Korean Job Discussion Forums

[Ruthdes]

Hi all,

I'm rediscovering cycling for the first time since I was a kid, and have acquired a bike from a friend that I'm enjoying riding around. It's not an expensive model (maybe 100-200K won), and I'm not sure if my problem is caused by the fact that it's just cheap, or if I can fix the problem myself, or have a bike shop fix it for me.

The problem is that the gears change really sloppily, and slip while I'm riding. It's pretty dangerous when I'm powering up a hill and it slips to a lower gear. Eventually I'm going to hurt myself or someone else. Sometimes they don't change at all, and I end up getting off and walking my bike up the hill.

So, I've read online that I can tighten the cable, but I couldn't find any simple instructions on how. Has anyone done it? I have a decent array of screwdrivers, allen keys and a pair of snub nose pliers. Can I do it myself, or should I just take it to a bike shop?

Could it be user error? The gears don't have exact settings, so I kinda just guess where they should be. No one ever taught me how to ride a bike with gears. I just got on and rode. Maybe I've been doing something wrong all this time.

Thanks in advance for any advice.

[le-paul]

it could be one of a few things.

best do it cheap first - check your deralieur (look on youtube for a 'how') and adjust it - its quite simple you should just neet to turn a screw.

second - it could be that your chain has been changed but the other parts wernt - maybe they dont fit anymore? (all the parts wear together and therefore fit together).

maybe theres too many gears for your derailieur?

id go for a tune up first - see if that works - like I say, youtube is usually pretty good for this kind of thing. Or just take it to one of those cycle shops theyll fix it for cheap.

hope that helps

[Ruthdes]

It's a good start, thanks

[Confused Canadian]

I had the same problem, and after a few trips to the bike shop, it turned out the front middle gear was more worn than the others, thus causing the chain to slip. Replaced the front and rear gears, new chain, and I was good to go.

[Kurtz]

100,000 won for a bike, lol, my tires costs me more than that!

Maybe the chain need oil, chain is worn, chain rings are worn, gear cable is stretched, front or rear derailleur needs adjusting. Take it to a bike shop.

[pkang0202]

I got the same problem. When I'm in the highest gear and I pedal real hard, the gear slips to the one lower.

Its a Dahon bike and only about 6 months old. I really gotta get it checked out. I wish I had time though.

[captain kirk]

[tefain]

Here's a good reference.
http://www.intownbicycles.com/how-to/bicycle-repair-videos/index.php?v=how-to-adjust-bicycle-gears

[runthegauntlet]

Don't mess with the screws unless your chain is being thrown off on either end. Those are limit screws and determine how far your derailleur will go in either direction.

If your gears are slipping, you may have one of a few problems: cable is too loose, chain is too worn, cogs (gears) are too worn.

To adjust the cable, look for a barrel adjuster coming out of the rear derailleur. You turn this counter clockwise to tighten the cable. If your bike doesn't have one of those, you should have a barrel adjuster either on the frame or on the rear shifter on the bars that you can try.

In the event that that doesn't work, have your chain length checked at a shop as it's probably stretched and needs to be replaced.

OR, your rear derailleur hanger could be bent. If you shift to your smallest cog you can visually check to see that your hanger (the aluminum piece your derailleur is bolted on) lines up correctly. If it doesn't, you can push a five mm allen wrench (or whatever you have) into the derailleur screw hole and try to pull it back, or just take it to the shop.

[runthegauntlet]

[Ruthdes]

Great! Thanks for all the help. I don't think the gears are worn, because the bike is only about 6 months old and hasn't been ridden that much. Having said that, I haven't had a good look at it yet, so that's my next step. I'll probably try tightening the cable and see if that makes a difference.

Yes, I know the bike is cheap, but as I said, this is a pass time that I'm rediscovering (I think that before getting this bike, I'd ridden a bike about 10 times since I was 13!). I'm hardly going to go out and buy an expensive bike. It would be nice to have one that just *works* though.

Now I just need more days like today - sunny! Waahh....I hate the rain!

[MattAwesome]

could be one of 2 things. the gears arent catching the chain because A: the sprocket(gears) are worn or B: the chain is loose.

[Gatsby]

Short answer:

When a bike slips gears while going up hill, the most common reason is wear due to dirt on the drive train. The proper fix is to replace the chain and the rear gear cassette (sometimes the front, too).

Explanation:

The wear is due to poor lubrication, specifically a wet oil, such as 3 in 1 or automotive motor oil. These are not suitable to derailleur type bikes. The oil picks up dirt and dust, which grinds down the teeth, which can be pretty small on bikes with lots of gears.

When the shape of the teeth is worn down, you tend to get slippage. This is compounded by wear to the chain pins, which can cause the links to be a bit farther apart. If you replace one, but not both, you can still have problems. (I know; I've been there.)

The problem usually appears first on the smallest gear, because it is most susceptible to wear, and it is used when climbing. With folding bikes, all the gears are small.

How to avoid:

Clean your gears and chain with diesel fuel -- best to remove them and soak them, but using wool yarn as a floss on gears works, too. Often, you need to do this on new bikes or parts because they come with bad lube mainly to prevent rust. On old bikes, you will want to clean your derailleurs, too.

Then apply only "dry" paraffin-based bike lube. It does not attract dirt and dust. Do not over-apply. Typically, you need to re-apply every two to four weeks, depending on use. Some people are able to keep their chains and gears looking new with dry lube. It also doesn't mess up your clothes as much. Examples:

http://www.nashbar.com/bikes/Product_10053_10052_208139_-1_201586_10000_200434

http://www.nashbar.com/bikes/Product_10053_10052_147198_-1_201895_10000_200434

Check the internet for more advice.

Even a $2,000 bike will have these problems if you use oil lube. But you can keep a $200 bike running pretty good if you use dry lube from the start.

However, my impression is bikes in Korea cost about twice as much as bikes in the States. Plus the components look like what were used on cheap kids' bikes in the States 40 years ago -- presumably a way to avoid paying any patent fees to Shimano. So a 100,000 won bike is really plumbing the bottom of the barrel. It's obvious that most Koreans view them as disposable, judging from the side of some roads. They just let them sit outside and rust, often never lubricating the chain at all. Great way to deter bike theft, I assume.

If you are really using your bike and it is worn out, get a new one and spend a bit more money. Look at the gears: Do they look like they are stamped out metal? Then obviously they won't last. If you get a bike that at least has name brand components and take good care of it, you will enjoy riding a lot more.

[shifty]

Thanks for the very informative post Gatsby!!

I ride a fair amount in South Africa, usually doing 60km stretches on a good road, without much dust, I like to think..

However, despite the relatively clear arena, invariably the chain starts jumping in the most used gears. Such that I from time to time need a change of chain and sprocket, a fairly expensive exercise.

The last time the bike shop slapped on an additional charge for 'bike had to be cleaned' even though they didn't actually even clean it. Obviously a charge just for the discomfort of working on a bike with a few traces of 'honest dirt'.

Got me thinking of getting the recommended dry lube, in place of me spraying the Q20 all over, like as per usual. I asked them the price and I nearly had a convulsion when they told me.

In conclusion, I feel it's better to forgo the right dry lube and just suck up the regular sprocket/chain jobs, since the cost of that stuff is a major proportion of the spanking new kit.

Although, it was just today that I cleaned the chain and was amazed at all the damn grit in it, amassed over a quite short time. Not sure which way to go, now.

[runthegauntlet]