Byebye Chinese bike! Calculating optimal suburb fuel saver.
by: prodigit - Jan 10, 2014 2:22:26 GMT -5
Post by prodigit on Jan 10, 2014 2:22:26 GMT -5
So, yesterday I got a reply from Superiorpowersports concerning the sealed bearing on the rear wheel axle of my Roketa MC-05-127
They basically told me they can not get their hands on a bearing.
I can not believe this!
In other words, this entire motorcycle is worthless after only 2k miles riding, when the bearing breaks!
I'm not about to look around for a new bearing and have it break again; and I'm just honestly tired of fixing my bikes.
All my chinese bikes have broken and needed maintenance, except for my EVO150, which is at ~2500 miles now, and in need for a valve adjustment.
My TaoTao ATM50 also has electrical wiring issues. A short somewhere.
It's rusting in the back yard, and no one anywhere willing to work on it.
Dealers of chinese scooters charge too much, and only give like $100 for a scooter like that.
Without it working, no one is willing to buy it, and I don't have the time to be wrenching on them.
It's byebye chinese bikes for me!
They've been a great experience, I've thoroughly enjoyed playing around with them.
They taught me a lot, and gave me a love for life on 2 wheels!
I noticed I really enjoyed life on 2 wheels, and think I will want to get more serious, and get better equipment.
Initially, a Chinese scooter was good in case should I want to ride, but later give up.
A $800 scooter is much more affordable, than a $4k motorcycle to just toss away after a while.
For this reason of me not wanting to work on my bikes anymore; I just ain't got the time for it anymore, my next bike will be a more serious model, a Japanese bike.
I'm thinking of getting either a Honda Rebel 250, which I love the seat and fuel mileage.
I tried a CB500X, but the bike was too small for me. I'm not comfy on it.
I'm not for sports bikes, so no ninja for me.
Their CTX700 is also not made for tall people (the knees are bumping against the tank fenders, not very nice feeling).
Their NC700X fits me well, but is quite expensive, and large, too much CC for what I need, and the gas tank is too small; but the gas mileage is relatively good.
A Kawasaki KLR650 is an excellent bike for tall people like me, and also too much CC for what I want it for, and I doubt I can improve that bike by doing a sprocket change, as it already has 6 gears.
I'm mainly interested in getting the best gas mileage out of a vehicle, going 40MPH.
Something nimble and small.
Something I don't need for long distance riding, but for short rides, as long distance riding in Florida almost guarantees you're going to get stuck in a rain storm somewhere along the way.
I set 40-45MPH as a baseline for all my calculations, as those are the speeds I usually ride on.
I live in the suburbs, where
% of the roads are 35-50MPH; on the 35MPH roads people usually ride 40MPH.
What I basically want to achieve is the highest MPG, with the smallest cc, at the lowest RPM, going 40MPH, while still being able to accelerate with the traffic, without feeling like you're pushing the engine.
Since most of my riding is at ~40MPH, I want to be able to maintain that speed in final gear, without the engine lugging (or going under 2k RPM).
Any lower than 1,5-2k RPM and you could lug the engine, or cause excessive engine vibrations, that will result in parts wear.
The higher the RPM, the less the vibrations, the more smooth the engine runs, the longer most parts (like electrical wiring, chassis mounts, fenders, body panels and tupperware, welds) last.
On the other hand, the higher the RPMs, the faster the engine will wear, and the lower your MPGs will be.
Suppose you could maintain a speed of 40MPH, at 2k RPM.
Doing this with a 200cc should result in better gas mileage than with a 400cc, because the cylinder content is larger on the latter one, causing it to suck in more fuel.
The 400cc would have more torque at that RPM. But a lot of the torque is unnecessary at that speed.
You need power at high speeds, but in order to maintain 40 MPH, even a 75cc is powerful enough .
There's a third factor that comes into play, and that's how far you are opening the throttle, causing the engine to rev too high.
Should you try to maintain 40MPH, at 2k RPM, on a 100cc, you'd have to open the throttle all the way, and acceleration would be painstakingly slow (worse than a 50cc revving up to 8k RPM).
Fuel efficiency goes down, once you start pushing the engine (usually last 10MPH on the speedo), but also last 10% of the throttle.
So bringing this all into calculation, and my experience with chinese motorcycles have given me this data:
50cc, ~7-8k RPM @ 40MPH throttle position 100% opened, MPG ~100MPG. 300LBS
127cc ~5k RPM, throttle 50% opened, 105-120MPG. (it barely accelerates fast enough from a stand still. Not enough torque) 300LBS
150cc ~5k RPM, throttle 50% opened, ~66 MPG. Good acceleration. ECU causes low MPG. 330LBS
260cc ~4k RPM, Throttle 33% opened ~82MPG. Very good acceleration, EFI, 450LBS
The higher the cc's, usually the higher the weight of the bike.
The 50cc, 127cc and 150cc, all where around the same weight 300-330LBS.
Larger bikes usually have sturdier materials, heavier frames. The increase in weight works negatively on the MPG's.
Since they almost don't make Japanese 200cc's, which would be my estimate on the perfect cc's; the closest to that is 250cc.
Most Japanese bikes are also slightly heavier than 300LBS (the Honda Rebel for instance has 234cc, and weighs 331LBS, pretty close to the motorcycle and scooter weights above, and the cc's is only 34cc up from my calculation).
Most 250cc's like the Honda's, Kawasakis, Yamaha's have too much torque, and too short gearing. And a their MPGs are too low compared to the Chinese bikes.
Their RPMs are too high in final gear ratio, and can be somewhat lowered with a sprocket or gear change.
Most of the time their gears are optimized for top speed in final gear, and they don't have an overdrive.
By doing a sprocket change, you could create that extra gear you felt was missing. Like a 6th gear.
That way, you can reach top speed in 4th gear, and 5th gear will just lower RPM, which will increase MPG, and engine life.
On Japanese bikes, if you want to have a decent overdrive, you basically will need a sprocket resulting in two gear changes (double overdrive); so that you can reach top speed in 3rd gear, and use 4th and 5th gear as overdrive/cruising gear to lower RPM even further.
That usually means 1/4th smaller rear sprocket (1/4th lower tooth count, or from 44T to 33T rear), or a combination of 1 tooth up on the front, and 6-9 down on the rear; resulting in harder starts from a dead stop, kind of making you start in second or third gear instead of first gear; needing quite some clutch work.
What helps is that the 250cc bikes of today generally are quite lightweight (see the Rebel at 330LBS), so they depart easier from a dead stop than heavy bikes.
Another negative, is that some 250's of today have parallel twin engines.
Parallel twin engines have 2 x ~125cc cylinders in parallel, which saves on engine size, overall cost (compared to a V-twin), increases top rev torque compared to a thumper (or single cylinder engine), but they have less bottom end torque. Which means at the 2k RPMs you probably could ride more efficiently with a thumper engine, than with a parallel twin engine.
So gathering all this info, I come to think that a 250cc parallel twin engine is really the best of both world, to create the perfect MPG monster.
The Honda Rebel 250 gets 80MPG, has 5 gears, however, one can easily up that number to 100MPG with a sprocket change, and still maintain relatively peppy bike, just as long as you rev it in the torque band.
Accelerating in the 2-4k RPM band probably may be pretty slow.
The 2013 and 2014 models have an air coushion seat pillow, which sits really well!
I'm still looking at alternatives, but think that this bike, is probably the number one on my list.
I'm not so much for offroad or dirt bikes, as their comfort of riding isn't very good (bad seats, almost no dash indicators, high price, etc..).
They basically told me they can not get their hands on a bearing.
I can not believe this!
In other words, this entire motorcycle is worthless after only 2k miles riding, when the bearing breaks!
I'm not about to look around for a new bearing and have it break again; and I'm just honestly tired of fixing my bikes.
All my chinese bikes have broken and needed maintenance, except for my EVO150, which is at ~2500 miles now, and in need for a valve adjustment.
My TaoTao ATM50 also has electrical wiring issues. A short somewhere.
It's rusting in the back yard, and no one anywhere willing to work on it.
Dealers of chinese scooters charge too much, and only give like $100 for a scooter like that.
Without it working, no one is willing to buy it, and I don't have the time to be wrenching on them.
It's byebye chinese bikes for me!
They've been a great experience, I've thoroughly enjoyed playing around with them.
They taught me a lot, and gave me a love for life on 2 wheels!
I noticed I really enjoyed life on 2 wheels, and think I will want to get more serious, and get better equipment.
Initially, a Chinese scooter was good in case should I want to ride, but later give up.
A $800 scooter is much more affordable, than a $4k motorcycle to just toss away after a while.
For this reason of me not wanting to work on my bikes anymore; I just ain't got the time for it anymore, my next bike will be a more serious model, a Japanese bike.
I'm thinking of getting either a Honda Rebel 250, which I love the seat and fuel mileage.
I tried a CB500X, but the bike was too small for me. I'm not comfy on it.
I'm not for sports bikes, so no ninja for me.
Their CTX700 is also not made for tall people (the knees are bumping against the tank fenders, not very nice feeling).
Their NC700X fits me well, but is quite expensive, and large, too much CC for what I need, and the gas tank is too small; but the gas mileage is relatively good.
A Kawasaki KLR650 is an excellent bike for tall people like me, and also too much CC for what I want it for, and I doubt I can improve that bike by doing a sprocket change, as it already has 6 gears.
I'm mainly interested in getting the best gas mileage out of a vehicle, going 40MPH.
Something nimble and small.
Something I don't need for long distance riding, but for short rides, as long distance riding in Florida almost guarantees you're going to get stuck in a rain storm somewhere along the way.
I set 40-45MPH as a baseline for all my calculations, as those are the speeds I usually ride on.
I live in the suburbs, where
% of the roads are 35-50MPH; on the 35MPH roads people usually ride 40MPH.What I basically want to achieve is the highest MPG, with the smallest cc, at the lowest RPM, going 40MPH, while still being able to accelerate with the traffic, without feeling like you're pushing the engine.
Since most of my riding is at ~40MPH, I want to be able to maintain that speed in final gear, without the engine lugging (or going under 2k RPM).
Any lower than 1,5-2k RPM and you could lug the engine, or cause excessive engine vibrations, that will result in parts wear.
The higher the RPM, the less the vibrations, the more smooth the engine runs, the longer most parts (like electrical wiring, chassis mounts, fenders, body panels and tupperware, welds) last.
On the other hand, the higher the RPMs, the faster the engine will wear, and the lower your MPGs will be.
Suppose you could maintain a speed of 40MPH, at 2k RPM.
Doing this with a 200cc should result in better gas mileage than with a 400cc, because the cylinder content is larger on the latter one, causing it to suck in more fuel.
The 400cc would have more torque at that RPM. But a lot of the torque is unnecessary at that speed.
You need power at high speeds, but in order to maintain 40 MPH, even a 75cc is powerful enough .
There's a third factor that comes into play, and that's how far you are opening the throttle, causing the engine to rev too high.
Should you try to maintain 40MPH, at 2k RPM, on a 100cc, you'd have to open the throttle all the way, and acceleration would be painstakingly slow (worse than a 50cc revving up to 8k RPM).
Fuel efficiency goes down, once you start pushing the engine (usually last 10MPH on the speedo), but also last 10% of the throttle.
So bringing this all into calculation, and my experience with chinese motorcycles have given me this data:
50cc, ~7-8k RPM @ 40MPH throttle position 100% opened, MPG ~100MPG. 300LBS
127cc ~5k RPM, throttle 50% opened, 105-120MPG. (it barely accelerates fast enough from a stand still. Not enough torque) 300LBS
150cc ~5k RPM, throttle 50% opened, ~66 MPG. Good acceleration. ECU causes low MPG. 330LBS
260cc ~4k RPM, Throttle 33% opened ~82MPG. Very good acceleration, EFI, 450LBS
The higher the cc's, usually the higher the weight of the bike.
The 50cc, 127cc and 150cc, all where around the same weight 300-330LBS.
Larger bikes usually have sturdier materials, heavier frames. The increase in weight works negatively on the MPG's.
Since they almost don't make Japanese 200cc's, which would be my estimate on the perfect cc's; the closest to that is 250cc.
Most Japanese bikes are also slightly heavier than 300LBS (the Honda Rebel for instance has 234cc, and weighs 331LBS, pretty close to the motorcycle and scooter weights above, and the cc's is only 34cc up from my calculation).
Most 250cc's like the Honda's, Kawasakis, Yamaha's have too much torque, and too short gearing. And a their MPGs are too low compared to the Chinese bikes.
Their RPMs are too high in final gear ratio, and can be somewhat lowered with a sprocket or gear change.
Most of the time their gears are optimized for top speed in final gear, and they don't have an overdrive.
By doing a sprocket change, you could create that extra gear you felt was missing. Like a 6th gear.
That way, you can reach top speed in 4th gear, and 5th gear will just lower RPM, which will increase MPG, and engine life.
On Japanese bikes, if you want to have a decent overdrive, you basically will need a sprocket resulting in two gear changes (double overdrive); so that you can reach top speed in 3rd gear, and use 4th and 5th gear as overdrive/cruising gear to lower RPM even further.
That usually means 1/4th smaller rear sprocket (1/4th lower tooth count, or from 44T to 33T rear), or a combination of 1 tooth up on the front, and 6-9 down on the rear; resulting in harder starts from a dead stop, kind of making you start in second or third gear instead of first gear; needing quite some clutch work.
What helps is that the 250cc bikes of today generally are quite lightweight (see the Rebel at 330LBS), so they depart easier from a dead stop than heavy bikes.
Another negative, is that some 250's of today have parallel twin engines.
Parallel twin engines have 2 x ~125cc cylinders in parallel, which saves on engine size, overall cost (compared to a V-twin), increases top rev torque compared to a thumper (or single cylinder engine), but they have less bottom end torque. Which means at the 2k RPMs you probably could ride more efficiently with a thumper engine, than with a parallel twin engine.
So gathering all this info, I come to think that a 250cc parallel twin engine is really the best of both world, to create the perfect MPG monster.
The Honda Rebel 250 gets 80MPG, has 5 gears, however, one can easily up that number to 100MPG with a sprocket change, and still maintain relatively peppy bike, just as long as you rev it in the torque band.
Accelerating in the 2-4k RPM band probably may be pretty slow.
The 2013 and 2014 models have an air coushion seat pillow, which sits really well!
I'm still looking at alternatives, but think that this bike, is probably the number one on my list.
I'm not so much for offroad or dirt bikes, as their comfort of riding isn't very good (bad seats, almost no dash indicators, high price, etc..).
The scooter thing isn't the only thing in the world with the label China and not the only thing that is use a while, throw away or fix it. 
Not going to get into the long drawn out drama about it but I will use my "own" experience and it's simple, I never expected my 50cc or 150cc scooters to be a work horse, nor would I expect that out of a name brand 50cc or a 150cc scooter, folks these type scooters are no more than a glorified lawn mower on two wheels instead of four. 
That for me means engine, gear oil changes, tire changes and a battery every 3 years, if memory serves me correctly name brand do the same. 
