Pain Behind Knee with Longer Stem

rdt

Last year I had a bike fitting done by Adrian Timmis, which I'm very happy about, as it resolved a long standing right knee pain I'd suffered from, and generally improved my cycling. The main changes he made were: cleat positions, lower seat, seat further back, shim for one shoe, slightly lower bars, changed lever positions.

The position has felt spot on for the year since, *except* that I've felt for some time that I could be stretched out a bit more (at the front), and to this end I recently fitted a 10mm longer stem. No other changes were made.

On the past few rides, I've developed some soreness/burning-pain at the back of my left knee (for want of a better description). This is the sort of pain that's usually a result of leg over-extension, I believe, and which would normally be resolved by lowering the seat a bit.

This pain aside, the longer stem feels more comfortable at the front, so I'm reluctant to go back to the shorter one. So that leaves the seat...

Should I just look at lowering the seat a touch, or should I change the fore/aft position too?

Bobbinogs

I would be carefull before you slip into the "just try one more thing" scenario and you end up regretting ever starting (most of my mechanics tend to go that way).

If you changed the stem and then developed a pain. Swap the old stem back and at least see if the pain goes away. If it does, sorted, since you have the source of your problem. If not, then look at changing another thing and see if that solves anything. Once you have sorted out your knee (which could well be just a normal/overuse injury?) then look at adding the longer stem back in.

It might be worth chatting to the chap who did your fit. For instance, mine gave a small range in terms of saddle height (one that was technically right in terms of angles and one which I was comfortable with that was an ok compromise).

cougie

+1 put the old stem back on and see if the pain goes away.

cougie

+1 put the old stem back on and see if the pain goes away.

sloppyschleckonds

Put the old stem back on and see if the pain goes away.

doyler78

Have you tried contacting Adrian to ask his opinion? Yeah it's been a while since you got fitted but no harm in asking. It's a fairly simply query so he might be able to give you a couple of tips to try and resolve the issue.

rdt

doyler78 wrote:

Have you tried contacting Adrian to ask his opinion? Yeah it's been a while since you got fitted but no harm in asking. It's a fairly simply query so he might be able to give you a couple of tips to try and resolve the issue.

Good suggestion.

morxy

It's good to make the bike fit you. But consider making a gesture towards your bike. What are you doing to enhance your body's ability to cycle?

Try stretching, increasing your flexibility and ranges of motion. Stretch daily. Stretch your hip flexors, hamstrings, calves, back... and strengthen them. If you can increase your flexibility by just 10-20%, your bike will feel much nicer, more comfortable, and your niggles may disappear, and it's a great preventive strategy for avoiding future niggles. A flexible body is less susceptible to injury.

So, yes, emphatically make the bike's contact points fit your body. But if you stretch and strengthen, you can be a better rider, more able to hold aerodynamic positions and ride longer hours etc..

One last thought. Were your cleats moved further back? I believe this effectively raises your saddle height, in that it calls for a slightly greater extension of the leg at the bottom of the pedal stroke. If you imagine an extreme case where the cleat's as far back as the heel, most people's leg would be locked out, totally straight, at the bottom of the pedal stroke, with their heel engaged in the pedal. So give that some thought too.

Incidentally, what's your height, saddle height and setback (horizontal distance from saddle nose to centre of bottom bracket)?

rdt

Sensible stuff, morxy. I did pilates for a couple of years, and have just restarted classes, so my core strength is good, I don't have back issues, and would be able (for example) to ride on the drops all day if I had to. However, some of my flexibility (hamstrings!) is not what it could be, as my recent pilates has highlighted, so I aim to improve this with more regular stretching.

During the bike fit, my cleats were moved forward - they'd been too far back, promoting a toe-down pedalling style, which together with the seat being too far forward, prevented proper recruitment of glutes and hamstrings. This is much better now as a result of the changes made in the fit.

I rode today after reducing both the seat height and setback by a couple of mm, and I seemed to have avoided the strain/pain that had begun to occur, so this looks promising. I know the original positions, so can restore everything if need be.

Having thought about this issue more, and thinking about what I've changed that may have contributed, I've realised that in addition to the stem length on my main bike, it's probably also linked to a slight change (slightly more stretched position) in my turbo trainer bike. I made this change months ago, but only begun to use the turbo bike more recently when the weather worsened. I'll adjust seat height/setback on this too, saame as the main bike, and see how it goes.

Thanks for the feedback.

doyler78

Longer stem = further forward so more stretched out.
Seat down = closer to the bars
Setback reduced = closer to the bars

Net effect - not much has changed if I read you right

morxy

I made this change months ago...

That's good. It suggests your new position is only slightly out. If it was way out, your body would've complained and injured much sooner.

Tiny adjustments and regular observations are the way forward. The body is very sensitive. Tweak the saddle 1-2mm, no more. Similarly for the setback: 1, 2 or 3mm, if anything. I wish stems could be tweaked! I wish they were available in 5mm increments instead of 10.

FWIW I've also had a minor posterior knee niggle on my left leg. I have 2 road bikes I've ridden regularly in the last 18 months.

Bike #1: saddle height 723mm, 172.5mm crank arms, 49.5mm saddle setback
Bike #2: saddle height 716mm, 170mm crank arms, 56mm saddle setback

Bike #1 is a bit more "aggressive" in that it seemingly requires a slightly longer leg extension. But the odd thing is that it's definitely bike #2 that's more likely to cause my left posterior knee niggle.

Bike geometry eh? Weird. Confusing.

I can only assume it's the fact that the saddle on bike #2 places my butt 6.5mm further behind the BB. The niggle is minor and relatively infrequent. I can't really call it an injury. So we're talking millimetres, nothing more. I'll be rectifying Bike #2's setback with a new seatpost to get its saddle farther forward.

rdt

doyler78 wrote:

Longer stem = further forward so more stretched out.
Seat down = closer to the bars
Setback reduced = closer to the bars

Net effect - not much has changed if I read you right

I know what you mean, but...

Stem is 10mm longer, and with a spacer change, the bar height is a fraction higher also. Seat was lowered 2-3mm and moved forward 2-3mm. So, definite net effect!

Prior to the stem change I felt a bit cramped at the front when riding in an aero position. After the stem change this feeling went.

Did a longer ride yesterday (glorious day up on the Cat & Fiddle), and it felt good still - no new straining behind the knee. I'll tweak the turbo trainer bike setup to match this one, and then see how it goes over the coming weeks.