No idea about any other scooters than the Roketa MC-05-127.
I just called Roketa Texas, and they sent me a new Sprocket adapter with bearing. Charged me a ridiculous $50 + $12.50 shipping (~$75); now it turns out I lost the sprockets, so I have to re-order them.
I will probably work on the sprocket adapter soon.
Turns out that the bearings break from tightening the chain too much. The chain needs to have more than 1" slack, as the swingarm needs to have sufficient chain length to have the rear suspension work.
I'm probably going for a 33T rear sprocket this time; but in the mean time, I need to get married (lol, in 2 weeks), so if you don't hear from me for a while, it'll be because the miss is taking more time than the bike does!
Keep in mind, when you put a BBK on it, to increase the front sprocket to at least a 15T (16t if it fits). It's a cheap way to make it go faster. If I where you, I would do the BBK, then the front sprocket, then fine tune the thing (you can find cheap K&N airfilters, but I doubt you need one on a 50cc 4 stroke, it just doesn't have enough air volume), and exhaust, yet again, I think that the stock exhaust is good enough for even a 125cc bike; at most drill it out a bit (to make it louder); and then reduce the rear sprocket, to where you like the acceleration, and top speed.
Those engines make most torque/HP at ~7500k rpm. If you want fastest top speed, on a level ground, and wind still area, you'd be best to keep on decreasing the rear sprocket's size until your revs stop climbing past 7.5-8k RPM in final gear. If the needle sticks around 7.5k rpm, when you're riding WOT, and the speedo climbed very slow you should be getting at least 55MPH with a 75cc BBK, and 42+ with the stock 50cc.
With those step-through gearboxes, keep in mind that you could get clutch slip, when doing prolonged rides at WOT, and high gear. For that reason I think it's better to keep a 50cc engine in place... I had clutch slip on my roketa mc05-127 when I changed the overtly large 41t rear sprocket with a 31t sprocket. I should have stayed at 34t on that bike...
Last Edit: Feb 23, 2015 23:18:39 GMT -5 by prodigit
Sorry I'm being a bit late. I saw the cheaper Roketa version of the SSR, about half the price.
The reason your motor hits the rev limiter so fast, is that the whole bike is made for a 50cc. Then equipped with a 75cc, you get 50% more power, but your sprockets aren't adjusted to it.
I've been looking at turning the original 50cc into a monster MPG machine! But like you said, the bike more than likely is extremely slow, starting off, since it needs to build RPMs to get higher acceleration power.
It gets around 100MPG with the original 50cc engine. One sprocket change that can be done on the 50cc, that I find of interest, is to change the front to 15t, and the rear so that the bike makes top speed in 3rd gear, and has 4th gear as an overdrive, just to attain something around 120MPG.
The overdrive gear gets you between 2 and 4MPH slower than the top speed, but it's nice to brag about going cross state (like 500 miles in Florida) on a 50cc scooter, on less than $15 on gas.
I don't have the ssr lazer 5, but am eyeing the Roketa mc-112-50. It has a 4 spd step through gearbox, which allows it to accelerate faster with it's 50cc, than with the ssr lazer's 75cc bbk without gearbox.
The roketa is more versatile, but due to its gearbox is seen as a motorcycle, not a moped.
Last Edit: Feb 24, 2015 3:29:22 GMT -5 by prodigit
I just use my GPS, and memorize the speed mapping. on my 50cc I didn't have to memorize anything. I knew that it's top speed was ~48MPH, and that's all I needed to know, because it took like what seemed like an eternity to get there anyway. On 150cc's its more important to know; as you could very quickly be speeding.
On my TaoTao ATM150/EVO150, the speed was displayed correctly.
I would agree with some, just use a permanent marker, and mark down the correct speeds on your speedo; or use stickers.
If you like the style, but with more cc's, you might be interested in Yamaha's SR400. Coming out in 2015, the perfect highway bike if you ask me; except for the price. Lightweight, nimble, and fast enough; and probably you can get the 66MPG up by 15% to 75MPG.
The bike on itself is a perfect city bike; but it would only be able to help you out on highways in emergencies; or a few exits. Not really meant to be going on the interstate with, or do longer rides.
I found that 300cc in my environment (flat Florida) would not be very useful, unless if it's a racing engine ( Ptwin ), with 10+k rev limiter (like the Ninja 300); to build up enough HP to be able to go at Interstate speeds. Though most interstate speeds here are posted 60MPH, most people don't go below 75MPH, 80MPH most of the time, and occasionally 100MPH.
A 300cc engine of this caliber would barely be able to get to 85MPH tops; and in some way is just like my Honda Rebel 250. If you are looking for this bike at 300cc, you might check out the Rebel 250 or Yamaha Vstar250 ; which is about 5MPH faster than the Suzuki Tu250; and has more HP/Torque. The Rebel because it has a high rev engine (9.5k RPM Ptwin engine), and the Yamaha, because it has a 249cc V-Twin (a bit more than the 234cc Ptwin of the Rebel).
If you want to do some interstate riding, at 80MPH and beyond, with some 15-20MPH headwind, you really want your bike to be able to do +MPH tops, so you can still ride it at 80MPH even with wind, and a 400cc (35lb ft torque, 35HP is really recommended).
Another note, A 250cc is somewhat the threshold of air cooling. 300cc and more should preferably be watercooled.
For that reason, I would recommend a 400-500cc bike; watercooled, which should be able to get you anywhere in the USA, tops out at -100MPH, and will handle longer highway speeds (80MPH) just fine, without running out of breath.
If I didn't have so much highway to do, I would probably have purchased this bike! I might purchase it for the local rides, and upgrade my Honda Rebel 250 to a 350-500cc thumper bike for interstate speeds. I feel the Rebel 250 can barely hold it's own at prolonged WOT rides (75-80MPH, 1+ hrs rides).
It took me some modding to get the Rebel past 80MPG (comes at 66MPG stock).
This sym would be the perfect city bike. Top speed 65MPH, which means actual usable (all day) speed is 55MPH; as those last 10MPH always feel like squeezing the juice out of the engine; and probably tops at 50MPH with a strong headwind. With some mods, probably 70-75MPH with wind in the back.
I know that a 125cc was too small for comfortable city riding; possible, but not comfy. 150cc is the perfect city size.
350-400cc is the perfect highway size, for speeds of all day ~80-90MPH.
Well, I started This thread, not to complain about my broken bike,but also to contribute to what is the best possible bike for my situation. For those are interested a Honda Rebel 250, or a Suzuki tu 250 X, are about the closest products available, that give optimal gas mileage. All they need is a sprocket change, and you could be riding 100mpg on those 250s.
my personal preference goes to the Honda Rebel, because of the twin cylinder which gives a little higher performance, while at the same time the cylinder content is only 234CC, which is not the full 249 CC which you get with the Suzuki.
It is as close to a 200cc as you can get. Why is 200cc so important? Because it produces the HP needed to go 40-45mph (4bhp) at ~2000-2500rpm. For a 300 lbs 50cc scooter to go 45, you'll have to run it in the torque band (7500 rpm). A 200cc would maintain this speed at the bottom of it's revs. For a 125cc, I only found with 4 gears, it really is missing a 5th gear, cruising 40mph at ~4k rpm. The 150s have only 1 motorcycle, an ugly chinese sports bike, that is sold in usa, all the rest have cvt. A cvt set up to do 8k rpm at 60mph, or 4k rpm at 30mph. I presume you could gear a 150cc to run 3k rpm at 40mph without lugging the engine, but any lower, and the bike will have trouble departing from a dead stop.
I'm not willing to go Chinese anymore. Only engine and transmission parts available. Most body parts are not available online. 200cc the same as 150cc Chinese bikes, no body parts anywhere. Most Japanese bikes start with 250cc, so there's not a lot of choice on the market to choose from if you want dealer support.
Kawasaki ninja 250 (carb), and ninja 300 (fuel injected), as well as the the older Honda CBR250R get ~60mpg in real life. With a sprocket change, you could get 80mpg, but seats are uncomfortable, suspension hard, not the type of cruiser bike you have in mind to relax either. The newer CBR250R s have fuel injection, 80mpg, better performance, but their suspension is rock hard, and everything about it screams 'cheaply made' and 'plastic'.
Honda Rebel 250 and Suzuki TU250X get stock 80+mpg. With sprocket change you can get close to 100 mpg. The Rebel being the faster one due to it's parallel twin engine, the tu250 having most low end torque, which makes most sense to mod to an mpg monster. It also has fuel injection, which the rebel does not have. However riding comfort is only slightly better than the sports bikes, while the Rebel is head and tails above with it's softer suspension, and it's most comfy air cushion seat.
The only con on the rebel is that the handlebars hit my knees, 35 inseam, 6'3" height. Easily solveable by either putting in handlebar riser pieces, or rotating the handlebars a bit more upward, which is possible with just 4 screws. The rebel was the only bike with that problem, seemingly made for people upto 33 inseam, or most people of upto ~6' tall.
The Suzuki GW250 was a lot heavier, lower mpg, suspension similar to the 300 and tu250 (pretty hard), and the point of gravity was significantly higher as well. The handlebars where ridiculously low compared to the higher seat height compared to the other bikes. For me the handlebars needed to be raised by almost 10 inch for my comfort (6in up, 4in backwards), which is just ridiculous! There's a reason this bike is priced the lowest, despite it's good looks.
The Yamaha Vstar had the best seating position for me, partly due to the more upright seating (foot pegs are more forward than with other bikes) handlebars almost perfect where I needed them. but suspension was in the likes of the gw250, 300,and tu250. Gas mileage is in the 60s of mpgs, because it's equipped with a vtwin engine, tweaked for performance, not fuel economy. The vtwin has about the same low end torque of the TU250x, and a lot more high end torque than the Rebel. It's not as fast as the short stroke engine sports bikes, but it's definitely the fastest 250cc cruiser bike, and pearl white is pretty too. Costs more than the rest as well. The vtwin gives a nicer exhaust tone, but that's nothing I worry about.
So overall, if best mpg is your goal, nothing beats the TU250x. But it's pretty much the slowest, and imho the ugliest bike, barely getting 75mph.
Second best mpg and best riding comfort, the rebel wins hands down. It is also the bike of my choice, but only comes in red or black.
Price: the GW250 has the lowest sales price, but also lowest comfort level. It is about as fast as the vstar, but in a more modern jacket (naked/street fighter style bike)
The Ninja 300 outperforms all sports bikes, except in gas mileage, as the 2014 CBR250s are now equipped with fuel injection as well. The cbr has about 75mpg, vs the 60mpg on the 300, however the cbrs suspension feels stiffer, and the ride feels cheaper than the ninja 300.
The vstar is somewhat a loner. It is interstate ready, able to almost go 90mph, but much more expensive. It's the 250cc bike for those with money, who want best performance, nicest looks, best seating ergonomics on a 250cc cruiser, and who don't care about mpg. Imho, for the price, yamaha should have equipped this bike with an air cushion, like the rebel, and made the suspension like the rebel as well..
That pretty much sums up my research in modern 250s, and experience on sitting on it at the dealerships. No actual ride experience though.
Last Edit: Jan 17, 2014 16:06:57 GMT -5 by prodigit
I'm thinking, if the reason was, for the sealed bearing to break, it might have something to do with the sprocket adapter. Try seeing if the smaller golden piece fits in between the wheel and the sprocket adapter somehow.
As far as the bearing goes, I don't know which one to choose. There's nothing left of the original bearing, save a rubber and metal ring, I have no dimensions.
Last Edit: Jan 17, 2014 14:52:44 GMT -5 by prodigit
For me, a 75cc is the absolute minimum a small person should consider when traveling mainly in the city. When you're a bit larger in weight, 200lbs+, you should think 100-125cc minimum. For the suburbs, with roads upto 45mph, the absolute minimum for a small person, would be 125cc, 150cc recommended. 150cc for a larger person minimum, 200cc recommended. For occasional 5-15 minute highway rides, a 250-300cc is recommended.
Aside from what's said before, a cvt is the way to go in start-stop traffic. Nothing more annoying than to have to shift endlessly between gears when the traffic isn't going at a steady pace. A second reason to go scooter is the added safety when a car slams you from the side. Most motorcycles come without crash bars, so if a car slams into you from the side, not only are your legs not crushed between car and motorcycle, but also when you come to slide, your legs have a lower chance on getting stuck between bike and asphalt while you slide.
Thirdly, a scooter protects the rider much more from rainfall, and has better storage solutions for electronic devices such as a cell phone or gps, than a motorcycle has. Not only to protect your electronics from rain, but also from being out of view, in case you need to quickly run into the store, and don't want to bring all the gadgets in.
That being said, if you live in the suburbs, or country side, or hills or lands with large open spaces, you will benefit more from a manually geared, chain driven bike, As with a simple $50 sprocket change, you can adjust the ride to your needs (better acceleration/performance, or better fuel economy/longer engine/transmission lifetime), which could save you precious $$$ over the course of the vehicle.
And, personally, I prefer gears, for anything but the city.