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i just got a 2012 this weekend and have ridden 30 miles so far. i think the bike's weak off the bottom revs, so i'm going to try a smaller fr sprocket soon. i know i'll loose some top speed for hwy use, but im only using this bike for school, so it's all light to light city riding. id rather have a bike that pulls harder from a stop than to have one that pulls past 80-90 mph.

i saw that there's room on the axle mount to pull the rr wheel farther back when i go to put a smaller sprockt on the front, so that's good b/c i won't need to shorten the chain. come to think of it, i haven't checked yet so i could be wrong, but i think this stock chain probably don't have a removable chain link, it's all riveted from honda. hope i don't have to shorten the chain, b/c i don't think we have a chain breaker.
 

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where did you buy the front sprocket from?
$24 from my sponsors Prestige Honda in Melville, thru Cassons the Aussie wholesaler lol.

I'm sure Renthal is avail in your country, google is your friend.
 

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I have not checked if it fits, but that same part number is listed for the cbr250 on the Renthal website, and Cassons say its definately the one.

Will let you all know if its correct in a day or 2 when I fit it.
 

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Yes and thank you for telling me that I can google it, I really had no clue that you could go to google.com and NOT find the sprocket which is why I asked which is the whole purpose of a forum. What is the purpose of having a forum that doesn't want to answer question and only want to say google it. Might as well shut down this forum because that is everyone's reply. Google it, search the forums, who cares if there is a 1000 post about an exhaust and someone else starts one, just tell them the answer.
 

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Yes and thank you for telling me that I can google it, I really had no clue that you could go to google.com and NOT find the sprocket which is why I asked which is the whole purpose of a forum. What is the purpose of having a forum that doesn't want to answer question and only want to say google it. Might as well shut down this forum because that is everyone's reply. Google it, search the forums, who cares if there is a 1000 post about an exhaust and someone else starts one, just tell them the answer.
I help more ppl on this forum than most, but not for much longer as it canes my brain cells.
BUT as I said Renthal has a listing.
 

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Yep, if the "thanks" system had existed on this forum from the start, Aufitt and Sendler would each have 3-4 times more than they already do... if not more.

What is it lately about giving people the information they need and them coming back and being jerks about it?
 

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You can use the website Gearing Commander to calculate what you want. 1st, I'd read this thread explaining why Gearing Commander will display about 400 RPM's lower than what the bike does due to the CBR250R's tach being about 400 RPM's optimistic around peak power.

See these possible scenarios in top gear...

Code:
SPROCKET COMBO		INDICATED 8,500 RPM 	ACTUAL 8,500 RPM
14/38 (stock)		81.3mph			85.3mph
14/39 (0/+1)		79.2mph			83.1mph
14/40 (0/+2)		77.2mph			81.1mph
13/38 (-1/0)		75.5mph			79.2mph
13/39 (-1/+1)		73.6mph			77.2mph
13/40 (-1/+2)		71.7mph			75.3mph
 

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Rusty its all relative regadless of indicated or actual.
Use Gearing commander to show the changes is all that matters.
 

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Aufitt, this is certainly true. I was just throwing that out there in the event of wanting to fine tune targeting max pull in top gear at a given speed. I also understand raising sprockets on the rear to be a little less stressful on the chain and sprockets than dropping in the front. Is this correct?
 

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Aufitt, this is certainly true. I was just throwing that out there in the event of wanting to fine tune targeting max pull in top gear at a given speed. I also understand raising sprockets on the rear to be a little less stressful on the chain and sprockets than dropping in the front. Is this correct?
Yes it is better to have a larger front sprocket , but in my case I'm experimenting , Ive a 13, a 14 a 38, 39 and a 40 to try in different combos and 2 chains.

Its also best to have an Odd/even combo if you want to be really fussy.
But thats a whole other theory.
 

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-1, +2 is about the same as riding around in 5th.
I noticed that too. I've debated leaving it stock, running my cruising RPM's higher, and using it as a 5-speed plus overdrive just to drop highway RPM's. I'm curious about the +2 rear because it'd also be nice to have a little more torque during roll-on. 5th gear feels pretty tall and thus has me stuck in the middle of which way to go with it. Tied into the OP's concern, I'm much more willing to sacrifice theoretical top speed to be able to get up to speed and modulate the throttle to navigate highway traffic though. This is because (in my case) with stock gearing, I can't make it to peak power in top gear under normal driving conditions. It plateaus around 80mph at 8k RPM's (actual). Coincidentally, as a target speed for peak power, I'd like to bring 80mph up to 8,500 RPM's and lose the overdrive affect as a trade off for having more torque to get to that speed. I actually only need to cruise at 75mph max for the area I live in, but I'd like to drop the RPM's just slightly and still have 5mph of breathing room to help overcome wind resistance in the event I need to speed up for safety.
 
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