Stock or custom?

[caducosity]

I've had a Kickr Bike for about a year-and-a-half and I started with a solid professional fitting and adjusted and adjusted (and adjusted) from there, until now I can ride a couple of hours on the trainer with no pain or numbness anywhere. It's great.

Now I'd like to get a bike that matches this setup (I have an IF Planet X that I bought through this forum about 15 years ago that just doesn't work for my older body), and I think I might have adjusted my way out of any stock options, but I'm not certain.

The Hx (BB to center of bar at stem) is 485. The Hy is 729. The drop from the top of the (ISM) saddle to the middle of the bar is -36mm. And the setback (again, keeping in mind that this is an ISM saddle) is 190(!). (My inseam is 843mm, I'm 6 feet tall, and have long arms).

Assuming that these are the dimensions and I don't want to adjust them, are there any stock bikes that might work? I've played around with a bunch of endurance frame numbers, but keep coming up short on the stack. Do I have to go custom?

[Peter P.]

90 percent of us can fit on a stock bike. I'm inclined to think you're over-thinking things.

And that seat fore/aft on that setback post looks all wrong and your position on the saddle makes no sense. You sure you had a "professional" fit?

[caducosity]

You sure you had a "professional" fit?

Ha, my current setup is very far from the professional fit. It was a good estimate for three hours in the shop, but there's no substitute for tweaking things at home over hundreds of miles.

Anyway, I realize it all looks wrong, but it's also totally comfortable, so I'm hoping to roll with it, but I'm not sure it's possible to recreate the fit on an actual bicycle.

your position on the saddle makes no sense

I do disagree with this, though. I think I'm actually riding the ISM saddle the way it's intended to be ridden, and it works well.

[giordana93]

you appear to have normal proportions. A stock bike should fit. Numbers might not be the same as the trainer but a trainer can't be ridden on the road and I doubt that a bike copying its numbers would ride well. A position that works well for a spin bike will not necessarily work well on the road but you can try. I would try on a stock bike first though. If nothing works, go custom, but even then, asking a custom builder who know bikes to build a frame that mimics a spin bike might be an issue.

as for the "wrong" look of your set-up. if that saddle fore-aft is right, it should be achieved by making the top tube extend more rearward so the saddle doesn't have to be slammed back. Your saddle height is pretty high so of course you gravitate to the nose of the saddle. If that works for you, fine, but being a little high prevents you from rolling forward at the hips, which is why you need your hands high. It's not necessarily wrong, as many people ride like that, but for a seasoned cyclist it is not always ideal.

[caducosity]

There's so much good info in that comment; thank you. The point about high saddle --> stuck hips --> high hands hadn't occurred to me.

Since lower saddle heights have led to almost instant knee pain, I need to think about how to find a way to roll my hips. Maybe I'll just start inching the handlebars down and see what complains.

I will say the reason I'm sitting on the tip of the saddle is that I found the ISM saddle to be more comfortable than anything else when I sit on it that way (and very uncomfortable when sat on farther back), so that actually contributes to the crazy setback, which allows me to sit on the tip of the saddle with a reasonable reach.

[davidb]

If you are sitting on the "tips" of the ISM, you are doing it right. ISM saddles if used on a road bicycle with a seat angle in the 72-74 degree range will be slammed back with a setback seatpost. A stock road bicycle could be improved here with a zero-degree setback seatpost. Then the saddle can be centered more on the rails. This will allow for a little smoother ride too. If you are interested PM me and I can get some measurements from your Wahoo and toss out some stack and reach numbers. Last bit your fit looks reasonable.

[giordana93]

Originally Posted by davidb

If you are sitting on the "tips" of the ISM, you are doing it right. ISM saddles if used on a road bicycle with a seat angle in the 72-74 degree range will be slammed back with a setback seatpost. A stock road bicycle could be improved here with a zero-degree setback seatpost. Then the saddle can be centered more on the rails. This will allow for a little smoother ride too. If you are interested PM me and I can get some measurements from your Wahoo and toss out some stack and reach numbers. Last bit your fit looks reasonable.

not sure how a setback post with a slammed saddle would equal a centered saddle on a zero setback post. If it were slammed forward, that would be true, but not for a rearward slam as is the case here. A zero setback post would prevent achieving the desired setback (assuming a fixed seat tube angle)

[davidb]

I am not getting into nor trying to start a forum argument. However, with some top tube measurements, and looking at the real-world seat angle of the Wahoo. Core fitness assessment. Maybe shorter cranks too. All of this could add up to the saddle moving forward a lot and the bars coming down. That is all I will add for free. To the 'OP" go find a competent bicycle fitter. do not rely on a forum for purchasing decisions of a stock bicycle over a custom.

[caducosity]

I appreciate all the feedback. To be clear, I've been to three fitters, and the third one I thought was very good. The reach on the Kickr is just a few mm off what he and I settled on in his shop, and some of the things he suggested have made a real positive difference.

I was really just curious whether my current Kickr bike measurements could be mapped to a real-world stock bike--something along the lines of "with your Kickr Hx and Hy, a bike with such-and-such dimensions could probably work".

[giordana93]

heavily edited after seeing you had seen 3 fitters. The only thing I will retain and repeat is that a bike ridden outdoors is very different from an indoor trainer because of weight distribution and the more dynamic nature of stopping, starting, coasting, etc. A good local bike shop should be able to get you on a properly set up bike and you can revisit the position with the help of a fitter as needed. There is a lot of play with stems and seatposts available so you should be able to find a stock one that fits. If you want custom just because, go for it, but I would still start with stock so you know what works and what doesn't in the real world.

[giordana93]

Originally Posted by caducosity

I was really just curious whether my current Kickr bike measurements could be mapped to a real-world stock bike--something along the lines of "with your Kickr Hx and Hy, a bike with such-and-such dimensions could probably work".

it is not so easy as transferring x & y. I edited out some stuff in previous post regarding STA (seat tube angle) that I'll add back here. Taller riders generally need a slacker sta (around 73) while shorter riders/small bikes are steeper (73.5 to 74, even 75) so people with short legs can get over the pedals. But if you are too far over the pedals (e.g. big guy on steep sta) too much weight is on the hands. You clearly are gravitating backwards (slacker sta) based on your rearward slam, which makes sense. The problem with just using a top tube length is that a given top tube, say 75, will be effectively longer on a steep sta, making it harder to extrapolate Hy. That is one reason why people talk more about stack and reach than top tube and seat tube lengths. They are related but not always easy to map out. But there is a reason a typical "52" or "56" will fall within certain parameters of the stock bikes and why venturing out into customs that fall outside these ranges might bring issues, especially if you fall within the normal bell curve numbers.

[whatshubdoc]

Not sure if this is factored into the equation but the "type" of bike will also determine if you want to go the custom route. You mentioned plugging and chugging endurance frame numbers - hopefully that's the "type" you want in terms of HTA/STA/CSL etc.

I picked up a custom bike (used, but magically, to the exact dimensions as to how I would have it built) because I wanted a "race bike" geo (73.5 HTA, <410mm chain stay) with a top tube of 560mm, a long head tube of 200mm, and more than 70mm BB drop. This type of bike does not exist in stock form and would either require me to ride 1 size up with a 90mm stem flipped up +6 deg, or a "correct-size" with 100m stem +17 deg with 40mm spacers.

[Anthonys]

Bike insights is a website that you can compare stock geo’s if you have an idea of which bikes fall in the same realm.

[PortlyPuncheur]

I like to use bikegeocalc.com to make these mock ups. Apologies to all for the length of this post.

Here are a couple of samples that get close to your fit. I chose the Trek Domane just to work with a common endurance geometry. Note that there are some assumptions - for example, I don't know which ISM saddle you have so I picked one at random. I also had to work backward to find your saddle height.

Your current position looks like it would be best suited to the 61cm, as the 58 would struggle to get you long enough. But you could choose to make up the difference with a bar that has longer reach.

Here is the 58cm (start and ends with {}, use the Export|Import button to load):
{
"backHubX": 342,
"bottomBracketDrop": 78,
"bottomBracketHeight": 264,
"bottomBracketToFrontHub": 609.7832189456683,
"bottomBracketX": 759.781043131447,
"bottomBracketY": 264,
"chainStayLength": 424.99999999999994,
"crankLength": 172.5,
"forkLength": 379.025510938176,
"forkRake": 47.99999999999985,
"frontHubX": 1363.4334279870232,
"handlebarAndHoodsReach": 120,
"handlebarBackX": 1197.5937859429466,
"handlebarDiameter": 31.8,
"handlebarTopY": 1007.8736848293622,
"headTubeAngle": 71.99999999999996,
"headTubeBottomCenterX": 1200.0393570345618,
"headTubeBottomCenterY": 689.5439793224451,
"headTubeLength": 194.99999999999997,
"headTubeTopCenterX": 1139.781043131447,
"headTubeTopCenterY": 875,
"headTubeTopToTopTubeCenter": 30,
"headsetBottomStack": 2.000000000000142,
"headsetSpacersStack": 30.000000000000014,
"headsetTopStack": 10,
"hoodsRestTopX": 1331.6707163044116,
"hoodsRestTopY": 1028.7114661493938,
"hubY": 342,
"name": "2022 Trek Domane AL 58cm",
"offsetX": 0,
"offsetY": 0,
"reach": 380,
"saddleAngle": 0,
"saddleBackX": 314.385245375376,
"saddleFrontToCenter": 75,
"saddleLength": 255,
"saddleStack": 40,
"saddleTopToBottomBracket": 755.9193188152491,
"saddleTopY": 971.7987617194092,
"seatTubeAngle": 72.99999999999999,
"seatTubeCenterToTop": 548,
"seatTubeTopCenterX": 599.5613489433871,
"seatTubeTopCenterY": 788.0550062677434,
"seatTubeTopToTopTubeCenter": 30,
"seatpostSetback": 25,
"stack": 611,
"stemAngle": -15,
"stemLength": 110.00000000000004,
"stemStack": 40,
"stemToHoodsAngle": -10,
"topTubeCenterToCenter": 547.6896286762228,
"topTubeHorizontal": 566.8014463712417,
"trail": 60.65234934821774,
"wheelBase": 1021.4334279870232,
"wheelRadius": 342
}


-------------------------------------------
Here is the 61cm:
{
"backHubX": 342,
"bottomBracketDrop": 75,
"bottomBracketHeight": 267,
"bottomBracketToFrontHub": 624.3903926103736,
"bottomBracketX": 760.3300132670379,
"bottomBracketY": 267,
"chainStayLength": 425.0000000000001,
"crankLength": 172.5,
"forkLength": 379.025510938176,
"forkRake": 47.999999999999844,
"frontHubX": 1380.199646645006,
"handlebarAndHoodsReach": 120.00000000000013,
"handlebarBackX": 1226.846223183157,
"handlebarDiameter": 31.8,
"handlebarTopY": 1015.580766568761,
"headTubeAngle": 72.1,
"headTubeBottomCenterX": 1217.5446128905526,
"headTubeBottomCenterY": 689.4192963468579,
"headTubeLength": 234.9537815078078,
"headTubeTopCenterX": 1145.3300132670379,
"headTubeTopCenterY": 913,
"headTubeTopToTopTubeCenter": 30,
"headsetBottomStack": 1.5698483081083339,
"headsetSpacersStack": 9.999999999999986,
"headsetTopStack": 10,
"hoodsRestTopX": 1360.9231535446222,
"hoodsRestTopY": 1036.4185478887925,
"hubY": 342,
"name": "2022 Trek Domane AL 61cm",
"offsetX": 0,
"offsetY": 0,
"reach": 385,
"saddleAngle": 0,
"saddleBackX": 315.3924821762779,
"saddleFrontToCenter": 75,
"saddleLength": 255,
"saddleStack": 40,
"saddleTopToBottomBracket": 756.0021691734025,
"saddleTopY": 975.0588848495742,
"seatTubeAngle": 72.67037046385644,
"seatTubeCenterToTop": 576,
"seatTubeTopCenterX": 588.7577154652017,
"seatTubeTopCenterY": 816.8535683497905,
"seatTubeTopToTopTubeCenter": 30,
"seatpostSetback": 25,
"stack": 646,
"stemAngle": -6,
"stemLength": 119.99999999999993,
"stemStack": 40,
"stemToHoodsAngle": -10,
"topTubeCenterToCenter": 565.1116469869646,
"topTubeHorizontal": 586.5731292107898,
"trail": 60.02133162478185,
"wheelBase": 1038.199646645006,
"wheelRadius": 342
}

[Radius PNW]

Originally Posted by giordana93

A position that works well for a spin bike will not necessarily work well on the road but you can try. I would try on a stock bike first though...

Agree 100% with this.

I do have this question for the OP:

You mention you have been on the trainer for over a year, and can ride for a couple of hours with no numbness. This is a great discovery!

I'm curious if you have the ability to visit 2 or 3 local bike shops (are there any available near you?) that could offer you test rides on bikes appropriate for your body dimensions?

As has been mentioned, there are real-world dynamics at play for riding actual bikes that simply do not make themselves evident during a thought experiment.

When you are on a real bike rolling down the road, there is every chance you will want a greater bias of weight on your hands to assist with steering control.

That said -- if you are able to test real, stock bikes, and discover that a taller bar position, as shown on your trainer, is indeed a non-negotiable -- then do consider that there are bikes that can have the stock stack figures, even if too low for you at first glance, mitigated by using a steel fork with a steel steerer tube -- these can run more spacers, in combination with a stem choice that would let you closer approximate your trainer fit than most any stock bike would likely yield.

An example of such a bike would be something like a bike made by Surly (they make many, including one called the Straggler, which comes immediately to mind).


Hope this helps,

-R.