600km Cycle 24 Hours Advice

600km in 24 hours is a big ask, even more so if you are planning to do it self supported.

You could consider doing it as part of an event like the recent 24 hour race in Mondello, or the National 24 hour TT championship (though I don't know if it will be on next year). Even if you decide to do it solo and unsupported, its worth taking a look at the data from the recent Mondello event to see what riders are doing in terms of moving vs stopped time. I think the winner in Mondello covered around 800km but was only stopped for a very short time - perhaps 10-15 minutes in total.

25kmh for the 24 hours may not sound too bad but as you've noted, you will be stopping. Ten minutes every 2 hours will loses nearly 2 hours and now your average speed needs to be over 27 kmh to hit the 600. Thats nearly 17% more power required.

There are some GPS units that may last 24 hours or more but its not possible with most. Audaxers and ultraracers will typically use battery banks to keep the unit topped up on the go.

600km on the open road in 24hrs is not easy, but it is possible.

You need to do 27.27km/h if you limit your time off bike to 2hrs; shorter is possible but it will take discipline, a reliable bike set up, planning with food and a little good luck.

You are looking at maybe 12000 cals but you are never going to eat that, so train to access fat along with eating food that agrees with you while exercising. I'd be limiting too much junk food but you will know best. GI distress is most likely cause of failure after "what the fu(k am I doing this for" taking over.

Start as early as you can; your body is used to getting up in the morning don't break that routine. No reason not to be on bike before 5am this time of year. In the meantime get used to riding in the dark and being comfortable with it.

If in Ireland picking a route with low climbing will mean lots of busy roads, so keep that in mind. Some of the audax routes out west seem to have reasonable levels of elevations compared to other areas. Don't forget to take account of 24hrs shops on sections of route between 10pm and 8am.

On GPS device, my own is old school (Etrex 20) and would do 600km on a single set of high capacity rechargeable AA batteries (2300mAh) but I think you'd need to charge on the go with most garmins/wahoos. Options there are a small power bank or dynamo.

Best of luck.

P.S you could just enter the Mondello 24 hr!

"Its all me so far on my own! Two other guys are interested also so that would be an advantage."

Nothing like do you fancy 600km in 24 hrs to get a WhatsApp chat to STFU 😀

I've done 600KM+ in 24 hours (2018 Audax Ireland 24hr TT) and missed out on doing it a couple of years before when a group of us attempted Mizen to Malin in 24hrs, two of the riders touched wheels in the middle of the night and we lost a lot of time after that and finished in 25hours.

I'd say to the OP that the way he's planning it will make it hard for him, mainly for logistical reasons, without some support he'll waste a lot of time supplying himself and his companions if indeed he can find any supplies in the wilds of Connemara in the middle of the night, and without having some fairly substantial bikepacking gear how he'd carry enough food and water to get himself through the times you can't easily source from shops or delis.

When I did the 24hr TT it was on a 44.5km loop in South Kildare, I had the van parked on the loop and also clubmates and family coming by to have stuff ready when I'd be coming by and wanted to stop.

https://www.strava.com/activities/1720279824

On food my experience would suggest a little and often approach, practice with the food you'd be planning to eat on your long training spins and once you're happy with your plan stick to it.

I only came across this podcast recently, it features Karen Cassidy who had just won the inaugural ladies solo prize at the Mondello 24, and recently defended her crown in style, but there's some great info in there for anyone thinking of doing something like a 24, well worth a listen. To make it better she's a Galway woman.

https://tritalkingsport.com/67-karen-cassidy-endurance-cyclist-going-solo-and-soaring-to-success/

Fair play to you for taking up the challenge, it's probably easier to do it as part of an ultra event, there was a Ultra in Galway the weekend of the Mondello 24, but just thinking about it and making a plan is a great start.

https://thewesternchallenge.ie/

I think to give yourself a chance of doing it, unless you are extraordinary strong, you'll need to minimize the amount of stuff you're hauling round, if you haven't done something like this it's hare to appreciate just how hard it gets in the second 12 hours, that's why a bit of support is such a help, as someone else has already said a 600km audax where support is not permitted has a time limit of something like 40 hours.

Even leaving provisions for yourself at points on the route that you can pickup as you go round would be a help..

Definitely your bike should be durable and well maintained but if speed is the priority then adding too much weight would be counterproductive

Galway TD Ciaran Cannon must have been reading this thread, he's currently half way through a 500km lap of County Galway, raising a few euro for the handinhand charity while he's at it.

https://twitter.com/ciarancannon/status/1543099282944888832

Bryton 420 gps lasts 35 hours.

Had a ponder about this, 26km loops somewhere flat with a car to grab water and stuff from. Don't stop for more than 60 seconds you'll never make it back up. Also need night lights, loads of MTB lights are well able for this but a nightmare for other road users.

26km and a chalk board takes away lap confusion if you start on an hour (in case your gps dies).

Start slow, don't change kit but do have a damp and a dry towel for face refreshment.

Rebuild the bike for comfort, probably raise the bars so drops and hoods are equally spaced from where the hoods are now. Fresh, thick tape?

Get used to calorie dense food. Pork scratchings, Bombay mix, gel blocks etc.

After about 8 hours you find the power you can pump out for ages so do a trial 12 hours or so. Will let you find the bits that are uncomfortable and where you are power wise into the 24ish.

Something sturdy to lean your bike against when stopped and premade water bottles (500ml an hour for me, oh, also think about a place to pee too). Someone making tea/coffee available is a very nice to have (feel bad about letting your pit bitch down so keep going).