Where the neck joins to the fork horizontal, the usual spot. I was riding along SIF ready to do either a sex change or hickflip and it snapped in half instantly leaving me with a seat/post in my hand and the rest on the pavement.
Yes, bad luck/bad equipment/bad weight. The gods must be crazy ( http://nz.youtube.com/watch?v=t127UCrtvLw )
I didn’t reread this but didn’t you put on an alluminum reinforcement pate onto your cf bace?
How did that work?
Also no direct experience, but:
The bolts would spin, but may be possible if you had a really tight fit.
I think some streight and some at 45 degrees would be good, or even all at slightly different angles.
You could make a slot with rounded ends (like a 1/4 mile running track shape). You only need two contact surfaces to keep the bolt from spinning.
But realistically, that’s engineering overkill for the holes that you drill in the CF base. You aren’t going to be making sharp enough corners to have to worry about the issue of the corners initiating cracks due to stress risers. Even if filing the hose square you’ll still end up with a small radius in the corners. Don’t worry about it.
Worry about stress concentrations where the seatpost bracket meets up with the CF seat base. Sharp contact points there can cause stress risers and initiate a crack. Minimizing stress concentrations there should be the goal.
Nah, I did not have any reinforcement in my CF base, tho I’m starting to think that it might just be a good idea.
Also, although overkill, I am thinking that oval holes and oval coach bolts is the way for me to go. Only slightly oval, which would stop spinning of the bolts and maybe keep it slightly stronger. I only want this base to last slightly longer than the last.
You know, you could just have round holes, put the base onto the post, then put the bolts through and tighten from the top and bottom, so the screws just dont spin around. Then once they are on tight, put the foam and cover onto the base.
All well and good until you try to take the bumpers off later for some reason. You’ll be caught in a catch-22.
To remove the bumper you need to be able to reach the back of the bolt. But to reach the back of the bolt you need to remove the bumper and seat cover…
For my next CF seat I’m probably going to use round holes for the seatpost mount holes and square carriage bolt holes for the bumpers. With the current KH Fusion seat cover it is easy enough to get to the insides if I ever need to tighten those four seatpost bolts again. I’ll use Loctite so likelihood of me needing to tighten them later is very low.
Well, those could have a notch or be squared. I dont think those areas have as much force going there compared to the 4 bolts connecting the post to the base.
Haha, I just read your second paragraph, so yeah, you typed out what I meant.
Yeah, thats what I was thinking too, only using oval holes for the post bolts.
I think this will help it last a little (if only days/weeks) longer.
How much money have you got to be able to afford ‘just a coupld of days longer’?!
(purely rhetorical, I would never ask about personal money)