MTB fitting

Cubic

Hi,

My girlfriend is getting into cross country riding, but she is getting some lower back pain and it seems to be getting worse and stopping her from doing longer distance rides.

I'm sure part of the solution is getting used to more time in the saddle and maybe doing some core strengthening exercises, but I think that her bike set up is a big factor too. I was wondering if anyone knows of a bike fitter in London or Surrey who can help setup a mountain bike? I know there are plenty of bike fitters around, but they seem to specialize in road or tri bikes, not mtb.

Any suggestions? Maybe a good mountain bike shop would be able to help us out, any recommendations?

Thanks.

mac-cos

You don't need a shop to work out if the saddle is the right height, lots of online guidance including here for that, simple one: heel on pedal whilst sitting on saddle should result in a slight bend at knee , if too high she'll be rocking the pelvis and if too low it wont be using muscles efficiently which could strain things
other stuff could be cranks too long, and too much stretch to bars (too long top tube/and or stem) though when wor lass had this issue she complained more about her lady bits being abused by the saddle.
And sometimes its pushing too high a gear up hill using back muscles to help.
IMO mountain bike sizing is more about being comfortable than optimum racing position and you may need a lower saddle than ideal for technical stuff, though I'd say if doing lots of seated peddling the getting it at or near optimum is better .
PS read the guides on here as the above is a aged memory snapshot. PPS a pic of her on the bike might help the perverts (I mean experts)

rockmonkeysc

I get back pain if my bike set up isn't right. I slipped a couple discs in a climbing accident. for me its all about saddle position relative to cranks and bike length. Too long or too short and I will suffer. It just took a bit of experimenting.
Bike fit is more of a roadie thing, I don't think it will work on a mountain bike.

Cubic

Thanks for the replies. Sounds like we need to do a bit of research online and then some experimentation. I'm from a road biking background and I wasn't sure if the same bike-fitting culture existed for mountain biking as well. It seems more of a DIY approach is usual.
We'll focus on trying to get the saddle right first, that seems to be the most important part.

And the photos I'll save just for myself!!!

rockmonkeysc

On a mountain bike you are moving around on the bike a lot more and out of the saddle a lot so fit isn't as critical as on a road bike where you are in the same position for hours spinning away on the cranks.

Levi_501

Is the bike set up for her? Girlie saddle, grips, narrow handle bars, gloves, shoes and bib tights/shorts etc?

Are all the settings, like gear and brake levers at the correct angle? As in she does not have to bend her wrists?

Also, is the suspension drop set for her? - Initially, I had a bit of an issue settings my wife's bike's Sids. She was not heavy enough to compress them on the minimum setting!

If the lower back pain persists, you could always try a shorter stem, or one with more incline.

Cubic

Yeah she's got a women's specific bike with bib tights, women's saddle etc.

We put her bike on the turbo trainer and followed some online bike fitting guides, and the biggest thing was moving the saddle forwards. It was previously set quite far back. She tried it last night and found it made a big difference. Still a bit of back pain, but much less than before.

We'll look at the suspension next. Thanks for the suggestion. I've got a shock pump and we'll find some guides online again to show us how to do it.

Palmer82

Stem and bar rise can also make a difference as this can cause her to be over-reaching in the same way a too long stem or top tube.