Honda CBR125 review - Nicer than an fxr but needs slightly MORE POWER!

[Buddha#81:Me]

If you think a road going standard FXR is 20 hp guess again. Even a ported, hot cam, race CDI, Pipe and Flatslide carbed fxr would struggle to tip 20hp. they're more like 15hp, and the FXR is oil cooled.

Iwas in Aussie last year and they were punting CBR125's out for $3995.

[motorbyclist]

I and the FXR is oil cooled.

tis primarily air cooled though

[jrandom]

Which humourless moron went and 'fixed' the spelling in the thread title?

[Slyer]

Moar!!!!!!

[motorbyclist]

don't worry guys, fixed it

[Slyer]

The heeeell? It's only fixed in one place?

[motorbyclist]

yeah wtf?

damn mods! BURN THEM!

[flyingbrick]

I fail to see what that has to do with it? DOHC might give you more RPM due to not using rockers, but the difference in redlines between them is only 1000rpm, so that's moot. You can get any cam opening profiles and combustion chamber design you like with SOHC and rockers that you can get with DOHC.

what are you failing to see?
Engines make more power when DOHC. When was the last time you saw anything modern, performance orientated and SOHC?

[Henk]

The CRF150R is a sigle cam and I'm pretty sure the CRF 250s are as well. They pump out plently of power for the capacity.

[xwhatsit]

what are you failing to see?
Engines make more power when DOHC. When was the last time you saw anything modern, performance orientated and SOHC?

Plenty of modern performance orientated SOHC engines. Above post lists but a few.

Care to explain why simply changing the head design to DOHC adds moar power?

The answer is it doesn't. The advantage of DOHC is simply less reciprocating mass, by eliminating the rockers. This lets it rev more with less stress on the valve train; however, as mentioned, it's irrelevant as the redlines on these two bikes are very close.

There's a few more advantages of DOHC, but not really to do with performance. No. 1 is less bits to wear out and go wrong -- rocker arms (and the pins they rotate on) wear out and mean more frequent tappet adjustments. Packaging is also a little better, I was reading an article about the 70s Kawasaki multis, how using DOHC meant they could have the combustion chamber design they wanted without making the engine too tall.

DOHC slapped on the side of your engine is about as useful as determining performance as a big red R decal on the tank of a GN250.

[flyingbrick]

NM. hahaha. im pretty sure you know more than i do.

[motorbyclist]

DOHC slapped on the side of your engine is about as useful as determining performance as a big red R decal on the tank of a GN250.

lol i remember back when i was 15, showing off my shiny new FXR150

one of my mates saw the "DOHC" on it and went, "dohc? on a 150?! what's the point?"

[samgab]

Thanks for the review, which is perfect for me.
I'm on my learners, and I'm actually weighing up whether to get either a brand new CBR125R for $4500 from Counties Honda, or a 2002 FXR150 from Trademe for under $2000.
I'm pretty much decided on the FXR.
The slightly greater power will be good.

(for the guy who said "you're dreaming if you think the FXR150 has 20hp":
http://en.wikipedia.org/wiki/Suzuki_FXR150 -it is)

[Kickaha]

(for the guy who said "you're dreaming if you think the FXR150 has 20hp":
http://en.wikipedia.org/wiki/Suzuki_FXR150 -it is)

He was right, just because it says so on there doesn't make it true

[motorbyclist]

according to suzuki the fxr puts out 20hp

and the only cbr figure we have comes from honda

so either dyno the two machines or use the numbers as a guide

or just believe me when i say the fxr has more grunt