Hey all, I built an extra wheelset for my 2024 Trek Domane AL5. They are specialized axis elites with tubes and I have a GK 40 on the front and 35 on the back. The rotors are 160mm and the cassette is a 12 speed ultegra, where as my road set is a 12 speed 105. I tried them out on some gravel yesterday and they were okay, as soon as I tried getting up a hill I lost traction and fell. Is this a novice issue? A bike/wheel issue? Or was the gravel possibly too chunky for this set up? I’ve ridden gravel before, not on this bike but can handle it. I was bummed out cause I set this up and was excited to try it, can’t quite figure out what’s wrong. Short video if you can tell how chunky the gravel is and I’ll put a photo of bike in the comments. Thanks in advance.
by gracemhe
16 Comments
Try putting more of your weight on the rear tire when it’s gravel uphill. Going out of the saddle on gravel uphill can be tricky, depending on tire / gravel combo.
sorry but skill issue.
What tire pressure are you running?
the rear tire is pretty narrow as far as gravel goes. You won’t be getting much traction with that. The gravel is pretty loose. You generally shouldn’t need to stand to climb on gravel as it will just reduce traction because of the extra weight, and the extra power will just make it slip more. If you’re riding that tire on loose gravel you’ll need to stay seated and watch your power output or your tire is going to slip.
where you coming out of the saddle when going up the hill? I’ll lose traction doing that unless i consciously shift my weight towards the rear wheel, lowering tire pressure can help too.
Is there a reason you only have 35 on the rears? 40’s all the way around might provide additional traction, I even went from 38 to 40 to 44. I also prefer knobbier tires than GK for mixed gravel….i know others ride GK without issue and i rode Tufo Thunderos for a long time but i never felt stable on hills and corners until i went with a knobbier tire…..which is likely a skill issue on my part as well but i just feel more confident in gravel on the knobbier Tufo Swamperos.
Try tubeless setup with lower pressure
Tubeless at around 35 psi max is the way to go, the tire will have more traction by a lot. I usually ride with around 28-30
You gotta dig in with weight on the rear wheel. Tire pressure should be pretty low too.
Sounds like there’s a lot of air in your tires.
– Tires could be the issue but not to blame especially for the falling part. 35mm is indeed pretty small for chunky gravel but there are ways to maximize their traction through rider weight distribution
– fwd/aft balance/distribution is key to maximizing any tire. Unless the climb is insane you likely want to stay in the saddle and lean your torso forward but not all the way. This takes practice but you can use your torso to control your weight distribution based on feel. Too far forward will result in spinning out the rear. Too far aft may have you popping a wheelie or in the case of mud you might sink in and spin too. You basically want to put enough weight in the rear so that the tire can really push into the terrain without digging yourself a hole. You have to feel and react… it’s a pretty easy intuition to gain, you just need to go play around with it. By that I mean go pick a hill and try going up it several times with different leaning and see how it works.
– As far as falling, that’s really just your ability to unclip your shoes as quickly as possible combined with your judgement of knowing WHEN you need to unclip based on your speed. Practice unclipping quickly so this is second nature.
– One more think since I’m thinking you’re on the newer side (no offense intended) but it cannot be overstated how important tire pressure is. This is why people run tubeless as well, because going too low with tubes WILL result in pinch flats when the tire gets pinched between a rock and the wheel rim. Basically off road you want to be sufficiently low that your tire can maximize its contact area. Use an online tire calculator like this one to give you an idea: https://silca.cc/pages/pro-tire-pressure-calculator
Good luck
Why you put 35 in back? I’d do the opposite.
From what I understand 35mm is very debatably a “gravel” tire. 35mm was common several years back before there was a general shift towards more tire clearance for gravel and people were just trying to make their road bikes work on things other than road. I think there are several people out there that will tell you gravel tires should be at minimum 37-38mm and that’s at the very lowest end of the spectrum. 50mm seems to be what most people are shooting for. Even Walmart is stocking 45mm on their budget gravel bike. Aside from that, standing instead of sitting with most of your weight on the back wheel is going to decrease traction quite a bit and with your thin rear tire, it’s probably too much of a loss in traction while standing. Another thing to consider is tire pressure, which with a 35mm tire that typically requires higher >80 psi pressures when running tubes might be too high for what you are trying to ride, you can always drop the pressure though, manufacturer recommendations are more about safety on the maximum psi end of the spectrum. You can probably make the 35s work with lower pressure (probably meaning going tubeless) and by sitting instead of standing when climbing.
With chunky gravel and steep climbs, it gets a little bit difficult to go uphill. You need to properly distribute your weight on the bicycle, manage the amount of power you put through the pedals and choose your line.
Sometimes it’s just easier to dismount, and walk it uphill or just choose another route if possible.
I assume you’re while riding up this hill? It sounds like a skill issue but the size 35 tire in the rear isn’t doing you a lot of favors. You can certainly go up gravel hills with a 35 but a larger tire will give you a larger surface area to maintain grip
Combo of 35mm tire, tubes vs lower pressure tubeless, and what sounds like one of your first times riding gravel?
Probably a combination of
1. Air pressure is too low
2. Gravel too loose
3. You’re admittedly a novice and dont have the experience yet. Need to learn how to distribute weight and read the trail/ choose lines
This will come with time, my child. Just keep getting out there and you will see improvement