zephyr

Errol, the simple design of your rig looks pretty good, but with the motor over the back wheel and the suspension fork in the front, it doesn't leave anywhere for a good beefy rack and panniers for carrying stuff. It takes away some of the utility of the machine. The weight of the motor is directly over the rear axle, and it looks like the rear axle will carry 85+ percent of the weight of the bike and rider. That means you can't easily add a rack to the rear and carry stuff on the rear, cause it would add yet more weight over the rear axle. I am guessing the drive belt on the left rear would eliminate the ability to use that side of the bike for a rear rack also.

Honeybee

I love them. I want one. However, backyard mechanics are buying crappy bikes and adding crappy engines=I will wait.

Tundra_Man 

I'm late to the discussion, but I have no problem with them as long as they follow the laws of their area (i.e. regarding bike paths, bike lanes, etc.) I doubt I'd ever be interested in one as I have a motorcycle for those days I don't feel like pedaling. Most days I pedal.

If one is worried about missing out on the exercise when they ride one of these, this would be easily solvable with a fixie conversion and some clipless pedals.

Honeybee

**that's hot!**

Honeybee

Solex:

Are they out of business?
https://www.solexus.com/store/solex_bikes.htm

2005 models available???
$1500 that's more than a scooter.

P.S. Love this thread! I have been seeing a lot of these ads on Craigslist too! I wanted one unlike the OP. LOL!
Prices are okay
https://miami.craigslist.org/brw/bik/1437400328.html
https://miami.craigslist.org/brw/bik/1437396294.html
https://miami.craigslist.org/brw/bik/1418146200.html


Electric bikes too but I haven't been pleased with the reviews of electrics. To buy one is just to say: "Hi everyone I have an electric bike." Not because they are particularly any better in reliability.
https://miami.craigslist.org/mdc/bik/1403191366.html

noisebeam

All the many I've encountered are easy to drop and technically where I live are prohibited from using a bike lane if traveling over 20mph, even though all the ones I've seen do so while at 24-26 or so.

somedood

So how come you get twice the mileage of a scooter w/the same size motor?

Luddite

I have the same opinion of gas powered bikes as battery assist bikes. Use your OWN power to roll your bike!

I'm proud of the kilometerage I've logged on my bike. I cycled every damn bit of it with my OWN power.

whatsmyname

Yeah, I'm not crazy about the aesthetics of the over-the-back-wheel motor. I find myself liking echotraveler's utility bike more.

wheeldeal

What size motor is on that HR?

kenkayak

I did not post the foolishness that you have posted here by kenkayak/Kenneth

bmt074

I'm sure most cyclists share your opinion (as I do) BUT I'm all for motorized bicycles if they are replacing cars for daily commuting - heck they could even gateway some people into full cycling.

adamtki

These gas motors are fine on the roads, but they shouldn't be ridden on sidewalks or MUPs. It's very inconsiderate to the other users who have to put up with the smell and sounds of these things.

I'm curious how much maintenance is required over extended use. I used by ebike for about 10,000 miles and it's gotten very little maintenance from me outside of normal bicycle maintenance. My brake pads are not replaced more often because I often use the regen motor as a brake (for slow stops). The chains are worn through at the same rate as a bicycle. The ebike motor and the electrical system has never given me any problems.

errolprowse

number one is change oil. if you dont it stops running. electrics are easier in that way because they have bushings that lubricate the internals automatically. i change my oil every 100 miles or so, others do it every month (very foolish). the oil is a couple table spoons at the most and you can use a liter of oil for a long time. if you have a 2 stroke piece of junk you have to add the oil every time you put gas in and those engines polute like no other on top of that.

another maintence issue is brake pads, keep a spare set because gas engines need to stop from pretty fast speeds quite often.

the kevlar belt i have on my bike lasts around 8,000 miles. its like 27 bucks.

i think any motor bike should have good strong slicks that will last a long time.

other maintence would include things that break over time. no matter what system you get, you should check everything, put oil in some places and make sure nothings wearing out super fast.

very true, i hate when idiot people ride motor bikes where they are not allowed. i have only ridden mine on the street with the same speed as traffic.

very true, i use a backpack because theres no real room for a rack and panniers. the motor wieghs 12 pounds, i wiegh 130 pounds, so theres not much problem with more wieght on the rear axle. if i was fat it would be. what others do is use the metal bars as a rack and put panniers on them. i wouldnt do this. best method is a one wheel trailer, but if your riding in traffic its not very good to have (people have a tough time seeing that small of a trailer behind a bike and if your in traffic taking up a full car space, people will run into it)

its called using the bike to get somewhere to do other sports. i dont want to use my car because of spending money on the car so i use my motor bike. i want to go to the beach/gym feeling good and full of energy. i understand that you need to warm up and its good to get cardio before a workout. i use the motor only when i need to conserve energy, like surfing or kiteboarding.

listen to this man because its true!!! they are mostly dangerous. the only one i like is the one in my picture, its called "golden eagle bicycle engines"(bikeengines.com) they have a good design and last a long time. they are not crappy engines (except there 2 strokes, i hate them), just get there "robin/subuaru engine" and you will be impressed. and please dont get a crappy bicycle and put it on, it just makes things extremely unsafe.


i guess you did not research!!! i have a 35cc engine. scooters usually have a 50cc engine and up. WOW!! hard math huh?? on top of that, my bicycle wieghs a bit over 40 pounds. scooters wiegh much more. thats how i get 250 mpg. oh and im not fat, i weigh 130 pounds of all muscle (i do a lot of gymnastics)

Reynolds 

I have nothing against motorized bicycles per se, but the examples I knew first hand didn't work too well. A normal bicycle isn't designed to take the extra stress and speed that a motor implies. Hubs, rims, brakes, frames, forks, wear very quickly or break. Not a good idea IMO, except if you only ride it around the block every now and then.

dogbitteneear

cutting to the chase....Most state have a 50 cc limitation on bicycle power.

errolprowse

wow, if you can ride something on a bicycle over 50cc your balls have to be the size of astroids. have you been on a 49cc engine attached to a bicycle?

thats why you buy stronger equipment. there are bicycle wheels built ONLY for motor bicycles. there spokes are almost the size of the ones on motorcycles. frames and forks are no worry, i havent had one break at all and havent hear of someone breaking one from using a motor.

wheeldeal

Ummm....how many watts does the the peloton put out when they're sprinting for the finish? Anyone know what Cav puts out on his sprints? I would assume it's north of 1,500 watts? That's about 2HP.

What does an average 4 stroke 50cc motor put out? 2HP? 3HP? Maybe a 2 stroke 50cc can generate 4 - 5HP.

But assuming, someone has a 49cc 4 stroke motor, it only generates 2 - 3HP max.

So, let me get this straight. Mark Cavendish can generate about 2HP+ for a few seconds during a sprint finish on his weak little 16lbs road bike and has no problem with the frame/wheels folding itself in half, yet you're afraid a beefy Specialized Hardrock is going to have reliability issues?

adamtki

Typical elitist remark.

It's not a race and I'm not looking for a ribbon. If I did, I'd take my regular bike for events such as the one day StP (double century ride) I did this past year.

I don't want a workout on every single commute run. And I don't want to take forever getting there either.

bautieri

Neato! Could you post a close up picture of the other side of the bike? I love all things mechanical and would really like to see a few more shots of this.

Did you make this yourself?

Reynolds 

Totally different scenario IMO. I never said it would break on a 15 sec effort. I think it isn't reliable day after day.
Those are little road bikes, but they are not weak. And they cost 6,000 - 10,000$ or more. Probably Cavendish can reach more than 1500W, and bigger sprinters about 2000W, but in my experience common riders rarely put out more than 200 - 250W. And the motor's high pitched vibrations are not present in human effort. They loosen bolts and cause cracks.
BTW, I've never seen a motor powered Cervelo, Scott, BMC, Pinarello, etc. You could buy a scooter for less than they cost.

wheeldeal

Trust me, those little road bikes are much weaker than a Hard Rock. The frame is butted and I'm sure they're paper thin in the middle to save weight. Same goes for the wheelset. If you take a hammer and lightly tap the middle of the TT or DT of the road bike and you do the same for a mountain bike, which do you think will crack?

If you have grease and a torque wrench, there is no way bolts will start loosening under vibration. If that's the case, we'll see cars/boats/motorcycles fall apart daily.

A 50cc motor's vibration causing cracks? Are you kidding me? Have you seen what people put their hardtails through? If it can take a 5ft drop on a trail, the vibrations from a dinky 50cc motor isn't going to stress the frame much.

IMO, the only stress will be to the wheel that gets the power. Maybe the spokes/hub will be stressed more than usual, but any hardtail frame will take it like a champ.

errolprowse

I bought a kit from bikeengines.com for like 650 bucks.
you have to put it together, but its not that hard at all. these kits actually last a long time and are worth every penny. the actual engine hangs off on one side. it seems wierd but you will never even notice it if you rode it.

im trying to find more pictures that i knew i took but i cant find them!! heres some of the drive system and how it attaches to the bike:

This is a view from the oppisite side of the engine. it is the drive belt and the clutch. it is centrifugal so all you have to do is pull the throttle and you go.

as you can see from this pic, the spokes on these wheels are humongous, the are like the same thickness as a small screwdriver (the metal shaft part)

everything you said was right, even the spokes part. wheels are one thing that you must buy that are made for motor bikes only. the wheels i run are extremely strong, heres there specs:

26" Triple V Rim - 6000 series aluminum

36 Spoke, 4 cross - 105 gauge High Quality Stainless Steel Straight Spokes.

ive used them for 2 years now and i havent had any problems at all. one rear wheel costs 89 dollars plus shipping. pretty cheap if you ask me.

wunderkind

THe ones I've encountered that often goes on the same bicycle lanes and MUPs are 2-stroke engines. They sound like lawnmowers, belch oil smoke everywhere and they go fairly fast. I think this whole idea of strapping a lawnmower engine on a bicycle that is not hauling freight goods is counter-intuitive from eco-friendly and exercise point of view of bicycles. These 2-stroke engines spew out more polution than a typical modern car!
If the fat lard is too lazy to pedal his/her own weight on a bike, either take a bus or work harder!
Rant off.

bautieri

Neither frame will crack from being lightly tapped with a hammer.

A single cylinder engine is commonly referred to as a "Thumper" as there is no opposing cylinder to balance the engine with counter rotation. Thumpers vibrate. A lot. Vibrations are bad. Over time this constant vibration will fatigue the metal. Eventually it will crack where the engine mounts, even if it is mounted with a rubber damper, eventually the mounting point will fail.

Yes, bolts loosen over time and this is generally due to vibrations. But if you're using that torq wrench on a fairly regular basis then this is a non issue.