AASQ #147: Are flat bar gravel bikes a reinvention of the humble mountain bike?
We know, there’s no such thing as a stupid question. But there are some questions you might not want to ask your local shop or riding buddies. AASQ is our weekly series where we get to the bottom of your questions – serious or otherwise. Hit the link at the bottom of the post to submit your own question.
Welcome back to the Bikerumor Ask A Stupid Question series. This week we are challenge manufacturers of flat bar gravel bikes, asking if they are simply attempting to reinvent mountain bikes from the 90s, or if this “new” breed of bicycle warrants a category designation of its own. Your contributors are:
What’s the difference between a modern flat bar gravel bike and a 90s Hardtail MTB? Are we not just reinventing the mountain bike here?
Enigma Bikes: The comparison between a flat bar gravel and MTB (and indeed a ‘hybrid’, dare I say it) is a valid one to make. Clearly there are similarities, but there are also a few key differences that make it a bike worthy of its own category.
Before I start, it’s worth pointing out that we produce this bike due to customer demand, we’re not trying to reinvent a rigid MTB with some bull**** marketing attached. We’ve already been making bikes like this as custom frames for years, and got to the stage where the numbers we were producing made it worthwhile to release a standard model in this style. We’re not trying to tell people what bars they should be riding, or saying that one bar is better than another, but just giving our customers all the options, there are many that simply prefer a flat bar!
Modern MTBs tend to be designed for much more extreme off road use than they were in the 90s, with low gearing, long travel suspension, slack geometry and wide tyres. All great for the typical trail riding you see these days, but if you’re using the bike partially on the road or ‘fire road’ type tracks then they can feel very unrewarding for the effort you’re putting in.
Back to the question, here are the key differences between our flat bar gravel bike and a MTB (90s or modern):
1) Gearing – Modern MTBs tend to fit a maximum 1x 34 tooth chainring or thereabouts. You would struggle to get a 1x 40 or 46/30 double on any MTB frame, which makes their road use limited. Our Escape will fit a 1 x 42 single or super compact double such as 48/31 GRX, whilst retaining clearance for a 700c x 50mm tyre (29″ x 2.0″ if you prefer). An older MTB would have fitted a triple with a 40 something tooth outer ring, but no one wants a triple any more, do they?
2) Forks – We believe the advantage of a gravel bike is that it’s simple and light compared to an MTB, and adding a suspension fork is perhaps a step too far towards MTB territory! Our frame is designed for our CSix ADV 395mm carbon gravel fork. This is very light (450g compared to 1226g for a Rock Shox Rudy XPLR) and looks much nicer than fitting a longer suspension corrected (480mm) rigid fork with a big gap above the tyre. Longer forks also make it difficult to fit a proper full length mudguard, and achieve a low stack height which is required on a small frame size.
3) Brakes – We don’t need to explain how much better modern hydraulic discs are compared to any rim or cable braking system. The 1990s can keep their canti brakes.
4) Geometry – Many old school MTB frames tended to be very low at the front end, with a long, high rise stem required to bring the bars to a comfortable level, limiting the range of adjustment available. Our Escape is aimed at bike packing and commuting as much as having fun off road, so having geometry that’s a little more comfortable is a key feature.
We believe our Escape is a vast improvement on the 90s MTB. You can fit similar width tyres and have the choice of 650b or 700c rims. It has far better brakes, is lighter, more comfortable, and has a modern gear system with ample range for road and offroad. It’s aimed at people who are touring, bike packing, commuting, and of course riding gravel, but we hope there will also be a few riders who will take it round their local singletrack and come back smiling!
Ritchey: The first thing that comes to mind is wheel size and BB height. A 90s MTB was limited to 26” wheels and relatively high BB for clearance. Not to mention the limit of tire size! Today’s gravel and adventure bikes have the option of combining wheel size with greatly increased diameter when compared to a 90s MTB.
Back then, a mountain bike would typically have a 26” x 1.9-2.1” tire. Compare that to the clearances most gravel bikes can clear today: 700c x 48mm and a much different axle height. If you kept the BB drop the same on a gravel bike as 90s MTB, your center of gravity would be ridiculous. Gravel bikes don’t always encounter the same obstacles as MTBs did in the 90s, so you can run a lower BB and benefit from a lower center of gravity.
If we dive a bit further into geometry, we know we cannot just look at one element without it affecting other aspects of the frame design. Looking back those MTB frames of the 90s we see the reach being relatively short while long, squirrely-handling 140-160mm stems accommodated the fit of the rider; whereas, today’s gravel bikes handle best and are more stable with shorter 90-100mm stems while a longer reach on the frame opens up that space for the rider. Sure, headtube angles might be similar, but not without serious adjustments to the rest of the frame.
We aren’t reinventing the wheel with modern gravel bikes, rather we’re making more terrain more fun by learning from our MTB predecessors and by improving on what we’ve learned in the decades since.
State Bicycle: Let’s go Mountain Biking in the 90s forever! The difference is time. We love Flat bar gravel. The simplicity of 1x gearing, threadless headsets, 31.8mm stems, and modern seatpost sizes separate gravel bikes from mountain bikes of old. What about wide 650b gravel tires, thru-axles, and disc brakes that actually work? Or tubeless tires that let you run less than 50 PSI without carrying 4 spare tubes on your ride? We are digging Flat Bar Gravel.
Got a question of your own? Click here to use the Ask A Stupid Question form to submit questions on any cycling-related topic of your choice, and we’ll get the experts to answer them for you!