Depends on what kind of tensioner you're talking about.
Chain tensioners for BMX/single-speed bikes consists of a washer connected to a yoke by a threaded rod. The washer goes over the wheel axle, the yoke fits over the end of the dropout and the threaded rod allows you to pull the wheel axle towards the end of the dropout and tension the chain.
Chain tensioners used for turning bikes with external gears into Single-Speed/internally geared bikes basically look like a rear derailer with only one pulley. They work by taking the slack out of the chain when chain tension can't be set by moving the wheel back & forth.
I have no idea what you mean by a "bmx bikes device".
ANSWER: I believe that Haro is the best BMX complete bikes for the money. I love my Haro BMX race bike.
yes they do
let me rephrase what the previous user said. i ride bmx and i know almost eveything about bikes. your chain gets loose because your frame dropouts are striped. when you pedal the strip is going towards the frame so your chain gets loose. the only best idea is to get washer, bring to bike shop to resurface it flat and recreate the integrated chain tensioner, or go on daqnscom.com to buy some chain tensioners that work really well.
BMX bikes weren't around in the 60s.
are framed bmx bikes any good
ruption bmx bikes are good but we the people are just a little bit better
Yes, they are professional bmx for street/park.
No. Some BMX chainrings have the same 4/5 bolt pattern as road bikes, but most use another method of attachment to the crank. If it is a 4/5 bolt chainring you first have to measure the bolt circle diameter to see how that fits. I'll post a link on that. Next is the thickness of the chain rings. BMXes are single-speed and use a thicker chain. Most road bikes have external gears and need a thinner, more flexible chain to work. I'm not sure if a road bike chain will fit on a BMX chainring. (Unless it's a single-speed road bike of course. Then you can run a BMX-style chain and all can be made to work.)
Cheap BMX bikes can be found on eBay, Kijiji, Craigslist, Bike Warehouse, Halfords, Walmart, Bicycles Direct, Amazon, Vital BMX, BMX Shop and DK Bikes.
yes
BMX bikes were invented in 1974. It became official when George E Esser founded the NBL. There is no main manufacturer of BMX bikes but there are many different ones.