Spec differences between RPS Hawk 250 and Xpro Hawk 250

[Lee1991]

Hi everyone,
I am trying to decide on my first bike and I have narrowed it down to a few options but I am bumping into a few issues. I am trying to get the most power for the money and am getting some contradictory numbers from different sites. below are some of the number I have found, Let me know what you all think.

RPS Hawk 250 DLX - 16HP and 16.5 NM of torque
X-Pro Hawk 250 DLX - 11.5HP and 16.5 NM of torque

RPS Hawk 250 - 16.1 HP and 16.5 NM of torque (a few sites do show this to have 14)
X-pro Hawk 250 - 14 HP and 16.5 NM of torque

Also debating;
X-Pro Titan DLX - 16 HP and 16.5 NM of torque
and
BSR Raven - 16HP

My understanding is that the RPS and X Pro were the same bikes? why the difference in performance numbers?

Does anyone know which bike in this price range and category has the most power or what the real power specs are without the marketing Bull from the websites.

Thanks for any help and information you have.

Lee

[tknj99]

I cant comment on figures but the 2 Hawk's you listed and BSR Raven all have the same CG250 engine so should all be identical. The XPro Titan has the same engine as the former RXB250L which is a CB250 overhead cam engine and should have a slightly higher hp/tq rating than the CG engine.
With that being said and being an owner of both a modded Bashan Brozz 250 (CG250 engine) as well as the Titan, i can say that the Titan in stock form is just as fast or faster than my modded Brozz and is superior for offroad riding plus is close to 40 pounds lighter.

[Lee1991]

Awesome that is exactly the information I was looking for. I was leaning that direction and just got caught up in the numbers.

Thanks

[tknj99]

A good resource i found:

https://www.thumpertalk.com/forums/t...eference-list/

[krat]

You are having difficulty with the numbers because the dealers do not understand the difference between the Imperial System, and the Metric system. You see, most of the china bike dealers are not too bright, so we have to deal with problems related to their stupidity.

Some of the websites list the 11.5 number as horsepower when it is kw and visa versa. I have also seen the NM (metric) torque numbers given as HP.

The engines are all the same, as is their power output for both watts/HP and torque in NM/foot pounds.

The real question is how was it measured? Was it measured with the choked to death carb and exhaust system complete with cat? Or was the engine measured on the bench unrestricted? Are we trying to get back up to the listed power, or are we working up from those numbers?

When you take one of these CG engines, no matter what the factory numbers were listed as, properly tune the carb and replace the exhaust it feels and acts like you are doubling the power.

Derestricting and proper tuning increased my top speed from 45mph to 60mph. Others here have had the same experience, or better.

[Deckard_Cain]

Originally Posted by krat

You are having difficulty with the numbers because the dealers do not understand the difference between the Imperial System, and the Metric system. You see, most of the china bike dealers are not too bright, so we have to deal with problems related to their stupidity.

Some of the websites list the 11.5 number as horsepower when it is Watts and visa versa. I have also seen the NM (metric) torque numbers given as HP.

The engines are all the same, as is their power output for both watts/HP and torque in NM/foot pounds.

The real question is how was it measured? Was it measured with the choked to death carb and exhaust system complete with cat? Or was the engine measured on the bench unrestricted? Are we trying to get back up to the listed power, or are we working up from those numbers?

When you take one of these CG engines, no matter what the factory numbers were listed as, properly tune the carb and replace the exhaust it feels and acts like you are doubling the power.

Derestricting and proper tuning increased my top speed from 45mph to 60mph. Others here have had the same experience, or better.

11.5 can't be the power in Watts. 1hp = 746W.

A 16hp engine produces almost 12,000W of power.

[Lighthouse 360]

Some motors based on their dealer specs like the TT 250 from CSC motorcycles have a high compression gasket which bumps up the horsepower a little bit otherwise they’re just guessing on the numbers no one’s ever put these bikes on a dino.

[Britt]

Originally Posted by Deckard_Cain

11.5 can't be the power in Watts. 1hp = 746W.

A 16hp engine produces almost 12,000W of power.

Not just Watts, but kW.

11.5kW =~ 15.4hp

[ProDigit]

I'm wondering if a different size gear ratio affects the hp values.
Too small gear ratio, and top speed as well as HP to the wheels is lowered.
Larger front sprocket and/or smaller rear sprocket, will bring more engine HP to the wheels.

[Megadan]

Originally Posted by ProDigit

I'm wondering if a different size gear ratio affects the hp values.
Too small gear ratio, and top speed as well as HP to the wheels is lowered.
Larger front sprocket and/or smaller rear sprocket, will bring more engine HP to the wheels.

No.
No.
Also, No.

We can start this discussion again, but the moderators will just delete it all. I can do all he math, again, but I am sure it will get deleted, again. Which is why I am not a big fan of deleting things, but I'm no a moderator. So, instead of linking the last thread this whole discussion took place in I would have to start from scratch, and I just don't feel like it.

Sprocket changes don't affect horsepower to the rear wheel, just the torque multiplication and wheel speed relative to engine speed.

[Sport Rider]

different sprockets change the RPM location at any given speed. That affects where you are in the HP and torque curves. it never changes what HP the motor is capable of producing.

[ProDigit]

Originally Posted by Sport Rider

different sprockets change the RPM location at any given speed. That affects where you are in the HP and torque curves. it never changes what HP the motor is capable of producing.

A- the HP values are mostly measured at the wheel, not the crank.

B- yes, engine HP values can differ between dynos, just based on the load the dyno puts on the engine.

At little to no load, HP values will be almost 0 HP. Consequently increase the load to max, the crank rotates slower, valves stay open longer, more air comes in and gets out, engine efficiency goes up, and engine output increases.

Saying HP doesn't go up under load is just as dumb as saying a 200cc air-cooled engine has the same HP as a water-cooled one.

The logic is very simple.

[Megadan]

You're wrong, we're all right. This is why.

hp =Fd/T

Math is right. K? Thanks, bye.

[Megadan]

How an engine brake dyno works. A high load is applied to an engine that it must overcome, giving maximum effort. This is known as brake horsepower, and that is an industry standard. Horsepower ratings are stated, at the engine, as the maximum output the engine can deliver, AKA - it doesn't go any higher.

Horsepower at the engine doesn't increase when put through gears. Ever. It will decrease from driveline loss, but the engine will never ever make more horsepower than it's brake horsepower rating. Ever. I proved that the last time you wouldn't let this go. I can prove it again. Math doesn't lie.

So, you're wrong, and you have always been wrong. If you keep thinking the way you do you will always be wrong. Want to prove me wrong, post an actual credible source that proves your claims. I can post endless articles from physicists and engineers on this proving me right. Give me an actual source that isn't you, and I will listen. Othewise...

Just because I am a jerk, and it's fitting.


I am saying nothing more on the subject. Good luck.