"Balance Bikes" are made for younger kids when learning how to ride 2-wheeled bikes without training wheels. These work great for both typical kids as well as children with special needs. Many parents find that using balance bikes instead of training wheels is a more effective way to teach kids how to ride a bike. In addition to the sheer joy brought about in children by learning to ride a 2-wheeler, you will also save a tremendous amount of money by not having to purchase the very expensive and cumbersome 3-wheeled bikes made traditionally for special needs children.
The Skuut bike is just this sort of bike and fits children of all abilities between the ages of about 2 and 5. The only issue of course is that they do not make bikes like these for older and bigger kids, at least that I have found. At any rate we have had great success in our practice by making our own balance bikes for older children.
How you might go about it:
Start with a bike that you don't care much about and remove the pedals. Next lower the seat down so your child can easily touch the ground and teach them how to walk along at a slow pace while holding the bike upright. I have found that in both young and older children, there is some degree of fear the first time or two, so be as patient and understanding as possible. Also in most cases the children do not enjoy hitting their ankle bones into the "crank" part of the bike and those are easily removed as well from the center area. If this job is too much for your mechanical skill level, the folks at any bike shop will do it for you in just minutes and usually for free when you tell them what you are trying to do.
It is quite likely that your child has never experienced this degree of freedom associated with a bicycle before, especially if they are used to training wheels or heavier 3-wheeled bikes. I also recommend that you give them a starting point and an ending point to begin with. For example you might tell them, "We're just going to ride your bike down the driveway to mailbox and then back and we'll be finished." By employing this strategy I have found success in keeping the stress to a minimum and many times they will ask to go farther or do it again.
After your child gets the hang of it a little, then you can start to increase the speed, within reason of course. The best way I have found to do this is on a gentle sloping driveway or sidewalk. To give you an idea, the angle of a typical handicapped ramp going into a building would be too steep at this point in the learning. The basic idea is to progress to the point where your child begins to push and run along for a few steps and then lift their feet off of the ground for a short distance and "coast."
For many children with special needs the concept of lifting their feet off of the ground and coasting is not an easy one to learn. Sometimes when first practicing I will push the kids along on the bike and cue them, "Now lift your feet"while I provide the stability for them to do so. After a few times they usually begin to get the idea. Of course as with most activities that we teach children with special needs, this activity is most likely going to take a little longer to master than the average child, don't worry about it, just have fun.
To give you a rough idea, if you start teaching your 10 or 12 year old with Down Syndrome the balance bike concept in April or May, they might have a good chance to ride a 2-wheeler by themselves by the end of the summer. The balancing and steering is really the most difficult part, not the peddling and it comes pretty easily once the first two are accomplished. Generally of course the earlier in your child's life you try the easier it is for them to learn.
As time goes your child will learn to balance and steer for longer periods of time and the whole activity will become great fun. It is very motivating to learn a skill that they have watched so many other children do. After some time you can try adding the pedals and see how it goes. Once the pedals are returned to the bike, there will be a learning curve as always, however, you will be quite amazed how quickly they will overcome it now that they can balance and steer more effectively.
Best regards and good luck,