Fixed Time Trial Bikes

Did a practice run on 81" just now. All did not go well. Going down a drag on the way out I span out. Just getting to the roundabout to turn and I get a puncture on the front. Feels like I need 84" but I'm gonna give 87" a go as it's my only other choice atm

I seem to remember Chris Boardman doing sub 18:00 on 88", i might be wrong ....