Assuming it's a bunch sprint, what gear do you start your sprint in?

53x11

All kidding aside, too many variables to tell you a specific gear.
For example:
Distance to finish, start speed of sprint, type of sprint, and on and on

41

I was going to but thought I would give the benefit of the doubt.

yes.

So a question about sprinting at the end of a RACE goes in the 41? Then what goes in Road Bike RACING? Twitter feeds?

Oh boy...
Ok I'll be nice.
In a flat crit I will start a sprint in a 53x12 and drop to a 53x11 assuming that the sprint starts in around 38-40 mph.

correct

speed, distance, headwind, tailwind, sidewind?

I hate flat sprints. I'd much rather go into a slight uphill or a real uphill.

Basically what rkwaki said is right - if the lead out is good and is going 38-40 mph, a 12 is about the easiest gear to jump in.

When things are not quite so good, speeds more like 35-36 mph, a 14 might do it, maybe a 13.

If there's a hairpin before the sprint maybe a 15 or 14. This also depends on wheel weight, since significantly lighter wheels will spin up quicker (maybe one or two fewer downstrokes).

I did a bit of semi-logical analysis of my sprint. I found that my best peak power came when I jumped at about 100-110 rpm. I think. I have to check my notes. Anyway whatever the rpm, it was at a higher rpm than where I normally jump (70-80 rpm). I consciously changed my sprint one week, actually checking my cadence on my computer about 200m to go, shifted into an easier gear to get into the right rpm range then sprinted.

I found my experiment:
https://sprinterdellacasa.blogspot.co...g-my-jump.html

So I guess I jump best at 95 rpm, give or take, and really taper at 105 rpm.

What that means is the answer to the original question is "whatever gear I need to be in, at the speed when I jump, to be pedaling at about 95 rpm."

cool CDR, thanks a lot.

The real question is "what lap do you start your sprint in".. I've heard of at least one person that starts it at the registration table, but he's usually wearing his loafers.

Like CDR alluded, a better question is "what rpm do you start your sprint in?"
Even then, the biggest factor will be your personal preference.

Pick the appropriate gear to start your sprint at a given rpm. The gear is the variable; it will depend on the conditions leading into said sprint.

Added in edit: FWIW, I never look down or consciously think about what gear I am in when I sprint during a race. I just pick a gear such that I launch from like 90-100 rpm.

Thanks.

Get off the bike and run.

True, I often start my sprint at the bell.

55x9, then I dial it up to 2000 watts for about 3 minutes.

Whatever feels right, I have no idea what the gear is but I always wonder afterwards.. but then I feel like puking and shift into the little ring to spin, so I never know.

I predict that WKO/etc will be smart enough to figure out what gear you were in based on power/cadence. Not that it would do much but would be kinda nifty.

95-150rpm.

Your question is too vague to be able to give a useful answer, similar to many questions in 41. However, you did get some decent answers.

Because we care.

It might be a good idea to be in the same gear that the guy you will be following is in.

Who's to say they are in the "right" gear. Or that it's the right gear for you.

I'm assuming that I am smart enough to be on a good wheel. If I plan on following a bad wheel it doesn't matter what gear I am in.

And I didn't say that I would finish the sprint in that gear.