hi ya im new to this site and was after some advise, i used to ride years ago but i got a car so it all stooped, but now i need to lose weight so what better way then to get a bike, i fetched it second hand as i can not afford to get a new one, the problem im having is its like the chains slipping, its ok when you ride it on flat ect but when you come up to a hill and have to peddle hard its slips, also dose it when i try to wheely it, i have no idea what to look far as i haven't been on one for years and i have forgotten what i learn all those years ago
thanx for any help guys

sounds like "chain skip" two things contribute to chain skip: 1) worn chain & 2) worn rear cog

the solution to both is replacing both. sad but true. it happens to all bikes. what experienced riders do is replace the chain twice as often as the rear cogs cuz the chain wears first and the rear cogs are expensive. but we all have to do it. I have some new chain waiting to be mounted on one of my bikes and I should probably do the same for my other bike. its best to make these changes before you get chain skip. you can try just the chain first but don't be surprised if you have to do both.

usually the smallest 2 gears in the back wear first cuz they are used most. you can try staying away from those gears - but thats no fun

ok thanx bud, the problem is its the 2nd and 3rd gears so a new one it is