Lots of replies. I'll try to deal with them all in one go...
531colin wrote: ↑6 Jul 2022, 9:05am
I don't even know why I posted on this thread yesterday, I wasn't in the right frame of mind.
From my DIY bike fit piece, a couple of photos...
Hoods position
foot level on bottom pedal by
531colin, on Flickr
Hoods position "hands off"
Balanced position by
531colin, on Flickr
Now, I rather doubt that on a flat bar bike you are leaning further forward than I am on the hoods?
So, you should be able to hold your position without propping your torso up on your arms, like I can.
If you can't, then you have too much weight on your hands, and your saddle needs to go BACK in order to be in balance.
Why not try it, what have you got to lose?
I'm sorry, who says this, that "you should be able to hold your position without propping your torso up on your arms"?
And you're not holding your position, you're putting your hands behind your back, which reduces the forward mass.
I did experiment with your suggestion, and sure enough, there was less weight on my hands when I slid back on the saddle. However, I still contend that this was at the expense of good control, and involved more extended elbows. This is precisely the problem when the reach is too great.
Forgive me for dismissing your argument, but when I first described the physics that challenges it, your response was to say that your advice was about moving the saddle further back
in combination with a shorter stem or other adjustments. I pointed out that this is not what you'd said originally, and you now appear to be reaffirming that this is independent of the stem/bars position.
As the photos demonstrate clearly, when you put your hands behind your back, your C of G changes completely (the weight of your arms isn't forward, it's now backward). A more valid test would surely be to simply move your hands sideways or even just stop holding the bars without moving. But that isn't possible, so the demonstration seems rather arbitrary to me. If, when riding normally, part of your body weight is resting on your hands on the bars, then you have to compensate somehow if you remove that support, or your you'll fall forward and hit your head on the pavement. If there's some rule of thumb that says, "put your hands behind your back - if you can still ride with your body in roughly the same position, your handlebars are in the right place," it seems like nonsense to me. Maybe you can explain the logic.
Re: bottom bracket, yes, it's my
Marinoni Special (an Italian, Giuseppe Marinoni, moved to Canada and started the company, after something of a sparkling career as a rider) with an early '80s Campagnolo BB with separate balls - just the single cup remains. I can't remember now if it's an Italian type or British - the latter, I think, which is one of the reasons it becomes so tight - like the fight I had to get the blumin' pedals off! - as bearings get dry and drag, it tightens up those threads that are designed that way so they don't fall off! Anyway, I have been extremely careful which way the thread goes and only ever tried to undo it.
It is confusing, and a weird coincidence. I've gone from a Marinoni to a Marin, but I don't know of any connection between the companies.
https://www.cyclingnews.com/features/gi ... heirlooms/
Thanks for the advice about shattering it - I hadn't thought of it that way, and I see now what you mean about doing that through the frame. God knows I've smacked it with cold chisels and all sorts, but not since I put some decent slots in it. We'll see whether it shatters or folds if I have another go at that. Thanks.
Thanks also for those confirmations that there's nothing special about these skewers. And thanks for the thread on setting up cantis, I'll have a read of that. Incidentally, I think the reason I thought I'd reset my brakes to where they were, but they didn't engage as soon, might be because I'd forgotten I'd raised the stem a bit, and, since I dropped the bracket with the stop below this back down to the crown, maybe this greater brake-lever-to-first-stop distance relaxed the system. I can't quite figure out how that works, but it must presumably give the same effect as winding the adjuster at the brake in!