Low back pain after new shoes and re-position

alexul

Hi all,
I need some help or any advice you may have. Last year when I purchased my road bike I chose to ride SPD and went to a quite expensive fitter. Overall I found a sweet spot on the bike, rode 3000 kms in 1-2 hours sessions. This year I decided to do less often but longer rides. After my first 100 km ride I decided to switch to road pedals because of the hotspots I had. So I went to a LBS to buy some shoes and pedals, and they were also Specialized BG fitters so I asked them to adjust the cleats and nothing more because I feel great on the bike. With my new shoes and on the trainer the guy said that my knee angle is way off, like 40 deg when it should be 30. Thinking that the new shoes and cleats are much taller I agreed to change the saddle position. He raised it by almost 3 cm and back by 8 mm to get to a knee angle of 30.
But after 2 short sessions of only 45 minutes I have some really bad lower back pains, especially on my right side where my sciatic nerve was awaken by this high position.
However, my knees and ankles are pain free so far, so I don't know exactly where I should make changes. To the seat or in the front. I'm already on a 9 cm stem, the one the bike came with.
Thank you a a lot.

wongataa

Well if you had no issues before moving your saddle, put it back in that position as it works better for you. Check your new shoes and pedals to see if there is any difference in heights compared to your previous ones. If there is adjust the saddle to compensate for that difference. It won't be a huge change if there is one.

geoffh73

If your saddle went back nearly 1cm but your stem is the same this could be the reason you have back pain. you will be more stretched out.
1 cm might not sound like much but in terms of comfort it can make a big difference,
Might be worth trying a 8cm stem

Geoff

markhewitt1978

Agree with the above. Change it back! I was under the impression road pedals would have a lower stack height than SPD anyway? So you're saddle would have to be lower to compensate?

rick_chasey

Can you raise the handlebars by the same amount as the saddle was raised?

And as above, if the saddle has moved back, get a shorter stem?


It partly depends on the pain. If it's just achey, I'd be tempted to say man up and build a stronger lower back. If it's more likely a nerve or something as you've described, either move it back (though there was method to the madness), or adjust everything else accordingly and keep the lower knee angle.

giropaul

I keep a record of key metrics for my position, and any bike I ride is set up identically.
- height of saddle from bracket centre to top of saddle at a certain point where my sit-bones are on the saddle
- set back of saddle from vertical line through the centre of the bracket
- sit-bone point to centre of handlebars
- Drop from saddle height to bars ( using a long spirit level)

I'd suggest that once a bike fit has been established, a record of a these numbers is kept - or do what Boardman did and keep a "reference bike".

I always use the same type/make of shoes, but I would alter saddle height ( hence everything else) if I had thicker/thinner soles.

Small changes in the frame geometry, especially seat tube angle and bracket height, will change how the parts sit on the frame.

cedargreen

As above, having a baseline for saddle height etc is useful so that you can revert to the original position. The fitter could be right but 3cm is a big increase in saddle height and I'm not sure knee angle is relevant.

I've always adjusted saddle height using the Guimard/Le Mond method, in which the distance from the centre of the bottom bracket to the top of the saddle= inside leg x 0.887. This has always worked for me- some variation can be made to allow for different crank lengths, shoe/cleat combinations etc.

i think the other thing is not to make too many adjustments at once, or you won't be able to identify the cause of any issues. For example, if you raise the saddle and get new shoes and pedals and then get foot pain, you won't really know the cause.

It also takes a while to get used to new positions/ shoes/ distances etc. It appears that you decided on new shoes/pedals after your first long ride. Given that you were fine over 1-2 hours this seems a bit drastic. basically, I would avoid further changes and just put your saddle back to its original position, and get used to the new shoes/pedals.

alexul

Hi all,
Thanks for the input. I measured the difference in stack height between the MTB and road systems. I estimated the road are taller by around 1 cm max because of the cleat, the MTB had the spd cleat recessed. Anyway, I lowered the saddle by 1.5 cm, half of the original raise. Felt somewhat better, not completely. On the next ride I will lower it even more, close to the original position. I do have the references before and after the fitting so hopefully the ideal values will be somewhere between.

I did try a ride with an 80mm stem. But the weather was horrible and had to give up after 30 minutes. It was more comfortable while cruising at low speeds but when I needed to speed up I had to lower myself a lot from my arms. Even after 30 minutes, my arms were quite tired. So I swapped back to 90 mm. Though I'm not eliminating the idea of a shorter stem. Good news is that I should get an indoor trainer tomorrow or in 2 days. I hope this will help me more to test and adjust settings. It's really difficult to have a feeling about efficiency and comfort when I ride against a blizzard

mugensi

If you were comfortable on the bike previously then put the saddle into the original position and only adjust it to compensate for the higher cleat position which in reality shouldn't be more than 5 or 6mm. I would leave the fore/aft position as it was and if you feel its effecting your comfort more it forward by 5mm.

Bike fits dont always work for everyone. I had been cycling for years when I got a fit done, I was very comfortable on the bike and never had any issues but thought the bike fit might have optimised my position for better power and speed.

The saddle was raised by 4cm during the fit and put back approx 7mm. The stem was also flipped to the 'stupid raised' position. The fitter (who has a very good reputation) told me that it would take time to get used to the new position but to stick to it. So I rode for nearly 3 months in the new lofty position, I hated it, I felt uncomfortable and unstable on the bike so much so that I started to cycle less and for shorter distances when I did go out. In the end, I reverted to my old position and told myself that I would gradually increase the saddle height and move the saddle rearwards ever so slightly each time. In reality I never did, I was comfortable, I could/can cycle long distances pain free and could average 28-30kmph over 100km distance so why would I change that??

cyberknight

MugenSi wrote:

If you were comfortable on the bike previously then put the saddle into the original position and only adjust it to compensate for the higher cleat position which in reality shouldn't be more than 5 or 6mm. I would leave the fore/aft position as it was and if you feel its effecting your comfort more it forward by 5mm.

Bike fits dont always work for everyone. I had been cycling for years when I got a fit done, I was very comfortable on the bike and never had any issues but thought the bike fit might have optimised my position for better power and speed.

The saddle was raised by 4cm during the fit and put back approx 7mm. The stem was also flipped to the 'stupid raised' position. The fitter (who has a very good reputation) told me that it would take time to get used to the new position but to stick to it. So I rode for nearly 3 months in the new lofty position, I hated it, I felt uncomfortable and unstable on the bike so much so that I started to cycle less and for shorter distances when I did go out. In the end, I reverted to my old position and told myself that I would gradually increase the saddle height and move the saddle rearwards ever so slightly each time. In reality I never did, I was comfortable, I could/can cycle long distances pain free and could average 28-30kmph over 100km distance so why would I change that??

Indeed , for years i tried to ride in a certain position with issues i put down to everything but bike fit , i eventually went with what felt comfortable along with some advice from cycling friends and now my fit works for me by being further back with a shorter stem i have unweighted my arms and relieved the neck/shoulder pain .

pilot_pete

3cm is a huge increase in saddle height! Have someone cycle behind you and tell you if your hips are rocking at all. If they are the sadlle is clearly too high, but if your knee angle is 30 degrees then that would be unlikely. Is your knee over the pedal spindle at the front of the pedal stroke as that is a good starting point for weight distribution?

Have you considered footbeds in your cycling shoes, rather than just the insoles they come with? I wear Sidi shoes and they assume you will get footbeds (or at least I assume they do) as the insoles are horrendous! I mean the heat mouldable ones like they have in ski boots? I have never looked back since getting a pair which make the shoes fit like a glove and help prevent hot spots.

Once you have the back end sorted get a picture of yourself side on (or video preferably) whilst on a turbo trainer. Your torso angle from the horizontal should be within the range of 30-50 degrees. 30 being more race orientated, 50 being more relaxed. This is adjusted by stem rise, stem spacers and stem length. Also affecting it is handlebar reach, and to a lesser extent hood placement on the bars.

Angle between hips/ shoulders/ upper arms should be approximately 80-90 degrees when riding on the hoods naturally (i.e. not tucked in like a pro on a solo break away trying to keep the peloton off with 3k to go!) If it is more than 90 degrees you will probably feel too stretched out.

Saddle to bar drop (number and size of stem spacers) and reach (stem length and angle) coupled to bar reach and lever position on the bars will all affect this. If you can get it to 90 degrees you shouldn't be over reaching and if you can position the bars (by rotating them in the stem) and levers (rotating them around the bars) to keep your wrists straight on drops and then tops you will be in the ball park.

If you need a much shorter stem it would suggest that the frame may be too big for you if the back end is set up correctly and you are still over-reaching, but it sounds like you were happy with the position before, so I would certainly go back to that as a starting point. 40 degrees knee angle at the bottom of the pedal stroke does suggest saddle a little low though, especially if you were also achieving KOPS.

PP