14T or 15T countershaft sprocket?

Its been awhile since I've seen any chatter about gearing. I seem to recall that Kenneth Webb and FabOneUp have made the change. One went 14T and the other 15T if I remember correctly. Since they've had quite a few rides with these setups, I wonder if they may have an opinion about which may be the best choice. Anybody else?

I've heard a few say they like the 15T on there, especially offroad. Never seen anyone try a 14T, that would be a pretty big change. Doesn't matter what combinations of teeth, you just need to compare the ratios.....like this:

47/16 (stock) = 2.94 ( means the crankshaft turns 2.94 times per one revolution of rear wheel )
47/15 = 3.13 ( 6.5% increase )
47/14 = 3.36 ( 14.3% increase )

I am in the process of changing my gearing combo to this:

49/16 = 3.06 ( 4.1% increase vs. stock )
49/15 = 3.27 ( 11.2% increase )

The stock gearing is just a bit too high in 1st gear, for my taste. It needs a bit more torque off the bottom, and I think a 4% increase ought to be the ticket. Seems another inmate tried this and was very happy with it, but I don't recall where I read it. Shouldn't hurt the top-end cruise at all....might actually improve it, giving it a little more pull in 5th gear against a headwind. That's not such an issue until you're running the slab with packed saddlebags catching a lot more wind resistance.

Then, it will be an easy swap to the 15T when I get out in the Rocky Mtns and want to ride some jeep trails or whatever. An 11% increase should be enough to make it a suitable rock-crawler. And, a one tooth swap will easily fit within the same chain length. A 47/14 combo appears overkill.

I'm just waiting on my Supersprox order to arrive, then I'll get after it.

HF

Hey HF....you wouldn't happen to have a part number for that 49T rear sprocket would you? I emailed Supersprox a while back and they never got back to me. Also, what (link count) chain did you get?

Kev.

Also went with the 15T on mine. Better out of the hole etc and did not lose too much on the top and would recommend it for normal use. But....I rode a dual sport ride with it and it had tight trails etc I can tell you that I will go down to the 14T for that type of riding. Reason being is that I wanted to run the bike more in second gear for the trails etc but it was geared to high. I think a 14 would have made second, third and fourth perfect. It would make first a granny gear but I would gladly sacrifice it for the better mid gears which is where I think it would run the best.

Sticking with my 16T/47T for Strada mode...as well as Terra mode for casual off-road riding. However, I've purchased a 14T front gear and will be swapping it in once I get to the UTBDR (15 minute job max with tools I carry) and do off-road technical stuff for 4 or 5 days straight. Swap back to the 16T as we then head towards Vegas for a shower.

I went with the 15 tooth. Very happy . One side effect is better gas mpg. Now, I know I should be getting less mpg however I now shift up sooner and the new gearing fits my riding style. 12 to 15 more miles per tank. I also rerouted the wires to the brake as I never liked them hanging out under the bike.

Be careful thinking your getting better mpg. I'm not sure if the TR computer continues to calculate miles, speed, or consumption based on the factory gearing. If it does, then your odometer may be off, and I believe in a way that appears to be better, but in reality may be worse. You may want to check miles and speed with a gps and carefully calculate mpg based on the gps and amount of fuel you actually put in. I could be wrong...

I spoke with them on the phone to figure out. They weren't 100% positive, but everything I've cross-checked indicates the TR650 rear hub is a match to the F650. They all use the same drive spline (TR, F650, G650, Sertao). So I ordered a whole kit for the BMW F650GS. Here are the details in their paperwork:

*********************************************************

We will be in touch as soon as possible about your order, the details of which are as follows:

Shipping Method: UPS Ground
--------------------------
Product ID: KIT51106500
Product Name: Kit RSB5 CST402 Chain for BMW F650 GS (520 chain) [1999-2009]
Quantity: 1
Unit Price: $273.69
> > > Chain : RK GB520GXW-120
> > > Front : 16
> > > Rear : 49 Red
> > > Drawing : 5
> > > Guarantee__ : Lifetime
> > > T-Shirt : XL
> > > Dispatch : Standard - in 7 days
--------------------------
Order Total : $273.69
Shipping : $0.00
Grand Total : $273.69

*********************************************************

I'll report back soon, after I receive the product, to confirm the fit. I think others have already done this before me, so I'm expecting it to be correct.

This is an excellent chain which I've used several times previous. Got one on my F800GS right now.....along with a Supersprox Stealth sprocket. Both have performed flawless under 85 HP and 500+ lbs of torture. So, it's bound to be good on the smaller Terra.

The chain comes in 120 Links, which I will trim down to fit.....using a rivet link.

HF

Oooooooooooooooooooooh...you got the red one!

Thank you for the info

The odometer and speedometer run off the ABS sensor ring on the rear wheel. Changing the gearing shouldn't have any affect on speed or distance displayed on the dash. The consumption is calculated off the EFI computer by just keeping a running total of the amount of fuel it's injecting into the engine. When I left my bike idling in the driveway while I heated up the oil before I did my oil change the consumption incremented with the bike stationary, as you would expect if the engine is running.

Ah, right. I've got jeeps on the brain. I spaced the fact that the sensor is at the wheel.

I went from 16t to 15t...still good for highway speeds and makes the gearing tolerably low for offroad.

If I wanted any lower gearing, I would not go to a 14t, I'd add three teeth out back and swap the countershaft when needed.

IMO going to a 15t keeps you in the meat of the power a bit better - the 16t is SO tall that it struggles to pull top gear up much of a grade.

It's quite simple really.

14t



15t



16t



But honestly, throw the 16t on the shelf. Order both the 14t and 15t if you have some mechanical savvy and swap as needed. If you need the shop to do your work then have them install the 15t. The 15t is a very nice compromise.

Ken and I rode them all back to back and they all have there uses. Choose what you need for where you are going to ride more or where you want the bike to perform the best. Not to confuse things, I will continue my opinion of the 14t on the next post.....or maybe to confuse things even more.

Contrary to belief, the 14t is king in my neighborhood, maybe not yours. I have the proof, I have the seat time, and I have the photos!

so, i don't know how else to ask this, but it sounds mean, but i don't mean it like that.....

are you old?

hah hah hah. so i really wasn't bein bitchy, it's just like you're the old guy that gets broken bones from getting tossed around in surf....

jesus christ abby.