My question concerns the best bike I could get for my son. The issue is that he is nearly 9 years old but is the size of a 6-7 year old and has mild diplegic cerebral palsy. His consultant has tried to push cycling to increase strength and balance. The major thing is he can't physically turn the pedals to obtain forward momentum. I have thought about this a lot recently and come up with the conclusion that the lighter the frame might be the way to go as over the years I've bought generic dysney then spiderman bikes etc, and found them to be heavier than my own bikes. In addition to this I feel reduced tread tyres might help due to there being less resistance. Any suggestions as to bike types and setups would be appreciated. In addition the bike/setup needs to be able to take stabilisers initially. Hope someone can help thanks.