Triathlon - Clipless pedals vs transition times

My brother just started doing short triathlons (sub sprint) with rides of about 10 miles. His question to me - how much faster will clipless pedals make him, compared to the 90 seconds he'll lose changing shoes in T2 (and maybe even a bit on the run out of T1)?

I never even thought about doing a ride in running shoes, but I suppose at some point, it's faster to just go with toe clips.

i always go clipless. it saves soo much time. not only more power/efficiency, but transition time. the best way is to put tri shoes clipped in to your bike with the strap(s) allt he way loose. run out barefoot and start pedaling, then pause once upto speed and put feet in one at a time (obviously not possible on fixed gear bike haha). saves mucho time.

this method means that in T1, all you have to do is toss helmet/sunglasses and race number on before grabbin your bike and leaving the transition

Changing shoes in T2 should in no way cost 90 seconds. My first tri, my T2 was 45 seconds, and I changed shoes.
It would have been faster without changing shoes, but I was doing a longer bike leg than your mentioned 10mi

It shouldn't take 90 seconds to change shoes. To go from bike shoes to running shoes in T2 should take about 5-10 seconds using the following method:

1. As you are finishing the bike portion, remove your feet from your shoes. Place your feet on top of the shoe/pedal unit.
2. Pedal into transition, and dismount the bike in your bare feet/socks, Run to your transition area.
3. Slip on your running shoes. If you're wearing socks, you'll need a few extra seconds to put them on.

The last step is where you spend your 5-10 seconds. The first two steps add no additional time to your overall time.

Worth mentioning that for my aforementioned T2 of 45 sec, I didn't even remove my feet from bike shoes until my bike was hung on the rack, and my butt was on my towel to change!

i always go clipless. it saves soo much time. not only more power/efficiency, but transition time. the best way is to put tri shoes clipped in to your bike with the strap(s) allt he way loose. run out barefoot and start pedaling, then pause once upto speed and put feet in one at a time (obviously not possible on fixed gear bike haha). saves mucho time.

this method means that in T1, all you have to do is toss helmet/sunglasses and race number on before grabbin your bike and leaving the transition
This requires a whole separate element added to your training. Make sure you have this down before you try it in a race ;)

Tell him to get speed laces or Zoot shoes. Putting them on takes all of 2 seconds.

It's not just the time time to think about, but also using clipless pedals will save his legs by making them more effecient on the pedal stroke... this will translate into a better/stronger run with more energy left after the bike.

It really depends on how serious he wants to be. If he wants to do a race a year and just have fun, then yeah, he can forego clipless pedals. If he wants to really get into the sport and maximize his efforts, clipless pedals are a must. They are also safer than toe clips. Toe clips are actually harder to get out of if you fall. Clipless pedals disconnect easily.