What causes the most propulsion in backstroke--arms or kicks

I tried doing four dolphins kicks off each turn in 2009, and I was going slower in my backstroke races. I was better off flutter kicking for a little bit off each turn and then surfacing about seven or eight yards from the wall, similar to my freestyle turn. I do four dolphin kicks off the start, only to help me get to the surface. I've been working on a shallower start, but it's slower at the moment. I think my backstroke might be more in line with yours. I don't have great underwater kicks. Yes, I still work them in practice but in races, it hasn't translated into improved speed. This morning, I did a backstroke set with a strap around my ankles to see how it affect my times. We were swimming short course meters. I was "pulling" 100 meter backstrokes and coming in around 1:20 per 100. The efforts weren't 100 % all out, as I was focused on getting a good catch and powering through the catch. There is no way I can kick scm that fast. I didn't kick off the wall, just pulled my way through the swims.

I think arms. Since my running days are over , my times have slowed from less kick - it's still an arm driven stroke.

Is it possible to be fast (not the fastest) while being weak in one or the other? Not really I beg to differ, Ande. If you saw underwater footage of my backstroke kick, you would know that I am a very weak kicker, hence the reason why I don't do dolphin kicks off any turn. Yet I've managed to win a few big Masters races. I understand that I may be an anomaly, but it is possible to be a strong upper-body backstroker and win a few races, even in short course. You just have to embrace our flaws and work on your strengths so it all balances out nicely.

Some say in backstroke propulsion comes mostly from the arm movement, while others say kicking is the most important. What do you think? Is it possible to be fast (not the fastest) while being weak in one or the other? Agreed with Chris regarding the kick and the percentage of relevance. It may not be a contributing factor to propulsion, but it's an integral part of the stroke. And the kick doesn't have to be exhausting. Just enough to create a boil of water under the surface at one's toes. Ideally the way to make backstroke more efficient is to avoid swimming flat on one's back. And a steady flutter kick ensures you'll be able to achieve a long reach and decent shoulder roll with each catch and pull. Shoulder rotation is very noticeable on any good backstroker. And the legs are the support system for making it all come together.YouTube - Backstroke Technique - Side View - Krayzelburg, Phelps, Lochte

I beg to differ, Ande. If you saw underwater footage of my backstroke kick, you would know that I am a very weak kicker, hence the reason why I don't do dolphin kicks off any turn. Yet I've managed to win a few big Masters races. I understand that I may be an anomaly, but it is possible to be a strong upper-body backstroker and win a few races, even in short course. You just have to embrace our flaws and work on your strengths so it all balances out nicely. Jeff, you don't do any underwater kicks? Do you flutter kick? How are far off the walls do you go before surfacing?