"Cheap" is just potential in disguise...
- Thread starter BarelyAWake
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About the title - there's been much (well deserved) criticism regarding the cheap Chinese engine kits, substandard components, poor castings, ill conceived mounting techniques and incorrect instructions... add in the propensity for people already looking to save a few bucks ordering through questionable ebay sources with little to no customer support and it's no wonder there's a plethora of disappointed and discouraged folks whom would denounce these kits as junk...
...and in many ways they're right
Yet what we have here is a bit of misrepresentation, an obvious example is how they're marketed. There is no "80cc" kit (it's actually 66cc) and while there's been some rumors that they use a different formula to measure displacement, that doesn't explain the 49cc kits... which actually are 49cc and legal in most states. That alone leads to disappointment and confusion when their "80cc" doesn't perform as expected.
But that's just the tip of the iceberg lol
They're sold as 'Bicycle Engine Kits' and they are - but it's not the "kit" people think it is, while it can be done it's not as simple as "bolt it to your bike and go" and while the kit does include everything necessary to motorize your average bicycle, those components are the barest minimum - their quality and design compromised in the interest of keeping the cost as low as possible while simultaneously attempting to offer a "one size fits all" - when we all know that means "one size fits none" heh
Yet with a slightly different outlook these "junk engine kits" become incredibly entertaining and actually amazingly reliable - the trick of it is quite simple, it's not so much a "bicycle engine kit" in that it's a kit to convert a bicycle, but much more an engine kit for a bicycle - in that if you consider the engine itself as a kit to be taken apart and cleaned, sloppy castings smoothed and polished, and the substandard components regarded as included "free" to be replaced and upgraded with ones more suitable - suddenly we have a wonderfully simple, well running engine perfect for it's application.
So while you can just "bolt n'go" and many have - you'll get exactly what you paid for, no more and even perhaps less... not really a surprise when you consider the entire motorized bicycle kit, let alone an internal combustion engine - can be had for less than a quality wheelset. So while I'll be the first to admit these kits are cheap junk - that doesn't mean there's isn't a ton of potential. In many ways it's no different than the crusty, unloved and forgotten Rollfast the motor is mounted on, if you're handy, willing and able to take the time to fix something up - if you get a kick out of making something yourself, then these motor kits are a pleasure... if not - then yea, they're pretty much disappointment in a box.
Thanks for the complements and taking the time to read my little rant lol, it just breaks my heart a little to see so many, the kids in particular that end up discouraged - misled by expectations and advertising.
About the title - there's been much (well deserved) criticism regarding the cheap Chinese engine kits, substandard components, poor castings, ill conceived mounting techniques and incorrect instructions... add in the propensity for people already looking to save a few bucks ordering through questionable ebay sources with little to no customer support and it's no wonder there's a plethora of disappointed and discouraged folks whom would denounce these kits as junk...
...and in many ways they're right
Yet what we have here is a bit of misrepresentation, an obvious example is how they're marketed. There is no "80cc" kit (it's actually 66cc) and while there's been some rumors that they use a different formula to measure displacement, that doesn't explain the 49cc kits... which actually are 49cc and legal in most states. That alone leads to disappointment and confusion when their "80cc" doesn't perform as expected.
But that's just the tip of the iceberg lol
They're sold as 'Bicycle Engine Kits' and they are - but it's not the "kit" people think it is, while it can be done it's not as simple as "bolt it to your bike and go" and while the kit does include everything necessary to motorize your average bicycle, those components are the barest minimum - their quality and design compromised in the interest of keeping the cost as low as possible while simultaneously attempting to offer a "one size fits all" - when we all know that means "one size fits none" heh
Yet with a slightly different outlook these "junk engine kits" become incredibly entertaining and actually amazingly reliable - the trick of it is quite simple, it's not so much a "bicycle engine kit" in that it's a kit to convert a bicycle, but much more an engine kit for a bicycle - in that if you consider the engine itself as a kit to be taken apart and cleaned, sloppy castings smoothed and polished, and the substandard components regarded as included "free" to be replaced and upgraded with ones more suitable - suddenly we have a wonderfully simple, well running engine perfect for it's application.
So while you can just "bolt n'go" and many have - you'll get exactly what you paid for, no more and even perhaps less... not really a surprise when you consider the entire motorized bicycle kit, let alone an internal combustion engine - can be had for less than a quality wheelset. So while I'll be the first to admit these kits are cheap junk - that doesn't mean there's isn't a ton of potential. In many ways it's no different than the crusty, unloved and forgotten Rollfast the motor is mounted on, if you're handy, willing and able to take the time to fix something up - if you get a kick out of making something yourself, then these motor kits are a pleasure... if not - then yea, they're pretty much disappointment in a box.
Thanks for the complements and taking the time to read my little rant lol, it just breaks my heart a little to see so many, the kids in particular that end up discouraged - misled by expectations and advertising.
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I've personally bought and assembled 5 of these kits, they are sometimes a big pain in the neck and the parts that come with the "kit"are cheaply made but when done right (buy the upgraded parts)they are fun to ride and look really nice. The big thing is to read the add carefully and see if your retailer offers parts for it. If they don't than DO NOT buy it from them, you may save a few bucks but in the long run it's better to know you bought a quality kit. After all YOU GET WHAT YOU PAY FOR !!! Also these kits are made for mostly 26" bikes. If you try to put them on 24" and 20" bikes you run into a crap load of problems you don't want to think about, although it can be done. I managed to get one into a tricked out bratz low-rider bike frame but had to drill a hole in the frame to route the throttle cable and had to clearance the seat tube to get the air cleaner to fit. Just remember ANYTHING is possible with enough time, patience, ingenuity, and when all else fails break out the big friggin' hammer.....HaHa
COOL :mrgreen:
Flattered to be sure & thank you for the complement - but I'd not go so far as to compare my bike to the pre-1911 Harley Davidsons or any of the beautiful ol' boardtrackers... "Inspired by" no doubt, but there's others that have made replicas far closer in look and feel :wink:
I made any number of small compromises in appearance for performance & function as it's a daily driver (I've about three thousand miles on it since it hit the road this past spring), forgoing a potential belt drive for a jackshaft chain drive allowed me to us a Sturmey Archer 3sp for gearing for both the engine as well as pedaling as an example, an expansion chamber exhaust system as another. I didn't have the heart to cut up an old Rollfast to make it a true drop loop frame either - there's no permanent alterations to the bike itself, the only welding I did to it was the dropstand mounts, and even those are only welded on the inside of the dropouts - those could be ground off with ease.
There's folks out there making amazing replicas, using the modern Worksman Newsboy as a starting point, they're cutting, stretching and making them droploops like this (not my bike) Worksman Drop Loop Frame ;
I made any number of small compromises in appearance for performance & function as it's a daily driver (I've about three thousand miles on it since it hit the road this past spring), forgoing a potential belt drive for a jackshaft chain drive allowed me to us a Sturmey Archer 3sp for gearing for both the engine as well as pedaling as an example, an expansion chamber exhaust system as another. I didn't have the heart to cut up an old Rollfast to make it a true drop loop frame either - there's no permanent alterations to the bike itself, the only welding I did to it was the dropstand mounts, and even those are only welded on the inside of the dropouts - those could be ground off with ease.
There's folks out there making amazing replicas, using the modern Worksman Newsboy as a starting point, they're cutting, stretching and making them droploops like this (not my bike) Worksman Drop Loop Frame ;
Glad you came to your senses barley LOL
welcome and glad to see the rollfast again
Sam
welcome and glad to see the rollfast again
Sam
Cool and retro. My motorized bike does not replace my pedal bikes. It gives me more to tinker with.
These 2 stroke motors are quieter than a lawn mower if you use the muffler supplied with the kit. You can quiet them even further by wrapping the muffler internals with fiberglass fabric and inserting flexible spacers between the cooling fins on the corners.
With the muffler supplied in the kit, you will not upset the neighbors.
With the muffler supplied in the kit, you will not upset the neighbors.
A heck of a lot quieter than a lawnmower actually, it's funny you should mention that as my neighbor is buggin' the heck outa me at the moment - thinkin' 7am on a Sunday mornin' is a fine time to mow the lawn
Problem is, the stock exhaust systems on these kits is one of the very first things I'd replace. While they're quiet - they're extremely restrictive and while they can be drilled out/modified, they're simply the incorrect design for a two stroke. The bike pictured has a proper expansion chamber exhaust, using the stock headpipe (port matched) and an extended glasspack silencer. With both the extended glasspack and a full length exhaust system (which puts the noise & fumes behind you) it's actually even quieter than stock.
Expansion chambers can be had for as little as $25, thanks to the pocket bike craze lol - but will require some modification to fit. Most are quite loud as there seems to be a correlation between noise and speed in most folk's view - but that's not necessarily true, with a lil extra work you can have the best of both worlds
Problem is, the stock exhaust systems on these kits is one of the very first things I'd replace. While they're quiet - they're extremely restrictive and while they can be drilled out/modified, they're simply the incorrect design for a two stroke. The bike pictured has a proper expansion chamber exhaust, using the stock headpipe (port matched) and an extended glasspack silencer. With both the extended glasspack and a full length exhaust system (which puts the noise & fumes behind you) it's actually even quieter than stock.
Expansion chambers can be had for as little as $25, thanks to the pocket bike craze lol - but will require some modification to fit. Most are quite loud as there seems to be a correlation between noise and speed in most folk's view - but that's not necessarily true, with a lil extra work you can have the best of both worlds
hmmmm, thanks for the input, i would have to do alot of moding here and there, the conversion kits you can get for cheep dont look at good as the ones in these pictures and i think that if a pedal bike is gonna have a motor it should fill the whole frame cage.
Perhaps I'm misunderstanding you - but all the above pics (except the ol' Harley ofc) are nothing but the engines you get in the cheap kits... but it's true there's been some modding goin' on
Before I even fit the engine to frame I took the motor apart, dressed the fins, did a port n'polish, lapped the head, rewired the magneto (soldered heaver leads on), replaced the hardware, made proper gaskets, painted the jug & reassembled...
...which isn't nearly as tedious as it sounds, remember there's only four nuts holdin' the top end on :mrgreen:
Before I even fit the engine to frame I took the motor apart, dressed the fins, did a port n'polish, lapped the head, rewired the magneto (soldered heaver leads on), replaced the hardware, made proper gaskets, painted the jug & reassembled...
...which isn't nearly as tedious as it sounds, remember there's only four nuts holdin' the top end on :mrgreen:
