Gravel/MTB Crossover Hot Takes

[liberationfab]

I’m laid up today after a fun crash last night in the local weekly crit so I’m craving a bit of drama!

As you may have seen here, my “aggressive gravel” bike bit the dust this weekend. Naturally, I’ve been thinking about what to make to replace it. I was pretty in love with the design, geometry, and overall feel of the frame, but would love to take what I’ve learned in the years since building it and create a really polished product.

I’d love to hear what y’all’s thoughts are on the “aggressive” side of gravel/“lite” side of mountain biking. Think 80-20 ratio of chunky gravel to relatively challenging singletrack.

Some potential topics to stir the pot:

• Is the Evil Chamois Hagar the future?
• Dropper posts: do they belong on a gravel bike?
• Is gravel suspension worth it?
• What tires too big for gravel riding?
• What tires are too small for mountain biking?
• Why does the Salsa Cutthroat look so bad?
• Drop bars with suspension - friends or foes?
• Are mullet drivetrains here to stay?
• What is the ideal head tube angle and why is it 69º?

[maxwellkeegan]

I’ll take the bait.

First off, I hope you recover quickly!

Dropper post belong on every bike. Drop bars look cool but flat bars make a bike much more capable off road. Suspension fork or big tires, and both if you want to put in a big day(s). Max tire size 2.6” minimum 2.0”.

Gravel bike is such a broad topic. Are you racing or enjoying riding gravel(off) roads?

[liberationfab]

Thank you!

@maxwellkeegan

Gravel bike is such a broad topic. Are you racing or enjoying riding gravel(off) roads?

My personal use is for single day or light overnight fast paced gravel race/events, but I’m interested in everyone’s take on this particular market segment. There’s obviously a huge spectrum between something like the Tanglefoot Hardtack and an Specialized Epic hardtail, but both are designed with a pretty big overlap of terrain in mind.

[Daniel_Y]

This is a fun topic of discussion. My personal opinion: I love road biking, I love mountain biking, I hate gravel bikes! I think the gravel bike debate comes down to marketing and identity.

Gravel is often marketed as suffering, pain, big rides, and under-biking.

Mountain biking is marketed as gnarly, fast, and gravity focused.

I wish everyone would get along. I wish mountain bikers would care more about their fitness and be willing to do bigger 40-50mi rides. I wish gravel and road bikers would work on their technical skills and appreciate the trails more.

I think gravel bikes have three main advantages:

• aerodynamics
• multiple hand positions
• lightweight

When you start adding wide bars, a suspension fork, 50mm tires, and dropper posts, you lose all those advantages and end up with a crappy mountain bike!

[sikocycles]

Gravel Bikes = 90s XC bikes and races. But I still have one and they are fun.

[liberationfab]

@Daniel_Y

Gravel is often marketed as suffering, pain, big rides, and under-biking.

Hahaha these are all my favorite things which explains why I love the genre so much

@Daniel_Y

I think gravel bikes have three main advantages:

• aerodynamics
• multiple hand positions
• lightweight

When you start adding wide bars, a suspension fork, 50mm tires, and dropper posts, you lose all those advantages and end up with a crappy mountain bike!

I definitely agree! There’s a balance between pavement performance and singletrack performance that seems pretty specific to the local terrain and trail conditions. I’ve ridden gravel races on 36mm cross tires and felt fine, but I’ve also ridden gravel routes on 2.1" XC tires and felt out of my depth.

Drop bars are interesting because they are great for ergonomics most of the time, but kinda suck for descending technical terrain. Riding in the drops on a bike with the bars below the saddle makes for a really sore lower back and glutes.

On the flipside, even with a decent amount of sweep, flat bars are still ergonomically and aerodynamically challenging. Adding aero bars to the setup helps but they’re tricky to use on anything but flat or rolling terrain.

It feels like the handlebar choice really trickles down to define everything else about the bike.

Drop bars? Probably best to go with flat mount brakes, non-boost hubs, and 395-420mm axle-crown rigid fork.

Flat bars? Likely going to use post mount brakes, boost hubs, and a suspension or suspension-corrected fork.

[Matt]

If this is a flame-war, you need absolutes!!

@liberationfab

• Is the Evil Chamois Hagar the future?

Maybe, I do like Evil’s

• Dropper posts: do they belong on a gravel bike?

yes

• Is gravel suspension worth it?

No

• What tires too big for gravel riding?

No such thing

• What tires are too small for mountain biking?

Under 2in

• Why does the Salsa Cutthroat look so bad?

Huge heat tube and in general front section, skinny fork, it’s an ugly combo, like alu frame and steel fork, carbon frames and metal forks, etc. The frame needs to be “skinnier” than the fork, otherwise looks like you “skipped leg day” - if you know what I mean.

• Drop bars with suspension - friends or foes?

Friend - but there are so many alt bars that… Are they really needed?

• Are mullet drivetrains here to stay?

If it works…

• What is the ideal head tube angle and why is it 69º?

lol

It’s funny that when I started the classic MTB was a 26in with 80mm fork on the front - and roadies would call a mtb anything with a tire that was over 25mm.
Now we have road bikes with suspension, even full suspension “gravel” bikes.

I feel like this applies well, my opinion on the industry and all this new categories:

[HomageFrameworks]

I love gravel bikes! (But not the name, was really hoping for “all road” to stick……)

It’s all about versatility. Having multiple bikes, and more importantly multiple high quality bikes with nice components, is a luxury so many riders don’t have. And similarly, so many riders aren’t pushing their bikes to the limits in terms of speed or adventure. People just want to ride. Road -yes. Gravel -yes. Midwestern singletrack -yes. Cat 4 cyclocross - run what ya brung.

For every 1 person doing the big name gravel races or epic adventure there are 1000 weekend warriors who just want to have a good ride on whatever route they can squeeze in.

#morepeopleonbikes is always the first goal. So to answer all your bullet points: whatever works for whatever you ride and whatever you body allows is the right choice.

[liberationfab]

Whoa whoa whoa I asked for hot takes, not a reasonable, well thought-out, and reflective response!

I do totally agree with you, but I also love obsessing over the smallest details of bike design. It’s what got me here in the first place!

I was just watching a video about Lael’s FKT attempt at the Oregon Outback.She rode with Jan Heine and it’s interesting to compare their bikes which are quite different:

It would be easy to look at these two and think they have almost nothing in common, but they were both purposefully built/chosen by the rider with that route in mind.

[sunshine.fab]

I’ve talked about this a lot with my dad. I bring him up because he’s (frustratingly still) a heckuva lot faster than me or anyone I know on anything that requires fitness, and as a result he’s done well at most gravel, road, and xc mtb events you can think of in the western US. He rides an Open O-1.0 with a remote lockout stepcast 32 on anything gravelly that involves any dirt whatsoever, and here’s his reasoning:

• When set up with carbon wheels and light (Thunder Burt, Renegade, Furious Fred, etc) tires, the bike weighs ~18lbs**, so he’s not lugging around much excess weight
• When set up in an “xc” like position (slammed stem and flat bar trimmed to 720mm (gasp)) he’s not that un-aerodynamic for any sections of a ride where that’s important
• If the terrain ever gets rough, he can unlock the fork immediately with the remote and have 100mm of travel to soak up the bumps and keep the front tire in contact with the ground, which is important for cornering quickly

** A caveat here is that he’s an old man and doesn’t believe in dropper posts. While I disagree with him here, not having a dropper post does cut down on the weight.

The thinking is that a (very) light hardtail mountain bike with the right tires isn’t a ton slower on the pavement than a gravel bike is, but it’s a ton faster on anything remotely resembling singletrack. Anyone reading this that was at the ENVE Grodeo last year on a gravel bike probably remembers being passed by a 62yo man on the singletrack descent for this reason.

His opinion is mostly formed by what allows him to go faster, and while I totally understand that there’s more to riding a bike than just going fast, I think it is interesting to look at what’s going on on his bike that makes him faster. To me it seems that a big reason it’s faster to have a mtb on singletrack is that the equipment is more suited to the terrain and thus generally more comfortable and therefore enjoyable. It’s less fatiguing. As you’ve pointed out, it sucks to ride down trails all hunched over in the drops, namely because it is uncomfortable. Underbiking can be fun, but so can normal biking.

I think part of the reason that gravelling has been so successful is that the marketing preys on all of our desires to feel like a hero. It feels cool and heroic to ride something on a woefully inequipped gravel bike that “normal people” would “only ride on a mountain bike.” Like you’re some kind of underdog pulling something off. Especially when you spray about it on social media. I mean seriously, you should have heard some of the self congratulatory toxic gravel-bro BS at the bottom of the Grodeo singletrack descent - . It’s certainly an effective marketing tactic, but it doesn’t hold up to the sort of thinking we apply to other disciplines of cycling, where we generally suit bikes to the terrain.

It’s not hard to notice that most people who do well at most feats and races, regardless of discipline or category, race on bikes that are exactly suited to the terrain. They don’t underbike or overbike. An interesting - albeit dated - example of this is Jared Graves winning the 2010 Sea Otter Classic Downhill race on a 4x bike, when all of his competition used DH bikes (overbiked). The course isn’t technical by any means, so he opted for a lighter and more maneuverable bike - one more suited to the terrain - and he was faster than the overbikers as a result. Maybe we can call his cunning-but-obvious move “correctbiking”… or maybe just biking?

To sum this up into the requested hot take: gravel bikes are dumb, get over yourself and get/build a light xc hardtail instead. If you wanna fight me about this you’ll have to catch up to me on a singletrack descent on your gravel bike… and you won’t.

[ElysianBikeCo]

My hot take:

• The idea of having a “quiver killer/one ring” is stupid and bikes are too expensive.
• Tomac knew what’s up.
• I want Shimano to make a DA/XTR level cable actuated disc brake that works with acoustic shifters.

[HomageFrameworks]

@liberationfab

but I also love obsessing over the smallest details of bike design. It’s what got me here in the first place!

I love the details too, and have learned a lot from you and other’s discussion about the details. I’ll re-summarize in hot-take format:

• Bikes Rule. Marketing Blows.

• The world is too big to ever establish best practice. Too many body types in too many locations with too many goals. Everything has a place.

[maxwellkeegan]

@Daniel_Y

When you start adding wide bars, a suspension fork, 50mm tires, and dropper posts, you lose all those advantages and end up with a crappy mountain bike!

This is the bike the majority of people have the skill set and fitness to ride! They are also really fun bikes!

Areo? Bikes generally get ridden outside. Pros and the elite benefit from areo because they practice a specific body position. They can hold that body position because they are fit!

Lightweight: is a marginal gain with huge cost implications.

Fitness: is something that can be achieved with low cost and has a huge benefit to health/well-being beyond bike riding (think living longer)

@HomageFrameworks

For every 1 person doing the big name gravel races or epic adventure there are 1000 weekend warriors who just want to have a good ride on whatever route they can squeeze in.

#morepeopleonbikes is always the first goal. So to answer all your bullet points: whatever works for whatever you ride and whatever you body allows is the right choice.

Yup

@sunshine.fab

A caveat here is that he’s an old man and doesn’t believe in dropper posts. While I disagree with him here, not having a dropper post does cut down on the weight.

I hope your pops comes around someday, his logic with bike set up is spot on otherwise! Hah

A person can achieve multiple hand positions on flat bars, with or without bolt on features.

[KWebb]

I like this discussion and have ponderd over many of these questions. I like the idea of underbiking because it may allow me to link trail systems and or use trails to spice up gravel rides. I do like riding gravel because I can do it basically all year and it keeps me away from cars.
I would pick a 2.25" tire because there’s a lot of options and it might still be narrow enough to allow gravel cranks. I have ruled out suspension for myself because the limestone dust where I ride is pretty tough on the actual suspension components. Suspension forks may help to extend the use of drop bars. I think there’s a wide range for geometry that’d work fine. I’d pick the amount of trail that I like with bb high enough to prevent pedal strikes.

I think the cutthroat looks bad because the downtube has suspension fork crown clearance and also curves at the bottom bracket end.

[manzanitacycles]

This is a fun topic to discuss because there’s little agreement as to what a gravel bike is or should be.

I like gravel bikes with wide tires, dropper posts, a slightly longer front center paired with a 50-70mm stem, and normal width handlebars with slight flare in the drops. This works well in my area (Reno, NV), where the dirt roads can be chunky and loose. I will ride gravel bikes on singletrack but only if the singletrack is tame and a small portion of a ride. Otherwise it’s so much more fun on a hardtail.

Wide tires allow you to run lower pressures, which give you more cornering grip and more bump compliance for your body. What you give up in aero benefits I believe you make up for in smoothness (lower suspension losses). Smooth is fast.

A longer front center paired with a shorter stem helps with confidence on descents. If you’re more confident you stay loose. Staying loose is safer and faster.

Dropper posts are essential on any off-road bike if you have to stand when descending. If your dirt roads are smooth enough that you can descend seated (anyone ridden in Vermont?), then save the weight.

I usually use a 70.5º head tube angle combined with 50-55mm fork offset to keep wheel flop and trail in check. That way you can use bar widths that you’d normally use on the road.

Here’s my current gravel bike. The only things I’d change would be to replace the 44mm Enve gravel bars with the 42mm Enve SES AR bars to reduce the flare in the drops and to swap the bar tape for the Campandgoslow tape because it looks nice

[Daniel_Y]

@sunshine.fab

The thinking is that a (very) light hardtail mountain bike with the right tires isn’t a ton slower on the pavement than a gravel bike is, but it’s a ton faster on anything remotely resembling singletrack.

I really want to experiment with a bike like that:

• Carbon rigid fork
• flat bars
• 27.2 seatpost
• 2.1-2.2 semi slicks

Should be a really fun, durable bike

Also, lots of fun takes in this thread. I’m enjoying the different perspectives.

Here is another fun curve ball: What is the difference between a gravel bike and a drop bar mountain bike?

For me, that boundary is:

• MTB BB and Crank (52mm chainline, 73mm BB)
• Suspension corrected fork (>450mm axle to crown)

Hub standards for gravel/mtb are murkier. Some gravel bikes (Focus Atlas) and most gravel e-bikes come with boost hub spacing.

[Matt]

You guys definitely need training on flame-wars!

[project12]

Damn, 2 days in Frankfurt and I have to read up on one of my favorite subjects!

But I love mountainbiking, get somewhat depressed on a real roadbike (while living in the flattest part of the world ) and if I would háve to choose one bike it would a gravelbike. My workshop is located in the east of the Netherlands where there is a nice mix of asphalt, double track, gravel and winding flowy singletrack. Something that can all be linked together in one ride on a gravelbike at a reasonable pace. I have built myself a “progressive” gravelbike to see how that would work (66HTA, 2" tyres, 50mm stem, long reach, but short fork and road widths) and while it is certainly a nice, fast and capable I am not sure theres a real advantages over the slighty sluggish handling on road. I think this is mostly due to the short stem in combination with the a regular gravelbar. I just sold this bike and have been riding our much more conservative Vittorio Randonneur and that feels a lot livelier on road and gravel and not that much worse on the singletracks. So I am currenlty building myself a new gravelbike with room for 50mm tyres, 67 HTA and an 80mm stem as I feel this might be a sweetspot.
My “progressive” gravelbike:

But to add to the flame war:

• That Evil sucks as a gravelbike
• Suspension on gravel needs to be forbidden (maybe apart from a seatpost?)
• Dropper: YES! One thing I truly miss while bombing down singletracks in the drops
• 50mm tyres should be more than enough
• Semislicks suck. A regular G-one allround (with the tiny dots) is so much better than the G-one RS out on the trails. Ask the tree I hit how I know
• Boost? Why?
• In my experience the dropbars a both comfort and an aero advantage. Long flat straights are a bore on my MTB, but pretty OK on the dropbar.

[Alex]

@liberationfab built the light XC bike last year for the Philly bike expo. It sounds like you preferred the monster gravel over the light xc for similar riding?

Is the goal ultimate speed (and on which medium), simplicity and enjoyment of riding, or some of both? I think that there is a spectrum there and riders land on different parts of it. I like to tour on the all-road bikes (or did before I had kids) and so they are oriented around simple components, good handling, all day comfort.

Having said that I’m currently having a lot of fun on a bike that I didn’t build which is oriented more towards the light XC end of the spectrum. It’s slower than my all-road bikes on pavement, but I don’t care too much about going fast right now. I still plan to put my framebuilding gear back together and make a lighter replacement for it.

[jimg]

Just gonna leave this here.