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Sprocket Change?

36K views 59 replies 26 participants last post by  Dutch500 
#1 · (Edited)
I'm thinking of changing the sprocket sizes when it's time for me to install a new chain and sprocket set. I've done some research on the forums and internet but still, I'm not certain if deviating from the stock teeth count will give me what I want from my CB500F. I would like some advice from others who have made this change and what you think.

I ride my 2015 CB500F to commute to work on congested city roads with slow-moving traffic on somewhat rough and uneven roads, reaching up to speeds of 40/50 MPH but mostly on speed limits of 30 MPH. I also take my bike out to bigger and faster roads with speed limits of up to 60 MPH. However, this is not done very often and I rarely ever use the motorway (highway)

I've found the gearing range to be very short with the stock sprocket ratios and having to work through the gears a bit too much to my taste. I often find first and second gear to be too responsive and jerky, very small throttle inputs give drastic acceleration or engine braking effects. I feather the clucth at slow speeds but i still find it to be jerky often. Third gear in traffic seems to lug the engine, be less responsive which does help reduce the throttle jerk, however, the bike just feels wrong and unhappy in this gear.

I was wondering if changing away from the standard sprocket sizes would allow me to stay in gear for longer and not work through the gears as much, while still having enough torque with slower speeds and RPM's while also being responsive enough but not so jerky in responsiveness nor be lugging the engine? Am I asking for too much or is this possible to achieve with sprocket teeth changes?

I think back to the 2017 Honda NC750S I learnt to ride on, obviously, it's not the same bike as the CB500F, but I could comfortably reach 20-30MPH in second gear on this bike without it screaming, nor did it have any jerky responses from small throttle inputs.
 
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#2 ·
I was wondering if changing away from the standard sprocket sizes would allow me to stay in gear for longer and not work through the gears as much, while still having enough torque with slower speeds and RPM's while also being responsive enough but not so jerky in responsiveness nor be lugging the engine? Am I asking for too much or is this possible to achieve with sprocket teeth changes?
I have a " Sprocket Calculator" link below. You can plug in your original sprockets' sizes, then insert your desired sizes to see the how they change the bike's torque and speed. It also tells you the proper number of links the chain has increased or decreased by the sprocket changes. Hope this helps. Good Luck :nerd:
https://sprocketcalculator.com/
 
#3 · (Edited)
I have '16 500F and the best mod ive done aside for gear indicator was to change the gearing... (stock gearing sucked IMHO)

JT Front Sprocket [JTF1381.16RB (55-138116R) steel 16 teeth with rubber damper](factory part has 15 teeth)
JT Rear Sprocket [JTR1303.39 steel 39 teeth] (factory part has 41 teeth)

I felt the factory gearing was too close.... i use my bike as daily commuter on crazy congested CA freeways and surface steeets. Before id often hit rev limiter on freeways and often feel gears were way too close together i could nearly take off from dead stop in second. I didnt like it at all... now the bike rides great - things are a bit more spaced out and since i have always driven a manual transmission vehicle - it feels way more natural in its current gearing configuration. Granted this mod did sacrifice a little acceleration but makes it purr a bit smoother, get better gas milage , and a tad more speed without hitting rev limiter. I still have plenty of torque but if i need more i can always downshift (like one should). Overall the bike so much more fun to ride.... would def recommend this mod to anyone... was so thinking about selling the bike before i did this mod and now i dont want to ever give it up. Id def add a DID Chain 520VX2-112FB (520 x-ring) & 12oclockLabs SpeedoDRD as well to complete the job.


I was wondering if changing away from the standard sprocket sizes would allow me to stay in gear for longer and not work through the gears as much, while still having enough torque with slower speeds and RPM's while also being responsive enough but not so jerky in responsiveness nor be lugging the engine?
YES!


is this possible to achieve with sprocket teeth changes
YES
 
#50 ·
I have '16 500F and the best mod ive done aside for gear indicator was to change the gearing... (stock gearing sucked IMHO)

JT Front Sprocket [JTF1381.16RB (55-138116R) steel 16 teeth with rubber damper](factory part has 15 teeth)
JT Rear Sprocket [JTR1303.39 steel 39 teeth] (factory part has 41 teeth)

I felt the factory gearing was too close.... i use my bike as daily commuter on crazy congested CA freeways and surface steeets. Before id often hit rev limiter on freeways and often feel gears were way too close together i could nearly take off from dead stop in second. I didnt like it at all... now the bike rides great - things are a bit more spaced out and since i have always driven a manual transmission vehicle - it feels way more natural in its current gearing configuration. Granted this mod did sacrifice a little acceleration but makes it purr a bit smoother, get better gas milage , and a tad more speed without hitting rev limiter. I still have plenty of torque but if i need more i can always downshift (like one should). Overall the bike so much more fun to ride.... would def recommend this mod to anyone... was so thinking about selling the bike before i did this mod and now i dont want to ever give it up. Id def add a DID Chain 520VX2-112FB (520 x-ring) & 12oclockLabs SpeedoDRD as well to complete the job.




YES!




YES
Thanks for this great information. I just got my bike and love it, but you are right, the gearing is way close. I can't wait to change mine out.
 
#4 · (Edited)
I'm very interested now, but I have more questions!

Steve77, If I change the front sprocket to a 16 tooth, will this fit without any issues on my 2015 CB500F? Also, If I change the rear sprocket to a 39 tooth, along with the 16 tooth front, will this still give me enough power to climb hills, as my commute to work does involve some semi-steep hills?

Considering perhaps only changing the rear sprocket to a 38 tooth or the front to a 16 tooth, not sure if this will give me what I want however. As mentioned in my first post, I'm not really looking to increase my top speed, I rarely ever do more than 70 MPH, 90% of the time i'm in 30/40 MPH zones, and I dont use the motorway. I want the gears to be taller but still have enough power at low speeds / RPM's to keep me going on flat ground and hills (nothing too crazy) without the engine bogging down, I fear this will happen if I change to a 16/39 tooth set but I have no idea if this is true

I used the SprocketCalculator airhead83 linked, If I change to a 16 tooth front / 39 rear sprocket set, It says I loose around 12% torque and gain 12% speed. I really dont care about the speed but the torque loss concerns me. Would losing 12% cause issues with hills?

If I change just the front sprocket to a 16 tooth and keep the 41 rear, I loose around 7% torque. This seems more reasonable to me but I'm unsure.
 
#5 ·
I recommend the 16T front sprocket change. I did that and liked it.
I tried also changing the rear sprocket to 39T with the 16T front.
It worked fine for my riding. Just remember that 5th gear acts much like the original 6th gear in that arrangement... so you don't loose out at all.

I went back the std on the rear and remained pleased with the 16T front. sprocket
 
#6 ·
Steve77, If I change the front sprocket to a 16 tooth, will this fit without any issues on my 2015 CB500F? Also, If I change the rear sprocket to a 39 tooth, along with the 16 tooth front, will this still give me enough power to climb hills, as my commute to work does involve some semi-steep hills?
I dont know... how steep we are talking like San Francisco steep ? I seem to have plenty of power and do take my bike on mountain runs on some weekends without issue. Sure i have to downshift sometimes but its not like a super dramatic maneuver. And didnt require any mods - although i did elect to install a new chain and a speedohealer.

I was pretty apprehensive when i was in your shoes (although for different reason).

But yes ExTex is right when he says..
Just remember that 5th gear acts much like the original 6th gear in that arrangement...
With my setup its almost like you have wider spaced gears and a new overdrive 6th gear (which is great as for my long commute it helps save fuel).
When i need more torque i can simply drop into 5th and go.

The setup works good at slow speeds (20-50) as well, as my commute isn't all on freeway. You wont be able to do a wheelie but doesn't seem like thats your jam anyhow. :)
 
#7 ·
After doing more research about the speedo being offer with non OEM sprocket sizes, I've been put off making the change. Unless changing the front to a 16 tooth would not cause the speedo to be too far out. However, the whole thing seems like a bit of an investment to try, which I'm not keen to make at the moment. Maybe sometime in the future, if I hang onto the bike for the long term. Just have to put up with how it rides stock for now.
 
#40 ·
I’m running a 16t front and 39t rear on a 2013 cb500F, at 65 mph in 6th gears the engine is running at about 5,000 rpm, 1st gear can be stretched to 40mph if you really want to twist the throttle but as someone mentioned, it’s not going to wheelie unless you clutch wheelie.
 
#11 ·
Would someone be kind enough to point me in the right direction as to what I would need to buy to correct my speedo on a 2017 CBR500R? I seem to only be finding modules for 13-15 year models. Also how easy is this to install or is it just a calibration tool that you plug in and reflash the ECU?

Thanks
 
#12 ·
With the conversion to a 17T counter shaft sprocket, my bikes speed is about 5-6 mph faster than the "true" speed. The OEM speedometer is about 10% fast. I just add 5 mph to whatever speed shows and leave it at that. I only worry if I am passing cars with regularity. I am not worried about going 2-3 mph faster than the posted speed. Police will not stop you for that. The rpm reduction at any speed for a 16T sprocket just did not strike me as sufficient. With the 17T, I definitely feel the difference. My '17s mileage consistently is in the 70+ range (converted from odometer reading being 13% low after the sprocket change).

There was enough adjustment available even with a new bike's chain to nor require a longer chain. I just moved the rear wheel as far forward as possible and then had enough slack to run the wheel back a bit for proper chain tension.

Ralph
 
#25 ·
With the conversion to a 17T counter shaft sprocket, my bikes speed is about 5-6 mph faster than the "true" speed. The OEM speedometer is about 10% fast. I just add 5 mph to whatever speed shows and leave it at that. I only worry if I am passing cars with regularity. I am not worried about going 2-3 mph faster than the posted speed. Police will not stop you for that. The rpm reduction at any speed for a 16T sprocket just did not strike me as sufficient. With the 17T, I definitely feel the difference. My '17s mileage consistently is in the 70+ range (converted from odometer reading being 13% low after the sprocket change).



There was enough adjustment available even with a new bike's chain to nor require a longer chain. I just moved the rear wheel as far forward as possible and then had enough slack to run the wheel back a bit for proper chain tension.



Ralph
I take it you're running a 17/41??

I've been thinking about doing it for the same reason as you, more or less, but was only looking for a 16 to start, would you say there is a big difference in characteristics between the two?

Sent from my LYA-L29 using Tapatalk
 
#13 · (Edited)
It appears that a 17/41 and 16/39 are roughly the same gear ratio. Ralph can you tell me what your RPMs are at 65 MPH? Or can anyone tell me what their sprocket combination os in relation to their RPMs at 65? My whole reasoning for even thinking about the change to 16/39 is to bring the RPMs down in 6th gear on the highway. Stock gearing is running around 5300 rpm at 65 mph. Any insight as to how far this will drop with the above sprocket change is very much appreciated.
 
#14 ·
It appears that a 17/41 and 16/39 are roughly the same gear ratio. Ralph can you tell me what your RPMs are at 65 MPH? Or can anyone tell me what their sprocket combination os in relation to their RPMs at 65? My whole reasoning for even thinking about the change to 16/39 is to bring the RPMs down in 6th gear on the highway. Stock gearing is running around 6300 rpm at 65 mph. Any insight as to how far this will drop with the above sprocket change is very much appreciated.
According to an old post on the site I found, 65 should be around 5100 rpm in 6th
The image from that post is below

And I'm pretty sure mine with factory sprockets runs 6000-6200 at 75ish
The previous owner of yours may have gone to a 14T sprocket
 

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#16 ·
Gear Up



Matt2911, I just did the 16T change this week (staying with 39T rear). In 4th gear 60kph (37mph) is around 3700 revs. If that helps. I found the bike much better around town from standing starts into turns at intersections I'm not grabbing 2nd halfway through anymore and in the curves I find it's comfortable now staying in 4th and revving up to 5 or 6 or if the curves are wider grabbing 5th and settling around 4/4500. Of course 6th is now also taller but I find the bike will comfortably cruise in top gear around 3500 revs on 70kph or 45mph. JT Front Sprocket 16T
 
#19 ·
I'm glad to see that a bunch of riders have responded with their feedback here. I have been contemplating a 16T up front since I've noticed that 1st and 3rd gear are too short in town but 4th is a bit too long. Also, I find that down shifting to 5th on the highway is basically not worth it since 5th will only go to about 90 MPH (at stock redline) and speed limits around here allow for cruising at 80 MPH. I'm hoping that the gear change will make 5th a bit more usable in my area.
 
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#22 ·
Google maps uses GPS but doesn't show your speed. Here maps is available on Android and maybe iPhone and does show your speed. If you check the Play Store or Apple store, you can find apps that give instant GPS speed readouts as well as 1/4 mile and 0-60 time tracking (just know they aren't as accurate as a VBox). Some apps track the route taken and can show elevation changes as well. Most of these apps are free but have ads.
 
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#29 ·
I have a 18 cbr500r and I just did a sprocket and chain change. Purchased off Revzilla. I don’t care about going 120-160 like I have on my other bikes in the past. I like going fast 0-80-90. So I went up in the back from 41 to 43 and dropped one in the front from 15 To 14. Big difference, feels like a different bike. Also I clutchless shift up whenever possible. It’s very easy. Have to be at least 75% of rpm in gear and with a little tap and a small roll off the throttle I am faster than traditional. I personally had several mechanics tell no big deal, it’s not much difference than paying all that money for a clutch less shifter, good luck
 
#31 ·
Not looking for a 7th gear any more. :)
I also changed to a 16T front sprocket (stock rear). I've found that I typically shift from 22-25mph from first to second whereas it used to be 14-17mph. In second, I'm shifting at 35 to 40 (35 is hovering around 5,000RPM) whereas before I was shifting around 25-28 mph to third. When I'm jumping on the highway, I'm accelerating to 70mph in 4th before I feel like I have to shift and I am finding myself constantly in 5th gear on the highway, cruising along just fine and then checking to see if I'm in 6th already by shifting and finding out I wasn't.

If I am in 6th gear and want to accelerate to pass (going 60-65mph), I definitely feel like I have to shift down to 5th as I don't really feel 6th gear pull like I did with the stock setup (not that it was a ton but I never felt I had to shift down unless I reeaalllyyyy wanted to accelerate as quickly as possible) until I'm running at around 75-80 mph. I'm definitely in 1st through entire turns from a stop way, way more than before.

Regarding speed correction, I do have a radar detector speed limit indicator sign where I work that shows my speedometer indicated speed is 1 mph slower than actual speed. I've also gone by other police radar speed limit indicator signs which show the same exact difference.
 
#33 ·
Maybe a larger rear sprocket? A stock CBR500R will do wheelies in 1st but 2nd requires a more aggressive procedure. Shorter gearing could get you what you're looking for if you don't care about redlining at 90 MPH. I don't think a CBR500R will ever be a good stunt bike though...
 
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#35 ·
Can any of you that went to the 16/39 combo tell me if they had to remove a link to 110 links instead of the stock 112? My chain has 5k miles in it and wasn't to worn yet but with the new change it is loose when the axle is pushed back as far as it will go. I also am not sure how far forward it will move the axle by removing a link. Also 112 is divisible by 16 so the chain and front sprocket will always hit the same teeth/links so a 110 change would be beneficial there as well. Any advice to what any of you did?
 
#37 ·
It seems quite a few people think the gearing is a bit on the revvy side. I find that 85 to 90 mph in top is in the sweet spot, I fancy going up two teeth on the rear but I am waiting for a guinea pig to do it first. You have more highways than the UK I think. My bike sits at 75mph on the motorway no probs.
 
#38 ·
85-90 mph at redline/fuel cutoff?

I don't really think it suits the style of bike, which is more relaxed and economical in my opinion. If I wanted it to be higher strung I'd have gotten the Ninja 400 instead. I also don't think it benefits much from shorter gearing since the engine is so tuned for low-end power. Just my $0.02.

You're right that we have a lot of highways here. Most of our roads are wide, straight, and flat, compared with Europe. To get anywhere in my city involves jumping on the freeway (100-120 km/h) for a bit unless you're staying local.
 
#39 ·
85 to 90mph in top is about 8,300 I think, limiter comes in at about 9,200. Don't like running it too long at that speed. The roads I ride are usually short and squirt, 2nd to 5th gear.I find it doesn't mind being revved. If you search the forum some riders are getting 100,000km out of these engines. It's a testimant to Honda reliability.
 
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