Bike upgrade basics: changing gearing
Discussion
I’ve owned my CBR600RR-6 for 6 months now. It’s a lovely bike – ideal for getting me back into motorcycles. Whilst getting to know it, I’ve discovered a few areas where I feel I could change the bike to make it suit me more, rather than looking at a replacement.
One of these things is gearing. Obviously, it’s a sports 600, so it’s peaky, but my theory is by changing the final drive, I can possibly allow the bike to remain in the power band (moreso) when changing up, and thus counteract the lack of torque – if that makes sense?
From a little reading, -1 on the front and +2 on the back should change the characteristics of the bike to make it accelerate quicker when moving. I don’t need 160mph top speed, so I can afford the lowering of that. Now, I will be replacing the chain as well as seems silly not do. I’ve read a little about 525 and 520 and it seems going to a 520 won’t lose me anything, really. However, is a chain a chain? Do I need a longer one or a shorter one, or do I simply buy the correct sprockets, a chain and hand it all to someone who knows that they are doing? (I’ll do some stuff on my own bike, but fitting a chain is beyond me…)
I’ve also got the problem of the speedo being out. What is involved in fixing this? Is there a plug and play thing that’s clever enough to work out the new speed given the sprocket changes, or is it more of a faff?
Any help appreciated – bit lost.
One of these things is gearing. Obviously, it’s a sports 600, so it’s peaky, but my theory is by changing the final drive, I can possibly allow the bike to remain in the power band (moreso) when changing up, and thus counteract the lack of torque – if that makes sense?
From a little reading, -1 on the front and +2 on the back should change the characteristics of the bike to make it accelerate quicker when moving. I don’t need 160mph top speed, so I can afford the lowering of that. Now, I will be replacing the chain as well as seems silly not do. I’ve read a little about 525 and 520 and it seems going to a 520 won’t lose me anything, really. However, is a chain a chain? Do I need a longer one or a shorter one, or do I simply buy the correct sprockets, a chain and hand it all to someone who knows that they are doing? (I’ll do some stuff on my own bike, but fitting a chain is beyond me…)
I’ve also got the problem of the speedo being out. What is involved in fixing this? Is there a plug and play thing that’s clever enough to work out the new speed given the sprocket changes, or is it more of a faff?
Any help appreciated – bit lost.
I have posted this already in another forum, but I had the same issue with my CB650F. Always felt it needed another gear, when I was in top.
Also, it was very 'snatchy' at low speeds.
The rear sprocket as standard is a 42 tooth one. I looked on the JT Sprocket web site and they give graphs showing the effect of front and rear sprocket changes.
In the end, I opted for a 39 tooth, dropping three teeth. My local Honda dealer did the swop, as the chain has to b broken and a new link rivetted in. This is a standard Honda part that can be ordered.
The result is that the engine revs have dropped by a 1000 rpm making the bike so much smoother and less 'revvy'.
It has probably dropped the acceleration a bit, but not noticable.
Havn't tried the top speed effect yet, it maxed out at 210 kph before and not many places over here that you want to do more than that, anyway
Also, it was very 'snatchy' at low speeds.
The rear sprocket as standard is a 42 tooth one. I looked on the JT Sprocket web site and they give graphs showing the effect of front and rear sprocket changes.
In the end, I opted for a 39 tooth, dropping three teeth. My local Honda dealer did the swop, as the chain has to b broken and a new link rivetted in. This is a standard Honda part that can be ordered.
The result is that the engine revs have dropped by a 1000 rpm making the bike so much smoother and less 'revvy'.
It has probably dropped the acceleration a bit, but not noticable.
Havn't tried the top speed effect yet, it maxed out at 210 kph before and not many places over here that you want to do more than that, anyway
Google works wonders OP. lol
Seriously though you need something like this:
http://www.healtech-electronics.com/products/sh/
Seriously though you need something like this:
http://www.healtech-electronics.com/products/sh/
gareth_r said:
Does the speedometer read wheel speed or gearbox speed?
That depends on the bike. Some have a cable or sensor on the gearbox, so the speedo will be affected. Others have a cable to the front wheel or a rear wheel speed sensor. No problem with either of those.
There are lots of bikes with free ECU mapping software out there. On many of these, you can set the speedo correction factor. I did this with TuneECU on my Sprint 1050.
abarber said:
gareth_r said:
Does the speedometer read wheel speed or gearbox speed?
That depends on the bike. Some have a cable or sensor on the gearbox, so the speedo will be affected. Others have a cable to the front wheel or a rear wheel speed sensor. No problem with either of those.
There are lots of bikes with free ECU mapping software out there. On many of these, you can set the speedo correction factor. I did this with TuneECU on my Sprint 1050.
Since the OP has a Honda CBR600RR he's gonna need the box of tricks
Given its driven/sensed off the gearboxhttp://www.600rr.net/vb/69-07-13-rr-modifications/... <someone has written a guide here OP
abarber said:
gareth_r said:
Does the speedometer read wheel speed or gearbox speed?
That depends on the bike. Some have a cable or sensor on the gearbox, so the speedo will be affected. Others have a cable to the front wheel or a rear wheel speed sensor. No problem with either of those.
Which does the CBR have? Also, have a play with http://www.gearingcommander.com/ to see how your suggested changes will affect road speed and revs.
bennyboysvuk said:
Also, have a play with http://www.gearingcommander.com/ to see how your suggested changes will affect road speed and revs.
That's quite interesting. Whilst I do lose some top speed, the roads I ride are usually 2-4th kinda stuff, and I'm not one for long trips in 6th, so...gotta be fun dropping the gearing a bit, right? 
cheesewotsit said:
bennyboysvuk said:
Also, have a play with http://www.gearingcommander.com/ to see how your suggested changes will affect road speed and revs.
That's quite interesting. Whilst I do lose some top speed, the roads I ride are usually 2-4th kinda stuff, and I'm not one for long trips in 6th, so...gotta be fun dropping the gearing a bit, right? I also have a speedo healer. Mine's a bit too accurate now actually (I need to adjust it). I'd far rather have it over-reading a little bit when I do finally round a bend to find a speed trap.
Regarding fitting. It's a really, really easy job and I did mine myself, but I'd expect a garage to quote a couple of hours, just in case.
When I had my Firestorm and everyone was dropping the gearing on theirs, I increased the gearing on mine. +1 on the front and -1 on the rear. It made high speed cruising more comfortable and did reduce the top gear roll-on ability but, on roads where gears were being used anyway, it made no noticeable reduction in acceleration. In fact, it felt like it improved things slightly as I was able to hang on to lower gears just a little longer.
The other advantage of lengthening the gearing was that the previously optimistic speedo now read almost exactly spot on (when checked against the sat. nav.) so there was no requirement for speedo healers.
The other advantage of lengthening the gearing was that the previously optimistic speedo now read almost exactly spot on (when checked against the sat. nav.) so there was no requirement for speedo healers.
Try here as well
http://shop.12oclocklabs.com/index.php?route=produ...
I've had one, for coming up to 3 years now on my CRF250L after going -1 +2
On that website there is also a calculator to find the 'value' to program the unit.
http://shop.12oclocklabs.com/index.php?route=produ...
I've had one, for coming up to 3 years now on my CRF250L after going -1 +2
On that website there is also a calculator to find the 'value' to program the unit.
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