My 5-year old son has just got an Islabike Beinn20 (small) for his birthday. Its secondhand, but in immaculate condition.
I'm trying to dissuade him from changing gears too much to start with but he does sometimes. Sometimes by accident, sometimes because he's realised he can go faster if he changes up.
The problem is, he can't change down, leaving him a bit stuck when he stops. I don't know if its the Sram 1:1 pull ratio, or what, but it is actually quite hard changing down. I've checked and the cables are free and easy, as is the gripshifter. It seems that the spring on the X4 mech is just very stiff. (mech bushings seem fine too)
Can it be replaced with a weaker one? Are other gear systems more suitable for little hands and arms? I can't believe Islabikes don't have the best one for kids though...