whats the largest 2 and 4 stroke motor your willing to intstall in a bicycle ?

rogergendron1 · Jan 2, 2014

alright guys and girls......... you read the tital....... whats the largest and most powerfull motor your willing to stuff in a motorized bike ?

i want to know what size 2 stroke is the largest most powerfull you would dare put in a bike

and whats the largest most powerfull 4 stoke you would put in a bike

and on a side note...... what would be your perfect motor ?

for me the biggest i would go with a 2 stroke would be a yamaha blaster 200cc or a 150cc rotax or yamaha kart motor ! no way on this earth could you get me to put anything more powerfull than an old school air cooled 250R honda atv motor in a bike frame ! thats asking for your own death at 75mph !!!!

now for a four stroke ... i know people use the predy 212cc but that motor is designed for industrial use and not realy a preformer out the box lol its large cc are misleading because a stock honda 70cc atv motor would smoke a moded preddy 212 almost all the time ! that being said the largest 4 banger i would ever dare to stuff in a bike would be a honda xr200 !

now my perfect 2 banger would be a honda cr85 2 stroke ! its small enough to fit in a gt lts frame and yet powerfull enough to send a bike flying up any hill and at any speed you wished !

my perfect 4 banger would be a honda cr50 style clone motor, only with a 150 cc big bore kit and all the mods you can toss at it lol that and a 4 speed auto !

i got a question.... why has nobody done a build with a 2 stroke kart motor ? there are pleanty of small 100cc 2 smokes that will fit bike frames with less modifacation and make more power than the preddy 212 ?

GearNut · Jan 2, 2014

Well... it's not a 2 or a 4 stroke, so I don't know if it qualifies.
Ok, it's sort of a 4 stroke.

It is a Wankel Aixro XR50.
32 pounds.
$5500.00 (Ouch!)
50 horsepower.
34+ ftlb torque.
Short video of one in a kart here.
Where to get one: here

Wanna race? >: D

Remember, it's only 50cc's.

bairdco · Jan 2, 2014

i'd like to use a ppg (powered paraglider motor) in a bike.

a company in canada makes a billet, tuned, 100cc two stroke with 30+ hp.

it's not much bigger than a china doll and should be good for 100mph or more...

professor · Jan 2, 2014

You are funny.
I am using a 212 and it has a similar pull to the Honda 250 three wheeler I had.
Stock engine, re-jetted, non stock exhaust.

wing nut · Jan 2, 2014

way back when they used to run clinton 2 stroke motors on karts , ive seen 1 with 2 clintons
also my arrow performs very well & i like it just like that

16v4nrbrgr · Jan 2, 2014

I went 60 on my KTM50 before I geared it lower to better utilize the powerband up hills and under normal conditions, I think the biggest I'd go on a beefy bike frame would be a 100cc two stroke or a 200ish cc four stroke, anything over 10HP and its worth just getting a supermoto or a small motorcycle with gears, so you don't have to worry about reliability or things falling apart. With a registered and insured motorcycle you can legally get on the freeway and don't have to worry about confusing drivers with your pedals, or lack of acceleration when stretching out the top speed of a smaller motor. Motorized bicycles and mopeds are awesome within their limitations, I've slapped up against those limitations with the KTM, with the pedals on there, drivers want to do dumb stuff and pass you even if you're going over the posted speed limit.

Dan · Jan 2, 2014

I don't think I would go much past 79cc with out proper/dependable lighting, suspension and MC wheels/tires.

I don't bounce half as well as I used to.

Tom posted this way back. Maybe on a FS, MTB. snork
http://motorbicycling.com/showpost.php?p=472032&postcount=6

Sidewinder Jerry · Jan 2, 2014

For myself without moving out of my home state (Tennessee) and operating on the public roadways, 49 cc 4 stroke, the legal limit here is 50 cc. For somebody else whatever they felt they could fit onto a bicycle. I'd be willing to help them build it.

2door · Jan 2, 2014

Unless you plan to race or do off road riding, why would anyone want a bicycle to go faster than a simple little 66cc 2 stroke could pull it?

I have four bikes currently, 3 of them will easily do 35 and 2 of them can hit 40+. (I rarely ride them faster than 25)
If I want to go faster than that on two wheels I'll buy a motorcycle; something designed and built to go faster with rims, tires, brakes and bearings meant to take those speeds.

The big problem I have with advocating bigger engines and more power/speed is the potential for an uninformed person to accomplish a big engine install without giving consideration to those other areas of a bike that will make it safe and reliable.

Another factor I see as a down-side to faster motorized bicycles is the negative attention they will surely get from law enforcement. Anyone with a vehicle with lots of power will be prone to use that power and it won't take long for John Law to notice. It certainly won't do our hobby any good. Almost without exception the current laws pertaining to our bikes have speed limits built in. When we start to violate those limits with big CC bikes someone is going to notice and that someone might be the law makers in your state or city.

Tom

xseler · Jan 2, 2014

Dan said:
I don't think I would go much past 79cc with out proper/dependable lighting, suspension and MC wheels/tires.

I don't bounce half as well as I used to.

Tom posted this way back. Maybe on a FS, MTB. snork
http://motorbicycling.com/showpost.php?p=472032&postcount=6

This is my thought as well......79cc for a 4 stroke, 66cc for a 2 stroke. Not only do I have a 'bouncing' issue, I've got a 'recovery' issue.

Don't get me wrong......I want all the performance out of whatever setup I have, but I just don't feel as inclined to over-reach as I did in the past.

scotto- · Jan 7, 2014

Is a 212cc Predator that's over 20hp big and fast enough for a beach cruiser bicycle? Besides a perfectly tight fit, why would you want anything bigger or more powerful? This bike will go as fast as you want to gear it to go......seriously.

On a two-wheeled single seat bicycle I would not put anything bigger than what I have here on my 212cc race bike. And on a tandem I wouldn't go to much bigger as well......maybe HF 346cc with some performance mods.

And as for a 2-stroke, I think the Yamaha KT-100 is plenty of engine to make any bicycle go ballistic!

BarelyAWake · Jan 7, 2014

I've honestly no idea why so many reference, even buy these engines based on CCs - if ever "there's no replacement for displacement" was a misnomer, it would be in reference to motorizing a bicycle lol

There's 50s pushing 12hp, there's 200s with a mere 5hp - there' no correlation between displacement and HP in our world, particularly as both are so oft suspect in any case...

...regardless, to answer what I think was the OP's intent - think me an ol' fuddy duddy if you must but for a street bike & even legality aside, I really can't fathom needing much more than an actual 5hp (I run about 1/2 that w/my most powerful build & a mere 1.3hp w/my daily driver) as there's an additional, even critical aspects so often ignored - which would be the machine's overall power to weight ratio & the engines preformance envelope, ie it's usable RPM range & torque as well.

These are the snarky lil details that'll getcha lol, dunno how many times I whipped a "manly" CR500 w/my lil "wuss bike" XR250, to be whipped in turn by some sassy 80 despite the massive power difference - just & only because the weight differences.

Yet, I do understand there will always be someone that says, "Ya outa stuff a 350 V8 up in it man" no matter what "it" may be

Intrepid Wheelwoman · Jan 7, 2014

98ccs and a big brass flywheel is all anybody needs

GearNut · Jan 7, 2014

BarelyAWake said:
Yet, I do understand there will always be someone that says, "Ya outa stuff a 350 V8 up in it man" no matter what "it" may be

http://www.hossflyinc.com/index.html

Dan · Jan 7, 2014

Wow GN! That is insane.

http://www.hossflyinc.com/specs.html

"Small block Chevy V-8 Complete or Kit
Big block Chevy V-8 Kit only
Forward Speed at 5,000 RPM 25 mph
Reverse 5 mph
Able to tow 2,000 lbs
Fits in short bed pickup truck
5 gallon fuel capacity
Remote start available
Radiator in rear makes the Hoss Fly cool and comfortable to ride"

BonusParts · Jan 7, 2014

I didnt read anything but the title.

Id put as big of an engine as is possible. without ruining it being a bike.

i'd love a 25hp bicycle

maniac57 · Jan 7, 2014

I think this will fit my Huffy Cranbrook with a little grinding...where's the welder?
http://www.youtube.com/watch?v=XCAPTMIMGtQ

Mike B · Jan 7, 2014

40cc, 2 HP.

That as big as I will ever install in a bicycle.

ridendirty · Jan 8, 2014

I'm thinking about putting a crf150r engine (with 22hp) on a Schwinn stingray spoiler. Scotto I may be mistaken but I thought a 212 pred only had 6.5hp, not over 20?

Nashville Kat · Jan 8, 2014

That 50 cc Wankel motor IS impressive!

Me, I'm just after a light moped that still pedals like a good bicycle for urban utility mostly- 25 to 30 mph range, with baskets

To that end, I'm about to sell my extra 66 motor, and be leaning more towards 50 china girls if I ever have to replace the current 66 I have built up .

I've been thinking though I'd really like about a 40 cc with a slightly longer pipe- to take the motor noise down even further
and a plastic tank about the size of a water bottle- 1 liter, on a nice diamond touring frame with light wheels- nothing fancy, just really towards the vintage touring bike angle-

I don't mind peddling up to get it going- or coasting back down after being at speed- good regular caliper brakes are perfectly fine.

whats the largest 2 and 4 stroke motor your willing to intstall in a bicycle ?

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