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-1 up front

I just put on a JT sprokets 13t front and I'd like to say that leaving ratios, the tachometer and speedometer out of my opinion and going by feel I'd say it's the best 15 bucks I've spent on a motorcycle. It brings the front up when going into 2nd now and pulls smoother all over. Definitely had a big grin all over
 

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I just put on a JT sprokets 13t front and I'd like to say that leaving ratios, the tachometer and speedometer out of my opinion and going by feel I'd say it's the best 15 bucks I've spent on a motorcycle. It brings the front up when going into 2nd now and pulls smoother all over. Definitely had a big grin all over
The tachometer itself isn't affected by sprocket changes... it will always tell you what the correct engine RPM's are regardless of what the sprocket sizes are, as the tachometer gets it's signals from the ignition system.

It's the speedometer which is thrown off either +/- by sprocket changes (a change in rear tire size to anything other than the stock size will also cause speedo inaccuracy).
 

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Haha this thread.

Wonder if the Eco riders magically found the 20hp needed to go faster with taller gearing.
or they found the throttle, and said
'stuff the environment, Imma gonna use a whole 25 cents more fuel today and have some fun"
 

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Haha this thread.

Wonder if the Eco riders magically found the 20hp needed to go faster with taller gearing.
or they found the throttle, and said
'stuff the environment, Imma gonna use a whole 25 cents more fuel today and have some fun"
I hear you...

Seems nearly everyone over on the CBR300R forum is changing from the stock 14T to a 15T front, and some are also changing the rear sprocket from the stock 36T to a 34T. Common complaint among 300R owners is that 1st gear is 'too jerky', and as a result they are having trouble making smooth starts and/or riding in 1st gear... who rides around in 1st gear anyway?

That, and many don't like running in the 7000 to 8000 RPM range in top gear at highway/freeway speeds.

I just don't understand why people would want to go to taller ratio, and make their bike even slower, when the stock gearing is already marginally too tall.
 

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Seems nearly everyone over on the CBR300R forum is changing from the stock 14T to a 15T front, and some are also changing the rear sprocket from the stock 36T to a 34T.
I think there's two main reasons for this:

1. the extra 4-5hp of the 300 makes it feel a bit short in the gearing and you find yourself reaching for the '7th gear'.

2. The 286 motor is not as sweetly balanced as the 249 motor and has a harsh (ish) vibration that kicks in around the 6 - 6500 mark so makes high speed cruising a little less enjoyable. Putting a little extra load on the motor with a 15T front sprocket seems to reduce the vibration. Ive geared mine so that I'm pulling 5700RPM at 60MPH and outside of the rough zone.

Having said all of that... gearing is as personal as your choice of underwear, there's no right or wrong cog but one for every occasion. :)
 

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I hear you...

Seems nearly everyone over on the CBR300R forum is changing from the stock 14T to a 15T front, and some are also changing the rear sprocket from the stock 36T to a 34T. Common complaint among 300R owners is that 1st gear is 'too jerky', and as a result they are having trouble making smooth starts and/or riding in 1st gear... who rides around in 1st gear anyway?

That, and many don't like running in the 7000 to 8000 RPM range in top gear at highway/freeway speeds.

I just don't understand why people would want to go to taller ratio, and make their bike even slower, when the stock gearing is already marginally too tall.
Ninjette forum is similar in some ways,
they say that cbr250's 'cant go on the highway' but a Ninja 'can' !???
yet in the real world a Ninja 250 is only faster once you jet it so it pulls hard between 11000 and 13000 (95-110mph)

So IF a Ninja 'can go on a Highway' n the USA where supposedly Camrys are faster than Camrys anywhere else in the world (facepalm)
Then they need to do at least 95mph to be milking it in 5th before hitting 6th for all its worth,
Meanwhile a cbr is doing at least 3000rpm less at 95mph and a gear higher.

My Ninja did 157kph with 43T, 159 with 45T, and 163 with 47T at the track.( datalogger , speedo says 175+)
Unless you held it open for a few miles in 5th and got a downhill run as you punched 6th, it will always be slower with a 43 (Stock)or taller

the Cbr has only got 23HP to play with, its a slow reving bike but can do 10,800rpm and not complain.

Then they gear it up and anyone whos ridden a Ninja knows the cbr is in front of a Ninja all the way to at least 9000rpm

It all makes me want to fire up the RZ and belch hydrocarbons into the atmosphere sucking back 20 litres per 100km (11.760729166666665 miles per gallon (US) ) and make an Eco rider pass out.
 

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34T fits on the rear hub? I need one! Who makes that?
I got mine off PMP sprockets in Texas, $49.95, just type the # of teeth you want into the box.

Honda CBR250 R (11-13)

They are made from Aluminium but mines done well over 10K miles and has still got life left in it.
I didnt go for the HardKoat option which adds a other $14. Various color options too.

With the 34T the inner edges of the side plates just hit the hub and put very small indentations in the aluminium hub of the wheel so if your a perfectionist then you may want to go for a 35T but it doesn't bother me and I wouldn't worry about it.
 

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I have a hard coated 36T rear from PMP Sprockets that is still not worn out after 35,000 miles and on it's second chain, which is a DID Gold Xring with 20,000 miles on it and is just needing it's first adjustment. She told me 35 was the lowest they could go but now we see that 34 can work with a slight self created mod for hub.
Your getting great mileage on your wear items there. Regarding the contact with the hub: that is with the endless OEM chain. An aftermarket chain with a slightly higher profile on the side plates could potentially be more problematic.
 

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I got 31,000 miles, 50,000 km out of my original front IRC tire. 15,000 miles out of the first rear and 16,000 out of the second rear. The Michelin Pilot Streets I have on there now will go even farther. And a 90 day average fuel consumption for this unusually dry summer is 115 mpgUS, 48.9 km/L.
I wonder if sendler will still update us from time to time..
 
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