Knee Pain cause theories

[Rich c]

Hi all,
This is my 1st post and I'm being cheeky and asking for advice!

Here's the problem, I have been riding a Specialized Rockhopper for around 9 months on a regular basis mainly on roads and local bridleways covering distances up to a max of 70 miles, more usually 30-40 miles on evenings 2-3 times per week. During this time I have experienced no knee pain.
In December I took the plunge and bought a Specialized Allez 58cm, now I have started to get pain in my left knee, on saturday I had a 50mile ride and experienced some discomfort after 30miles, but afterwards and on Sunday my knee was slightly swollen and hot to touch. The pain occurs only when the knee is moved and is on the inside of my knee at the side of the Patella.
My LBS where the bike was purchased checked the saddle height and cleat position, they increased the saddle height by approx 10-15mm and said the cleats were ok (still using mtb shoes and mtb SPD pedals on Allez).
The LBS thought that the switch to a road bike and a more fixed riding position rather than moving around as you do on a mountain bike may be the cause, however as I covered a lot of road miles on the Rockhopper i'm not so sure.
One thing that I have noticed is the distance widthways between the pedals on the two bikes, the Rockhopper pedals are 360mm apart, but the Allez pedals are 305mm, is a difference of 55mm likely to cause any problems? if so how could I alleviate the problem? Can you buy "offset" cranks to increase the pedal distance? Or am I barking up the wrong tree?

I'm hoping someone could offer some advice, I know i should only change one thing at a time so it would be nice to get it right first time.
My plan at the moment is to let the knee calm down and to ride the Rockhopper and make sure this is still pain free, then I'm a bit stuck.
Any advice greatfully recieved

Thanks in anticipation

Rich

 

[ChrisKH]

Well Rich if you do get a response I would be particularly interested. I bought a Specialized Allez 58cm last year and have experienced exactly the same pain in my left knee as soon as I get beyond 15-20 miles. I thought it was a set-up or shoe problem but maybe it's not?

I think this post should possibly be in Know How, but let's see if we get any worthy responses. You road guys out there - any ideas???????

 

[col]

I seem to remember this problem from a long time ago,i think it did indeed have something to do with the width of the pedals from each other,but back then you just popped a longer or shorter axle in the bottom bracket.Today i guess there will be varying lengths of axle with sealed units ,but i dont know as i havnt needed to look at them,hope you get sorted.

 

[Blue]

Hi all,
One thing that I have noticed is the distance widthways between the pedals on the two bikes, the Rockhopper pedals are 360mm apart, but the Allez pedals are 305mm, is a difference of 55mm likely to cause any problems? if so how could I alleviate the problem? Can you buy "offset" cranks to increase the pedal distance? Or am I barking up the wrong tree?
Rich

That difference is, indeed, significant. I found putting 2mm of shims on each pedal made a difference for me. You may find that addressing this issue may help. I'm still experimenting in my search for a solution to a similar problem!!

The distance being discussed alters what is known as the 'Q factor' and does have a major impact on the knees etc.. You may have to look for a pedal with a longer axle that will allow you to put spacers between the pedal and the crank and get the distance back to what suits you. Be careful that you leave enough axle to screw well into the cranks to avoid the pedal working loose. You can also check whether your cleats can be moved outwards to widen the distance, although this would then require different shoes for each bike or an alteration every time you switch.

There is a company in Wales that make specialist pedals for this sort of thing. I can't recall the name but maybe someone else will.

Good luck.

 

[ChrisKH]

Excellent response Blue; this is what I found from the first google:

http://www.kneesaver.net/

 

[Rich c]

Thanks guys,
Looks like the Kneesavers may do the trick.
I'm going to let the pain clear and try the Rockhopper again to see if I still get pain free pedalling, then try some Kneesavers, does anyone know if there is a UK distributor?

Chris let me know how you get on if you buy some.
Thanks for the info Blue and Col

Rich

 

[fossyant]

I'd also recommend getting the tape measure out as well on the saddle height and double check your ball of foot to axel fore/aft and the angle of your shoes - make sure both sets are the same. 55mm difference in axel width is large.

My MTB's axel is about 130mm and the road bikes approx 105 - so only 25mm and I ride my MTB to work most of the time...

 

[Rich c]

Thanks for the Advice Fossyant,
I have checked the crank length from pedal centre to crank centre on both bikes, which is what I understand you mean by ball of foot to axle, these are almost identical, probably within 5mm of each other.

The shoes and pedal type I'm using are the same on both bikes.

The saddle height does vary a little on the MTB depending on terrain, but when set up for the road it's pretty much the same as the Allez.

Cheers

Rich

 

[fossyant]

Sorry, meant you ball of your foot should be directly over the axle, so should your other bike/shoes or slightly in front / behind ...but both should be the same.

Rule of thumb is ball of foot directly over pedal axle when crank parallel to road (out front).

If possible, maybe narrowing your MTB axle width might help the difference between the two (but only if your frame allows) - but I'd err on caution - not too much as this will knacker your knees - i.e. bring in the width to nearer the road bike, and maybe get a slightly wider road Bottom Bracket. - Be careful as we don't want the MTB doing in your knees as well - small changes only.

Both will need new BB's though to do this... not cheap.

 

[Ludwig]

Riding with a rucksack can cause knee problems. Also riding too low on you seat and heavy on your pedals will add stress on the joint. A lot of newbie riders lack general fitness due to modern lifestyles and the very little PE in schools these days.

 

[02GF74]

I cannot work out if you are using the same pedal or new ones. People have had problems with some SPD typoe pedal due to the amount of float. You could try fitting the old pedals onto the new bike and see how that goes.

Also are you using the same shoes/boots? The usual rule of thumb to determine seat height is to have crank in line with seat tube so when you rest your heel on centre of crank, your leg should be straight.