I’ve searched the threads but can’t find my exact question.
Switching to inside riding more and have noticeable left hip pain on indoor training bike. I’m sure this is a lingering injury that is exacerbated on the trainer due to longer times in static position. I compared my mountain bike(s) versus my indoor trainer bike and found a few differences in setup. First, I use the same pedals and shoes on all bikes. I have the same crank length. I set the seat height the same (crank to seat) but the indoor trainer bike has a different seat angle so my seat is actually behind the center of pedal more. I also measured the Q factor and have about 25mm difference (narrower) on the trainer bike. I’ve move the seat on the trainer more forward as a first start but I’m also wondering if pedal extenders would be the next logical answer to get the Q factor fixed? Is there a calculator for incorporating seat height with seat tube angle on various bikes? I have thought about running shorter cranks, but will I need to do this on all bikes?
I don’t have the ability to adapt my mtb to the trainer.
I’m also working through strengthening my core, glutes, hamstrings etc to try to remedy it.
Thanks much, looking forward to a productive indoor training season.
I would get the pedal spacers for your Q factor adjustment. The pain could be caused by new hip/knee alignment. See how that goes before making more adjustments.
I bought this to transfer fits between bikes. It’s not perfect but can get you close. I will say it’s a bit tricky to use and takes a bit to figure out how to match to the 2nd bike. But it’s helped figure out the fit on bikes with different seat post angles for me.
The distance from the front of seat to the bottom bracket is referred to as your setback. Regardless of the seat tube angle, the setback should still be the same/similar.
Are you running the same saddle on both bikes? Saddle length can make a difference between how/where setback matters between two bikes as well.
How tall are you/inseam and what’s your crank length? I’m 5’9 with around a 33” inseam. Switching from 172.5 to 165 cranks made a huge difference in opening up my hip angle. I had hip surgery for a torn labrum last year, so am very mindful of that now.
When you switch to shorter cranks, you do have to raise your seat respective of the crank length difference to maintain the same knee angle and the bottom of the stroke.
You technically don’t need to change it on all bikes, but it would be beneficial if you decided it was an improvement.
Lastly, regardless of all the dimensions mentioned above, a more aggressive position of the trainer bike (stack height, drop from seat to HB, etc.) will place your hip at a tighter angle.
I will not propose any solution for the problem, but I’ll just mention that often the best time to test alternative fit adjustments is when one can feel the pain from the injury. You get this very direct feedback from any adjustment you make.
Last year I was having a knee issue that would only show up when doing longer distances (>150km) several days in a row or with little rest in between. It was being almost impossible to find a root cause as the triggering conditions were not that frequent. I then ended up flaring up the knee by doing 500km in 2.5 days with a full bikepacking load, to the point I couldn’t pedal anymore.
The moment I got back home, with almost no recovery, I jumped on the bike and started experimenting. Turns out that some cleat and saddle adjustments were all that was needed for the pain to almost immediately go away. I kept that setup and never had that issue again.
Would hardly get to the solution without experimenting while still in pain.
PS : I’m talking about just experimenting on the trainer or driveway, not some epic ride
I think I still have a standing order for the longer pedal axles for Shimano Ultegra pedals. Never have been available as far as my experience. If there are extenders that don’t risk damage to the cranks, rock them!