The Bike Fitting Mega-Thread

Equipment
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1156

Assuming the front and rear facing views were recorded under load (90-95% FTP), then i would avoid introducing any changes to your stance. Your knees appear to be tracking well.

I am personally not in agreement with the discussions above regarding the size of your frame being incorrect. From the details you’ve shared in conjunction with your recordings, a 56cm frame is more than sufficient to work with, and setback and reach can be find tuned as needed.

My experience with unstable hips at high cadence is that most people drive power through their legs instead of their hips and core.
Strong core/hip agreement will push the stroke through the top with minimal float, and the same should be true flicking through the 6 o’clock. My point about your pelvis rotation above still stands and i believe symptoms of this can be seen in how you tense your core at the 4 second mark in the rearward angle. There is also a noticable lull in your lower back seen from the side angle.

Consider the relation of your sit bones with the saddle as you play around. The connection here may also be weak, which could help strengthen the argument for scaling up core and posterior chain work.

1157

Riding consistently at 110-120 rpm is a skill that takes time to learn…very few of us can just jump on a bike and spin that fast smoothly right from the beginning. It doesn’t necessarily mean you have “hip instability”.

1158

I have been keeping out of this with many cooks in the kitchen. But I totally agree with @Power13 on the cadence/stability issue. Unless you have trained it well over time, it is not easy to do that clean and controlled. I seen plenty of people who get sloppy at just 100-105.

As mentioned, slow your roll and work your way up to those higher cadences only after nailing the “slower fast stuff” first. Get clean at 100-105 and progress from there. Jumping to 110-120 without proper progression will nearly always lead to sloppy riding.

1159

Just picking up on this. @mcneese.chad would you mind briefly explaining why too short an effective reach can cause back pain? It would be much appreciated.

1160

Short Reach could effectively “push back” the rider in a way that changes their pelvic tilt and/or back shape such that it does not mimic their “natural back shape”. That might lead to inward or outward shape (kyphotic / lordotic) that are not what the rider actually needs. Discomfort or pain can occur and may be more likely for those with prior injuries or trauma.

How’s that for a start?

1161

Im another one with issue of left/right discrepancy for half size (my left feet is shorter then right one).

I tried to mitigate problem using custom insoles and some insert to feel the empty space in the left shoe using 43 pair both side… This worked for some time, but for longer rides i feel a pain from the insert in the front… If i dont use the empty space insert in front of my left feet, too much space so i have to overtight the shoe (especially on hard efforts/sprints etc…)

Interested if u have this same issue, have u ever tried to use different size shoes left/right? Do u think this will be better sollution (maybe definitely solution) for the problem you (we) have?

So please comment ur opinion for using different size left right shoes to mitigate this obviosly not that rare problem…

Thanks

1162
  • What / where exactly was the spacer? Toe, heel, other?

I have only been able to test short periods with mixed size shoes (43L / 42R) and I liked it. This seemed like a potential solution, but the obvious issue is the need to get 2 pairs to start. If you find a person with the inverse size relationship, it could workout to be a wash for $$$.

Barring that, it may not be perfect, but I am happy with the compromise position in matching sizes.

1163

The insert was in the front of my feet to feel that empty front space, and heel clamped in the back…

With those custom insoles and that insert in the front (just peace of hard sponge or something to feel that empty space in front of left feet), i had best power transfer ever (i guess because of ideally matched varus/vagus and form of my feet with custom insoles, and not moving in the front in same time), but on longer rides a lot of pain in the left feet… And custom insoles was very thick and without ventilation so summer time even more pain from the heat…

BTW, Im using Gaerne shoes, so those were G.Stilo model from around 2017…

Then i realized that Italian brands (who produce their shoes in the fascilities by hand) , if u find good dealer can made separate left/right shoes for pre order, so u dont have to buy two pairs…

I ordered G.Stilo from 2019 and G.Stl from 2021 like this (left 42 1/2, right 43) and thought the problem will be totaly fixed now, but still not ideal…

If i use stock soles there is no support at all for my arch, so i lack whole feet power transfer… Im trying now with SQ Lab insoles or Specialized, but insoles a bit on thick side so left one feel a bit tight on the sides (Gaerne are narrow shoes)… So now back to stock insoles and experimenting with this…

What i realized: Left feet probably from long time using too big shoe have some weird varus angle, so not ideal power transfer… To fix this i have to overtighten rear boa on the left side (still comfortable), and make it looser front boa… I also tried using Varus Specialized Wedges but not success as i was expecting…

Just for test i tried 43 for left shoe as well, but too big in the front :slight_smile: so get back 42 1/2 left, 43 right…

So now experimenting with totaly reseting my cleat position from what i was riding last years… I was riding with a wider stance (was trying to compensate issues with bigger shoes) and now trying to go as narrow as possible, and realize that this way i have better power transfer and even maybe a bit more comfortable (body get used on bad adjustments from the past, so now im trying to clear that body memory :slight_smile: and adjust for best pedaling based on my knees etc…)

One mistake that i was doing i was putting left cleat a bit more in front (to compensate for left feet beeing a bit shorter), but that put me in not so simetrical way of pedaling and also not ideal power on left side… I also tried opposite: Too put right (longer) cleat in the front, and left one (shorter) on the back… This feel more natural, except i feel left side even more shorter now :slight_smile:

So maybe ideal will be:

  • 42 1/2 left shoe, 43 right shoe

  • Cleat on left shoe more on the on the back and using wedge to compensate for length, Cleat on right shoe sligthly front

  • And trying to find insoles that are thin enough to dont feel tight, but in same time to provide arch support. (if u have idea about insoles providing this please share it with me)

If i adjust (finally) my feets/shoes/cleats, i feel that i’ll get bigger power and comfort upgrade ever in all this years… But seem like neverending story for now :slight_smile: So that why in same time was happy to see that im not the only one with this problem, and also liked to hear ur opinion based on all ur experience…

Sorry for long post, but im sure there is others with similar issue, and maybe interested in other experiences so that why i shared what i tried by now…

1164

That makes perfect sense (and explains a few things). Thank you

1165

Lake Cycling do a custom shoe option allowing different sizes. Cheaper than buying two pairs of different sizes.

I’m looking at Lintaman for my fitting studio as they offer different sizes for a small charge too.

HTH

1166

That’s cool, thanks for the info :smiley:

1167

Actually, another question/observation, if I may. There does seem a bit of a trend in the UK for what I’ll call ‘short and low’ fits at the moment (an influential youtube channel and a bike shop in an expensive suburb of London may have something to do with it… :innocent:)

After struggling with on/off back pain for several years, a recent fit added almost 2cm to my reach and pretty much the same to bar height. I’ve never been more comfortable and the fitter suggested that I could maybe go 5mm longer and higher still, but he was wary of increasing what was already such a big change. Obviously it’s wholly anecdotal, but this fitter (an older gentleman) said that he’s doing this more and more lately, with a trend of riders on bikes set up too short and too low, and sometimes just plain too small. He said too short a reach was always quite rare*, until quite recently when he’s started seeing a real crop of it. (Ultra narrow bars and saddles too low were his other ‘bad trends’ just OOI, and he and I both suspect the same cause)

I’d be interested to know if you’ve observed anything similar.

*in men. He noted that over his time fitting, men were likely to err on the large side in sizing, whereas women tended to err on the small side.

1168

Great discussion point. Keep in mind my clients are often the typical average cyclist and not many are the more “hardcore” racers. As such, many come in with road bikes that are “uncomfortable” and the most common source is a reach that is too long. The dead giveaway in most cases is me letting them hope on the bike/trainer and I tell them to just warm up a bit.

I am actively looking at all parts of the fit and their positioning without telling them that. The most common sign I see with reach too long is the rider setting their hands on the hood section of the bar, but back anywhere from 10mm to 25mm behind the main hood body. This may be accompanied by locked elbows, stiff shoulders or a combo. We often alter stem length, angle and spacers to shorten and raise the bars. Again, this is more for people looking for a “comfort” fit and often when they are on a “race” bike rather than an Endurance bike. More people on those Endurance bikes (shorter reach and taller stack than race bikes usually), are better off as a starting point.

All that said, I have been testing myself and a few others lately by going the other direction. Personally, I am 5’ 10" tall, with a true 34" inseam which means I have LOTS of leg and a short torso. I have usually picked a 56cm bike for the need to meet seat height without crazy long seat post extension. But that longer reach frame (compared to 54cm that I could technically ride) lead me to drop the stock stem down 10mm in most cases. That would be me adding a 90mm to replace the typical 100mm.

But I have since swapped all my road and gravel bikes to longer reach and am liking the change. I am 100mm on my Emonda racer, and 110mm on my two Endurance bikes (Roubaix and Domane). I feel more “open” and comfortable in all positions, but notably when in the drops and getting extra low. The longer reach gives me more room and I feel less cramped. A few others I know have felt similarly when I tweaked their setups.

Plenty depends on the rider ability, injury history and general preferences. But I do think that sometimes a longer reach is actually better for a number of reasons. I try to use a quick-adjustable stem in most of my fits, and I run a range from too long to short. I watch the results as well as get feedback from the rider to see where that happy medium is.

Re sizing: I am not sure on who gets what, but I tend to struggle with it at times. For more casual riders, I tend to like a smaller frame to cut the Reach a bit. I can usually go longer and higher for stem/bar setup than a frame on the plus side. Road bikes with 60-80mm stems look and ride a bit odd for the 54-58cm sizes I typically fit. But those shorties are one way to get people to a comfort fit in those case. I also swap bars to short reach models too, but that is more complicated swap than a simple stem change.

1169
  • OK. I have never done a spacer up front. I just slip the shoe on and then kick my foot on the floor to seat my heel fully back in both feet (including the short foot). Then I tighten the upper and mid straps to “lock” my foot in that “rearward” position. There is extra gap up front, but the shoe upper and straps hole me in place. I think I would hate having anything fill that gap up front. I want toes free to wiggle and move with no contact on the front end of the shoe.
1170

Lake will do different sizes.
I’m sure there’s an up charge

Hump

1171

@mcneese.chad What about on a mountain bike.

I’m 5-9 and log legs short torso. I’ve been experimenting with shorter and longer stems on my XC race bike.

Been up to a 90, currently at 70.

It’s a medium Pivot Mach4SL

Hump

1172

That is a whole 'nother kettle O fish. Handling and body position are generally more dynamic, so roadie ideas won’t often apply… at least not without a bunch of qualifiers.

The rider back angle willl be more upright with less overall reach in some ways. But when you factor in actual reach to the rider grip, it all gets interesting. The bike in use and discipline of interest all play together too. Hard to make broad statements to a degree.

You want enough open reach to allow low position for hip hinge, but not too forward to be extended too far over the front axle. Most modern bikes fix that to a degree with the slack head tube angle, so you can still handle a longish stem on newer XC/DC bikes, if that’s the goal.

Here more than road, I consider frame sizing and stuff like wheelbase along with front center. More playful riders may want shorter reach for snappy turns, while bashers or anyone prizing stability might go longer.

1173

That insert in front while stabilized my foot and removed any movements in the shoe (i can tighten there to be stabilized just with BOA, but have to crank them a lot, which also produce pain in whole feet… So idea with that front insert was to have stabilized foot but to dont have to overtighten whole shoe), but after a while there was pain in the fingers so removed that insert…

Then i also experimented with heel inserts in same shoe :slight_smile: to move my feet in the front… It worked somehow but also not ideal since i needed two heel inserts to remove movements…

So that why i was interested in ur opinion using different size shoes left/right as maybe best solution for problem, and potential problems that can arrive from that solution…So if u have something more to say about this from ur experience or suggestion in cleat adjustments (even in theory :slight_smile: ) please dont hesitate to share it… :slight_smile: Another brand beside Lake and Gaerne that can offer different sizes left/right is SIDI (not based on my personal experience but im almost sure that i read it somewhere…)

1174

I like the quick handling aspects, less the rip a straight line.

On the East Coast, I’m more concerned with quick and fast cornering than with blitzing straight down a hill.

I also want quick climbing.

Hump

1175

Quick question I’d like the hive’s opinion on.

On my road bike I have a fancy 3T carbon “aero” bar. Problem is that it’s wider then ideal. 420mm.
A new nice bar or bar/stem is on my wish list but not at the top of it…

I now have a bar that has the width I want. 380mm laying around that came with a bike i bought used. But it’s a cheap alu bar.

Would you put the cheaper but narrower on the road bike? I’m suspecting it might just be vanity stopping me from putting the alu bar on my carbon bike?

  • Cheap but correct width
  • Keep fancy bar that is too wide until buying new one

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