New Here - Question about Bike / Rider ergonomics

RaleighActive

Hello all, I hope someone can help and its ok for me to post in this forum.
I think I am very much a novice in comparison to most here.
I am just cycling for fitness and pleasure.

I have reduced lung function so its imperitive to my health to keep active to help prevent deterioration in my health. I am in my 50s and have just bought a new bike raleigh active fold bike, I thought it would easily fit me as the handle bars and seat height are adjustable and the bike only has 20" wheels. It has only just occurred to me about the pedal arm length and my question is:

Is it ok for my highest thigh - leg position to be above the horizontal line to the hip joint?

I have looked at the website that gives the dynamics (a link someone posted previously), its hard to decide from the video if my position is correct on the bike) I don't want to cause hip joint problems as I already have osteoporosis in my right hip.

Grateful for any advice. :?:

Many thanks RA

my bike is the Active Fold-A 20 Inch Bike by Raleigh - Unisex.

EKE_38BPM

Welcome.

Your knee is above your hip when the pedals are in the 12 o'clock/6 o'clock position? That doesn't sound right to me. Have you tried raising the saddle to see if it feels better?

UndercoverElephant

Hi there,

Generally your saddle height should be such that you're able to stand on the pedals with your heels, while the pedals are at 6 o'clock, and the saddle should be, erm, right up there. You may not be able to touch the ground whilst seated, but whilst riding it'll feel much better.

RaleighActive

Thank you both for replying. I got this new bike so I would be able to reach the floor for safety reasons, I found it too difficult on my other bike to have to keep dismounting every time I had to stop (its more difficult with a lung problem).

I'll have to try to see if I can manage with the saddle a bit higher to see if I can get the 12 o'clock position with knee horizontal in line with hip joint, but I am not sure if that is going to be ok even.

UndercoverElephant do you mean with toes on the ground and heels on the pedals at 9 and 3 o'clock? I don't understand how that could be possible.

I thought I was getting a bike that fits me, now I think I've made a mistake with this purchase by not taking into account the pedal arm height. So disappointing.

bigmat

The pedal arm (crank) length is unlikely to be the issue. Short cranks tend to be say 165mm, extra long ones 180mm - we're talking a cm or two difference. It sounds like you aren't comfortable with dismounting when you stop and this is the problem. The truth is the "correct" position on a regular bike has the saddle at a height where you won't be able to touch the floor with your feet off the pedals. Really, to have the saddle at the right height, you need to stand up when you come to a stop. At a push, you can stretch your legs so you can stand on tip toes, or lean the bike to one side and stand on one leg. To be honest, with the saddle at a proper height you might find the whole act of getting out of the saddle when you stop a bit less like hard work as you won't be having to "stand up" from a seated position, it will be more a case of shuffling forward a little bit.

SimonAH

As an approximation, with your posterior on the saddle and the ball of a foot on a pedal at the six O'clock position the leg should be only very slightly bent. This is, of course, for optimum pedalling dynamics and there is nothing to stop you lowering the saddle - it will just be far less efficient (think adult on a kid's bike).

If your knee is coming up above your hip however you are ridiculously low, or your bike is actually a recumbent.

vermin

This may be obvious but... If you don't like to stand forward of the seat when you come to a stop, just raise the seat as high as possible such that you can just reach the ground with the tips of your toes, with your heels a couple of inches off the floor. That way you won't be too far from the ideal saddle height, but can still stop without dismounting.

Tricycleboy

I agree with BIgmat- crank arm length is much of a muchness.

On a folder you've no great need for extremely efficient pedaling, so i reckon have the saddle as high as you can but are still comfortable with. A higher saddle means there is less bend in your knee and hip joints as you pedal which would generally cause less problems.

good luck with the riding- i'm sure it'll be really good for you. Have a go tweaking the position before you give up on the bike you've bought- there's a decent chance it'll be fine. Maybe pop back into the shop you bought it from and ask for some help in person?

rjsterry

Folding bikes tend to compromise the 'perfect' frame geometry to make them easier to fold.



They tend to have a relatively low saddle height, even with the seat post fully extended. Indeed some folders, like the Brompton, have an optional longer seat post for taller riders. They also tend to have the bottom bracket - the axle where the cranks are attached - set quite low to the ground. So, the ideal riding position for a road bike is not really going to apply here. That said, your knees shouldn't be coming up above your hips. Try experimenting with different saddle heights until you find one that is high enough to be comfortable, but not so high that you can't at least get the balls of your feet on the ground. There is normally a maximum extension line marked on the seat post so don't set the saddle any higher than this.

RaleighActive

Thank you all for some great advice, I am going to try some saddle adjustment and see how I get on. You've been great, thanks for all your help.