13/48 for offf-road?

Gravelin Gary wrote:

Hey JAXBAX, I'm in the same boat you are. WWGuy turned me onto this sticky when I started my process.https://wr250rforum.forumotion.com/t5-chains-and-sprockets

I ended up going 13/47 for street & casual gravel and 13/50 for rides I expect mud and or single track. I roll both with a 112 link chain.

Hope this helps a bit.

THANKS for this. It is def helpful!!

I ran a 13/47 combo for over 9,000 miles, and I consider it to be an excellent ratio for true dual sport riding.  I recently switch to 13/50, and I couldn't believe how much better the bike did in the dirt, especially sand.  The engine now gets into the power band very quickly, and the throttle is way more responsive.  The downside is my freeway cruising speed is down to around 55-60, but that's fine, as I truly ride mostly in the dirt these days.  My back tire is a Pirelli XCMH, which is a 110/100-18.  The 112 link chain fit perfectly.

Lee

Hey VW_Lee,
                 
That matches my experience also except my top cruising speed is 60-65 with 13/50. No engine mods but my air box is opened up so....

VW_Lee wrote:

I ran a 13/47 combo for over 9,000 miles, and I consider it to be an excellent ratio for true dual sport riding.  I recently switch to 13/50, and I couldn't believe how much better the bike did in the dirt, especially sand.  The engine now gets into the power band very quickly, and the throttle is way more responsive.  The downside is my freeway cruising speed is down to around 55-60, but that's fine, as I truly ride mostly in the dirt these days.  My back tire is a Pirelli XCMH, which is a 110/100-18.  The 112 link chain fit perfectly.

Lee

Gravelin Gary wrote:

Hey VW_Lee,
                 
That matches my experience also except my top cruising speed is 60-65 with 13/50. No engine mods but my air box is opened up so....

AWESOME GUYS! Exactly the feedback I was looking for. Gonna Run the Stock 13 up front, and order a 47t and a 50t Rear to have the best of all worlds, with minimal effort!!

Gravelin Gary,

I'm only basing my cruising speed on the sound from the engine, so it's entirely possible I'm being overly cautious. Not having a tach makes it difficult to tell exactly what the engine is doing. I've kicked it up to 70 MPH a couple of times, but the engine seemed to be screaming. My speedometer has been corrected with a Speedo DRD and verified with GPS, and it's also possible that my GPS isn't the most accurate thing in the world.

JAXBAX,

Sounds good! You're going to love the effect the regearing has on the bike. It really transforms it.

Lee

Here's a great online calculator where you can experiment with variations on sprockets and tires and see the effect on RPM and MPH etc.

http://www.gearingcommander.com/

wwguy,

Thanks for the link.  It looks like the engine is spinning a little over 8,000 RPM in order to do 65 MPH, and from what I've read that is within the acceptable range for sustained cruising.  It had been a few hundred RPM less with the 13/47 setup, and the stock 13/43 setup was pretty much only good for downhill sections.  

Lee

AWESOME GUYS! Exactly the feedback I was looking for. Gonna Run the Stock 13 up front, and order a 47t and a 50t Rear to have the best of all worlds, with minimal effort!! [/quote]

I hope your experience turns out as good for you as mine and VW_Lee's has.

VW_Lee,

You're right, without a tach it's a bit tough. I think there can also be other hard to explain variances. For instance I have seen posts where others get like 70 mpg and the best I have ever seen is the low 60's. For all I know their altitude and terrain might be completely different.

All I know for sure is it gives me a lot more smiles per mile than headaches!  

13/48 isn't really all that low of gearing for 90% offroading. I just changed to this gearing and it just feels 'normal' now. Best of both worlds, I do a lot of street riding. It's better on the trail, but I'd go 50 or even 52 if top end wasn't an issue on the road.

Hey Gravelin Gary,

I'm also puzzled by those mileage claims of 70 MPG. The low sixties is the best I've seen as well, and that's with a Speedo DRD corrector calibrated to my GPS and all easy street riding. In the sand, it can dip into the upper forties. I think my speedo is pretty close, as those roadside radar signs jive pretty well with my speedo. As I recall, the odometer is off when the speed is correct, and I think it counts too slowly, which would give worse MPG readings. Oh well, best not to think about it!

Von551,

You're right that the 50T rear sprocket is really good off-road. I only ran into issues when trying to keep up with traffic in the canyon. Like you said, top end becomes the issue with that setup.

Lee