Cbr125r full exhaust system | GTAMotorcycle.com

Cbr125r full exhaust system

Ollie

Member
Hey guys,

I've been thinking about pulling the trigger on a full Hindle exhaust system for my 2011 cbr125r this year. The good news is that I can get the system for 25% off, but the bad news is it will still cost about $450. I know everyone says not to dump any money into a 125, but I'm a student and will likely be keeping this bike for another 2 full riding seasons to save on insurance and operating costs. Overall I have no regrets buying the bike since 90% of my driving is in the city, but a little more power for 100km/h highway drives would be appreciated. I'm fully aware that the torque/power gain won't be huge, but every little bit helps when your bike tops out around 130km/h flat out.
The only thing other than cost which is stopping me is the fact that in order to fit the new exhaust the catalyzer would have to be removed. The 2011 cbr125's exhaust doesn't allow the use of a slip on. Being a somewhat environmentally conscious person I hesitate to do this, but since I only drive a couple thousand km a year the difference would probably be pretty negligible. I look forward to any feedback or opinions that you guys can offer.
 

matthew

Well-known member
Site Supporter
If you're environmentally conscious, a motorcycle isn't for you. Aside from that, I think you should save your $450 since you most likely won't notice a difference in performance. If you want to save weight on your 125, go for a jog instead and lose 5lbs.
 

Ollie

Member
If you're environmentally conscious, a motorcycle isn't for you. Aside from that, I think you should save your $450 since you most likely won't notice a difference in performance. If you want to save weight on your 125, go for a jog instead and lose 5lbs.
I know they're not fantastic for the environment, but damn it they're just too much fun to ride for me to stop :)
Can't lose 5Ibs. either since I'm only 140 to begin with. Hardly anything left to lose. Thanks for the input though.
 

Jlin

Well-known member
I know they're not fantastic for the environment, but damn it they're just too much fun to ride for me to stop :)
Can't lose 5Ibs. either since I'm only 140 to begin with. Hardly anything left to lose. Thanks for the input though.
try to find one used. I can get a new slip on for my r6 for that kind of money. just not worth it to spend it on something you're eventually going to move on from. being a full time student myself, i can see better ways to spend that money; useful things such as textbooks and tuition fees.
 

matthew

Well-known member
Site Supporter

Brian P

Well-known member
Moderator
Site Supporter
The stock exhaust system on that bike is a better match for the engine than any aftermarket one that I have seen. All of the aftermarket ones have a header pipe that is too big for the engine. (Small engine wants a small exhaust system!)

From what other people have tried, with the aftermarket exhausts with the bigger header pipe, the engine runs OK with a wide open muffler but then it is obnoxiously loud (edit: see above dyno chart that was posted while I was typing - this is almost certainly with a wide open muffler - in my opinion, this dyno chart is a little optimistic), but if you put in the noise-reducing baffle, then it's still loud but makes no more power than stock (and has worse mid-range).

The previous models worked OK with stock header pipe and a bolt-on muffler (and that's essentially what I had before), but that's a no-go on the new one.

Leave well enough alone. I have one of those bikes now (sold my 2007, bought a 2011) and although I've changed some other things, the exhaust system is not one of them! The bike works very well in stock form, far beyond what its modest price and specifications would suggest.

As you note, the environmental situation is a lot better with the catalyst in place. That engine uses closed-loop fuel injection with 3-way catalyst and runs very cleanly. It's more sophisticated in that respect than a good many larger bikes use.

If you insist on doing something with the exhaust ... then do this. Take the exhaust system off and measure the diameter of the exhaust port at the cylinder head face (not counting the copper gasket - measure the diameter of the outlet in the aluminum head casting). Take a look at how it matches up to the exhaust system itself. See that nasty step inside where the pipe is welded to the inside of the flange ... Take a die grinder to that and grind a taper in the inside of that pipe to the same starting diameter as the port in the head, just to smooth out the flow a little. Then put it back together. No effect on noise, no effect on emissions. No idea whether it'll help performance, but it won't hurt. I did this with mine, but it was in conjunction with a number of other things at the same time ...
 

Ollie

Member
Interesting read Brian. Thanks for taking the time to write all that down. I'm by no means sold on the idea of changing my exhaust. I suppose I'm suffering from the winter blues and am just trying to find something to tinker with in order to get my biking fix. I'll probably end up buying a braided steel front brake line instead. Cheaper and more useful.
 

Jlin

Well-known member
Interesting read Brian. Thanks for taking the time to write all that down. I'm by no means sold on the idea of changing my exhaust. I suppose I'm suffering from the winter blues and am just trying to find something to tinker with in order to get my biking fix. I'll probably end up buying a braided steel front brake line instead. Cheaper and more useful.
+1 on the steel braided lines! day and night difference.
 

crankcall

Well-known member
Site Supporter
+2 on braided lines, every percentage of squeeze helps on those calipers.
Getting from 130 to 0 is sometime more important than getting from 0 to 130.
 

rukus

Banned
Site Supporter
stupid hippie
 
Changing the exhaust for "performance" requires a remapping of the fuel. Stock ECU is designed for the stock exhaust. There are some low cost ways to acheive the mapping but will require way to much fiddling on your part. If you really want an exhaust buy it from a bike dealer with a service department that knows about performance mods. They will install your exhaust and tune the fuel delivery to match your exhaust. You will pay more but will be better off because of their experience.
 
S

sleezyray

Guest
To the OP. You should look more into changing your gear ratios thru sproket changes. It will afford you top end speed at a slightly reduced low end power. Honestly, sell the bike, come up with another 500 + 450+ plus bike sale to get a 250 ninja. Or leave things as it is till you have enough experience to know what bike suites you best. Cbr 125 is not suited for our higgways.
 

JOHNNYUTAH

New member
If you want to make this little bike faster go with a non-oring chain from motovan i have the number somewhere if you are interested p.m me if you need anymore info , done some dyno runs with these machines .
 

vrus

Well-known member
here is what i would do :

sell the 2011 cbr 125.

buy an older ninja 250r.

pocket that extra 450 you were going to spend for the additional insurance cost.
 

GSXMAER

Well-known member
Leave the damn bike alone.

If you want to go faster, save up and buy a faster bike.

so this explains why you bought a SLOWER bike........you couldn't handle a 600 SPORT bike.....
 

JOHNNYUTAH

New member
I think if you read his post he is a student and is going to be riding this bike for the next 2 years and save on insurance so if he want's to dump money into this bike i say go for it , it doesn't matter which bike you own usually everyone changes something on the bike , buy a exhaust for a 600 dump a grand on a full system gain 5 hp , if ollie here want's to pimp out his 125 go for it.
 

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