epic ride yesterday in the pissing rain up at Blair Athol and had great fun negotiating the through peat bogs and rivers.

I did however notice a lot of lower back pain on the climbs and was wondering if this may be due to ovestretching on the bike? Not really pain, more like a buld up of lactic acid across the lower back. I have a 90mm stem which I asume standard/normal for XC, should I try a shorter one?

I have moved my saddle forward and inch to see if that has any effect.

There is no standard for XC and there many things that can cause the back pain, Your right over stretching is one and is common, really you need someone to check out your riding posture to see it they can spot anything.

Try touching your toes – how far down can you get?

I can touch my toes no problem.

poor core strength is the most common cause for back pain …..

think thats where goan will go next , he gave me the same lecture last week !

Poor core strength is for sure one of the most common causes.

I notice some LBP (low back pain) when I'm tired and I relax my lower back when riding. As soon as the whole area is 'held' a little more firmly the pain/ache goes away.

MIght also find tilting the saddle forward a bit might help, cured my back ache and mine wasn't set back, it was flat. it now sits a bit nose down, tilting the hips forwards and starightening the lumber area.

tight quads?

Mine started like that then got sciatica down the back of right leg.
My advice would be to forget Doctor but go staright to the Physio
and book yourself in.
Find out where your nearest Physio centre (NHS) is in your area.
Also keep calling for cancellations too.
Its faster to get seen this way.

Drink plenty of fluid in case it's a kidney infection.

Let your back heal up and then re-diagnose the problem and sort it-could just be a one off.

Strengthen your core and add flexibility and get a pal or a decent bike shop to assess your ride posture.

Job sorted 😀

Also check your bed for support.

If it was serious you'd know and touching your toes -well you're fine and just probably over did it like most of us do.

Go and focus on something else for a while.

Yer and thats not including laying on your Mrs

I get that on the Orange 5, but not on the Trek Fuel. It is like a band of tightness accross my lower back. I can stretch it out so it is very obviously muscular (nothing to to with core strength, or kidney infections). I have put it down to riding position on different bikes, and actually if the saddle is only half an inch too high on the 5 it can be worse. I'm still working on the non-achey riding position….

CM – why would it have nothing to do with core strength?

Why am i not surprised that you're still looking for the non-achy position?

I get lower back pains cos I have super tight hamstrings apparently. Pulling at my lower back. Physio usually gives them a battering and that sorts it for a while.

Something I've noticed when riding other peoples bikes, all of which are the typical sit-up-and beg stance of most current MTBs, is how much strain I get on my lower back, as if I'm pushing with this area and not my legs.
I always wonder if the 'shorter and higher' position could be putting the spine into a very inefficient posture for riding, and people then get into a vicious circle of going even shorter/ higher ?
Just my two pence worth.

You need to use you muscles in a certain part of their range of they have to work a hell of a lot harder.

Physio gave me some exercises when I did my back in last year, after recovery it has been fine if not better than before. Core stability is what the exercises helped with me, not just my back strength.

Goan – the fact that I get it on one bike, and not the other made me think it was bike related rather than just me. Although I do not stretch enough(like most people) my core strength is good – pilates every week keeps me flexible and strong………I'm with you on the core strength thing believe me but the two bikes obviously sit me in a different position (the trek is smaller) therefore the load on my muscles is different when riding each one.

I had a similar thing on my ss road hack today and it ended up with back pain and pins and needles down one side. I'll switch the seat angle a bit but if that doesn't work, any tips for core strength other than "more exercise"?

I tried a reflexologist such as http://www.relaxwithreflexology.co.uk

SS'ing should give you enough core conditioning – provided you're doing enough hills?

Mine is definitely bike related as I am fine on my road bike for my daily commute, (except having and extremely sore arse this morning from saturdays ride).

My core strength is probably weak at the moment and i need to get back to my circuit training class.

I will have a play around with my saddle angle/position to see if this helps.

This is the bike, but no pics of me on it.

Saddle does look a little far back now that i look at it?

I had a Giant XTC once and remember how much the ali frame used to beat me up…

Wouldn't have thought the seat position will make too much difference. That looks OK

Try a thudbuster and see if that makes any difference

Whats a thudbuster?

This is a carbon frame so quite forgiving, almost like it has rear suspension!

Ooops, my bad sorry, thought it was aluminium.

Thudbuster – 'suspension' seatpost

Make sure your seatpost isn't too high. I had this on my road bike and kept getting back pain. Lowered it by 15-20mm and it went – something about rotating hips?!

Riding position was not overly affected either.