[ D a i l y - B i k e - T h r e a d ] - /dbt/

>not 48 cylinder 1 stroke literbike

>radial engine bikes
When?

>no liter diesel single stroke biturbo intercooled v1

youtube.com/watch?v=bUBm4TXqp94

like this? Leave it to the germans

more than a hundred years ago
youtube.com/watch?v=IOSIvQcFmt0

the new VFR's are pigfat turds, the old ones were cool.

>pigfat
Have you tried not being a weak manlet?

They're like 500lbs

Doesn't help the bike being overweight and underpowered compared to all the competitors

>that model
>FWD

Why?

Cool story bro!

Damn I love riding in the Dolomites.

>those reflectors on forks
>those reflectors on plate

You're fooling nobody, Cleetus

the challenge i guess?

youtu.be/hirsRnytTkU

here is a more sophisticated bike

Scenic as fuuuck

When a major market goes back to having a special legal category for 250cc bikes with no other stipulations to make 250s that cost more than 650s desirable, so never.

>that little propeller

stop destroying my dreams and hopes user

mmkay

>plate over a fake Italian plate
>those sockets

What is this even supposed to mean?

Even if it existed you wouldn't buy one.

NSR250Rs are lighter and more desirable than CBR250RRs anyways.

americans are required to have those retarded reflectors on the sides

don't even get me started on how much I'd like 2 strokes back

you're making me cry user

Tourance or Anakee 2?

youtube.com/watch?v=RBCYS4tK-5c

>you will NEVER have something like this.

I've literally never heard of anybody getting fined for that.

I'm sure if you were an asshole to the cop and he started looking for ways to get you, he could write you up for it but they're not too strict on it.

I've kept mine on my current bike because I don't want some dingus hitting it when it's parked on the street.

>not a 24 cylinder 2-stroke litrebike with 24 individual expansion pipes

JUST

get reflective rim stripes man

I've thought about it. What colour though?

He's assuming a Murrikan would never go live in Italy for a few years and take his US spec bike with him.

Vehicles have to come with them, it depends on the state where you need to keep them to be legal.

those italian ones i guess?

only other choice i see is white.

is that in switzerland ? i think i know this road

youtube.com/watch?v=2RZ3JbJaVdc

>YWN own a rotary baiku

No, it's near Longarone in Italy.

it's not that far fetched user

>Longarone
You're long alone?

an old bike of mine

youtube.com/watch?v=fGfIKaCpyYQ

especially not this one

they cost more than a lot of older classics these days.

I guess thats expectid when
>Norton
and
>exotic engine

come together though

Where you at, nigga? I live in the Dolomites.

>switzerland
>dolomites
The dolomites are only in Italy, South Tyrol and partially Veneto.

I was just there a couple weeks ago

Does anybody else cringe while watching nutnfancy?

nice jdm exhaust

ok but I have an RS250

New scoot as of yesterday. It feels good to no longer be nobike.

>ape hangers on a 4-cyl jap cruiser

That's how I bought it, that doesn't mean that's how I'm gonna keep it.

Why are there no high horsepower 250cc engines? Like is the size of the motor the ONLY determining factor for horsepower numbers?

...

...

size and cycle mate

a race prepped RS250 can produce 100hp without too much stress
a street prepped NSR250 produces something like 60hp

Power is energy per time.
That means that if you make a lot of energy in a short amount of time, you get high power output.
By increasing the maximum RPM, you can burn energy in a shorter amount of time, which means you can burn fuel more often, which means you make more power.
By increasing the displacement, you increase the amount of fuel that gets burnt on every cycle, increasing power output. HOWEVER higher displacement means larger moving parts which means higher inertia necessitating lower maximum RPM.
By adding forced aspiration (turbo or supercharger) you force more air/fuel to be burned in the same amount of space (displacement), allowing for higher energy throughput.

250s need to rev very high to make the same power as liter bikes, but there's a certain cutoff where you can't make the moving parts any smaller, thus not allowing you to exceed a certain max RPM (I think the CBR250RR was pretty much as high as it gets at like 18k).
Theoretically, since a 250 has 1/4 the displacement that a liter has, it would have to rev 4 times as high to make the same power (this is a VERY simplified explanation). They can't, so they can't make the same power.

no, compression also
Answer to your question is regulations.

Look up motocross 250s, even 4 strokes have more power than roadbikes.

Then look up CBR250RR MC22

What is your idea of "high horsepower" for 250cc?

Moto3 bikes can push out over 55 bhp while weighing only ~90kg

>Of course the cc size is the ONLY determining factor...

The compression ratio/number of cylinders/ohv vs sohc/dohc, variable timing, cam lift/duration and naturally aspirated or forced induction and number of strokes NEVER EVEN COME INTO PLAY

>By increasing the maximum RPM, you can burn energy in a shorter amount of time, which means you can burn fuel more often, which means you make more power.
So why isn't peak HP always at the limiter?

Ignition timing, valve timing.

so... at this point i'm comfortable riding at around 60kph in 3rd gear, already planning next week's ride

>a race prepped RS250 can produce 100hp without too much stress
source? I find that hard to believe

Something similar to your average 600cc sportbike. I'm obviously talking about a ridiculous power-to-weight ratio but then again, why hasn't it been done?

Thanks man actually learned something. So basically engines are giant air eaters, the more air you have the more power you have, is that correct?

it's something like 70hp stock desu

racingsm.org/hondars.php
Honda does 85
Aprilia does 75-80

PYB

> why hasn't it been done
it has

I used to have one of dem too

Actually preferred the wee strom to the 1000

>the more air you have the more power you have
Yes and no, you obviously also want fuel. You use a lot more air than fuel though, and in carbed engines since the fuel is drawn by the air current going through the carb, the amount of fuel injected into the engine is automatically increased. On bikes with electronic fuel injection you would have to manually increase the amount of fuel injected into the engine.

There are 250s with over 100hp?

>couldn't afford a 1200

I doubt that's even possible with current materials science.

>DAT SOUND
FUCK I want a new rotary-engined bike. If KTM can crack getting a new 2-smoke past emissions regs, someone can do a modern fuel-injected Wankel based on the dev work from Maxda on the late-model RX-8 (and RX-9 if rumours are to be believed).

I think it'd be absolutely possible for a 2 stroke engine nowadays

Who would honestly buy that? Maintenance would be crazy and the cost would be extreme. Could trump it with a mid 90's sportbike for like 3k.

vitalmx.com/forums/Non-Moto,21/2-stroke-250-Yamaha-made-97-hp-300-rpm-powerband,1230012

>in the market for new bike
>want to get something powerful
>dad saying be sensible, don't go crazy

REEEEEEE

I said it would be possible, not cheap or that I'd buy it user

Get a Supermoto.

Powerful depending on which bike you choose, and they don't really have that high of a top speed.

rs250w
tz250
yzr250
, which were used in motogp, had about 97-103 hp
Honestly this is such a retarded question. I can understand "why modern 4st 250s don't make 50hp" or some shit, but 100?

newish

sportrider.com/norton-nrv588-rotary-revival

Get something that doesn't look like a sportbike to appease him.

>yeah dad it's just a farm bike with road wheels to make it safer for my commuting

My friend is in the fucking hospital, he crashed his R6

He wasn't even hooning or anything, he just lost traction around a corner at fairly low speed and skidded across the road and into a garden. If he had been wearing gear he would have been fine but he's a fucking moron and now he's lose a huge chink of his left hand side. like chunks are missing from his arm and leg

Play stupid games win stupid prizes

>squid getting what he deserves
There is justice in this world.

He just wants you to live

for the guy that was talking about the Alpinestars SP-8 last thread, I love mine, they're 4 years old and have 20k+ miles of use and they're still holding together very well. I wish they had a rain wiper on the thumb though, that's my only complaint, but it looks like they've added the finger bridge to it too

I like my Anakee 3's

See, perfect bike.

SuMo's are fun but need moar powa

what's a good website for headlight bulbs? I'd like to put a nice, high quality LED bulb in my street bob.