Bike fit question- weight balance on bike

Before you dive into a fit, it might be worth watching the YouTube video series published by Cam Nichols and Neill Stanbury on Cam’s channel, and his newer Road Cycling Academy channel. A lot of great info in there, and it will at least give you a point of reference to think about on the issues you’re experiencing. Also, it might help you have more pointed questions for any fitter you may choose:

https://www.youtube.com/playlist?list=PLL1_j_gcxtpxJ-b9ptUikhStxEvkm1V7E

https://www.youtube.com/channel/UCeW11HsUiXwnRbPqNlh6fHw/videos

3 Likes

The actual spec for bars/stem is 1 1/4". Vendors usually say their spec is 31.7 or 31.8mm. 1 1/4" is between 31.7 and 31.8mm. If you use different makes of bars and stem, it’s possible to have an undersized 31.7mm bar and a 31.8mm stem which can lead to slipping or it being difficult to get it tight enough.

The carbon paste should help and I think some slippage on a really hard hit can actually be a good thing. It’s better than a bar breaking.

If the bar breaks, it breaks. You have to put your faith in the manufacturer at least designing a bar with enough safety factor to survive a big impact. The front wheel should buckle before the bar breaks. But no matter what happens install your bars properly so they don’t move! Eliminate a potentially catastrophic failure mode.
If the bars rotate down a little and your hands slip off the hoods you’re in for a bad day. Maybe if the stem had been tighter it wouldn’t have slipped, and the bar still wouldn’t have broken? Could have saved yourself a trip to the ER. If the bar and stem don’t work together to tighten properly then replace them.

I’ve been watching these a bit recently, I really like Niell and the way he thinks about and presents bike fit info!

1 Like

Another +1 for those Neil stanbury videos. Great resource

I was about to suggest Cam’s videos when That you’ve already did that. I think it is important to have some insights about how to deal with bike fit because as your fitness changes you may need to adjust your bike accordingly.

2 Likes

Yup, a common assumption is that fits are a “one and done” type of thing. They most certainly not that.

Fit may need changes from aging, injury, fitness changes (gain or loss of weight in particular), flexibility changes and the like. It’s not always a total rewrite of the fit, but some tweaks to saddle and bar position are quite common and helpful over time.

Honestly this is what has been confounding me about bike fits. I’ve only recently gotten serious about training and I feel like my bike fitness is changing quite noticeably and rapidly. On the one hand I’m hesitant to get a fit and then have to get another one soon, plus I have a mtb that needs replacing and would like to get fit on that too etc., on the other hand I feel like all the time I’m not getting a bike fit is me adapting to a less than ideal bike position.

Bike fit is not as definitive as some might imply or like to think. Close counts for most of us and something in the ballpark is plenty.

  • Unless you are having real pain, discomfort or other notable issue, you are probably OK.

  • Some fitting can improve overall performance by better position for power production, aerodynamics, comfort and such. But unless you are REALLY out of position, you may not be missing out on that much.

  • My personal order of approach (unless the rider dictates otherwise) is to dial in comfort first, power second, and aero last. The last two don’t matter much if you can’t ride without pain, or maintain the related position. Not to mention that power and aero are more than a bit subjective and difficult to nail without more testing and info that may not be available at all to the rider.

Overall point, fits are great. I am a fitter and love seeing the smile on a rider’s face when we get the right combo of settings. But unless you are really hurting or suspect a big problem, I wouldn’t lose sleep over lack of fit necessarily.

Doing a bit of research and some testing on your own may yield great results. I’ve had some people come in and not make any real chances. But they got peace of mind that at least I thought they were in good position for their needs.

1 Like

My 2 pennies about fit:

  1. The various computer/video systems available are potentially useful, but beware of a fitter who is simply trying to move parts around to get you into pre-determined angles. Any decent fitter will have an ‘eye’, and will be asking your for your bio-feedback. An example; 2/3 fits I have had have put the saddle too high, even though the numbers and angles are textbook. I know this because if I put it at ‘the number’ I get saddle discomfort fairly quickly and a marked R/L power imbalance. If I drop it 4-5mm, both of those disappear.

  2. As noted above, there isn’t any one definitive fit. There is a range. I would beware any fitter who is too prescriptive.

  3. I would ideally go and see an independent bike fitter - i.e. one who doesn’t sell bikes/frames. That way, you know they don’t have a horse in the race.

  4. Fit can’t compensate for all problems. For example, if you have hugely under-active glutes and abs, a fit probably won’t relieve the back pain you have [hypothetical example, obviously]. Just be aware it’s not magic.

Having said all this, a good bike fit and consistent adherence to a few well-chosen mobility or strength exercises can dramatically increase your comfort and power, and in pretty short order.

Good luck!

Edit: and as an example…

1 Like

I appreciate your perspective, especially with the bike fitting experience you have… thank you.
I am not really hurting to be honest, although I’m guessing my comfort could be improved and from multiple fronts (bike fit, core strengthening, mobility work).
However, I pretty much just slapped my cleats onto my shoes (having no real intelligent basis to make better judgement with), I’m 100% sure my trainer (mtb) setup is way different than my road setup, and I suspect one of my legs may be a little longer than the other but I can’t seem to measure accurately enough to tell.
I’m a hot mess but it seems to be going ok I guess?!

1 Like

Thanks for this, I do actually occasionally suffer from lower back issues. My core seems strong enough until it doesn’t! Looking forward to catching up on the thread you linked to.

I would bet that you have at least some room for improvement, even without major issues. The differences may well be minor, but sometimes it’s crazy to see how just a few degrees or millimeters of change can have a real impact on the rider. So I think they are very worthwhile for many people.

I’d say you can try to get one when time is right and you find a fitter you trust. But keep chugging along for now and maybe tinker a bit based on the various resources here to see what works and learn a bit more about the whole process.

1 Like

Bike fit and saddle preference is very individualized. Your pelvis may prefer a more forward position. I am bias forward myself. The best thing to do is make sure your saddle is wide enough for your sitbones (usually add 20-30 mm) from sit-bone width. Then find a saddle that encourages a more forward position. That’s how I solved my issues.

1 Like

I agree they are gold! I think his videos lay out so much great information, in an understandable, practical format.

1 Like

I tried the sit on cardboard and use a crayon to identify sit bones and then measure center to center., then added 25mm I think. Not sure how well it worked or if my saddle is optimal, without trying a bunch I don’t know what I’m maybe missing.
I think my biggest problem is I have no real confidence that I’m measuring myself correctly, and not just related to sit bones.

Filming yourself when you’re on a trainer can be a good start. If you position the camera so it is filming from behind will most likely reveal any leg length issues.

1 Like

Sounds like you did it just fine. Also, remember, getting sit-bone width is when when are backs are more vertical. If you race or do hard group rides where your pelvis rotates more, it’s not just sit-bone support. And it’s not a super hard fast rule but I’m sure you probably measured correctly. Definitely try to find saddles that are more forward bias. I chose the Pro stealth because it encourages a more forward position and because of this it provides great support for me. I have wider than average sit-bones (125 mm) , but the stealth in 142 supports me fine. The 152 was too wide for me. Hope this helps.

1 Like

Filming is a great idea. Pure side, pure rear, pure front and 3/4 angle from front and rear are all good. It’s essentially what I do when viewing a rider in a fit. No single view serves all purposes, and you really need to get the fuller range of views to get the most telling story.

As to finding leg length, vids on the bike only go so far. We are amazing machines, and I have seen large length discrepancies effectively “hidden” because one or more parts of the body adjust to fit on a symmetric bike. You can look for things like rocking hips, unbalanced leg extension, uneven foot angle through the circle or generally odd motion on one or both sides.

Any of those are nothing more than a signal, and doing a lower body traction test is about the best way to see a leg length issue short of x-rays (that I know at least). I just caution about seeing one oddity and trying to extrapolate too much from it without considering the many possible factors. Especially important if you are coming in with a preconceived notion, as you may miss something else when trying to find something that may or may not be there.

2 Likes

Start with your bike fit. You have a road bike, ie, not TT.
Bike geometry begins with getting about 60% of your body through the rear wheel. So, getting your butt in the right place is the best place to begin. The saddle top should be parallel with the ground, ie, not tipped up, (which yours looks it it might be), neither down.
There are many fancy ways of getting the leg length right, but the old way is still relatively accurate:
with your bike in a doorway, you can balance the bike with your hands on the door frame, with your cycling shoes on, and your heal, not toes, on the pedal extend the pedal so that it is in line with the seat tube, you should just lock your knee out of your shorter leg, so back pedal and test each leg, and raise/lower the saddle accordingly.
Next adjust fore and after, in your case this is possibly the cause. With your cranks horizontal, ie, 3 and 9 oclock, and your feet in the pedals, the front of your knee, the big tendon, should be directly over the pedal spindle., adjust fore and aft of the saddle, by undoing the saddle bolt and sliding the saddle alng its ‘rails’, when you tighten them, make sure the saddle is still parallel with the ground, now recheck the leg length, in most cases that will be ok.
In this position, your weight should keep you butt in the right place, and reduce the tendency to slide forwards or back.
Now think about your bars position, height and length, they are much more about comfort. Your arms should have a slight bend when on the hoods, ie, flex in your elbows, never locked out.
In this position you now reduce the direct weight on the bars, as your body weight is spread about the saddle, pedals and bars.
This is a good starting point. Fine tune these adjustments. With leg length if your hips rock side to side as you pedal, the saddle is a little too high, ie, you are having to stretch your legs to maintain pedal contact.
Give this a go.

3 Likes