# Left sit bone slipping off saddle



## willhub (29 Jul 2020)

Right got a bloody weird issue and it's driving me insane. I don't know if this is a new issue or an issue I've just realised, either way, I don't know what could cause it and how to fix it. The issue is, my right sit bone is firmly on the saddle, but my left sit bone is slipping off, I've even tried offsetting the saddle so the centre of the saddle is further to the left rather than centered on the bike, and doesn't change it, I've tried 145 and 155 of a specialized body geometry bridge saddle, and a selle italia Novus boost. It's genuinely starting to drive me crazy, the saddle is semetrical and my sit bones will be, so what's going on??


----------



## screenman (29 Jul 2020)

willhub said:


> Right got a bloody weird issue and it's driving me insane. I don't know if this is a new issue or an issue I've just realised, either way, I don't know what could cause it and how to fix it. The issue is, my right sit bone is firmly on the saddle, but my left sit bone is slipping off, I've even tried offsetting the saddle so the centre of the saddle is further to the left rather than centered on the bike, and doesn't change it, I've tried 145 and 155 of a specialized body geometry bridge saddle, and a selle italia Novus boost. It's genuinely starting to drive me crazy, the saddle is semetrical and my sit bones will be, so what's going on??



Tight hip flexor possibly.


----------



## willhub (29 Jul 2020)

I don't understand how does it cause one side to slip off the saddle? 

The tendon that runs from knee to hip is tighter on my left than right, but can't understand how these impact on the saddle.


----------



## ColinJ (29 Jul 2020)

Maybe you are like me and have one leg significantly longer than the other, so you don't sit straight centrally on the saddle? 







I was wearing my shorts and saddle out on one side. (I'm not sure why I wasn't wearing shorts that day. Perhaps it was a bit chilly!)


----------



## vickster (29 Jul 2020)

See a physio for an assessment, preferably one who does bike fits 
Pretty sure the Manchester velodrome has a team (looking at your location)
https://pedalprecision.com/price_list/


----------



## T.M.H.N.E.T (29 Jul 2020)

Bet good money it's due to saddle height and/or a difference in leg length


----------



## antnee (3 Sep 2020)

I have a similar issue to this in as much as it affects the left leg right at the top of my inner thigh and the bottom of the left cheek of my backside! For some time I thought it was width of of saddle as have been riding with a Fizik arione R3 which is 134 mm wide and having measured my sit bones found I needed one 10 mm wider so I got a prolog saddle not having funds for another Fizik saddle also thought the wider area at the rear of the saddle could help? I have since put an inner sole in the left shoe to see if that helps though not tested properly yet.
I might add that I shattered my left heel bone which didn't set quite as it should and feel that may have some bearing on the problem though have always had some soreness on that side.
I wonder if anybody else has this ?? thanks


----------



## willhub (20 Jun 2021)

Hi,

I've been struggling along all this time .

I've tried multiple bike position changes, I went to Pedal Precision, was given a few exercises that o didn't quite understand. But there was no follow up or anything so that was a dead end, I can't afford more bike fits.

I have physio appt tomorrow because of my frequent back issues pulling muscles.

Nothing is correction this saddle slip and I can't lower my saddle more than the 72.5cm it's at.

I do need some exercises that help strengthen back (lower and upper) traps, neck, glutes, hips, hamstrings and hip flexors.

I need a series of exercises I can put into a routine.

I've even tried to ensure I'm balanced and moved the saddle all the way back as far as it'll go, I still get numb hands, now I've moved saddle as close to my 4cm setback from BB from 2015 bike fit but I can only get to 5cm.

I've moved my cleats backwards about 4mm from "5" to "3" on my Giro shoes, it possibly is comfier like that but I haven't ridden enough. 

The saddle slip though, well it's still there, slightly improved but the front end is wobbly now, 11cm stem on it could that be why?


----------



## Ming the Merciless (20 Jun 2021)

Are you cycling in a side saddle position?


----------



## willhub (20 Jun 2021)

Ming the Merciless said:


> Are you cycling in a side saddle position?



Sorry what do you mean?


----------



## Ming the Merciless (20 Jun 2021)

willhub said:


> Sorry what do you mean?



Lobsided as you pedal. You can get it with different leg or foot lengths etc. Even handlebars not centered can cause it.


----------



## willhub (20 Jun 2021)

Ming the Merciless said:


> Lobsided as you pedal. You can get it with different leg or foot lengths etc. Even handlebars not centered can cause it.



Definitely could be lop sided

I do notice that at the top of the pedal stroke, so if I back pedal, getting over the top is a bit tight on the right hip, left is perfectly fine. I'm on 170mm cranks. So need to work on a bit of flexibility there, isn't so noticeable actually riding.

Left side I do feel is shorter but I've tried stacking shims and it doesn't seem to help the slipping .

Left sitbone is the one that slips


----------



## wonderloaf (20 Jun 2021)

I've got a similar problem but the other way round, my left buttock is as comfy as anything, but my right buttock keeps trying to slip off the saddle, which makes that side uncomfortable. In my case I'm pretty sure that it's due to my leg length discrepancy, I broke my hip a few years ago (fell off on black ice) and after an operation to fix the hip the surgeon told me my right leg is now about 10mm shorter than the left , so I'm assuming that as my right leg is shorter than the left I have to reach further for the pedal on the downstroke which causes the left / right imbalance.

I've done a few things which have improved my situation:
1. added a 3mm shim under the right shoe SPD cleat and an extra inner sole (about 2mm thick) to try to increase the effective right leg length.
2. moved the right hand cleat slightly forward with respect to the left hand cleat, again to try and increase the effective leg length.
3. twisted the saddle very slightly to the left, probably only a couple of millimeters off centre. Don't why this works, it just does!

The above have helped to make things much more comfortable for me at very little cost and a bit of trial & error, although still not quite perfect.
If you search around the 'net there are quite a few bike fit videos dealing with leg length discrepancy, that's where I got the ideas for 1. & 2. above!


----------



## willhub (20 Jun 2021)

Before were you so unstable the bike could not be kept straight without using too much effort that effectively leads to aches and pains?

I could move the cleat forward on my left shoe but I can't imagine miss matched clears would feel right ?

To be honest they're exactly even right now but I always feel my left foot is at a different fore/aft to my right


----------



## PaulSB (21 Jun 2021)

willhub said:


> Hi,
> 
> I've been struggling along all this time .
> 
> ...


My first thought is you need a bike fit.

Second thought is how do you know you need all of these strengthen exercises? I have a programme I follow four times a week targeting most of these areas. My priority is to maintain suppleness as I get older as cycling alone doesn't provide this. I see a personal trainer every 6-8 weeks who is aware of my goals and guides me accordingly.

On the sit bone issue I think it likely you have one leg longer than the other. I have by 0.5cm. I was 63 before this was diagnosed!! It's easy to perform a basic check. Sit with bare feet pushed against the skirting board and note the position of your ankle bones relative to each other. If there is a significant difference see a podiatrist.

I have a friend who is a podiatrist specialising in bio-mechanics. One day on a ride she asked me "Do you know you pronate?" Yes, I did but thought it was only when walking but no also on the bike.

After examination she provided me with a 0.5cm heel raiser for my left, shorter leg. The outcome was dramatic, pronation ceased, saddle height raised by 1cm, perhaps 1.5cm as I forget, my tendency to pull to the right on my bike disappeared and I became a more stable and upright cyclist.

For decades my seat position was a compromise between the needs of my left and right legs. The end result was a tendency to constantly pull to the right. I thought I was simply a poor rider in this respect. The heel raiser and other adjustments changed this in 10-14 days.


----------



## willhub (21 Jun 2021)

I had a bike fit at Pedal Precision in Manchester.

Bike was changed only slightly.

I was given exercises to help stability.
I was told I had a functional leg lengths discrepancy.

In 2015 I was given a shim however this was angled to tip my ankle to the left on my leg food. 

The consensus on leg length says it's impossible to get an exact indication of leg length discrepancy without an MRI scan because it can be a lot of other things giving the effect, so as a result I've never managed to get an exact indication in mm of any leg length discrepancy. 

I have about 8mm worth of shims (combination of 2mm shims and 1mm shims) also have one that is angled. 

When I tried shimming the left side this slip on the saddle didn't go away.


----------



## PaulSB (21 Jun 2021)

@willhub it may well be impossible to determine the exact leg length difference. It's definitely possible to determine it to an extent, in my case sufficient to correct pronation, largely eliminate hip pain, eliminate a tendency to pull right and change my saddle position.

My GP and three podiatrists, one private, two NHS, have diagnosed it and I can see for myself. Was your bike fit guy suitably qualified to provide a diagnosis?

In my view slipping off the saddle can only result from your overall position on the bike.


----------



## willhub (21 Jun 2021)

I've been to Pedal Precision where the guy I expect would be and also bike fit in 2015 was Cyclefit precision, they're only based in London now.

I can't really afford to go for another bike fit or put money on it any more, my partner won't let me especially with a baby due.

I'm sat waiting to see a physio about my back but I don't think I can tell them about leg length and bike fit they'd just fall asleep especially with it been on the NHS.

I'm going to try a 10cm stem because if I move my seat back 1.7cm I can't see that been any detriment it should be better re balance. Then the 10cm stem.

That would give a reach of 66.7cm, 7mm further than it is now, the 2mm can be adjusted for so I think 66.5 is closest I can get. Reason I want to try this is I'm wondering if my arm angle is wrong at 67cm as currently with the seat pushed as far forward with a setback from BB of 5cm and the reach at 5cm I feel like it's a better position over the bars.

Perhaps shorter stem would help handling too?

Or should I leave it as it is and mess with shims again? I'm just trying everything but it's so draining, loosing time for riding, 3 hours faffing last night that could have been a 60 mile ride if I could actually ride comfy.


----------



## willhub (21 Jun 2021)

I'm been referred at the doctor's he wants to check me out further as has suspicious of Rhumatoid Spondyloarthritis and also to be checked for HLA.B27 which my mum and uncle has, doesn't effect my mum but ours my uncle in a wheelchair when it seems to occur.

Hopefully I don't have either but wonder of either could explain on the bike issues


----------



## wonderloaf (21 Jun 2021)

willhub said:


> Before were you so unstable the bike could not be kept straight without using too much effort that effectively leads to aches and pains?
> 
> I could move the cleat forward on my left shoe but I can't imagine miss matched clears would feel right ?
> 
> To be honest they're exactly even right now but I always feel my left foot is at a different fore/aft to my right


Moving the cleat did feel strange at first but I don't notice it much now, especially when riding on a flat road. However when I get out of the saddle on a hill that's when I do notice the difference, but this is better than having an unhappy buttock!


----------



## willhub (22 Jun 2021)

I've moved the cleat from "3" to "5" on my left shoe and kept the cleat as far back ony right foot at "3", I'm sure it felt a bit more stable and straight.

I've added a further movement from "5" to "5.5" and will see how this works. 

That's a clear different of around 8mm further forward on the left leg


----------



## willhub (22 Jun 2021)

RESULTS:

6mm further forward cleat on left shoe effectively lowering saddle for that leg.

Much more stable, better acceleration, better stopping, better more stable power.

Still not perfect, unsure if I should add a shim or move even further forward or just persevere until bike fit on 29th.


----------



## OldShep (22 Jun 2021)

willhub said:


> I've even tried to ensure I'm balanced and moved the saddle all the way back as far as it'll go, I still get numb hands, now I've moved saddle as close to my 4cm setback from BB from 2015 bike fit but I can only get to 5cm.


Are you a small person? That’s less than half of my set back I’m 6‘


----------



## willhub (22 Jun 2021)

OldShep said:


> Are you a small person? That’s less than half of my set back I’m 6‘



I'm 5ft 10.

Setback is approx 5.5cm currently. 8cm setback would 100% be too much for me.

What is your inseam measurement?


----------



## OldShep (22 Jun 2021)

willhub said:


> I'm 5ft 10.
> 
> Setback is approx 5.5cm currently. 8cm setback would 100% be too much for me.
> 
> What is your inseam measurement?


Can’t remember exactly but with the book at crotch method think it’s somewhere between 33-34. Set back IMO is more akin to your balance point than getting KoS. When you say you’ve numb hands then it sounds like you’re leaning in them and need your saddle back.


----------



## willhub (22 Jun 2021)

Possibility, did have it as far back as it could go and still got numb hands, now it's as farforward and still get same amount of numb hands.

Your inseam is about 3cm more than mine so you've got longer legs


----------



## OldShep (23 Jun 2021)

willhub said:


> Possibility, did have it as far back as it could go and still got numb hands, now it's as farforward and still get same amount of numb hands.
> 
> Your inseam is about 3cm more than mine so you've got longer legs


Which in turn means that it’s possible you have a longer body in relation to your legs. To balance that longer trunk and take away weight from your hands you have to stick more of it out the back. 
Stand against a wall and bend forward see how far you get before falling. Next step forward away from the wall and repeat. See the result when your bum can stick out.


----------



## willhub (23 Jun 2021)

OldShep said:


> Which in turn means that it’s possible you have a longer body in relation to your legs. To balance that longer trunk and take away weight from your hands you have to stick more of it out the back.
> Stand against a wall and bend forward see how far you get before falling. Next step forward away from the wall and repeat. See the result when your bum can stick out.



Just tried that and it's about the same amount of bend :s


----------



## willhub (23 Jun 2021)

I have made a few vids on YouTube of my position, changed it a bit since then but maybe the various videos will shed some light ?


View: https://youtu.be/1BqHEOvnkes


----------



## PaulSB (23 Jun 2021)

Clearly it's all personal, and therefore subjective, opinion. My position is somewhat different and I would want to do the following:


Move the saddle forward so that in the six o'clock position there is a straight line between the centre of my hip and my heel
Extend the leg more in the six o'clock position
Move the foot further forward on the pedal
The combination of these would give a more upright position and a flatter back. I would start with the saddle height and position first.


----------



## willhub (24 Jun 2021)

If I have moved my cleat forward 6mm on the left side and I match the clear back to the right side, how much shim extension in mm would I need for the effective same reduction in saddle height.

Would it be 5mm of shimming be the same as 6mm of cleat stagger ?


----------



## PaulSB (24 Jun 2021)

willhub said:


> If I have moved my cleat forward 6mm on the left side and I match the clear back to the right side, how much shim extension in mm would I need for the effective same reduction in saddle height.
> 
> Would it be 5mm of shimming be the same as 6mm of cleat stagger ?


I'm afraid I don't understand the question. I don't know what shimming or cleat stagger are.

My set up is to position my feet so my feet are comfortable on the pedal - this has no bearing on or relationship to saddle height. For me comfortable means no pins and needles etc.

My saddle position - forward/back is based on reach and achieving a straight line between my hip and ankle in the six o'clock position.

My saddle height is based on achieving a slight bend in the knee. Convention says this should be 15⁰ but mine is more like 10⁰

I think you need to consider balancing your leg length with a heel raiser. I asked my podiatrist friend who is also a very good cyclist about a "shim." She had never heard the term before.


----------



## willhub (24 Jun 2021)

So shimming is where you have the 1 to 2mm thick plastic spacers under your cleat, so simplistic, if one leg was 5mm shorter you'd have 5mm of cleat shims (the spacers)

The stagger is where my left cleat is 6mm further forward on my shoe than my right.

This has had the effect of stabilising me to some degree and allowing me to apply a more consistent power as I can apply effort with my left leg now, however it's not perfect.

What I want to do is remove the cleat stagger, so move my left cleat back so that it matches the position of the right cleat, this will then apply this instability I'm getting again.

I want to try the shims (cleat spacers).

Both of which effectively lowers the saddle in relation to the leg reaching the pedal.

I have a feeling I may get a better result with the left cleat using the shims instead, however I want to know how many millimetres of shimming will be equal to the effect of the cleat stagger (the left cleat further forward)


----------



## PaulSB (24 Jun 2021)

OK I understand now. My view would be you're making it very complicated by overthinking things.

Under instruction from a podiatrist who specializes in bio-mechanics I simply insert a 5mm heel raiser to correct the difference in my leg length. Doing this immediately improved my stability as it allowed me to raise my saddle. By equalising my leg length I eliminated my tendency to pull to the right - my longer leg.

In your position I would go back to basics. Ditch the shims etc. Set your cleats equally. Measure the difference in leg length simply by sitting with your feet against the skirting board. Then insert the appropriate size heel raiser. Set up your saddle accordingly.

The podiatrist who helped me with a heel raiser and shoe supports resolved all of the walking and hip issues I had. The added bonus was to improve cycling.

Don't overcomplicate things.


----------



## PaulSB (24 Jun 2021)

PS - for a heel raiser you need nothing more than a piece of cork.


----------



## willhub (24 Jun 2021)

Well the skirting board thing would show hardly any difference maybe a mm in length but it seems effectively bigger on the bike. 

A heel raised wouldn't work in my shoes they'd restricted my feet unfortunately. 

And 2mm of shim to reduce the amount of reach to the pedal does nothing, almost unrideable the bike is.


----------



## PaulSB (24 Jun 2021)

I'll leave you to it. Good luck.


----------



## willhub (24 Jun 2021)

I've done the skirting board and surprisingly the difference seems about 1cm, this never used to be the case. 

It looks like my pelvis is not level. I am been referred by physio to someone who deals with arthritis. Also bike fit on 29th, I'd hope they can do something. 

You probably think I'm ignoring your advice but I'm not, I'm simply at the end of my tether, I've been constantly tweaking my position for 12 months and had 2 bike fits, all because of this specific problem. 

I gave up the other day as I've got the bike fit coming up, I've tried everything really, I haven't however tried staggering cleats or more than 3mm or so of shimming. 

So after just jumping off my bike and pushing the left cleat forward I thought wow it's made me a bit stable. But it seems doing this is not recommended.

So I thought eight well I'll try the shims that are widely recommended.

The question I'm looking at is effective leg length compensation of 6mm difference between the left and right cleat, aligning cleats and using the shims how much mm of shims are needed to equate to the same equivalent change in saddle height compared to the cleat stagger.


----------

