Product Reviews


Product/Service: Thrust Gearing
Manufacturer/Provider:
Moto-Heaven
Reviewed by:
Jeff Kufalk with additional manufacturer information


Bar none, the easiest way to gain the feel of performance on your bike is through changing gearing. A quick and inexpensive way to really feel the punch you're looking for, and if you're a racer, you know that having numerous sets of gearing is a must.

Changing the gearing will move the powerband of the bike down lower in the RPM range, and give you a heck of a lot more low-end grunt.

The Stage 1 kit is the most commonly used, and will provide you the ability to get off the line much faster, or for you to pull wheelies like never before :-)

To see the difference in speeds on the Stock setup versus the Stage 1 Thrust kit, please see the following:

 

OEM 16:43              

Thrust Stage 1
15:45

           
Motor     GEAR         Motor     GEAR      
rpm x 1000 1st 2nd 3rd 4th 5th 6th   rpm x 1000 1st 2nd 3rd 4th 5th 6th
                           
1 4.88 6.71 7.83 9.23 10.12 11.15   1 4.37 6.01 7.01 8.27 9.06 9.99
1.5 7.32 10.07 11.74 13.84 15.18 16.73   1.5 6.55 9.02 10.52 12.40 13.60 14.98
2 9.75 13.43 15.66 18.46 20.24 22.30   2 8.74 12.03 14.03 16.53 18.13 19.98
2.5 12.19 16.78 19.57 23.07 25.30 27.88   2.5 10.92 15.03 17.53 20.67 22.66 24.97
3 14.63 20.14 23.48 27.68 30.36 33.45   3 13.11 18.04 21.04 24.80 27.19 29.97
3.5 17.07 23.49 27.40 32.30 35.41 39.03   3.5 15.29 21.05 24.54 28.93 31.73 34.96
4 19.51 26.85 31.31 36.91 40.47 44.60   4 17.48 24.05 28.05 33.07 36.26 39.96
4.5 21.95 30.21 35.23 41.53 45.53 50.18   4.5 19.66 27.06 31.56 37.20 40.79 44.95
5 24.39 33.56 39.14 46.14 50.59 55.76   5 21.85 30.07 35.06 41.33 45.32 49.95
5.5 26.82 36.92 43.05 50.75 55.65 61.33   5.5 24.03 33.07 38.57 45.47 49.85 54.94
6 29.26 40.28 46.97 55.37 60.71 66.91   6 26.21 36.08 42.08 49.60 54.39 59.94
6.5 31.70 43.63 50.88 59.98 65.77 72.48   6.5 28.40 39.09 45.58 53.73 58.92 64.93
7 34.14 46.99 54.80 64.60 70.83 78.06   7 30.58 42.09 49.09 57.87 63.45 69.93
7.5 36.58 50.34 58.71 69.21 75.89 83.63   7.5 32.77 45.10 52.59 62.00 67.98 74.92
8 39.02 53.70 62.62 73.82 80.95 89.21   8 34.95 48.11 56.10 66.13 72.52 79.92
8.5 41.46 57.06 66.54 78.44 86.01 94.78   8.5 37.14 51.11 59.61 70.27 77.05 84.91
9 43.89 60.41 70.45 83.05 91.07 100.36   9 39.32 54.12 63.11 74.40 81.58 89.91
9.5 46.33 63.77 74.37 87.67 96.13 105.94   9.5 41.51 57.13 66.62 78.53 86.11 94.90
10 48.77 67.13 78.28 92.28 101.18 111.51   10 43.69 60.13 70.13 82.67 90.64 99.90
10.5 51.21 70.48 82.19 96.89 106.24 117.09   10.5 45.87 63.14 73.63 86.80 95.18 104.89
11 53.65 73.84 86.11 101.51 111.30 122.66   11 48.06 66.15 77.14 90.93 99.71 109.89
11.5 56.09 77.19 90.02 106.12 116.36 128.24   11.5 50.24 69.15 80.64 95.07 104.24 114.88
12 58.52 80.55 93.94 110.74 121.42 133.81   12 52.43 72.16 84.15 99.20 108.77 119.87
12.5 60.96 83.91 97.85 115.35 126.48 139.39   12.5 54.61 75.17 87.66 103.33 113.31 124.87
13 63.40 87.26 101.76 119.96 131.54 144.96   13 56.80 78.17 91.16 107.47 117.84 129.86
13.5 65.84 90.62 105.68 124.58 136.60 150.54   13.5 58.98 81.18 94.67 111.60 122.37 134.86
14 68.28 93.98 109.59 129.19 141.66 156.12   14 61.17 84.19 98.18 115.73 126.90 139.85
14.5 70.72 97.33 113.51 133.81 146.72 161.69   14.5 63.35 87.19 101.68 119.87 131.43 144.85
15 73.16 100.69 117.42 138.42 151.78 167.27   15 65.54 90.20 105.19 124.00 135.97 149.84

Using the above illustration, on the highway, at approximately 65mph, instead of being at 6000 RPM's, your roughly 6500 RPM's. The chart also shows that the top speed drops from 167.27mph down to 149.84. People seem to get hung up on this, but let me point out a few things to think about.

1. How often do you REALLY go 150+mph???
2. Most modern sportbikes cannot reach redline in 6th gear due to power loss and wind resistence. That being the case, many times, by gearing down, you can achive an actual top speed higher than that of stock gearing!


Things you'll need to change your gearing? The stock tool-kit can help you out with some of it, but really you need decent tools, including the following:

You can get away with some improvision, (hang rear of bike from rafters, etc) but don't ask me if you can use a crescent wrench or an SAE wrench that's "close enough" because you won't like my answer. If it's "that bad", take it to a shop and have them do it.

Steps to change gearing:


Other stages/gearing combinations are available, and they are starting at $60 for the set. If you have a special need in mind, use the following spreadsheet to determine what will work for you!

Download this MS Excel Spreadsheet to work up your combination! This sheet is applicable to the 2003/2004 Honda CBR600RR only.

This portion is comments from Phil Caudill, owner of Moto-Heaven, and proud sponsor of CBR600RR.com Racing

Stunter Sprocket Sets

Moto-heaven is offering Thrust brand pre-packaged and custom sprocket sets that offer all riders an unmatched increase in acceleration and pull, or thrust, than any other bolt-on modification you can make for the money.

Available in a Stage I, Stage II, and Pro, they have a kit to fit everyone's needs. If you're looking for that extra rush when you twist the throttle or to be able to loft the front wheel easier (and at slower speeds) then they have what your looking for.

The kits are readily available for all modern sportbikes and can also be custom packaged for any bike on the road. The beauty of the Thrust Kits is that you can retain your stock chain. You don't even have to remove the chain to install the new kit. And step-by-step installation procedures and quick tips are included. There is no guesswork for you.

There is no other less expensive, easier, quicker, no-hassle way of increasing the sheer feel of acceleration than with one of these kits.

Here is what two recent customers had to say-
"I just wanted to thank you for getting me that sprocket set so fast. I installed them right away last night and rode all morning. It's F'in amazing! It feels like a completely different bike. If you have a catalog I'd like one. Thanks again.
Brian T."

"Very nice !!! I now have a 130HP unicycle!
Loren M."

If you're looking for that extra rush when you twist the throttle or to be able to loft the front wheel easier (and at slower speeds) then they have what you're looking for.

All Thrust sprockets are Made in the USA. The rears of 7075-T6 aerospace aluminum and are machined to exact specs with tolerances 7 times greater than OE sprockets. The front sprockets are made of heat-treated steel for optimum durability, and in most cases are machined for superb accuracy vs. cast. You might not think tolerances are that important- but, when think about how many times a sprocket tooth comes in contact with a chain, and at the speed and force at which the contact takes place, you should begin to realize just how much an accurately made sprocket can increase the life of itself and your chain.

Details on different products-
Stage I - Will retain about 95% of top speed from stock gearing, while moving all shift points and powerband hit up about 1 gear for any given speed. So, if your front end lifts under hard acceleration in 1st now, then it will now act the same way in second and lift very easily in first. Another example would be if you now see 60mph in 2nd, then you'll now be shifting into 3rd and accelerating harder within the same distance. And, in some case where a bike is geared fairly high, this kit will increase the terminal top speed because it will allow you to accelerate and pull all the way into the area of redline in top gear.

Stage II - This kit will retain about 85% of a bikes top speed while changing all changing all power and shift points by two gears.

Pro - This type of kit is designed and meant for 100% stunt riding. Although ideal combinations have been determined, these kits can also be put together on a custom basis. Installation of this kit does require the installation on a custom length chain. Expected top speed will be 80-90mph. However, this is the preferred setup for performing very technical stunts such as: Slow 12's, No-handers, Coasters, Circle wheelies, etc.

Technical Q&A
Why does a sprocket change work so well for increasing acceleration?
Modern sportbikes are geared for speed. They have very high revving engines in order to produce the hp required to obtain these high terminal speeds. However, the hp and torque required to do this is made in the very high rpm range and therefore at high speeds. What the lowering of the final drive through the sprocket does is brings this power and torque down to slower speeds. This is also why the terminal speed will be reduced as you lower the final drive ratio.

Why does lowering the final drive with a Thrust Sprocket Set make wheelies so much easier?
What you are doing by lowering the final drive ratio is allowing the bike motor to rev into the powerband much quicker and at much slower ground speeds than they are originally designed. How this helps is it allows you to use the bikes hp to lift the front end while doing so at a much safer, more controllable, and comfortable speed. And at the slower speeds you aren't fighting the gyroscopic effects created by the wheels spinning even faster.

Moto-heaven also offers Thrust 520 Conversion Kits for most bikes for when you're ready to get serious about performance, track day riding, road racing, or drag racing.



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