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Optimum Offroad's NEW Polaris Gear Reduction

8K views 24 replies 10 participants last post by  tjZ06 
#1 ·
The Optimum 10

Rated at 500 horsepower and designed as a stand-alone 10% final drive reduction for the racer running stock sized or larger tires, the mud rider who wants a little more reduction and the weekend driver who wants to run 32" tires on his RZR and not loose the "power punch" that you had with the stock 29" tires. The spur or straight cut gear design is more efficient at transferring power and eliminating thrust load (sideways force) on the shaft and bearing that cause most case fractures. There are fitments for the Turbo, XP1000 (+HL & Gold), XP900, General, S900/S1000 and many Ranger models- all of these models can go up 3 tire sizes.

A word to the GNCC & WORCS racers who have tried and broken other gear reductions- give us a try, you won't break the 10.

I'm going to start with the price. $695.00. More than what you would pay for a gearstack reduction.

Now, let's look at what that extra money gets you..


SIGNIFICANTLY REDUCES IDLER SHAFT CASE FRACTURES

Where the reduction takes place in the Polaris XP style transmission is very important. A lot of you have had broken cases and some of those cracks and breaks happen shortly after gearstack reductions are installed. All of the driveline after the reduction is under the same stress and load as though there were no reduction. Said another way- If you are running 32" tires (or 37's lol) and have a gearstack reduction all of your driveline from the wheels up to the gearstack remains under the same load as if you just kept your stock gearing. This is where portal boxes shine, they do a very good job of removing stress from your driveline but unfortunately unless a vehicle is designed for portals or used mostly for low speed operation, they do a poor job of everything else. Another option would be new ring and pinions, unfortunately on the RZR and other Polaris products, that is difficult and would be very expensive to build. Which leads us back to the transmission. The rear ring gear is driven by the same shaft that powers the front driveshaft and that shaft is called the pinion shaft. Our reduction happens here, at the pinion shaft, the first place in the transmission that can send power to the front & rear at the same ratio. Because our reduction is closer to the wheels your transmission sees less strain, stress and load. As noted above, the straight cut gear also creates no side to side thrust load to keep you transmission case safe from cracks.

STAND ALONE FINAL DRIVE REDUCTION OR COMPOUND

Another big Optimum 10 benefit is compounded reduction. First, owners of Highlifters and the new Gold Rock Crawlers would have additional 10% reduction with us because this new design happens closer to the wheels. Also, anyone who is running a gearstack reduction would see a further reduction using the Optimum 10.

NOT THE CHEAP STUFF

Made in the U.S.A, in San Diego, California. We use 9310 alloy which makes a strong and VERY TOUGH gear. Used extensively in NASCAR and very common in offroad racing.

EASIER TO INSTALL

After the transmission case is split, installing our set does not require disassembly of the gearstack, just move it out of the way so the idler shaft behind it can be removed and replaced with ours. You do not even have to remove the pinion shaft, the Optimum reduction gear that replaces the stock pinion shaft driven gear is designed to be installed with a light to moderate tap fit.[/SIZE}]

Patent Pending

Check out Optimum Offroad - Home for more information and to order. Thanks for looking, PM me or reply to this thread with questions.
 

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#5 ·
I have been thinking about doing this to mine. Running 32" Pro Armor crawlers, I think this would help wake the XP4 back up. Even with an exhaust and clutch kit, I believe that this will give me some power back.

This is a quality product. If any of you have followed desert racing you will know the name Mendeola and the quality that that team puts forth in all the high end gear boxes that they make which is who Optimum has partnered with to manufacture these. So you know you are getting a high quality with this.
 
#6 ·
Thanks. I approached Mike November of 2015 with ideas about how to push this sport forward. He has been very receptive and added his own input based on more than 40 years of of racing and winning.

I questioned releasing the 10. Everyone who I talked to on the West coast had no interest in gear reduction with most people just doing clutch work when jumping up on tire size. Then we started putting test miles on the 10 and were all super impressed with the power on the trail and tractability in the rocks and technical riding. The seat of the pants feeling of power with the 10 makes it worthwhile for most guys running bigger tires. My stock Turbo on 32's will pull a stock Turbo with stock tires.
 
#12 ·
10% reduction is nice for guys like me with a turbo on 32's. Thing will tear ass out of the hole... I don't do anything over 60mph anyways
 
#13 ·
Exactly. Most people would give up a few miles an hour on the top end for more power in the midrange where it's mostly used. Most of the test miles on the 10 were in RZR Turbos and this relatively small percentage change really wakes the car up. Over the next couple weeks I'm going to have before and after dyno numbers and put actual data to the seat of the pants feeling.
 
#14 ·
With the 10% reduction... if the rig does 80mph now.. minus the 10%, it now does 72mlh.. or is the math not like that lol
 
#15 ·
Good question. Clutching, tire size, tire & wheel weight and a few other details complicate an exact top speed difference stock tire size vs. stock tire size. Obviously if you're going from 29" stock tires to 32's then you would be making the difference back up in diameter and therefore effective final drive ratio.
 
#21 · (Edited)
Just ordered your setup for this:







It is on 33x10.5-15"s, so it'll still be sliiiiightly higher gearing than the stock trans gearing with stock wheels/tires. I also have these for it (31" STUs):





Which "should" result in basically perfect gearing. The car has a Z1 swap w/ STM clutches, which I believe actually give a little deeper initial ratio, so if anything it should come out of the hole a little better than stock.

-TJ
 
#22 ·
Just ordered your setup for this:















It is on 33x10.5-15"s, so it'll still be sliiiiightly higher gearing than the stock trans gearing with stock wheels/tires. I also have these for it (31" STUs):











Which "should" result in basically perfect gearing. The car has a Z1 swap w/ STM clutches, which I believe actually give a little deeper initial ratio, so if anything it should come out of the hole a little better than stock.



-TJ


Thanks for the order, it shipped today. Your usage is what the 10 was designed for. Were those pics taken on the Rubicon?


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