Tall rider and steep climbs

Yesterday in GCN Breakaway Wiggins mentioned something that tall riders have problems with steep climbs because of big bikes frames. The focus was on bikes and not on riders weight. Hugh Carty is 1.93cm and “just” 69kg.

Can someone explain how frame size affects climbing?

At 6’6" and 220lbs, I’m going to be an extreme example, but I’ll give you a rundown of what I run into.

When climbing, riders “collapse” their position to move their weight forward on the bike (otherwise it doesn’t stay centered over the bb area). With seat tubes being located generally behind the bb, this takes more forward lean from the bigger riders to get to the same “balance” point.

At my height and weight, it’s possible to “loop out” a bike just pedaling up a steep hill if I lose concentration and don’t keep the weight forward. This also means any surges in power affect your handling and balance more because you have less steer/countersteer help with your balance because your bike become less responsive if you make the front end light enough.

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Not as tall as you, but absolutely on steep climbs I struggle to keep the front wheel down due to weight balance point also known as center of mass or center of gravity.

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I’ve experienced the same thing and on steep wet climbs it seems like I end up having to fight between either leaning back and the front wheel comes up or leaning too far forward and the back wheel slips out. It’s something much more noticeable riding gravel than on the road.

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Yeah, not knowing the full context, there is some guessing involved. Road use is not much of an issue in most cases. Maybe you hit something when you get into wet roads and extreme pitches like 12% and up, but there is usually enough traction that you won’t fight that end at least.

When you get into loose conditions, the balance between proper weight on the rear wheel and controlling the front on steep stuff is more of on a issue with gravel and MTB. In either case, the “tall rider” issue likely related to geometry.

Weight distribution is linked to the wheelbase, chainstay length, bottom bracket drop, seat tube angle (including final saddle fore-aft with seatpost offset as a factor), and handlebar position. We often see the same chainstay length on a full size run of bikes, while the seat post angle may change. Even if STA changes (often forward, but not always), it may not be enough to handle the final saddle location and it’s relationship to the rear wheel.

As Nate has mentioned, a tall rider ends up farther back on the fore-aft spectrum and potentially more over the rear wheel. This can lead to the seesaw effect of fighting to find the precise body position to keep enough weight on the rear tire for grip, but also enough on the front to keep wheelies in check. Couple that with the final upper body position to help in weight distribution and it is all a careful act in placement.

The big bikes tend to make this more precarious even when the wheelbase lengthens, since the chainstay section is often the same. Some bike makers also adjust CSL to deal with weight distribution, with the aforementioned seat tube angle to try and get a bike that handles similarly in all sizes. But it is an interesting challenge, especially when you start looking at full suspension bikes and the fact that they often go cheap on tooling and fixtures, to use the same chainstay / swingarm for all bike sizes.

In an ideal world, we’d see fine tuned geo’s to account for these issues, but they come with a prices when we look at carbon MFG or even fixture based metal frames. Making and stocking another frame section that is size specific becomes a challenge, and is one reason we saw shared parts in so many frames in the past.

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Endurance road bike, 7-9% climb, and tall rider. Thats all it takes for me to start having trouble with my front wheel.

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This is real. I’m not as tall (6 foot 3) but was a similar weight l(circa 215lbs) ast year riding up Wrynose pass and Hardknott pass in the UK Lake District.

A few times it felt like I was going to tip backwards and I had to exaggerate my forward leaning to prevent the front wheel lifting. This reduced the effectiveness of my power transfer and I nearly came to a dead stop a couple of times on the steepest bits!

Admittedly an extreme example but hopefully illustrates the point ?

yup. I am 192cm I have crashed out on a 22% ramp when the front wheel lifted and skated. I took out two other riders. I don’t hump the stem when climbing so I always thought my balance point was good. I was on the hoods. Now when I hit ramps I climb on the drops. Seems to help. Touch wood…

I was just about to share my experiences of Hardknott Pass too.

I’m 6"3 and 178lbs. I never had this issue with weight distribution. At the sort of gradients that I imagine would cause issues with front wheel weighting, your road bike gearing is likely to be a limiter first.

In other words, I’m riding out the saddle long before the road is steep enough to cause major weight distribution issues. You’d have to be riding with some serious power or super low gears or cadence to be sat down on a road bike at 20% or more? I was on 34x32 and I’m not a fan of riding out the saddle so I’ll stay seated as long as possible,

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Classic photo from Hardknott (Photo by Steve Fleming)

Note the guy on the right who is pulling an unintentional wheelie.
I am not tall (5’10"/178cm) so can’t add much to this but going up Hardknott I’m either out of the saddle or on the hoods with dropped elbows, never on the tops.

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Yep exactly. Plus you just reminded me. My TR forum profile pics is one of Steve’s, on Hardknott Pass:

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I’m 5”11 and tend to be quite far forward. Maybe too much but I guess we each have a “style”. :grinning:

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Lee McCormick unlocked steep MTB climbs for me. I’ll talk about it on the podcast in detail.

Short answer:

  • stand almost straight up with hips next to bars
  • pull back with both hands at once (this was the key for me). It levers your rear wheel into the ground for traction.
  • you sort of “hump the bars” with each pedal stroke and pull back.

I haven’t tried it in a road bike yet but I was able to climb stuff that I’ve never thought I’d be able to climb with this technique.

It would be really hard to do for a long climb. Works well for loose MTB steep pitches.

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Have you even ridden the Fred if you don’t have the photo!

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I still don’t quite get what it has to do with being tall… I get that a tall rider has a higher center of gravity than a shorter rider, but is this an issue for a tall, very light rider?
I have never had balancing issues on a climb. I am tall (191cm) but also light (70 ish kg).

If you think about it like this there is a stability envelope shaped like a triangle. The base is the ‘horizontal’ distance between the contact patches. Steeper incline less horizontal distance. So long as the center of gravity remains in side that you’re good. Get your CoG out the rear of the triangle: front wheel up. Taller people have less margin horizontally as we are further up the triangle. Any number of reasons why you have more margin than most tall guys.

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Yup, running short on time, but here is what I sketched up real quick.

The issue is that as the rider is taller, the saddle height increases, and yields a center of mass further over the rear wheel compared to shorter riders. Again, this is with consideration of bike design, and the common chainstay length relative to bottom bracket. Means that the higher your seat height, the more rearward your center of mass over the rear wheel.

  • Rider center of mass is around the belly button.
  • Line from center of rear wheel goes perpendicular to the road surface.
  • Line from that tire contact patch goes up vertically.
  • Horizontal line from that vertical to estimated rider center of mass.
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Is this an argument for straight seat posts, as opposed to setback, for tall people? It seems like having your seat further back in relation to the BB would matter to some degree all the time, not just climbing.

Most likely not “straight” if you mean vertical to the ground (or line between the axles). That would lead to super odd position over the bottom bracket and therefore the pedals. TT & Tri bikes have seat tube angles around 78-80* where road bikes are 70-75*. Doesn’t seem to be a huge difference until you see how that impacts the actual feel on the bike.

As I mentioned above, the more likely adjustment to handle rider size is to alter chainstay length along the size run. Bike makers already adjust the front center (bb to front axle) via changing the wheel base. And some (many/most?) do alter seat tube angle along the size range too. But chainstay length is very likely to be the same from a 48cm up to a 64cm bike, which is not “ideal”.

Here is the new SL7 Tarmac:

  • Note that the Seat Tube Angle does change, but it actually slackens on the larger sizes. This leads to the rear shift of the rider center of mass even at the same saddle height (I realize the oversimplification on fore-aft position purely along the STA, but do so to keep things easier for discussion).
  • And it gets even worse when you consider that slack angle with a longer seat height setting. So this is a double shift in the wrong direction with respect to stability on the rear wheel.
  • See the Chainstay Length is identical on the full size range.
  • Only Front Center and Wheelbase change to the better in this bike.
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Thanks for the detailed response! I just meant “straight” as in no setback, as compared to setback seat posts.

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