As little as possible. I was off for 45 seconds last time I did the Newbury one: no support crew so I had to stop to change bottles. If I'd had a helper I wouldn't have stopped. Needed a long piss at the end though, and recall it was rather painful.
That still probably cost me almost a mile in distance, stop time plus it maybe takes a minute to slow down and another minute to get back up to speed.
As little as possible. I was off for 45 seconds last time I did the Newbury one: no support crew so I had to stop to change bottles. If I'd had a helper I wouldn't have stopped. Needed a long piss at the end though, and recall it was rather painful.
That still probably cost me almost a mile in distance, stop time plus it maybe takes a minute to slow down and another minute to get back up to speed.