GEAR COMMANDER and CHOICE OF SPROCKETS

[cobbadiggabuddyblooo]

http://www.gearingcommander.com/

for example the three choices I made to start.
kept the std TRX gearing and tyre size as stock for a reference..
STOCK... 17 / 39 160 / 60 tyre

CURRENT... 16 / 40 170 / 60 tyre

CUSTOM... 17 / 41 180 / 55 tyre



For the lads who haven't ventured here yet.
A handy tool for when you choose your final drive gearing with the next sprocket change.
Take the time to just check out all the functions on offer with the software in this program.
Not only the speed and rpm with choices of gearing, but you can calculate the changes with different tyre choices and outcomes here too.
It allows you to compare 3 choices at once...the std TRX gearing ,to whatever gearing you may currently have and a third custom gearing you may want to try.
All these give you the option of tyre size too and the actual tyre circumference as different manufactures are different sizes all be it the same aspect ratio.. (160/60- etc)
The MP. R.P.M section comes into play where you set the revs for comparisons of speed with gear changes at the pre designated RPM you place here. ( Handy when you know your torque curve)

Under the 5 tables of figures it produces you will see other functions that allow you to produce graphs for scenarios you place in your original 3 sprocket setting choices to start.
Handy tools for noting your rev range and speed in each gear and if you have an idea of where your torque range for your motor and lots more.
If you have a spare hr or 2 just check the info at hand as each graph/ table has it's own help guide.
There are wear tables and I now also remember why I've chosen to change the gearing I have from an even number of teeth back to an odd number and no longer running 16/40 this time around..

You will also note on these tables it also equates the movement in length in the swingarm when making these changes as ultimately shortening or lengthening this every few mm will play on the suspension settings with compression and rebound because of the leverage factors involved.
All be it ,this may only be 1 or 2 clicks but as I found those 1 or 2 clicks can make all the difference on your trackdays.

Handy information on chain maintainence and adjustment and information on chain pitch and roller width.
520-525-530 all have the same pitch but different roller width = more friction..

So my quest goes on to find my ultimate final gearing for my intended purpose.

[Con Rod]

just picked up a new chain and sprockets to go on today. Decided to go 17 / 41 as I hope to make around town a little more pleasant given I run the bike fairly lean and don't mind sacrificing a few km of top speed

Wear wise it should not adversely effect chain life.

Got 40,000km out of the old chain and sprockets

[cobbadiggabuddyblooo]

That the same I was looking at myself as I found the 16/40 I'd find the limiter in top at just over 230kph with 60 series front and 160 rear.
Figured with the rebuild I could still pull my own through the midrange but just give me that little more down the straight in top without over reving the motor..
It was pretty evident how tyre choice can make a difference as the 70 series on the front changed speedo the reading and was about 6kmh out every 100kph.
170 rear also made the gearing a little taller with a higher circumfrence tyre so I would only just find 215kph on a good day.

[M.V.]

My TRX wouldn't pull to redline with stock or even 41R gearing, but it does with a 45 tooth rear!

Gets an indicated 210 or with a 60 section front, I think I only ever saw just over 220 with stock gearing, so it wasn't as big a drop as I expected, plus it's much easier around town.

[cobbadiggabuddyblooo]

gotta love those FCR's and larger exhaust ..makes all the difference..
I put the std headers back on with the staintunes/fcr's for a couple of days and that killed the top end too as I struggled to get close to 8000rpm in top.
Just couldn't get the gasses away fast enough

[Con Rod]

gotta love those FCR's and larger exhaust ..makes all the difference..
I put the std headers back on with the staintunes/fcr's for a couple of days and that killed the top end too as I struggled to get close to 8000rpm in top.
Just couldn't get the gasses away fast enough

I agree with this logic, just reducing the main jet size in the stock carbs also makes a big difference, the TRX stock is WAY to rich at wide open throttle

back on topic put the new chain and sprockets on so stock 16 on the front and up to 41 from 39 and the rear. Took it for a bit of a spin which was around town and a bit of freeway at 80 and 110.

Its good, not a huge change, but it does let me go up a cog when cruising on the freeway, probably only another 250rpm but buts the engine in a happier place

around town its great, on slow corners she puts cleanly in 2nd where she used to bog a bit and really you can leave it in 2nd.

Yes to see how it goes a higher speeds but initial impressions are good.

Not to mention the fact that having a new chain is delightful on the gear changes.

[Con Rod]

Went away overnight on Saturday/Sunday and gave the bike a good work out. I have decided to revert back to the 39 rear (from 41)

While the 16/41 setup is better around town at lower speeds when riding hard it doesn't really give me much more than running the engine at higher rpm and worse fuel economy,

for high speed stuff, at 140kmph and above you are loosing at lot of 4th gear. That said it will happily pull to 200kmph so not loosing anything meaningful in terms of top speed, but I would rather that better fuel economy and lower engine rpm

If anyone would like to try the 41 rear I will sell mine once I have gotten a replacement, it only has 1200km on it on a new chain