the chain keeps coming off.is there anything i could do to stop this?pls answer asap
2006-09-09 22:50:10 · 7 answers · asked by Anonymous in Sports ➔ Cycling
Change bike at the bike shop.
2006-09-09 22:55:50 · answer #1 · answered by Angel Answer 2 · 1⤊ 0⤋
You question seems to indicate that the bike did not come from a bike shop, which would either not have the problem or already been fixed. There's an exception or 2 that'll I'll mention last.
In the case of a BMX or single speed bike, just remove the rear wheel and then put it back on nicely centered. Check to make sure that the front chainring isn't bent. If so, just bend it back straight with a 10" adjustable wrench. Hint: Tape a wire to the frame so that it goes straight out and touches the chainring. Turn the cranks. You can now easily see if the chainring is straight. If it isn't, make it straight. Remove the wire.
In the case of a used bike, just take it in to the shop for its yearly tune-up. That probably hasn't been done in quite a while.
In the case of a toy department bike, either replace it with an adult quality bike or just replace its derailleurs and gear cables with basic grade Shimano Tourney.
The Tourney TX50 and TX70 rear derailleurs are about $18 and available in both clamp-on (cheap bike) and bolt on (adult bike) varieties.
The Tourney TX22, $7, front derailleur is suitable for a 28-38-48 crankset, but you would need an $11 Alivio front derailleur if your crankset is smaller sized (mountain technical max chainring = 44 or 46).
Toy department bikes aften use cheap brake cables instead of shift cables, so you'll need some economical bike-store-quality shift cables.
*Be wary of putting money into a toy-department bike to fill a lack that the manufacturer didn't care enough to do. Considering: 1) The low cost of the most basic components required to make it work right and 2) That the manufacturer put disfunctional Chinese parts on (that the Chinese don't even use themselves)--is in indication about the qualities of the rest of the bike.
In the case of a derailleur on the back, but not on the front, like a 7 speed Shimano Mega-Range on the back, but only 1 chainring on the front, yes it will throw off the chain. You can put a $7 Shimano Tourney TY22 front derailleur on it and just turn the low limit screw to "lock" it in place holding the chain onto the 1 front chainring. This will stop the chain from coming off, and that derailleur is the compact design, short enough to fit under many chainguards. It can be adjusted and then widened just a tad so that the chain doesn't rub the sides on either the lowest or highest gear. Problem gone!
The exception:
A chain that has been worn more than 2000 miles or a very cheap chain that ran a few miles, or usage of a non-clear "gunky" chain lubricant--will all eat up your gears.
To check, measure 1 foot of chain. That's 24 links because every chain link is 1/2" long. Measure a foot of chain, pin center to pin center. If it is past 12 1/8" inches, you'll need to buy a new chain AND all new gears. Fortunately, there are plentiful inexpensive and well working gears for replacement.
Your local bike store and aebike.com can be a useful place to look for any needed parts.
2006-09-10 22:49:03 · answer #2 · answered by Daniel H 3 · 0⤊ 1⤋
You don't give very much informatiion to work with.Is it a free wheel or a fixed gear system?If its a free wheel system (Gears) than your derailers might need to be adjusted on both front and rear.It's also possible that your chain has stretched which sometimes happens on new bikes The shop where you purchased the bike should have told you to come back after so many miles of riding so they could check and make any adjustments which might be needed. That is usually included in the purchase price.In the interest of your safety I would get in touch with the bike shop as soon as possible and get the problem taken care of...Good Luck !
2006-09-10 06:08:55 · answer #3 · answered by javajoe 4 · 1⤊ 0⤋
Go to a bike shop. They should adjust the deraileurs (which are the components that shift gears), and maybe make sure the chain is the right length.
2006-09-10 07:45:30 · answer #4 · answered by Roberto 7 · 2⤊ 0⤋
What kind of bike do you have? How many speeds? How are you pedaling when the chain comes off? Are you shifting when it comes off? Give us more clues.
2006-09-10 23:42:05 · answer #5 · answered by Mars 2 · 1⤊ 0⤋
take the bike to a garage and have the chain tightned or cut two-or-three levers from the chain to tighten it. it will be fine.
2006-09-10 06:00:50 · answer #6 · answered by cooldude 1 · 0⤊ 1⤋
Simply fasten the chain. If you cant do it yourself, go the automobile technician and get it fixed.
2006-09-10 05:59:10 · answer #7 · answered by Anonymous · 0⤊ 3⤋