Dr1v3n

Are there any general "try these remedies" for low back soreness while riding MTB? I have a Giant Trance FS bike and it seems to occur mostly after longer ascents, and longer periods in the saddle. Steps I have tried with their results:

1. Taking short stretch breaks - this completely relieves the soreness each time, and it doesn't come back for at least 10-20 minutes after beginning riding again
2. Changing my posture on the bike: Sometimes I put more weight/lean more forward, and other times I throw my weight to the back (especially on smooth/flat surfaces). This can help a bit to at least "mix it up" for my back
3. I just discovered this yesterday - Squeezing my glutes more when I have to put down power into the tires. I noticed that when I began to actively "squeeze" my glutes while pedaling, it seemed to relieve some soreness. This leads me to believe that hamgstring or quad fatigue/tightness/weakness could be part of the problem.

I highly doubt "weakness" though as I am 175lbs and I routinely (2x per week) deadlift 275lbs, rack pull 315lbs, squat 315lbs, and angle legpress 475-585lbs. Unless (and I'm not a psysiologist) it's that my slow-twitch fibers are weaker than my fast-twitch or something like that.

Also note that I also have a Giant Revolt and while I do occasionally get such back pain on the Revolt, its far less common. Meaning, when I ride the Revolt I may get it once or twice over a 2-3 hour long ride. However, on the Trance, especially if I am doing more XC type stuff, I may have to take 4-6 breaks during that same time frame. If pictures would even help, let me know which positions I should take pictures in (I dont think its going to help taking standing photos) and I could probably upload a couple. Note though that the LBS did observe and do an initial fit for me on this bike.

NOTE: I would not call this an "injury" - it's temporary soreness/pain that goes away the moment I hop off the bike and stretch. So therefore, I am not asking for or expecting medical advice.

prj71

Lower back soreness is a result of a weak core. While some lower back stretches (look up on google or YouTube) will give you some temporary relief, the best thing you can do is is core work...Planks, push-ups etc. Strengthen your core and your back problems will disappear.

Kapusta

I find that pedaling hard while in too upright a position tightens my lower back.

Also, when leaning forward, it is important for me to bend at the hip (tilt my pelvis forward) not at the waist.

In short I try to keep my lower back straight while still tilted forward.

i also found hamstring stretching (regularly, not as part of a pre ride routine) helps in this regard.

GhostRider62

Your back pain source is from the psoas and/or iliacus muscles.

Compare the pedal to saddle height on both bikes and the saddle to handlebar distance. I bet there is a big difference (say half an inch or more)

If not, those two muscles are probably weak and shortened from sitting a lot. And, need to be worked out. Another remote possibility is pulling back hard on the pedal stroke......if so, stop doing that and just stomp the pedals

Mr. 66

Are you getting enough hydration? That's where I start. I think I would water up consistently for a couple of days ahead of time, even a week in advance if you are in competition riding. The next thing I would check is nutrition, keep up on the vitamin and potassium iron...

Another possible would be to tone your weight training from strength to endurance.

rosefarts

When I got back into cycling I got that. Then I got in much better shape and it went away.

A far as the weight room goes, I’m not sure that matters as I was quite strong physically too.

Ride more, get punished.

Trakhak

Yes. Not saying that this is the case with the OP, but springtime is when these kinds of complaints start showing up. "My saddle is killing me. What should I buy?" "Is it a new saddle?" "No, I rode a bunch of 100-mile rides on it last year and it was fine. What should I replace it with?"