Spoonrobot 

Sure - a couple mentioned in this thread: Soma Fog Cutter & Focus Parlane. Both are essentially fat-tire road bikes with what would be considered aggressive gravel geometry but sort of relaxed road geometry. This is mainly due to fitting tires bigger than 25s.

You may also want to look at the Endpoint Coffe Grinder or the Specialized Diverge Expert. There are lots of other models I'm just not familiar with them - Performance and REI have house models as well.

Most of these bikes will fit a 38 or 35 smooth tread tire - anything with knobs is probably going to be limited to 32s. This is inherent in the design compromises mentioned above. If you want fast and aggressive like a road bike you need shorter chainstays at or under 420mm - which barring some wacky seat tube antics - you are limited to 35/38s for most frames. 420+ and you're in gravel bike territory, not saying those frames aren't fast or can't be aggressive but I don't feel they're a match for something with shorter chainstays and wheelbase.

Did you mention what you currently ride? I think you mentioned elsewhere but I don't remember off the top of my head.

HTupolev

Long wheelbase is far more aggressive: if you take a typical road bike to a road ride, it peacefully blends in, but if your bike has 470mm chainstays, people will start scratching their heads and asking questions about it.

Spoonrobot 

If I see you at a road ride with 470mm chainstays, I'm going to try to sell you some overpriced twine or MUSA shorts.

Garfield Cat

If you think Cervelo, then you want to see what Gerard Vroomen is doing.

TimothyH

Alright, this is some of why I posted, to learn a bit about adventure/gravel/road geometry. I'm not good at deciphering the geometry charts.

Right now I ride a 2002 Fuji Roubaix updated with modern 105 groupset, compact cranks, C24's and Rubino Pro Speed graphene. I also ride fixed gear on the road, a highly modified Bianch Pista.

What I'm taking away from this is that everything is a compromise. Short chainstays and limited tire width, more relaxed geometry with wider tires available.

Was trail running up @ Allatoona today, thinking about the reality of taking the thing on more gnarly roads. Not sure. Either way, this thread is really, really good.

Really appreciate everyone's posts more than you all know.


-Tim-

googldocs1101

Exactly what I was thinking. The redone geometry looks awesome!

DarKris

You mean Open/3T I assume?

Barrettscv 

It's a interesting topic. The goal of riding gravel on a bike that holds speed like a fast road bike is the holy grail for gravel riding.

Using a race level Cyclocross on gravel can deliver speed on the flats and climbs, but the higher bottom bracket, smaller tires and short wheelbase on a true Cyclocross bike is a demanding experience on faster downhill sections at higher speed. Most riders moderate their speed rather than risk instability.

A second issue related to Cyclocross geometry is the ongoing input needed to maintain stability on loose-over-firm conditions common on gravel. It's easier to hold a line on a bike with slack angles and a longer wheelbase than on a classic Cyclocross frame.

I've been using a Carbon Fiber Cyclocross bike for several years. It's fast and response, but requires extra concentration and a little luck when the gravel is soft and the substrate is less than smooth, washboard is common in Missouri. I also have a steel "Monstercross" bike with 700x45 WTB Riddler tires. It's incredibly stable and predictable at 30mph while descending choppy loose over firm gravel. It's extra comfortable over longer distances.

Ideally, a faster gravel bike will be lighter and responsive, like a race-ready Cyclocross with but with more stable geometry and room for a 700x38 tire.

Searching among racing Cyclocross models with lower bottom bracket and room for a 700x38 should yield a result: fast and stable gravel rides with efficiently maintained speed.

DarKris

First thing that came to mind was the Specialized Crux: 425mm Chainstay, 67-71 BB Drop depending on size, can run 40mm tires. That's an option.

chaadster

I'm mostly with Spoonrobot's line of thinking in this discussion, although I don't share the opinion that a "fast, aggressive road bike," as you stated in the OP, TimothyH, needs or ought to wear 35c and 38c rubber.

I mean, it all depends on what you need, of course, specifically what kind of roads you ride and how much you weigh, and where you're ready to make sacrifices to the "fast, aggressive" thing.

Personally, I ride a "fast, aggressive" road bike for gravel, and mostly keep it on 30c rubber for that, sometimes 25c for spring training paved road rides. I come in at about 225lbs, and my gravel surfaces are mostly hardpacked or with a thin light coverage of small, natural stones. I also ride proper gravel roads, not singletrack, or double track, or fire cuts or any of that kind of stuff, just rural dirt roads as we call them around here.

My main concern is to have a fast, agile bike that's fun on both paved and dirt roads, something I can fender up for fast, wet spring club training rides on the road and not have feel like a truck, and use for a fast, weekly AM group dirt road ride in the summers, in the fall and winter for the same. Just today I did a 30mi snow packed gravel ride on the 30c tires, was doing 29mph at times on downhills without any issues. Sure, big tires are nice for stability, but they're antithetical when it comes to feeling spry and sporty, mostly.

My gravel rig is a '15 Kinesis Racelight 4S. With matching 73.5º HT and ST angles, 420mm stays, and a 1016mm wheelbase in the 60cm size, it's steeper and shorter than anything mentioned thus far (I think), and subsequently limited to a 30c (slick) max. But, it serves my needs exactly, and I can even get Crud RoadRoacer Mk.3 fenders on the 30c rubber:



Kinesis renamed this model for 2017 as the T3, in order to distinguish it from the Racelight 4S Disc, which has some frame design features which my caliper-braked R4S did not have, but the T3 and R4S caliper brake model are the same. EDIT: I just took a closer look at my 4S "caliper" (4SC) and the new T3, and I was incorrect that they are the same aside from brake type. In fact, they are substantially different. Top and down tubes on T3 do not have the external butting or shaping of the 4SC (or the 4SDisc for that matter). I will write to KinesisUK and ask after the nature of the changes.

Kinesis Racelight T3 Training Bike - Kinesis Bikes

Now, going back to everything said, my 30c do not make me decisively faster than my ride mates running 35c and 38c tires, but, I do think they give me a bit of a slight speed advantage on pavement, and if we were going full out, I'd want every advantage I can get. Whether there's an advantage there or not, what's also important to me is the feel of the bike, and it's good; road-going weight (i.e. with bottle cages, pedals, and 30c tires) is 19lbs, so that helps, too.

The English make lots of bikes like these, which they call "winter" or "audax" bikes, basically defined by the ability to wear larger, like 28c tires, and fenders for nasty weather, but to handle like a racer. For example, the Mason Definition is such a bike, are the Genesis Equilibrium and Condor Italia. And don't forget the Swiss: BMC Roadmachine 03 fits 32c tires. If you really do want larger tire capacity, I'd look at bikes like the Open U.P, which I think I mentioned earlier, the Enigma Ecroix, and the aforementioned 3T Exploro.

Sorry to run on. My point in all of this is that I strongly suggest the OP takes a good look at what they want, what they need, and what's possible, and make decisions based on that rather than what others think "gravel riding" means. Also, remember you don't really buy speed, but you do buy feel and versatility.

Best of luck!

HTupolev

It's a pretty small compromise. AFAIK, the main reason that road bikes moved to smaller chainstays is marginal-gains weight weenieism; a smaller structure requires less material to be just as strong as stiff as a bigger one, so you save a tiny bit of frame weight. They also decrease paceline spacing, although again the effect is pretty marginal when fighting over a few centimeters (and in some circumstances may even be beneficial, such as if the person behind you rightfully deserves punishment for being that guy with a squeaky pedal).

As far as "relaxedness" goes, chainstay length doesn't really do anything. Fit is dependent on the frame's front triangle. You could remove the seatstays and chainstays from a bike, and replace them with ones that put the rear wheel 10 feet behind the cranks, without affecting the positions of the saddle, cranks, and handlebars at all.

Long chainstays also don't doom a bike to sluggish handling.
How a bike feels to handle is mostly dependent on trail and bottom bracket drop. Look at track bikes; extremely short chainstays and wheelbases, but they frequently handle heavier than road bikes, which to my understanding is mostly due to the high bottom brackets.
How sharply a bike can corner on the road is mostly a matter of tire contact stability, which if anything will be better with the wider tires permitted by longer chainstays.

Garfield Cat

There's that close relationship between these two companies.

https://www.3tcycling.com/road/en/ge...tz-acquire-3t/

Spoonrobot 

Longer chainstays change the way a bike feels under acceleration, especially out of the saddle, and works with trail and fit to determine how fast a bike will want to turn left/right. Some riders, by virtue of their fit and how they turn their bike are less sensitive to cs length than others. Long chainstays and extremely long chainstays provide obvious additional frame compliance this comes at the expense of responsive to pedaling inputs and cornering ability. Now, for some people the difference between 415mm and 430mm is nothing and they don't notice - to others it is noticeable.

BB drop doesn't affect handling by itself. It changes other frame characteristics as it changes but to say it is a major determinant of handling is incorrect.

Track bikes could be perceived as sluggish or "handle heavy" because they have high trail - bb height does not affect this. High trail provides high speed stability which is needed on a banked surface. Track bike trail is usually 70mm+, road bike trail is usually 50-60mm. Now, at slower speeds high trail requires much more counter-steer than mid or low trail and turning the handlebars left/right feels harder and slower because the rider is lift/lowering the wheel so much more.

This is really obvious with mountain bikes, a modern 29er race hardtail is anything but sluggish and is going to have trail figures 75mm+. Turning is done by counter-steering and leaning the body opposite the turn while turning the bike deeper into the turn. You wouldn't try to turn a mountain bike like a road bike so it never occurs to most people to make the comparison and describe the bike in that way.

Geometry has a huge affect on how sharply a bike can corner. As trail changes the bike's lean angle changes as well - a high trail bike requires significantly more lean than a mid-trail bike and can easily exceed the grip of the tires at a slower speed than a mid-trail bike.

Dave Moulton's blog is a wealth of information but these posts are germane to this discussion:
Dave Moulton's Blog - Dave Moulton's Bike Blog - Trail, fork rake, and a little bit of history
Dave Moulton's Bike Blog: Squirrelly
Dave Moulton's Blog - Dave Moulton's Bike Blog - Bottom Bracket Height

This is a great post - I had forgotten about audax bikes.

shoota 

Fantastic info, thank you.

athrowawaynic

Not sure what you mean by "adventure bike", but for the rest of us, the Salsa Warbird is a pretty nice example of an adventure bike.

HTupolev

I get the theory, but it doesn't seem to add up. If it was meaningfully representing a significant factor, the length itself would be getting lost in the noise compared with how the stays are constructed. Why does 420mm make lots of sense for both an aluminum bike with super-wide tubes and a steel bike with ridiculously narrow stays? And if it's so sensitive that a few percent difference in chainstay length can make the ride significantly less tight and stable on a modern bike, why aren't vintage bikes universally unrideable?

I'm not so sure. I agree with Moulton that the center-of-gravity argument doesn't make much sense in terms of an analogy to car dynamics, but I don't think that rules out a low BB having handling merit. Another half-explanation I've seen is that, picturing the rider as being on a lever pivoting about the tires, raising the butt increases the rotational intertia against leaning. And it's at least fairly certain that lowering the butt without also lowering the crankset can help handling; dropper posts are a quite proven tech, for instance.

Who makes track bikes with 70mm+ of trail? Most of the big builders have it at pretty similar to their road bikes, sometimes very slightly higher. The only notable exception seems to be for the very small sizes, where it looks like the use of 700c wheels is making the geometry a mess (i.e. Specialized's Langster goes from 69mm in the smallest size to 50mm (!) in the largest).

There is a lean:turn-radius relationship created by the geometry, but that's a sort of adjustable matter that can be compensated for and tuned. If the wheelbase is longer, using less trail than a shorter bike can make it behave quite a lot like the shorter bike; you have to steer more for a given turn radius, but you lean less per steering, so it all works out similar. What I meant to get at is that, for road riding, a long wheelbase won't individually doom a bike to poor cornering: if the turn radius is the same, and the lean angle is the same, and the centripetal forces are the same, etc, it doesn't matter much whether the wheels are three feet apart or six, the dynamics on the tires are pretty similar.

Your first link disagrees with this interpretation:
https://davesbikeblog.squarespace.com...f-history.html

TheRef

I've been looking for the same thing as you are. A decent gravel bike that doesn't put me sitting up like a hybrid bike. The new Fuji Jari has caught my attention. I'm supposed to go test ride one as soon as my local Performance store gets one in stock.

TimothyH

I wish I had titled this thread more along the lines of this.

Not sure that "adventure bike" was the right term or if it is really a matter of semantics but that's what I want, a more aggressive, sporty gravel bike with the option to go 40mm tires if I choose to ride on rougher stuff.

A few bikes in this thread have piqued my interest.

TheRef

DO check out the new Jari. Fits a 40mm tire, great sporty position with lots of options for adjusting aggressively or more laid back. Decent priced and a few builds to choose from.

shoota 

Well then check out the Raleigh gravel bikes. I just ordered the Tamland 1 for $799. For a gravel bike it's got a shortish headtube and a longish reach. I think it'll work out just right. And heck for the price they simply can't be beaten.

shoota 

Not a bad looking bike. It looks well thought out.

TheRef

Where di dyou find the Tamland 1 for $799.

Barrettscv 

Jackman won the 50 miles Red Dog Gravel Race in Missouri on a Fuji Jari last year.

chas58

I was going to write some stuff, but @Barrettscv and @Spoonrobot summed it up pretty well.

I agree that if you are doing fast downhills, with turns that push your ability, a stable low gravel bike would be the way to go.

For me, that isn't my limiting factor. I need a bike that can thread a single track, or handle sharp changes in direction in an urban environment - one that can turn quick and hard. So, I choose a cyclocross bike:

I

• t feels snappy/lively, not "stable"
• It has a higher bottom bracket so I can power hard through a sharp turn without pedal strike,
• Reasonably short chain stays allow me to snake through urban or rural obstacles,
• reasonably steep head tube angle makes it responsive to steering inputs.
• Higher b

ottom bracket and shorter chain stays help it accelerate better.

chas58

Gravel bikes like the GT Grade, which is about 73mm (Very slack slack head tube angle). I wanted to buy that bike so badly, but its handling was so sluggish...