Hi, sounds have been coming from beneth the saddle down to the pedal/chain area, i was cycling yesterday and something at the back wheel slipped. the back wheel is now pressed forward and touching off the metal in front so it is hard to wheel/move it. the nearest bike shop is very far away i dont know how i am going to get it there! any assistance/advice would be greatly appreciated

Hi, yes you can fix yourself. Follow the accelerator (gas pedal) cable to the carburetor, at the carb. there should be a spring (this could have come off) that makes the cable retract, have any helper push the gas pedal. You watch the movement in the engine area with the ENGINE SWITCHED OFF. Follow the movement of the cable and check for return action. Lubricate with spray lube on all moving parts. All the best.

the saber zike is a elliptical bicycle. All answers above think you have a motorcycle or they have no clue. Is the chain on the sprocket, It seems to be off the gear. Zike recomends switching 1 gear at a time. Do not go from 7th to first gear in one shift or chain will come off the gear .It happened to me .Chain id not easy to put back on as a bike, that you can turn upside down and have it support itself on the seat and handlebars. The saber you must hold the back wheel off the ground and try somehow to turn the peddle backwards. I am not sure how to make an elliptical chain go backwards like a bike does without resistance.

Thanks for the inquiry!
From your information I can't tell if this is a off-road bike or a street bike. With the extended swing arm I'm suspecting off-road. In either case it's very much same issues. You have two issues and we will deal with them separately.
Chain catching sound:
In low gear when you have maximum torque applied to your rear sprocket & wheel many times the primary sprocket (smallest one under the engine side cover) will slip and actually jump teeth. You indicated this is the third season, so it's seen a lot of wear. It would also explain that when you adjust/ tighten the chain tensioner the noise is gone as the front sprocket is not slipping in the chain. If this happens a couple of times the front sprocket is ruined. Pull the front sprocket cover and inspect the teeth. The teeth will be smooth and ground away if this has occurred. Most off-road riders go through 1 - 2 sprocket and chain sets per season with the abrasion form the sand and mud if they are serious about their riding. Replace front sprocket or both sprockets & chain.
Other possibilities are that you have lost your chain guide or the plastic wear plates inside the chain guide are gone and the chain is banging against the metallic sides or your swing arm making the chain jumping sound you have described. Replace the guide or wear plates to solve this.
Whooping sound on front of bike while coasting: This familiar sound appears to be related to your front wheel. The best way to test this is to set your bike on a bench, crate, or test stand so the front wheel/tire is off the floor/ground and spin the wheel. Your rim may be bent allowing the tire to rub against the fork tubes or front fender making the whooping sound. The engine noise drown's it out under power but noise is audible when coasting with the clutch in and engine idling. The simple fix is a spoke tightening and adjustment to properly true the wheel. You will hear if its a bearing or something else being rubbed against by a wooble or something out of round (run out) causing the whooping sound.
I hope I've provided you useful assistance and that this information allows you to make an informed decision as to how to proceed from here. Please be sure to vote on my response. I hope I've earned a good rating from you today.
Please post a comment if you need additional assistance so that I can help you further.
Happy cycling,
TF

Put the chain to the inside of the front cog wheel, beside the pedals, first but not onto it, so you have plenty of room for pulling the chain to the rear. Fit the wheel back into place and before tightening it pull down the spring loaded arm, with the small cog wheel beside the back wheel. This takes the tension off the chain and allows you to put it into place on the back wheel. Tighten up the wheel. When it's tightened fit the chain onto the top of the front cog wheel. Lift the back wheel off the ground and turn the pedals forward. The chain will click onto the front cog wheel when you have turned the pedals one complete turn.

If you need to see a picture of how it should look at the back you can see one at http://orangecounty.craigslist.org/bik/2409696114.html

This happens when the back wheel is not lined up properly with the bicycle frame. Because the gears are not in a straight line with the chain it can slip. If it slips to the right, away from the wheel, then loosen the wheel and move the end of the wheel next the pedals slightly to the right as you stand behind the bike. If it slips to the left, in towards the wheel, then move the end of the wheel nearest to the pedals to the left. Once the wheel and the chain are in line it should stop changing on it's own.

There's a trick to putting a chain back on a bike. First fit it onto the back wheel. Then hold it on the top of the front cog wheel (at the pedals) Get someone to lift the back of the bike so the wheel is off the ground. While the wheel is off the ground and you're holding the chain on the top of the front cog wheel turn the pedals forward, with your other hand, as when you're cycling and as it turns the chain will go on.

If you don't have someone to hold the back wheel up off the ground you could hold the chain on the bottom of the front cog wheel and turn the pedal backwards. The chain will still go on.

If the chain has just slipped of the best way get it back on is to physically lift it into place at the top of the chain ring (the cog where the pedals are).
Then turn the pedals in the direction you would usually pedal (you may have to lift the back wheel off the ground).
This ought to pull the chain back on and let you get back on the open road.

Your rear sprocket is worn. As your put the pressure on the pedals the chain is riding over the teeth and makes a crunching sound. The teeth could appear slightly hooked. You will probably find this does not happen in a different gear. You need to replace both the cassette (rear sprocket assembly) and the chain together because the chain wears to match the sprocket and if you just replace one you will still get the slipping. The front chain ring also wears but at a much slower than the rear so check it as well. Also check the rear derailleur that it is tensioning the chain correctly and not damaged or if the bike is a single speed the rear wheel is positioned to give the correct chain tension.

Your chain is too loose, you need to get it tightned by shortning its lenght and get it greased.