Road Etiquette part 2

If they aren't good enough friends that you'd wait for them, then don't do it.

If you think it's for training, don't do it. Go riding by yourself or with a faster group/club instead. better use of your time and things wont have the potential to get any more awkward with your friends.

I would play it by ear. Set a sensible pace for the first half but stick with your mates. Have a break at 50k and see how much time you have left.
Second half i would lay down a marker - saying that you want to be back for 4 so will aim for that - if you stick with me then good for you. If you drop off - tough.
A 100k charity ride is meant to be a challenge - not a leisure ride.
The clue is in the word 'challenge'. if you friends arent willing to put in the graft then drop em.

Here is how you do it:

Set out with them, try and get the speed up and put them in the red, lambast them for not trying hard enough or training enough. Then adopt German accent and scream "Shut up Friends" when they moan. Leave them for dead Sprint off to the finish and then head to the pub and wait for them there.

I did a 30 mile training session with a friend who is heavily overweight ( desperate to lose it) and he was fine for the first 15 mile because we had the wind behind us, the last 15 took us two and and half hours would usually take me just shy of an hour and I did feel really sorry for him as I could tell he was close to crying but having to stop every quarterof a mile was intensely boring, I was going my slowest I could manage at some points and still was putting 60 yrds between us, but you know what I am glad I did stick with him as he couldn't thank me enough for helping him through and we are closer as friends now. so as someone else had said it depends what type of friends they are or what you want them to be in the future. if they are just mere post time friends then just be honest and explain that there standard is lower than yours and at some point you may drop them, myself I would appreciate the honesty and respect them for it.

7 hours to do 100k sounds a bit boring - I think AbuDhabiChris is right, are they real friends?

Alternatively, when I went out with a friend who I was willing to ride slowly for, I ended up using it as an interval session. Pootle along on the flat, and every time we hit a hill, I gave it the beans, then waited at the top. She was cool with that, didn't mind at all.

I went on a tour across France, Belgium and Holland with a group of 6, 2 of them weren't up to the same level but I was using the trip to train for a few sportives later this year.
I ended up going off on my own or with one of the others and we did shifts with the slower riders. This probably works over a week long period but I wouldn't feel bad about dropping them if there are others with the slower riders.

It is incredibly frustrating and waiting for them to catch up is the worst part.
Good Luck with the ride though.

It really depends on the nature of the friendship doesn't it. There are people I would do that for, because they might do the same for me, and people I wouldn't.

Assuming they fall in the Wouldn't camp, I would remind them that the deadline is 4pm and you will be riding to meet it. Usually you have to book a place on the return buses and trucks don't you, so that's an easy excuse, if you've already booked and paid.

If they can keep up then great, if not then they have to be prepared to make their own arrangements. From the sounds of your training trip they are perfectly capable of doing so.

9mph!? They should be ashamed. Rule 5.

Seriously though, if they're having fun, let them. If you want to race, do!

Sounds like new friends are needed.

I'd set off with them and ride with but occasionally,and especially on climbs just dance on the pedals and disappear down the road

I guess they have known about it for a while.

What time do you set off?

Because its not a race and a charity ride. I would be tempted to stick with them and just rip them to shreds with abuse about not getting training miles in and other encouragements like that.

After all, its only 100k, if you set off at 9am, still gives you 7 hours

Someone who has done no preparation should expect to be dropped