new sprocket

[akskidoo]

I just bought a 13 tooth sprocket for my LTR-450 that is in the shop getting welded. Will the stock chain still work and be able to be tightened, or will I have to buy another chain? Please advise.

[AL Elks]

Stock chain will be fine. There is enough adjustment there.

[KWAD GAWD]

I second that.

[quadracer3]

DOES TH 13 HELP THE BOTTOM END POWER

[akskidoo]

I was told it would since I moved up to 20" rear tires to ride in the dessert. The bike needs some more low end.

[IDEX]

Where did you get the sprocket? I've been looking for one but everyone is out of them?

Thanks

[akskidoo]

I bought it at a local parts shop here in Las Vegas. It is the same as the Z-400. I verified the part numbers of the stock 14 tooth from both bikes before I bought it. I purchased an Renthal part #432-520-13P that cost me $20.

[onesavage]

when you move up to 20 inch rear tires and switch the front sprocket to a 13T it will not give you more bottom end. it will be very close to the stock gearing with the 18 inch tires and the 14T. 13 37 with 20 inch tires is darn near identical to the stock set up. hope this helps anyone/someone.

[akskidoo]

Thank you for the info. I am new to the gearing game and I just know since moving to the 20's I have not been to happy, especially when I put on the paddles for the sand. My dealer told me my bike is finished being welded and they should have it back together in the next day so I can put the gear on and try it out.

[onesavage]

you are welcome. no problem. here is where i learned it. hoLou, you can calculate the gear ratios...

Factory gearing is 14T front sprocket and 36T rear: 36/14=2.57 (any number bigger is geared lower and any number smaller is geared higher)

If you drop a tooth on the front: 36/13=2.77 (dropping teeth on the front lowers gear ratio)
If you raise a tooth on the back: 37/14=2.64 (adding teeth on the back lowers gear ratio)

If you add a tooth on the front: 36/15=2.4 (adding teeth on the front raises the gear ratio)
If you drop a tooth on the rear: 35/14=2.5 (dropping teeth on the rar raises the gear ratio)

It is commonly accepted that one tooth change on the front sprocket equals three on the rear sprocket...let's test it out:
If you drop a tooth on the front: 36/13=2.77
If you add 3 teeth to the rear: 39/14=2.79

Pretty close...

Hmm, now, how did changing your tires affect everything? Taller tires raise your gear ratio and shorter tires lower it...
Here is a sample calculator for your tire changes...
Find new gear ratio with new tire size calc
Your old tires were 18" tall, your new tires are 20" tall, your factory gear ratio is 2.57...according to the calculator you will need a gear ratio of 2.86 to have the same ratio with your new tires as the bike had stock...which would be a 13T front and a 37T rear...37/13=2.85.

Does this make sense?



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05 TRX 450R
04 KFX 700
05 Predator 90
06 LT-R450

RockinHorseWeb...Check It Out!pefully this works. good luck.

[onesavage]

http://www.dirtroadmagazine.com/gears.htm

[Chad W]

Good info.

[akskidoo]

I put the gear on the bike and all I can say it is the best $20 I ever spent, other than down in the Philipines but that is another story. The performance of the bike is back where is should be. I rode with my friend on his YFZ-450 that has done the exhaust and jetting, and beat him everytime. He was upset and put his bike up for sale so he could buy an LTR. Again thanks for the information.

[turtleboy]

what shop out here in vegas did you go to get the recall done? How did their work come out? Thanks!

[KWAD GAWD]

If you want 20s and want lower gearing still - drop the front down to 13, and go up 2 in the rear. I agree, my bike needs to be lower geared. I like third to rip harder, and right now it boggs coming out of some turns in third.

[akskidoo]

Las Vegas Motor Sports on Craig is where I brought my bike. They basically strip off the plastics and sent it out to a certified welder. It took just over 2 weeks due to the 4th of July. The weld was good but everything was loose. I had to go through the bike and lock-tight and tighten everything again. My chasis skid plate was so loose it rattled when it was idling. Also do not buy parts there, they are to expensive. Example, cherry-bomb $50, Yoshi full exhaust $675. Visit Sam's Cycle shop on Rancho, they will work with you.

[turtleboy]

Thanks for the tips! I'll have to go check out Sams Cycle shop. Did you get your 20" tires there?