyDante]

Thanks guys., I'll probably stick with the combination that I have now.  I thought I read somewhere that having a 42 with the 14 put stress on the chain or something.  I don't mind the performance I'm currently getting, and I think if I really wanted to make a difference there I should shed some pounds of my own.

[DoubleEagle]

Thanks guys., I'll probably stick with the combination that I have now.  I thought I read somewhere that having a 42 with the 14 put stress on the chain or something.  I don't mind the performance I'm currently getting, and I think if I really wanted to make a difference there I should shed some pounds of my own.

Shedding pounds of your own is  ALWAYS a good idea Dante.

I'm trying it myself.

Dolph       

[NoisyDante]

Definitely is.  My main obstacle is the Warner Bros. commissary.  It's both good and expensive, that place is gonna make me fat and broke.   

[Raux]

well think how much it would cost to take 10lbs off your bike vs 10lbs off of you

[Speeddog]

At 14/42, you're at 3.00:1.

At the same ratio, a 15/45 would treat your chain a bit nicer.
It's not a night/day thing, it just changes everything a little bit towards a longer-lasting drivetrain.

Ideally, a 15/44 or 15/46 would get you away from the 'even' ratio.
Sometimes the 'even' ratios produce vibrations and harmonics that are annoying.

[stopintime]

............

Ideally, a 15/44 or 15/46 would get you away from the 'even' ratio.
Sometimes the 'even' ratios produce vibrations and harmonics that are annoying.

Is that what has been described as "the hunting tooth"?

[Speeddog]

IIRC, 'hunting tooth' originally was for gears, but it's basically the same thing.

Even better, both sprockets an odd number of teeth and a non-integer ratio, like a 15/39, 15/41, 15/43, 15/47, etc.

Odd number of teeth spreads the sideplate wear onto all teeth, instead of every other tooth.