Diamondback Bicycles Jr Viper 20" Wheel Youth BMX Bike

A great 20'' bike for the price and seems fairly solid.Assembly wasn't challenging at all, as it came mostly assembled with tyres pre-inflated.The bike comes with a wrench and three allen keys to assemble it.Technical specifications :Frame material : High tensile steelFork material : High tensile steelCrankset : 140mmCrankset type : 1 pieceCrankset material : SteelBottom bracket type : LooseballBottom bracket size : American 19mmRear cog : 18tSprocket : 36TGear ratio : 36/18 (2.0:1) 40Brake type : Rim brakeBrakes : Rush linear rear with coaster hubBrake levers : Rush RX2.1Rims : 36h aluminium, 30mm wideRear hub : 36h steel shell with 3/8'' axleWheel size : 20''Tyres : Comp III style 20 x 1.75Handlebar shape : Riser barHandlebar material : High tensile steelHandlebar dimensions : 24'' wide x 6'' riseHandlebar type : 2 pieceStem : 1'' quill steel base with alloy clampSeat post material : SteelSeat post size : 22.2mm (Note : The size of the seatpost is 22.2mm where the saddle mounts the top of the post, the base of the post is 25.4mm, while you can use a 22.2mm seatpost - you'll need a 25.4mm shim)Pedals : ResinPedal type : PlatformHeadset : Threaded 1''Chain : KMC Z410Chain size : 1/2 x 1/8Weight : 25lbs

My oldest is between sizes of bikes (16"-too small, 20" models of most brands -too high) he couldn't stand with feet on ground when stradling the crossbar. We looked at alternatives including big box stores and bike shops yet less than a few fit. The models that did fit were only at bike shops.This bike falls in the goldilocks zone and will fit a taller than median 4-5 year old. The price is great compared to the specialty shops charging 2x or more for essentially the same bike.I seriously dreaded the thought of assembling a bike but, this bike assembly was far easier than I expected. Colors are great and the essentials are all there.FYI for child bikes:1. Single hand brake PLUS coaster (back pedal) brakes2. Chain guard to protect pant legs3. NO GEARS4. Adjustable handlebars5. 20" wheels for 48" kids6. HELMET AND PADS!If you have the patience to chase your child's seat for a while - Skip the training wheels! Plenty of guides on internet for teaching a first time rider to balance and coast. If you must, admit the lack of time and attention available for such intensive such as myself, buy the $10 Razkulls [sic]? training wheels from Amazon.

This is an excellent transition bike for kids freshly coming off a 16" bike. Most 20" BMX bikes are much too large for kids around 48" and 6-7 years of age but this bike nicely bridges the gap. The crankset is very short so they can easily reach the pedals and the seat goes down very far allowing plenty of room to grow. One thing to note is that the blue on the navy blue/white combo is much deeper blue plus it has a really awesome metallic flake in the paint that you cannot see on the stock photos (check out my pic). My only gripe is that they should have thrown in a kickstand and made the grips a little shorter for smaller riders.

Got this for my 7 year old son as he had outgrown his starter bike. Everything we needed to put the bike together was in the box including the instructions, crescent wrench, and allen wrenches. It took about 20 minutes to get everything unpacked and put together (pedals, seat, handle bars, and wheels). The wheels were a little under inflated out of the box, but they were filled enough to be ridden.The bike is well made if a little heavy. The paint on the bike was great (and we received the correct blue/white combo we ordered). The pedal action is smooth (I even tried it out myself) and the breaks (coaster and rear handbrake) both work great. My son loves the bike and I expect this will hold up as well as the excellent Diamondback mountain bike I had years ago.

I went with Diamondback because a co-worker, who is a very serious bike rider, and who has a few kids, told me that it would be a great bike for the money. I read several reviews on this bike about bad packaging and missing parts, so I was a little apprehensive, but mine came well packaged, with lots of protective pieces. All the parts were there and I got the color I ordered. The only explanation I can think of is that I ordered the size and color combo offered with Prime shipping, but the other color and size combos are only offered by third party sellers Maybe one of those sellers isn't so good. I initially thought some bolts were missing, but they were just lodged inside the white plastic protective caps that had been on the wheels. If you thing you are missing bolts for the wheels, check those caps.Anyway...It was easy to assemble. The instructions are not great, but it isn't hard to figure out. The rear tire, brake, and chain are already assembled, so the most complicated parts are done for you. I used the included tools. They are cheap, but perfectly adequate for the task. I have a garage full of mechanics tools that I didn't bother to go get.This bike is definitely a big step up in quality from the huffy My son had been riding. It's a bit heavy, but that's not a huge deal. His old 14 inch bike was almost as heavy and much smaller.My son is 46 inches tall and he is just barely big enough to ride this thing with the seat bottomed out and the handle bars tilted slightly back. That's fine. He'll grow into it, but I'm glad I didn't buy it any earlier.The blue and highlighter-yellow color scheme is a bit flashy for my tastes, but my 6 year old loves it, and I have to admit it does look nice. The paint is well done and all the parts seem to be of good quality. I wouldn't hesitate to recommend this bike to a friend for their kid.

The frame is expertly welded and all of the components are high quality. The packaging is exceptional, with plenty of protection for the things on a bike that tend to get damaged in shipping (bar ends, grips, chain cover, axles etc..). This is everything you'd expect from Diamondback, in a cool 5-8 year old package. As an adult Diamondback owner, I was pleasantly surprised at the quality of this 16" BMX. The kicker is that this bike is only a few dollars more than a junky/heavy/poor quality/sloppy welded "box-store" bike. I would not hesitate to recommend this bike to anyone looking in the 16" boys BMX category. Plus it's Amazon, where the item is somehow shipped to me even before I click purchase lol..

Great bike. My 4 yr old son loves it. Quality is at the high level of the kids bikes at real bike shops but at a low price like the crap at department stores. Assembly is very very simple and it even includes the needed Crescent and Allen wrenches... all you need is a Phillips screwdriver for the reflectors. As others have posted the blue is darker than it appears on the amazon pictures.

Bike is excellent quality and well made. Miles above what you would get at any big box store. My (almost) 4 yr old is just a tiny bit too short to get on and off himself easily, but has no issues riding it without training wheels. Very pleased with the bike, only deducted 1 star because we did not receive the tools that the instructions said were included. Can't comment on the training wheels as we didn't need/use them.

Bought for my 4 year old birthday, quality bike, as you'd expect from Diamond Back. Actually robust enough for Daddy (190lbs) to set-up then take for a rip and bicstbsome old school bunny god on. My thinking way better than big box store bikes and will retain its value, when it's time to resale and upgrade when he outgrows.

Bought for my 4 year old. He is a taller kid but he fit it and now he's turning 6 and still riding it. Everything has been great except the plastic chain guard broke off within a few weeks, but now that my younger son is ready to move up from his run bike I am looking at this bike again for him. Great bike!!