Another Myth Shot To Heck

[kz1000st]

For years I had heard that the Chinese version CN-250 had smaller main bearings than a Helix engine and I just figured it would mean a less sturdy motor that wouldn't last as long. I finally found out today what that difference in size is. A Honda motor has bearings with an outer diameter of 72mm, a Chinese has 68. You know what that works out to? How about 4mm or all of .156 of an inch. Somewhere between 1/8 and 3/16 of an inch. "Wow! What a huge difference!", he said sarcastically. Isn't it amazing how the Myths of Chinese Inferiority just keep tumbling. My crappy main bearings are 2.677 inch, a Mighty Honda has 2.834 mains.

I think I'll live with that.

[wheelbender6]

I guess you wouldn't be able to tell the difference without a micrometer.
I always keep one in my lunch box.

[cheapeto]

The agriculture quality bearing and precision bearing may be exactly the same size, but as a person that was sent the wrong bearings to replace in a newspaper folder once, they are NOTHING alike.
The Ag bearing lasted less than 1 day, and failed.
The precision bearing will lasted years, with proper PM.
Ag bearing $5.00 Precision bearing $65.00 (this was back in the 90's.)
Once I got it apart the second time, I took them to a bearing dealer, and he told what happened.
Showed me how to read the bearing numbers, but honestly, it was not part of my field, that was up to the engineers and expeditors, to send me the right parts for the work scheduled, where ever that work was.

[kz1000st]

The bearings in a CF Moto Fashion all come from Japan. I would think if I had an Ag bearing it would have failed by 12,000 miles yet it doesn't seem to have come apart. If you look around the web most Chinese CN-250s seem to be spared from Main Bearing failures, head gasket issues yes, but not main bearings.

Just out of curiosity I priced the Fashion crankshaft. The unit, with bearings, costs $298 for a Genuine OEM CF Moto crank. Parts for Scooters does stock this for less.

http://www.partsforscooters.com/180-119_Crankshaft?sc=34&category=133358

Ready for this? I just priced a Genuine OEM Helix crank with bearings. $248. I hope there are no Ag bearings in that one.

http://www.cheapcycleparts.com/oemparts/a/hon/506be9e8f870023420a29711/crankshaft-piston

[kz1000st]

You see, my lurking at Modernvespa finally paid off. There was a thread where somebody listed all the troubles he's had with his Piaggio. Finally one of the Rabid defenders of Piaggio said this.

Well, I have 10k on my BV350 and have done nothing to it but scheduled service and a rear tire. I have owned 5 Piaggio scooters. I have never experienced anything but routine wear on any of them. Is it how the bike is cared for or is it luck? I suspect that those whose bike continues to run well believe that good treatment and conscientious maintenance did the trick, while those who have frustrating/expensive failures believe it is bad luck or poor Piaggio workmanship.

So let me paraphrase that last statement inserting my belief in why Chinese scooters fail

"I suspect that those whose bike continues to run well believe that good treatment and conscientious maintenance did the trick, while those who have frustrating/expensive failures believe it is bad luck or poor Chinese workmanship."

[Shadowfire]

Well, MOST people expect their vehicles to run for 10K or more (these days... a LOT more) miles without doing anything other than "standard" maintenance as listed in the user manual. Oil changes, fluid level checks, consumables (for a bike this means belts and tires).

When the starter motor starts screeching after 3,500 miles, people will think that there is a quality problem.
When the bike as shipped has loose wiring off the pallet, causing the instrument cluster to misbehave, people will think "No, that wasn't me, that was someone assembling it incorrectly at the factory." Also, did I mention that the mechanical trip meter reset button is fubared?
When the radiator boils over at 4000 miles, even though antifreeze was changed, and bled (and has had no prior overheating issues), all because the head gasket sprang a leak, people will think "No, that wasn't me, that was a problem with the gasket or the way that the engine was put together".
When the front and rear discs start vibrating after 500 miles, people will think "Holy crap, how did the the rotors warp so soon!", not "Damn, that's what I get for not keeping up on my maintenance."
When the bike as delivered has a leak in a tire valve core causing the loss of 5 psi each day it sits, it does NOT seem to be a lack of conscientious maintenance that is the problem. Maintenance is what found the problem.
When the bike's floorboard and front panel plastic panels never lined up quite right (and there's no evidence of any collision or drop), and then you spend two hours futzing with the panels and can't line them up perfectly no matter what you try... it could be you. It could also be that someone said "Fuck it, lets just ship it that way" AND NOBODY ELSE WHO LOOKED AT IT SAW IT AS AN ISSUE.

These are all problems I've had on a 250cc Chinese scoot over the course of 6 months, on a bike which was 6 months old when I received it. I changed the tranny oil and motor oil every 1000 miles, and all fluids when I first got it.

You simply do NOT have this many problems, on one vehicle, in such a short span of time, when you buy Japanese or Taiwanese. The chinese scooters have Q.A./workmanship problems and it DOES NOT matter how much maintenance you do.


I mean, for crying out loud, we have people coming onto the forums and saying "ITS NORMAL FOR BIKE WIRING HARNESSES TO CATCH FIRE IN SOME SHORT CIRCUITS" (paraphrased). It may be "normal" for a scooter, where the engineer decided "We can put a 15A fuse on this 16 gauge wire circuit!" and then the OEM proceeds to change the 16 gauge wire over to a 24 gauge wire in the instrument cluster. But HELL NO!!! IT IS NOT NORMAL FOR BIKE WIRING HARNESSES TO CATCH FIRE IN A SHORT.

[kz1000st]

I don't doubt that there are problems with Chinese scooters. My CF Moto has belched a transmission shaft and a starter motor in 12,500 miles. The 150 has had a few problems but I inflicted many of those with mechanical clumsiness.

BUT. Go back and see who built that flaming scooter and who imported it. Bashan, Znen and CF Moto are light years better than a Shanghai Shenke, JM Star or Dong Fang. If that scooter came from Scooter Depot you're lucky it ever ran. They chintz out on everything to make a buck.

Lastly. Those Japanese and Taiwanese scooters in the 300 class are not cheap. The SYM Citicom is $4900 and it's the lightest on the wallet. How about a $6500 Vespa? The others fall in between. Of course there's always the used market. You can have a Reflex for two grand plus or minus and it's only 10 years old. Somebody paid the $6000 though when it was new.

I paid $1200 for the Fashion, used with 1900 miles. I paid $1200 for the Bashan, new with a one year warranty. I paid $600 for the 50cc bike. Total=$3000. The Honda Rebel was $3350 plus expenses.

I only know that my scooters motor on with little fanfare. Rich Carmen owned a Fashion, did all the maintenances on schedule and blew the motor to heck running full bore on his 80 mile round trip commute with less than 10,000 miles. I won't push beyond 63 mph because I know what these engines can stand. 12,700 miles to date on the Fashion and it runs better than ever after the valve adjustment.

[cheapeto]

I'm sure this will not be of any interest to most riders.
I wanted to see whats going on in the bearing world. I've been away from it for so long now, and I found this site and this info.
It is really damn dry reading, but I think it backs up my outdated description of bearing grades.
Some good info in the FAQ's also.
http://www.astbearings.com/bearing-tolerances-precision-levels.html

[kz1000st]

All very interesting and notice that the Chinese do have guidelines to follow as major bearing manufacturers. In all my years of reading numerous forums I haven't seen bearing failure as an issue for the Chinese which is fairly incredible considering this.

The motorcycle industry of the People’s Republic of China exceeds that of any country in the world with a motorcycle output of 22,891,700 in 2013, with 39.75% of the total production exported

https://en.wikipedia.org/wiki/Motorcycle_industry_in_China

My own personal experience is this. Most of the problems with Chinese machines is issues with the ancillary items like plastic bits and some metal parts. The engines seem to keep on running and generally get better with age when ridden with caution and respect for cost.

I will tell you this. Numerous times I've challenged certain "Name Brand" scooter owners to put up or be quiet. "How many miles do I have to go before you stop with the Chinese junk cracks!" You know what I get instead of a mileage answer? Insults and spoken to like I have Downs Syndrome. You would be astounded at the arrogance of Helix owners. They make Vespa owners look like Nuns.

My list of mileages speak for themselves. I'm on the original engines on all of them. I would think that I would have seen a bearing failure if they were using Pot Metal ball bearings by now.

I can't change the minds of everyone towards Chinese engines. After all it took almost 25 years for the "Japanese Rice Burner" cracks to abate.

[cheapeto]

I'm not sure if your post is aimed at me or not, but I simply posted a site to better understand bearings in general.
I have no agenda to help any builder of scooters.
I simply wanted to see whats new in the bearing world, and thought someone that has assembled anything with them, it would be a nice read.

[kz1000st]

No, it was not aimed at you. You Sir, have always been a gentleman.

Yes, the article is a fascinating read and quite informative. My position has always been against statements that somehow slam Chinese scooters with veiled references that indicate that they're put together in a slap-dash manner with no concern for longevity, quality or safety and won't last a week. Do I think a $2000 Roketa is assembled with the same materials as a $6000 Forza has-No.

I do think ridden sensibly and maintained properly a Chinese scooter will return its price to its owner. Sadly too many Chinese scooters land in the hands of people who don't know what terms like Sensibly and Maintained Properly are. Then they slam them because their $1000 Chinese piece of junk 150 didn't last like his neighbor's $5000 Vespa 150 did.

My $1200 crate scooter didn't get to 9,400 miles and seven years by luck.

[Shadowfire]

You know, you can keep repeating that message until you believe its true.
Go back and redo your calculations about how much your Chinese scooter costed you, but this time add $75/hour (typical repair rate) for all the labor you put into it for after-purchase issues - the kind of things that if you bought a dealer-supported bike, would be covered under warranty. Unless you've been amazingly lucky, you're already past the price of a brand new Taiwanese bike. Is your speedometer and gas gauge accurate? Is your instrument cluster even readable during the day (mine is built with convex plastic covers so that no matter where the sun is, glare makes it difficult)? Does all the instrumentation and electronics/buttons still work? How many hours did you put in to do the PDI? Did your brake rotors need to be replaced because they were warped (instead of because they were worn)? Did the super-thin key backs break when you accidentally forgot to push down on the ignition before trying to turn it? Is the frame welded/aligned properly, and did they even bother to get rid of the burs on the tubes before they welded it, or are the welds a stabbing accident waiting to happen while working on the bike? Is every single hose clamp on the bike a "1 use ONLY because of material quality" type which will need to be replaced if you ever have to take it off?
They simply are not a good value unless you're doing the repairs yourself, AND you believe that your time is free.

[rks]

My 150 is not as old as yours KZ, and cost a bit more, $1350...but it did come in a crate, is nearing the end of it's 4th season of use, has 8,300 miles clocked, and has been a joy to own. It still has the original NGK copper core plug in it, infact, the whole ignition system is original, except the plug boot. I have taken the carb off one time, June 7, 2012 at 366miles, when I removed the air box, to install a K&N cone filter, and up jetted to a 115 main. I haven't needed to touch it since, no adjudtments, no cleanings. I have yet to replace a light bulb, haven't adjust the valves since the 2500 mile mark....they just haven't needed to be.

And as you said, it runs better all the time. I have records for every ounce of fuel it has burned. The 2nd seasons fuel mileage was better than the 1st years.....the 3rd year better than the 2nd, and the 4th (this year) better than last years. The average displayed in the fuelly banner below is a combination of last years 84.9 mpg for 31 fill ups, and the 25 fill ups so far this year that average 89.38 mpg.

So I feel i got more than my investment back....and this Chinese scooter is a long, long way from being worn out.

It's not a Honda, it's not a Vespa....I knew that before I bought it....I operate it appropriately, rarely sees even 6000 rpm's, I monitor vitals such as oil temps, and voltage output with installed gauges. Thus far it has been totally dependable, and never left me stranded.

I don't care what anyone says about me, or my Chinese scoot.....it has treated me right, and I will continue to enjoy owning and riding it.

[kz1000st]

Is your speedometer and gas gauge accurate? About as accurate as any Japanese motorcycle I owned, at least the speedometer, and I trust my gas gauge to be true enough.

Is your instrument cluster even readable during the day Completely. I've ridden it at just about all hours from 4 AM to 9 PM.

Does all the instrumentation and electronics/buttons still work? Absolutely. Even the horn, which about crapped out on all my Kawasakis.

Did your brake rotors need to be replaced because they were warped Nope. You see the mileage on my Bashan. Original rotor and pads.

Did the super-thin key backs break when you accidentally forgot to push down on the ignition before trying to turn it? Uh, no. Maybe because mine isn't super thin and the same thickness as the Honda Rebel.

Is the frame welded/aligned properly, and did they even bother to get rid of the burs on the tubes before they welded it, or are the welds a stabbing accident waiting to happen while working on the bike? Frame is straight and true. I've had the scoot open to do valve adjustments and not seen anything resembling bad welds or slag over spill. You must have bought a real Lemon.

Is every single hose clamp on the bike a "1 use ONLY because of material quality" type which will need to be replaced if you ever have to take it off? Uh, no again. I haven't replaced a single clamp and ALL The hoses and clamps are all original after seven years, So is the front tire which has not a single dry rot crack.

They simply are not a good value unless you're doing the repairs yourself, AND you believe that your time is free. You see,out in my garage sits a $2200 2010 Kymco Like 50cc that so far needed a starter motor and stator, something my 150cc POS still hasn't needed a replacement for. Now, you can scream,"It was made in China" forever because my retort is "And built to Taiwanese specs, source inspected by Kymco and cost $2200" or three Chinese 50cc scoots. I have about five or six hours into it tracking wiring to deduce that the starter was bad as is the stator. It starts after great effort and doesn't idle correctly yet. Something I'm sure I'll overcome after another two or three hours once I have the charging system corrected. Let's see, eight or nine hours at $75, that's...carry the three...a lot of money repairing a $2200 scooter with only 2,400 miles.

So which is the better, more reliable scooter? The Bashan with 9.400 miles or the Kymco with 2,400 and a blown starter and stator?

Oh, and how many hours did the PDI take? I don't do the over cautious, redundant PDIs I've seen. I put the scooter together, gave the nuts and bolts I could see a little hit, changed the oil and off I went. Seven years, 9,452 miles and any issues I did have was me shooting myself in the foot. It has never left me stranded.

Something the former owner of the $2200 Kymco Like 50 in my garage could not say.