Broken Chain

[mr_1306]

Hi...

i just got my new A-bike plus about 1 month ago... have been using it maybe for total about 10 km.
Suddenly today, I ride it when the street is a bit uphill street, and suddenly the chain got loose. First it's only causing some noise, but I still can use it... (First i don't know it's the chain problem).
Later I can't use it anymore, since the pedals can't get be turned anymore.
So at home I check it, and found the chain problem.
Here's the picture


any suggestion on how to fix this???

[Amuro Lee]

Hi,

Here's a video on the Official A-bike Support Network teaching how to replace the chains of an A-bike:
http://abikesupport.ning.com/video/1184976:Video:206

I think you can follow the steps in the video to open the crank box of your A-bike Plus and check that if there're other broken parts inside. After that, order the broken parts from your local distributor and then replace them by following the steps in the videos on the site.

I hope this can help you.

[mr_1306]

thanks just what i need.

btw how is the warranty policy of this bike? can I ask a replacement? considering it is still very new.
And also where I can get the chain replacement? coz i look into the my dealer website but they don't sell the chain sparepart

[Nigel Kellett]

Don't know where you're based, but if you can telephone Mayhem in London with full details, they should be able to replace any parts required within warranty.

[mr_1306]

I'm based on germany.

is it possible to find the replacement in the ordinary bicycle shop? I just open up the crank and release the chain, and it is busted, can't be fixed...
will post the detail picture later

[mr_1306]

Sh*t... still no reply either from my dealer or from Mayhem about getting a chain replacement...

any one can help me to get the replacement?

[rongood]

There is a design flaw on the crankcase housing. Turn the bike upside-down and look at the housing as it fits on the chain side of the wheel. You will see a small cut-out for removing the wheel, which was cut out of a lip that runs on the inside of the bottom of the housing parallel to the chain. That narrow lip or ridge has caused lots of trouble including yours. It makes the space between the housing and the wheel too narrow for the chain to drop between. If your chain gets even slightly loose, it can get caught in the narrow space and chew up the tire, or the chain may even break.

The EASY solution is to file off this annoying lip. It is completely unnecessary. I used my Dremel rotary tool. I took the housing off the bike to avoid getting shards of plastic up in the works, and I simply ground off the lip for the entire span parallel to the chain. You could use an ordinary file.

In effect, I extended the little drop-out so that that edge is now smooth and has no lip. Ever since, all my chain chattering and clunking has stopped. It is no big deal if the chain is a little stretched, it will not fall off and the bike pedals better than ever.

I should post some photos, but you can see the unnecessary narrowing in the photo you posted.

oh, and don't give up. Your dealer or Mayhem definitely has to replace the chain and it looks like you need a new tire as well. Also, check the bearings and make sure they are still turning smoothly. The chain getting caught during pedaling can tear up the bearings. Then before putting on the new chain, file off that nasty ridge.

[mr_1306]

hi ron,

could u post the photo of the part u mention about? i didn't quiet understand which is the design flaw part.
Eniwei, I called my dealer, but the phone that are available in the website didn't work... so another sh*t... I go to a big bike retailer asking whether they have spare chain, but nothing at all... so another waste of time.
Anyone could help me? i'm start to be desperate now...

[rongood]

do not despair. Where are you located? You should call A-bike Telephone sales: 0870 766 8498 (UK)
Telephone sales: +44 20 8752 8443 (outside UK), tell them where you bought the bike and what happened, that the chain broke after such a short time.
I have attached photos to demonstrate better what I mean about the problem "lip".
I hope these photos will show what i mean. When the chain gets caught, all hell breaks loose, and you get a ruined tyre, or a broken chain, or torn up bearings.

here you see the lip, left of the chain in photo, before being shaved off

abike fix 9D.jpg (35.6 KiB) Viewed 75164 times

the lip is gone, in this photo to the right of the chain

abike fix 7D.jpg (37.33 KiB) Viewed 74958 times

you can see that the chain now has just enough room to fit between the wheel and the housing

abike fix 8D.jpg (26.99 KiB) Viewed 74934 times

[mr_1306]

Thx ron...

yup, guess i need to call them. eniwei thx again for your tips and advices

[mr_1306]

latest news,

my dealer finally contacted me by e-mail and he will send me a replacement chain although at first he instructed me to send the whole a-bike back to him.
wew... what a relief. Gonna check about this "lip" that have been mentioned by Ron and get rid of it before the same "accident" happens again.

[Amuro Lee]

Gonna check about this "lip" that have been mentioned by Ron and get rid of it before the same "accident" happens again.

I don't think the "lip" actually causes such "accident".
I've been using my A-bike for 2 years but never get any broken chain problem although I broke some parts within this 2 years by heavily "torturing" the bike.
viewtopic.php?f=2&t=635

[rongood]

Gonna check about this "lip" that have been mentioned by Ron and get rid of it before the same "accident" happens again.

I don't think the "lip" actually causes such "accident".
I've been using my A-bike for 2 years but never get any broken chain problem although I broke some parts within this 2 years by heavily "torturing" the bike.
viewtopic.php?f=2&t=635

It doesn't always cause these problems, but if you have a slightly loose chain and you hear a lot of noise and grinding, or if your pedaling suddenly becomes labored, it is likely that the chain is getting caught between the tyre and that lip on the housing. I had a lot of noise which i just attributed to the chain being too loose, then there were times when the pedaling would freeze up and i could hear grinding. When I finally got rid of the lip, all the noise stopped. Some A-bikes may have slightly greater clearance than others. When i got my third A-bike, this time a Plus, i had high hopes--but after only three rides, the pedaling froze up on a curve, and i was in no place to stop, so i kept going and tore up the bearings on the rear wheel. That was when i decided that damn lip had to go. The chain should have just enough room to drop beside the wheel without getting jammed.

[Amuro Lee]

How about adjusting the chain tension or just shorten the chain by removing a link from it?
viewtopic.php?f=2&t=225

[rongood]

How about adjusting the chain tension or just shorten the chain by removing a link from it?
http://www.abikecentral.com/forum/viewt ... ?f=2&t=225

I have found that adjusting chain tension by turning the bearings from M (medium) to H (high) can cause significant damage. The adjustment can cause the chain to be too tight and tear up the bearings. So you really should only do it if the chain is very loose indeed. Removing a link, or a half-link, is possible, but again you need to be cautious not to make the chain over-tight.
I think it far easier and more prudent, if you have the symptoms of a loose chain getting caught and grinding against the tyre, to just shave off the lip on the inside of the bottom of the housing parallel to the chain. You do no damage to the bike and you simply allow for the moderate stretching of the chain which is bound to happen. Of course, chains eventually must be replaced, but you should get at least 2000 km on a chain. Judging from what i've seen, many A-bikers are swapping out chains after only a month or few. The A-bike will perform just fine with a moderately stretched chain for a long, long time, as long as there is somewhere for the chain to ride safely.