I am curious about the conflicting information you have reviewed regarding which type of situation puts the back in a more open, relaxed position. I had researched this last fall and I thought there was a consensus that the geometry of a tri-bike permitted the hip angle to be opened up more than any road bike with aero bars added on. I think these two bike options have to be taken together with the resulting range of fit options which become available. In other words, a relaxed fit on a road bike with aero bars might be more relaxed and open than an extreme drop/tight fit on a tri-bike. There might be some overlap in body geometry which is possible between these two options, but my understanding is that a tri bike would enable a more relaxed/open fit.

Immediately after an International distance tri last year, I suffered a low back injury. It was at least two months before my doctor and physical therapist would release me back to bike riding. Swimming was permitted first, then running, then biking. I learned to incorporate more core work and hip flexor work into my strength/flexibility training.

I had just put aero bars on my road bike (specialized allez) and had it re-fit at my local bike shop earlier the same year I was injured. So, I was pretty confident about the culprit of my problem.

This past winter I invested in a Felt DA4 and had it professionally fitted to me by a triathlon specific fitter. Have not had a problem since (yet). Noticeably increased my speed and ability to put out more power.

Like you, I would be very hesitant to try long distance triathlons. In general, my back starts to feel tight after about two hours. Albeit, I have not trained for long distance either.

Guy with back issues here.

Back in the late 80's and early 90's a road bike with aero-bars was a triathlon bike. I usually found that I was too stretched out and that my hip angle was more closed. This hurt my back, I recall lots of people squirming around and sitting up late in the bike leg so I don't think I was alone. I would guess that my hip angle is pretty close to the same on my tri bike and on my road bike (without aero-bars). I don't know that one is easier on my back but sometimes it seems like being on the aero-bars takes some stress off, as my upper body is supported on the arm rests rather than through my arms. On rough roads the road bike seems better as the arms help absorb the shock.

I believe this is the part where I have read conflicting information, most of which has been anecdotal.

Thanks for sharing your similar research, glad to hear. It's always nice to get that extra vote of confidence before dumping a few grand on a new toy. But like I really needed and excuse.

It would be great to hear a few more stories about bad backs being helped by the switch to tri bikes if anyone is willing to share.

Thanks!

I'll jump in with my experience.

I have two herniated disks in my low back from a skiing wreck. I find my tri bike to be more comfortable and causes much less low back pain than my road bike. The key is to find a saddle that you can really relax your core and rotate forward on to maintain a flat back without rounding your lower back.

So you can ride 2 hours, in your aerobars on your current bike and no back pain; but 2 hours on the road in your aerobars gives you pain?

Yes. The only time I may get a bit of back pain while on the trainer is while doing low cadence work. Otherwise the pain starts in on the road rides anywhere from 30 minutes to 2.5 hours in. I thought perhaps the balancing and micro adjustments required on the road may be the difference pointing to a weak core. Thoughts?

I've had chronic back issues for nearly 25 years, after being hit by a car.

Back in '87 I found out that slapping a set of aerobars on an otherwise properly fit road bike was not comfortable or efficient at all. Most of the people I trained with were installing high rise, short reach mtb stems to sit up a little higher. After playing around with various setups, I discovered that if I reversed my seatpost and slammed my seat forward, and then installed a slightly longer stem, I could get lower while being more comfortable and faster. That position is virtually identical to what I have now.

On my current bikes, my hip angle on my road bike is identical to the angle on my tri bike, the difference is that I'm sitting farther back and more upright on the road bike. My back is more comfortable on the tri bike, since it isn't really doing anything to support me. Sometimes on days where my back is giving me problems, I'll set up my tri bike on the trainer and just sit on it while watching TV, it helps to relax and stretch out my back...

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"I'm thinking of a number between 1 and 10, and I don't know why!"

You may need to rotate ur pelvis forward like this to get a more of a neutral spine I find that the right saddle with it further back allows you to rotate and push your bum out and belly down to the top tube, allows for better breathing and main source of power is from the glutes. Also its very aero

My road bike is currently fit with the seat far forward (~ -60mm setback) and an effective seat tube angle of around 77 degrees. Aerobars are not aggressive at only a 6cm drop. Tried lowering them and back hurt even more.

Good to hear that others with back issues have found some relief.

I am still curious if anyone suspects that it may be more a weak core issue given that I get little to no pain on my trainer in aero position for 2 hours but on the road my back starts to give me trouble well before then.