Recently changed gravel bikes, and although my saddle-pedal distance, reach etc. are pretty close between them, the new bike activates – and puts a lot of strain on – my hamstrings while asking less of my quads. What have I done wrong?
Maybe. Forwards or back?
Back will put more on your hamstrings. Lower will too. You might give it a chance, though- I moved my seat back and down a few years ago, and although it took time to adjust, I feel stronger and cramp way less. It gets your butt involved too.
I might move the saddle forward a few mm and see what happens… thanks!
sounds like excess setback. are you further behind the bottom bracket? try moving your saddle forward in max. 2mm adjustments.
My take, more posterior chain activation is usually a good thing. At least for me.
Second that. Using different muscles is not good or bad, but it is valuable information. If your hamstrings were freeloaders before of course they will complain about contributing but that doesn’t automatically mean they should get relief. Getting a bit out of them could make a huge difference.
At the same time they are not the prime mover, and if involving them gets your quads out of the movement that’s no win.
I personally would train your new position for a month or so and see if things come into balance. If the hammies are still complaining then try moving the seat forward a touch until they’re in balance with the quads. But don’t automatically assume the previous position was a perfect spot to be regained.