The Kimblewick (or Kimberwick, the same bit with a different spelling) has D-shaped cheeks and is ridden on a single rein with a curb chain. With your hands in a normal position it rides much like a snaffle. Lower your hands and the rein slides down the D, which brings in the curb chain and a little poll pressure.
So the leverage depends on where your hands are. That suits a capable child on a pony who sometimes takes off, which is why you see so many on ponies. It suits a rider with unsteady hands less well, because the leverage comes and goes with them.
The slotted version, often called an Uxeter, has slots in the D that fix the rein in place, so the leverage stays the same whatever your hands do. Compare the plain Lozenge Kimblewick with the Rubber Uxeter Slotted Kimblewick, or browse all Kimblewick bits.
The Kimblehook is Fager’s take on the idea, and it’s the reason “Kimblehook vs Kimblewick” is such a common search. It’s a short-shanked curb with set rein positions, and Fager describes its effect as more direct than curbs with longer shanks. The lower you place the rein, the sharper it gets.
The practical difference is that the leverage is chosen when you buckle on the reins, not by where your hands happen to be. Fager also offers its full range of mouthpieces on the Kimblehook. The Fager Martin Sweet Iron Kimblehook, for example, has a double-jointed mouthpiece that locks like a straight bar under contact, which suits strong but sensitive horses. The rest are under Fager bits.
The Tom Thumb is a different animal. It sits somewhere between an American gag and an Elevator, with a lifting action at the front that helps a horse who leans and lets the rider sit him back on his hocks for a tight turn. That’s why it’s a favourite in the showjumping ring and across country. Its cheeks back up the turning aid and can’t pull through the mouth.
The Blue Sweet Iron Tom Thumb Lozenge is a good all-rounder, and the Tom Thumb Waterford suits a horse that takes hold.
One warning: a Tom Thumb Weymouth is a short curb for a double bridle, and a different bit altogether. Check the product name before you order.
| Rein position | Action | Best for | |
|---|---|---|---|
| Kimblewick | Slides on the D | Leverage varies with hand height | Strong ponies with capable riders |
| Uxeter Kimblewick | Fixed in a slot | Consistent leverage | Riders who want the same feel every time |
| Kimblehook | Set positions | Sharper the lower the rein | Strong but sensitive horses |
| Tom Thumb | On the cheek | Lifts at the front | Jumpers that lean |
Any bit with a curb chain adds pressure points beyond the mouth, so it’s worth reading leverage bits explained before you move up from a snaffle.
Moving to leverage is a decision best tested, not guessed. The sweet iron Fager Kimblehooks and the Blue Sweet Iron Tom Thumb can go out on a 30-day Bit Bank trial. For advice on whether your horse needs leverage at all, call our Bitting Specialists on 01405 861800, option 3.