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Discussion Starter · #1 ·
Anyone have a similar dilemma? I have had lower back issues the past few autumns when transitioning to my road bike on the indoor trainer. When I drop the saddle .25," the power and fluidity returns to my pedal stroke and my back feels great--and I am able to go very hard. One major variable is that I run 175mm on my MTB and 170 on my road bike. I work long hours on a computer, and try to frequent breaks for posture and breathing. Stretch regularly as well.
 

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Discussion Starter · #3 ·
Why don't you just put your MTB on the trainer?
I have geared and SS 29ers, have to get a smooth tire for it. Didn't want to go through that hassle. I have considered that and have a 26er in the attack I can reassemble and put on the trainer. Should be able to set it up pretty much identically as my 29er (bar width and height). I am anticipating that I will still have to run a lower saddle height though, and I did take in account the crank length difference when when I set up my road bike position. Thanks for the reply.
 

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Are you using a wheel block on the front? Not sure, but that might make a difference.

Are there trainer slicks that would fit on a 29" with 28mm outer width rims?
 

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Discussion Starter · #5 ·
Yep. Good thought though, I did measure everything back and it the relative "level" should be correct.

I haven't checked for 29er slicks in a couple of years, but I have been trying to get around removing my sealed up tire.
 

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Same here, that's why I'm currently running my CC bike on there, which I rarely ride outside. I guess the real solution would be a second wheel/cassette for indoors. Still doesn't solve your initial issue unfortunately.

I've also heard that monitor/whatever screen you're staring at can cause issues.
 

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Discussion Starter · #7 ·
I have both road and CX bikes that are inexpensive. I'll ride MTB given the opportunity, but a long spell of bad weather and a charity ride type of thing will put me on the CX or road bike.

One other point, I am 53 now, and this situation ramped up more after 50 (imagine that...)
 

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I am 50+ also

What comes to mind immediately, is it's not your seat height, but your stem height/reach and/or seat position relative to BB.

Not sure how you are comparing saddle heights to both bikes. I start with crank arm at bottom dead center, arm parallel with seat tube, foot unclipped and so heal barely brushes pedal with leg straight. This is on the high side, but helps keep away knee pain. But, if saddle to far back, it will put more stress on back.

What year is this road bike? Some of these bikes have real short head tubes for aggressive race position (bent over).

I had a "Pro Fit" done on my road bike and I regret not doing it sooner. Ended up moving cleats forward on shoes, saddle forward and shortening stem - saddle height stayed the same. I am glad i did it in December - the little movements made it surprisingly uncomfortable to ride for a while.
 

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As twobigwheels alluded, your saddle might be at the same height. But what about setback? Is it the same saddle?

And, how is your hip angle? I'm guessing that changes between bikes, too.
 

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Also stack height of the pedals/cleats/shoes if they're different between the bikes.
Maybe the lower seat height is better for you? Pro fits and various guidelines are just guidelines. Tom Boonen discovered that he makes more power with the saddle "1 inch too low" when it slipped during a ride.

When experimenting with saddle height I've found that lowering it often makes me feel better but it doesn't last. Eventually I get used to the new position and it no longer feels better. And then, if it's significantly lower than the LeMond formula, my knees start hurting.
 

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Discussion Starter · #11 ·
I am 50+ also

What comes to mind immediately, is it's not your seat height, but your stem height/reach and/or seat position relative to BB.

Not sure how you are comparing saddle heights to both bikes. I start with crank arm at bottom dead center, arm parallel with seat tube, foot unclipped and so heal barely brushes pedal with leg straight. This is on the high side, but helps keep away knee pain. But, if saddle to far back, it will put more stress on back.

What year is this road bike? Some of these bikes have real short head tubes for aggressive race position (bent over).

I had a "Pro Fit" done on my road bike and I regret not doing it sooner. Ended up moving cleats forward on shoes, saddle forward and shortening stem - saddle height stayed the same. I am glad i did it in December - the little movements made it surprisingly uncomfortable to ride for a while.
I actually measure everything out from the bottom center of the BB. For handlebar reach, I use the measurement from the back of the saddle to the center of hand position on the grips and also from the center of the BB to the same spot (this takes in account bar width and its effect on reach). Feel like I have all that figured out and all the units are pretty consistent. It is a little more complicated since I have 3 crankarm lengths, 170-road, 172.5-CX, and 175 MTB. Probably be smart to just make them all 172.5 or something, that that would be a pretty good bit of cash. My road bike is Giant Defy--they have a tall headtube. Makes for a super comfy ride.

Still have to think it's somehow related to tighter hamstrings and/or psoas, even though I can't really seem to feel anything different while stretching...
 

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Discussion Starter · #12 ·
Also stack height of the pedals/cleats/shoes if they're different between the bikes.
Maybe the lower seat height is better for you? Pro fits and various guidelines are just guidelines. Tom Boonen discovered that he makes more power with the saddle "1 inch too low" when it slipped during a ride.

When experimenting with saddle height I've found that lowering it often makes me feel better but it doesn't last. Eventually I get used to the new position and it no longer feels better. And then, if it's significantly lower than the LeMond formula, my knees start hurting.
Interesting you pointed that out. I had been feeling like I get more power from the lower saddle height, but like you, I started to develop some knee pain on the lower outside. Finally figured out that was from the angle at the top of the pedal stroke being too restrictive. I was really bringing my forefoot up high to clear. I raised the saddle 1/8" and it as pretty good. Over the next month (this was last spring), I raised it 1/8th again, and that seemed to be the sweet spot. I do use the same saddles (charge spoon) and the same shoes and cleats. Years ago a friend and I did the Wrench Science fit, and it said I needed to be at 28.25", but had settled on 27.75" for a good while, then got into raising it back up some. Was hoping 28" was the final sweet spot, but it doesn't seem that way. Again, this fall, when I started doing more trainer time, my back wasn't feeling good... dropped it from 28" to 27.75," and I was doing 3) 9:00 at LT-LT-5 x 6:00 easy spin intervals, and the lower saddle height felt great keeping the power down over that period of time.
 

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I actually measure everything out from the bottom center of the BB. For handlebar reach, I use the measurement from the back of the saddle to the center of hand position on the grips and also from the center of the BB to the same spot (this takes in account bar width and its effect on reach). Feel like I have all that figured out and all the units are pretty consistent. It is a little more complicated since I have 3 crankarm lengths, 170-road, 172.5-CX, and 175 MTB. Probably be smart to just make them all 172.5 or something, that that would be a pretty good bit of cash. My road bike is Giant Defy--they have a tall headtube. Makes for a super comfy ride.

Still have to think it's somehow related to tighter hamstrings and/or psoas, even though I can't really seem to feel anything different while stretching...
It doesn't sound like u have it figured out or that it's very comfy with back pain
 
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