This is a copy of an email I sent a mate who asked the same question the other day. I have a Kokua for my 3yr old and she loves it. She can do feet-up for well over 50m, over rough ground. The Kokua is great and well made, but the price is quite high these days I think.
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Wiggle have some. Look quite nice, and have a brake
http://www.wiggle.co.uk/p/Cycle/7/Adventure_Zooom_Beginner_Pedal-Free_Kids_Bike/5360039622/
Others:
Islabike:
http://www.islabikes.co.uk/index.html
Specialized:
http://www.cyclestore.co.uk/productDetails.asp?productID=16045
and
http://www.evanscycles.com/categories/complete-bikes/childrens-bikes/scooters-runners
also
http://cgi.ebay.co.uk/Kokua-Jumper-Like-a-Bike-Boys-Girls-Kids-Trainer-Bike_W0QQitemZ330298326451QQcmdZViewItemQQptZUK_Bikes_GL?hash=item330298326451&_trksid=p3286.c0.m14&_trkparms=72%3A1298%7C66%3A2%7C65%3A12%7C39%3A1%7C240%3A1318
there also some wooden ones here
http://www.thekidswindow.co.uk/childrens-wooden-bikes.htm
and some here but the seat look quite high so may be a tad big
http://www.halfords.com/webapp/wcs/stores/servlet/product_storeId_10001_catalogId_10151_productId_503457_langId__categoryId_205254
and a similar version here
http://www.kids-bike.co.uk/balance_bike.asp
The expensive ones are obviously better (Islabike, Kokua, Specialized) and remember when you sell it you’ll get back probably half of the initial cost (if it’s in reasonable nick) so the actual cost of ownership is lower than first glance.
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