I have a SEKAI sprint 1000 bike which is a tiny bit big for me as I have problems reaching with my feet to the ground. The existing seat is already down to the lowest level so can't reduce the height any further. What I am thinking is to change the wheel to a smaller size. The current size is 27 1/4" (rim). Can I install smaller wheel on this bike without having replace virtually everything? If there is a seat available which has slightly lower seat frame so that if I replace the seat then it goes a bit lower (hope this makes sense?) The first problem with changing the wheel size is surely the brakes. Assuming they're rim brakes, they won't be in the right place for a smaller wheel. In any case, is it the distance to the ground that is an issue or the distance to the pedals? If it's the latter, then changing the wheel size won't help, however, you might get an extra 5 or 10 mm by using shorter cranks - if this is appropriate for your height. I would imagine that it's probably better and not much more expensive to trade the whole bike in for one which fits you.

As many others have stated it is possible to mount smaller wheels. The issue will be mainly a cost versus return on investment. The brakes may be able to be adjusted to reach and the frame may be spread to fit the wider hubs. Replacement Toilet Seat Hinges ChromeThe google images I have seen of a SEKAI sprint 1000 appear to be an older 10 speed. Teak Outdoor Furniture AdirondackIt most likely is equipped with a 5 gear freewheel using a 5 speed chain. Aloe Vera Juice For Weight LossThe more modern and smaller diameter 700 c and 650b size wheels will most likely use a cassette with at least a 8 gears. This means your old crank, derailleurs and chain may be incompatable with the new wheel. The 8 speed chain may be too narrow to fit on your present crank and your old chain may be too wide to fit on the cassette

The question I would want to know is...how old are you and how tall you currently are? If you are young, like early teens, it's likely you'll be growing a few more inches, so you may not need to convert the bike wheels to a smaller size, ( that's asking for more problems with braking accuracy on the rims ), and trying to find a different seat. This may cause your riding position to be way off in the saddle to pedal height. As other posters indicated, you'll be changing parts to try and fit a bike to your body size, and spend money and time accomplishing this task. You may be able to find a bike that fits you that can be ridden for a season or two until you grow into this bike. If you are much older than early teens and have reached your growth potential, I'd consider finding a bike of the proper frame size so you can enjoy the bike rather than curse at its short comings and spend money on something you may not be happy with as far as results.Browse other questions tagged wheels saddle bike-fit or ask your own question.

I currently ride a hybrid that came with 700x32c tires. Can I swap out a narrower tire without changing the rims, or do rims only fit a specific size of tire? How small can I go before I have to buy new rims? I hear having narrower tires makes you go quite a bit faster. Does it really help that much? Most 700c rims will work with essentially any size of tire. Yes, smaller tires generally reduce rolling resistance a little, but unless you're road racing, it's rarely worth going below about 700x23c, IMO. Also note that just being smaller doesn't necessarily mean lower rolling resistance -- one brand of 700x19c might have higher rolling resistance than another brand of 700x20c, for example. The big change (if any) happens when you switch to slick tires (and most 700x32c tires have fairly substantial tread if not outright knobs). For smooth tires, rolling resistance is a relatively small factor in terms of your overall performance. The optimal tire depends on your riding conditions and personal riding style.

Narrower does not automatically equate to faster - there are both terrible narrow tires and excellent wide tires available today. If a tire otherwise possesses the characteristics you desire - such as grip, flat resistance, cost, handling - you'll probably be just fine riding it from a pure performance perspective. It's also categorically false that maximizing the pressure in your tires will make you faster. There is a "sweet spot" in inflation where the tire is stiff enough to roll smoothly but still able to smooth out road vibrations that lead to fatigue. Bicycle Quarterly tested and published a handy inflation cheat sheet that may help you dial in your optimal riding pressure. As far as rim compatibility, the width of you rim will affect the shape of the tire; if you plan on running any tire narrower than 28mm you should measure your rim and consult this handy chart. It's overly-cautious but a useful rule of thumb for the new mechanic.Browse other questions tagged tire performance or ask your own question.

Are you a daily commuter who wants to avoid flats? The dirt enthusiast who lives for singletrack? Or an occasional cyclist looking for a comfortable ride? Depending on the type of riding you do, you’ll want to choose the appropriate bike tire. Beyond the obvious—a tire suited to your rim size—you have a range of options. No matter what type of rider you are, sharp tread edges are a must. When they're worn down to the point where you're getting lots of flats, your bike is handling poorly and/or the tread appears rounded or uneven, replace your tires to guarantee more fun and more safety. Shop REI's selection of bike tires. How do you know your current tire size? Easy—check the tire sidewall. Mountain bike tires: On mountain bike tires you’ll see a number pairing that looks like 27.5x2.0. This is the approximate outer tire diameter (27.5") by the width (2"). A cross-country bike will have tires in the 1.9" to 2.25" width range. Trail and all-mountain bike will have tires in the 2.25" to 2.4" width range.

But downhill bikes, which are meant to withstand the abuse of drops and rock gardens, are equipped with tires ranging up to 2.5" wide. Road touring and racing tires: On road bike tires, you'll see a number pairing such as 700x23. The first number (700) is a size that roughly corresponds to the outer diameter of the tire in millimeters. The second number (23) denotes the actual tire width in millimeters. Exceptions include a few 650s (used on front wheels for faster acceleration and/or for smaller riders to decrease stand-over clearance) and the 27" size used on older bikes. The letter at the end of a tire size is a throwback to an old French system when the letters a, b and c designated different inner (wheel rim) tire diameters. These letters sometimes still appear in tire sizes. Typically, any 700 tire today is essentially the same size as an old 700c tire. You do see 650b, which is the same as today's 27.5" mountain bike tire, as well as 650c, which has a slightly smaller inner diameter than a 650b tire and is found on a few road bikes.

Most racers run 700 tires in widths ranging from 18 to 23mm — the narrowest options. Those who live for epic tours are more likely to be riding tires in widths ranging from 25 to 28mm for a bit more stability and comfort. Cyclocross tires: These have small knobbies but are designed in a narrow-width 700 size to fit the geometry of cyclocross racing frames. 29ers: 29er mountain bikes run a wider, knobbier variation of the 700 tires used for cyclocross, but otherwise look like your typical mountain bike tire. 29ers are designed to roll more easily over technical trail sections and through mud and sand. Cornering and climbing traction may also be better due to their increased contact with the trail. BMX tires usually come in a 20" diameter. More tread typically means more grip—but also more rolling resistance. So you'll need to balance your need for speed with your desire for grip. Slick bike tires: Designed for road, city/commuter, touring and mountain bikes, slicks appear almost smooth, with a barely perceptible tread pattern.

Slicks are designed for smooth surfaces like asphalt, slickrock and groomed singletrack (with the width of the tire determining the best use).  V-shaped grooves on some improve cornering on rain-soaked roads. Semi-slick bike tires: These tires are designed with a smooth center, for minimal rolling resistance and faster acceleration, and aggressive treads on the side to help with cornering. They’re used for mostly smooth surfaces with some off-road applications. Inverted tread tires: Tires designed with an inverted tread have more grip—and rolling resistance—than slicks, but less rolling resistance than knobbies. Use these tires if you suspect you might venture off asphalt or ride on roads with lots of ruts and potholes. Knobby tires: Different knobby tread styles are designed for specific trail situations. Smaller knobs are faster and suitable for smooth singletrack. Taller knobs offer more grip in technical terrain like roots and rocks. Wider tires with sturdy paddle-like knobs are best for soft trail conditions.

Knobs that are wider at the base will corner better on hardpack. Tires with tall, widely spaced knobs offer versatility in loose and hardpacked conditions. Tires designed for mud have widely-spaced knobbies so that mud sheds from the tire. (Otherwise you'll essentially be running slicks when mud gets packed between the knobs.) Front- or Rear-Wheel Tire Treads When shopping for mountain-bike tires, look for front- or rear-wheel specific treads. Front tires are designed for front-end traction when cornering. Rear tires give optimal power transmission and rear wheel control. Mount them with the tread facing the proper direction. To do so, check the sidewall for an arrow that points in the correct rotation direction. Road tires are less complicated. Front- and rear-specific treads are often sold as sets. And because road tires grip the irregularities in pavement, you won't see as many tread variations as you will with mountain-bike tires. Presta valves are narrower and have built-in valve caps that you loosen to pump up the tire and tighten afterwards.

Prestas are more typically seen on higher-end bikes, especially those designed for road riding. Do not use a Presta tube in a Schrader-size hole in your rim, as it will shift too much and possibly sever the valve. Schrader valves are wider than Prestas, with a valve like those on car tires. These are most commonly found on inexpensive and mid-range bikes. Schraders won't even fit in a Presta-size hole. If your wheel has a Schrader-size hole, it is possible to get an adapter so that you can safely run Presta valves. Instead of a wire bead (the edge of the tire that holds the tire onto the rim), these tires often have an aramid-fiber bead (such as Kevlar®). This makes them light and foldable for easy transport and storage. Foldable tires are available for both mountain bike and road riding. The downside is that they are usually more expensive. These are gaining in popularity. Depending on your weight and the terrain, you can run lower tire pressures—down to 20 psi (pounds per square inch)—for better traction without pinch flats.

Plus, the ride tends to be smoother.The installation process is a little more complicated, as is fixing a tubeless flat. You can carry a tube on your rides, though, to simplify fixing a flat on the trail or on the road. To make the switch to a tubeless setup you'll probably want to invest in tubeless-ready tires and rims. You can also buy conversion kits for standard tires and rims. Studded bike tires typically feature steel or aluminum studs with carbide pins to provide greater traction for riding on snowy or icy terrain. These tires won't feel as speedy as standard bike tires, but commuters, in particular, are likely to experience fewer flats. Many tire makers employ a durable belt of aramid fibers (such as the well-known Kevlar® brand) to resist punctures; others simply increase the tread thickness. Soft or Hard Rubber Bike Tires Most tires use primarily one type of rubber. Soft, sticky rubber is grippier while hard rubber is more durable. Most riders determine what type of tire to buy based on budget and performance requirements.