i have a mongoose 16" black magic bike bought online .there isn't any way i can  elevate the seat  the way i want to and keep it that way....there is a shaft and i can move the seat through that but whenever i seat it goes down back again..plz,anybody?
215341
You probably have a seatpost quick release on your bike. It's probably tight enough that you can't move it with your hands, but when you sit on it, there's far greater force being exerted that is causing the seatpost to slide back into the seattube on the frame.\n\nYou need to ensure that the quick release is tight enough when you flip the lever shut (you don't screw a quick release lever shut; it relies on the compression that comes with the cam-type of action the lever offers).\n\nIf that still doesn't work, I'd replace the quick release with a standard seatpost fixing bolt (non-quick release).
390625
It was £1600 new, aluminium frame, should be kitted out with XT level components, its was an excellent bike at the time. It is quite old now so it might only be worth a shade over £200 these days. If you don't know much about bikes then it might be an idea to stay clear of it as it could end up being a lot of work if the pivot is on it's way out and the components are worn or, it could be totally mint and be a bargain. Difficult to say without seeing it I'm afraid.
667586
pick a gear where you dont have to pedal that hard, you want to use your body weight as a counterbalance...lean back and pull up your handlebars hard...after a few tries you will pedal longer.\n\nif you pull up too hard or lean back to far,your bicycle will flip out from under you..its all about balance...it doesnt come to you overnight but with work and practice you will know how hard to pull up and how far to lean back.
409135
That's allot of bike and at his weight trying to muscle that around is asking for disaster I ride a 125cc  (I'm 230lbs) and way prefer is because its easy to chuck around I'm thinking that's more what hes into anyways and the 650 is not the bike for that.  My thought on the whole thing is he should do what I did at his age, bust his ass to make some extra money and get what he wants,ultimately he will have allot more respect for it and in the long run he will thank you for making him do it, I know I did my mom refused to buy one or pay for the repairs so I busted my ass working at any construction site that would let me (yes digging goon spooning) and learned how do do my own repairs...hope this helped.
4681
You made an excelent question, and often an overlooked factor when buying a bicycle.\n\nAs a rule of thumb never buy a serious bike at a departament store, always go to a local bike shop, where you will get great advise.\n\nThe most important measures when buying a bike are\n\n1.- Frame size. There should be 1 or 2 inches between your crotch and the top tube. A longer top tube will give you more stability.\n\n2.- Saddle height. Your leg should be slightly bent while sitting on the saddle and the pedal is at the lowest.\n\n3.- Handlebar Height/lenght. Depending on what you want to do, your handle bar could be 1 or 2 inches below the saddle (mostly MTB and race bikes) or even with the saddle ( touring ) - A short stem will gove you better handling.\n\n4.- Saddle. Once again it will be determined by your riding style, you should find the center of gravity for your riding\n\nThere are a lot of internet sites that could help you make a decision, I suggest you read more on the subject and most important, go to a local bike shop where you will get expert advice.
127202
Geez, why the hostility?  People are trying to be helpful.\n\nTalk to a knowledgeable person at a bike shop.  Sometimes the most padded ones like the gel seats can actually cause you to sort of rotate forward putting less pressure on your butt but more on your genital area.  Look for a seat that is gender specific.  It might take a few tries to find the one that's just right for you.  The shop I got mine from taped the rails with electrical tape so that if I rode with it a few times and it didn't work out for me, I could take it off and it would be in good enough condition to return.  See if you can find a shop that will let you experiment a little that way.
199028
the only possible way for you to be able to go "up & down"...\n\nif your bum is made of rubber cause its gonna hit the ground ground ground.\n\n:)
387903
Before u go buy a fancy cycle, pls consult ur doctor to know whether u can ride a bicycle at all. U don't want to aggravate ur back problem further....
662904
there may be some old BMXer from EBAY ( www.ebay.com) who has your spare parts. Or read 'Lowrider'----the ones with the NASTY designed bicycles you see on the cover.  They have shops that sell VINTAGE parts .
543730
Most likely your seat is too low. That's the #1 most common problem I see with people who are "casual" bikers. You want your leg to be almost fully extended but not locked when seated and pedaling with your ball of your foot over the pedal axle. \n\nKnee pain can also be caused or aggravated by pedaling in too hard of a gear. Learn how to use your shifters, and try to pedal at least 60 rpm, or similar to your running cadence.\n\nGood idea would be to take your bike into your local bike shop, ask for a quick checkover and if they can help you adjust your seat height. They may ask for a $100+ fitting, and it may be worth it if you're serious about riding. \n\nGood luck\nScott
528682
Your saddle should not be putting you in the wrong position.\nIs the saddle the right size for your body? If it is not to big you should be fine.\nThey are made with a really deep seat and swept back swells to keep you locked into position and to stay centered whne you turn corneres fast.\nBut if you feet are behind you it sounds more like you are sitting up on your crotch an not on your seat bones.\nIf you have a trainer have them look at you or have someone take a vidoe of you riding like in an arena. \nSee if your feet are in line with your hips and shoulders. If not you need to practice the proper position. Have someone set you into the position and get the feel of where you should be. \nPractice practice practice it takes time to get a good seat. \nIf you are not comfortable in the barrel saddle look at other models you may find something that fits you better or puts you into a better position.\nGood luck.
117838
Your derailer needs adjusting, you can find how to do this on lOAds of cycling web pages.\nBasically you have to adjust the two screws so you can get the biggest and smallest gears then you need to adjust the cable tension to be able to select the gear straight away.\n\nTo do this put the gear leaver in the second SMALLEST gear and adjust the cable tension untill the derailer is in that gear. Then slightly adjust the cable adjuster to it changes smoothly up and down. \nNow recheck the top and bottom limit screws to make sure the chain does not run off the biggest or smallest cogs.\nAny probs let me know.
580310
Seat posts range in size.  With most common being 27.2 mm.  There are 26.4, 27.0 etc.  Do not guess, if the seatpost is too small and you try to ride on it, it can irreversably damage the frame. If it's too large, then obviously it will not fit.  The way to go is to take the bike to a bikeshop, they will have a special measurment pipe that's inserted into the frame and tells you precise diameter.  Seatposts are not cheap, but it would make sense to buy at the bike shop as well, rather than to wait for 2 weeks on ebay and save 10 bucks.  \nTo prevent stolen seatpost get a special leash that goes on the seat and attaches to a frame ($6) or go for extra cool and secure Onguard seatpost skewer (usually $50 in a set along with two wheel skewers).
529131
The simplest and least expensive way is to drop the forks a bit (that is, raise them in the triple clamps), increase the rear spring pre-load, and shave some foam off the seat.  However, those suspension mods will affect handling (sharper steering and stiffer shock action) -- but that might be okay for a learner (if she's not going very fast).\n\nThe next step up is to take your suspension (front and back) to a motorcycle suspension shop where they may be able to reduce the effective ride height of the forks and put a shorter shaft on the shock.  However, I'm not sure that's possible with the stock shock on a TTR230...  Those mods are somewhat pricey though.\n\nYou can also look into lowering linkages for TTR's, though I haven't seen them myself.
360247
Road bikes are measured from the center of the bottom bracket (BB) to the top tube (TT) under the saddle.  This section of the bike frame is called the seat tube.  Trek will have a list of dimensions on their website that you can look at.  They build bike frame proportional to the average riders size.  So as the frame size goes up, the seat tube length and the top tube length will increase in length.  A quality bike shop will be able to fit you properly.  I suggest test driving a few different bikes at a couple different shops to get a good idea of what you like.  Every bike rides and feels different because they use different components or the way the frame is built and they type of material used.
561745
Tie it to the back of the bicycle of your friend and tell him to slowly pull away..\n\nI think that's the 3456725th question of this.\nDon't you guys ever bother to read other questions and answers if you're serious about this? Alternatively do some research on the Internet...
466759
I don't know where you can go, but I have a suggestion. Take the pedals off the bike and practice scooting around on it. You'll eventually be able to coast farther and farther. When you get comfortable balancing for longer periods, put the pedals back on.