front vs rear sprocket

[Ferdinand]

Just want some opinions. Do you think it's better to change out rear sprocket to get the approximate same ratio as changing out frnt? Example would be 14,45 or 15, 47. Would it be any less stressful for parts and bike to change out rear to 47 and keep 15 frt or doesn't it make much difference which you change to get about the same ratio? thanks

[weskc35k]

14/45 is about 15/42 ish(15/41 point something) not 15/47, 15/47 is a bit taller but a strong 650r will pull it easy.

Front sprockets are generally cheaper,also going bigger on the front helps with less rolling resistance to the chain and there may be less chain slap on the swingarm as well.

[ghoti]

Just want some opinions. Do you think it's better to change out rear sprocket to get the approximate same ratio as changing out frnt? Example would be 14,45 or 15, 47. Would it be any less stressful for parts and bike to change out rear to 47 and keep 15 frt or doesn't it make much difference which you change to get about the same ratio? thanks

Going one tooth smaller on the front is about the same as going three larger on the back. It's cheaper and easier to change the front sprocket. I went with a 48 rear and 15 front for my street riding and swap the front to a 13 or 14 for the dirt.

[TREADMARKS]

Going one tooth smaller on the front is about the same as going three larger on the back. It's cheaper and easier to change the front sprocket. I went with a 48 rear and 15 front for my street riding and swap the front to a 13 or 14 for the dirt.

I have the 48 on the rear as well. I am running 14/48 now.

What did you use for a chain guide?

[ghoti]

I have the 48 on the rear as well. I am running 14/48 now.

What did you use for a chain guide?

I'm using the stock one.

[XR250rdr]

14/45 is about 15/42 ish(15/41 point something) not 15/47, 15/47 is a bit taller but a strong 650r will pull it easy.

Front sprockets are generally cheaper,also going bigger on the front helps with less rolling resistance to the chain and there may be less chain slap on the swingarm as well.

what??? 15/41 is much taller than 14/45. 13/41 is close though.

[weskc35k]

Christ don't mind me yeah 14/45 is about 15/48 what am i on today.

Sorry my bad.

[Triple B]

Here is a sprocket ratio chart

http://www.dropbears.com/u/utilities/sprocket.htm

Hope this helps remember the higher the number the lower the gear

[Ferdinand]

Thanks for the responses, I guess what I was trying to stay is, would there be less stress and wear to shaft, motor, parts etc changing to a smaller sprocket in the front or changing to a larger in the back. Maybe it doesn't make much difference I just thought maybe changing out the back sprocket would be better for bike. thanks again

[goblin127]

Thanks for the responses, I guess what I was trying to stay is, would there be less stress and wear to shaft, motor, parts etc changing to a smaller sprocket in the front or changing to a larger in the back. Maybe it doesn't make much difference I just thought maybe changing out the back sprocket would be better for bike. thanks again

I was always led to believe it was better to change the rear than the front stress wise.

[qadsan]

I was always led to believe it was better to change the rear than the front stress wise.

Technically you're right IMO, but I still change the front on my bikes because its easy for me to swap between 13, 14 & 15 front sprockets (I like the versatility). Most of the time I'm using the 14/48 on my off road bike which is enough for me, but it seems I'm either on the gas WOT or off the gas and stabbing the brakes much of the time as opposed to simply cruising steadily at high speeds. The more highway riding I do in terms of cruising, the more I see the need for the taller gearing. The 14/48 has been great for my city needs, but even the 15/48 gets buzzy on the freeway. I don't look at my speedo / tach too much, but as I recall, at 15/45, I'm taching at about ~5500 RPM at 70MPH and closer to 6200 RPM at 80MPH. After sustaining those speeds for a while, the growl from the engine gets old as well as the howl from the D739 knobbies, but fuel economy isn't too bad compared to my truck .

[Triple B]

Thanks for the responses, I guess what I was trying to stay is, would there be less stress and wear to shaft, motor, parts etc changing to a smaller sprocket in the front or changing to a larger in the back. Maybe it doesn't make much difference I just thought maybe changing out the back sprocket would be better for bike. thanks again

The larger the sprockets the more contact with the chain equals less stress on the individual teeth making the parts last longer in theory. For example a 15 tooth CS is may have 7 teeth contacting the chain at one time were a 13 tooth CS is may only have 6 teeth.

If you put a smaller front sprocket you also run the risk of wearing down your chain guide quicker.

[XR4DEZ]

14/47 is pretty good all around desert gearing and it keeps the tire of the mud flap. Whay kind of riding do you do primarily? If it's tight stuff ,the 13/48 is good. If it's Baja speed, 15/47 is what the Honda 650 boys run.

[big t]

I run 13/50 for the riding around here.

[XR650L_Dave]

The larger the sprockets the more contact with the chain equals less stress on the individual teeth making the parts last longer in theory. For example a 15 tooth CS is may have 7 teeth contacting the chain at one time were a 13 tooth CS is may only have 6 teeth.

If you put a smaller front sprocket you also run the risk of wearing down your chain guide quicker.

On the flip side, a smaller front sprocket will exert less stress on the countershaft, particularly side-to-side (transverse torque).

A small effect, to be sure, but leverage is leverage.

Dave

[4Takt]

If you go up a tooth on the front (say for higher top speed) you'll have to adjust the rear wheel further in for the same chain slack. That's good for the handling of the XRR.

If you try to achieve the same effect by going 3 smaller on the rear, you'll have to adjust your wheel further out, which is bad for the handling.

4Takt

[goblin127]

Technically you're right IMO, but I still change the front on my bikes because its easy for me to swap between 13, 14 & 15 front sprockets (I like the versatility). Most of the time I'm using the 14/48 on my off road bike which is enough for me, but it seems I'm either on the gas WOT or off the gas and stabbing the brakes much of the time as opposed to simply cruising steadily at high speeds. The more highway riding I do in terms of cruising, the more I see the need for the taller gearing. The 14/48 has been great for my city needs, but even the 15/48 gets buzzy on the freeway. I don't look at my speedo / tach too much, but as I recall, at 15/45, I'm taching at about ~5500 RPM at 70MPH and closer to 6200 RPM at 80MPH. After sustaining those speeds for a while, the growl from the engine gets old as well as the howl from the D739 knobbies, but fuel economy isn't too bad compared to my truck .

I ment only sress but yea I do the same with the front beause of ease and cheaper. Dave has a good point also as far as a larger force side to side on the counter shaft.