That is not how a binomial probability is calculated. Consider the case where you flip a coin twice - do you have a 2 * 1/2, or 100% chance of getting a 'head'? Obviously not – you have a 75% chance.

The actual way you calculate the probability of an event with a binomial distribution is by taking the inverse probability and raising it to the power of the attempts, then subtracting from 1. So in the case of two coin flips, that is 1 - (1/2 ^ 2), or a 75% of getting a 'head'. That would mean, with a huge host of assumptions, that a motorcyclist's chance of dying over 30 years would be 1 - (99928/100000)^30, or (funnily enough), 2.13%.

edit: I said bimodal when I meant binomial.