Gearing, who picked that final drive???

[old3]

I love the new wider ratio trans, much better than the old 250 which was so limited in power it was made to just wail at highway cruise speeds when it had gearing that would actually move you briskly from a stop. However, the gearing on the 300 is very low in first, and I was using second gear most of the time from a dead stop. Even with a passenger it was better than first which was more noise than action IMO.

On went a 2008-12 15t counter shaft sprocket, fit perfectly and suddenly I have a useable first gear! Nice mod, and I'm a guy who runs super short gears on everything I own. My Mustang has 4.56s and my KTM 950 SMR had a -2 front CS so I like my peppy gearing.

Another +, I think the speedo will be closer to actual speed now, stock it runs higher than actual speed. I'll verify that with a GPS ASAP but so far I'm convinced it is actually dong the speed it is reading.

Best $12 I have spent on the bike.

[csmith12]

[old3]

True GPS speeds = the speedo with a +1 CS!

Top speed in each gear at the rev limiter;

1st=37 MPH
2nd=57
3rd=72
4th=88
5th=?
6th=?

I've been to 100 in both 5th & 6th, gotta find a spot to stretch it to the top of the tach soon.

GPS confirmed!!! Speedo is right on the $ every 10 MPH up to 70 MPH.

[choneofakind]

Cool! So where's it running now at highway speeds in 6th gear, call it 75 mph?

[geeker]

Originally Posted by choneofakind

Cool! So where's it running now at highway speeds in 6th gear, call it 75 mph?

6th Gear (stock)
50 MPH is 6000 RPM
70 MPH is 8000 RPM
80 MPH is 9000 RPM

[old3]

Top speed in each gear at the rev limiter;

1st=37 MPH
2nd=57
3rd=72
4th=88
5th=?
6th=?

I've confirmed the reading on the speedo now matched actual speed via GPS. I don't think there is much difference in RPM vs speedo reading except the speedo is actually correct with a +1 CS. ie, you weren't really going 70 MPH when it read 70 before.

[old3]

8k RPM = actual GPS confirmed 72 MPH

8300k RPM = 75 MPH

[beazy411]

Originally Posted by old3

8k RPM = actual GPS confirmed 72 MPH

8300k RPM = 75 MPH

Is that in 6th gear? If so that's pretty nice, still have an extra 4700 rpm to play with on the highway if needed.

[old3]

Yes, 6th gear

[tnr4]

Thread revival! @old3, I just ordered a 1539.15 sprocket -- totally excited. The more I commute on this bike the more I agree that first gear is practically unusable. So my question is this: if I don't have an impact wrench or anything beyond basic tools, will I be able to do this myself? It seems crazy to pay someone to do something so close to the surface, but I don't know if I'll be able to get the CS nut off, or if I'll be able to button up everything correctly without a torque wrench (I know, it's embarrassing that I don't have one).

I do have a buddy I could get to come over and stand on the rear break; will that be enough? Would you be hesitant to do it without a torque wrench?

Thanks in advance!

[old3]

A few guys have gotten the nut off alone, others can't get it with a helper. You just have to try it IMO. As to the torque wrench, I don't use one for the countershaft sprocket. I use some red lock-tite and make sure the locking washer is good and crimped firmly. As to the torque, I give it a "good & tight" on the old arm. I don't kill it, and the recommended torque is usually pretty high. Between the lock washer and thread locker it isn't going anywhere.

Of course, I recommend anyone else go strictly by the book!

[geeker]

Maybe it's my inner child, but I can't read your post above without laughing. Lmao

[old3]

Was it the "gotten the nut off alone" part?

[tnr4]

Originally Posted by geeker

Maybe it's my inner child, but I can't read your post above without laughing. Lmao

Originally Posted by old3

Was it the "gotten the nut off alone" part?

Hahahahaha!

And thanks for the advice, Jim. Looking forward to getting this thing on there!

[geeker]

Others can't get it with a helper...

...I give it a "good & tight" on the old arm. I don't kill it...

[old3]

Originally Posted by geeker

Others can't get it with a helper...

...I give it a "good & tight" on the old arm. I don't kill it...

I get that arm calibrated every day FWIW!

Getting older has one benefit, you don't have the strength to break off a bolt anymore!

Seriously I do so many sprockets I just set them to where I feel is OK, not too tight. I know it should get the torque wrench but with all our family's race bikes none ever come loose so I must be getting it close enough. The KTMs require pressure from that bolt to seal the shaft from oil leaks so I don't just ham fist it, but I never measure it either.

Seeing all the riders that can't get the factory nut loose tells me that they don't necessarily torque them either!

[tnr4]

Hey @old3 (and anyone with more mechanical savvy than me -- so, everybody):

So, my CS nut defeated me. I'll have to find someone with real tools to help me. However, I ran into a another problem: when I gave up and was buttoning her up, I made a mistake. The bolt that holds the speedo relay (I think that's what it is?) is real soft, and I somehow torqued it too hard by just giving it a final twist on the wrench. The head popped off, with the threaded bit firmly embedded in the sprocket cover. I attached a pic to make clear the bolt that I buried.

The bolt is slightly redundant, since the plastic cove holds it in place, and the 'plug' end fits inside the metal sprocket cover. So I just cursed a bunch, finished putting it all together, and took it for a spin. No noise, speedometer read just fine. So I'm not worried about it in the short term, but I don't know what to do long term. Will someone with mechanic's tools have a magical way to unthread that decapitated bolt? Or will I just need to buy a replacement metal sprocket cover?

Advice?

[old3]

It should be able to be drilled and unscrewed with an easy out tool. With those 6mm bolts I just center a T handle wrench in my fist and go to my wrist strength, not any leverage on the wrench at all. They abound on my KTM and Husky race bikes so I am dealing with 6mm bolts all the time.

If you can unbolt the component and slide it off the remaining stud you might be able to unscrew it with simple pliers too.

edit, I might be thinking of a different bolt, is it the gold one to the right of the sensor? An easy out should still work, or if you can expose it pliers. I don't recall if I even took that one out now.

[tnr4]

Thanks, Jim. Yes, you have the right bolt now -- the gold one. It's only job is to hold the sensor in place. Unfortunately, nothing is sticking out, so I couldn't nab it with pliers. I've got some buddies at the local dealership, though, so I might ride out there when the weather clears as I'm sure they'll have an easy-out tool, and they may be willing to help me throw the sprocket on as well.

Now, to google easy-out.

[choneofakind]

Originally Posted by tnr4

]Now, to google easy-out.

It's a reverse threaded drill bit. You drill into the bolt in question, then use the reverse threaded bit to extract the shaft. As you turn the drill CCW, it bites into the bolt and unscrews it. Sometimes they work, sometimes they don't. Best of luck with it

[old3]

There are easy out kits at sears or home depot too I believe that screw into a hole you drill. It should come right out as there is no pressure on it or cross threading. When you drill you need to use the correct size and obviously avoid the threads.

Can you pop the sensor off? That would expose the shaft. If not, it might be fine to just leave it alone.

You might also try a small screwdriver, regular or phillips and just put light pressure on it and turn counter clockwise. It may come right out.

[jaybo]

usually when the head pops off it takes the tension off of the threads so you can take a nice sharp centerpunch and a hammer. get close to the edge and make a dimple, then lean the centerpunch so your angle of impact is pushing counter clockwise and tap the bolt around easy untill you can get your fingers or pliers on it and remove it. If that does not work I usually weld a nut to it and take it out with a socket. Easy outs work also and given the quality of the hardware on this bike it should be easy to drill.

goog luck bro

[tnr4]

So I'm lame and decided to just go to my local shop and pay the nice guys there to fix my booboo and throw the sprocket on. They were cool about it, and I didn't have to spend any more of my (currently non-existing) time on it.

Upshot: rode home with the new sprocket this afternoon, and man what a difference. I actually caught myself about to downshift into first for a turn! Soooo much nicer. I agree with Jim: this is how the bike should have come stock. And it really does feel faster rather than slower off the bottom. Overall, although I'm bummed I wasn't able to do it myself and keep it a $14 dollar mod, it's still a fantastic change to the bike. Thanks, @old3, for the reviews that got me interested!