Gravel Bike vs. Mountain Bike
Aren’t gravel bikes just repurposed mountain bike technology? We get this comment a lot and decided to compare geometries between the modern “gravel” all-road bike and a 84 Stumpjumper. We also talk about reasons why we choose a drop bar style gravel bike over a mountain bike for the rides and events we like to do.
Zoltan July 12, 2019 at 6:20 pm
How about a touring bike with gravel tyres? You get the more road oriented geometry of the gravel bike and the sturdyness of the mtb…
Matt March 15, 2019 at 11:03 pm
Good stuff, as usual! Still wondering if you’ll consider doing a post about which frames make ideal ‘gravel’ conversions. The mid 90’s Specialized Stumpjumpers have a tighter rear end and slightly less slack headtube than the older one you compared this to in your last video. You can find these frames a dime a dozen on eBay or Craigslist. I get the sense many of your fans are tinkerers, like me. It’d be awesome to see what everyone is up to and how they’ve built a modern bike on a budget. Sure, new bikes like the Warbird are great. But man, are they expensive!
Also, to the previous commenter’s point, tire and wheel size make a huge difference in handling. Yes, the old Stumpy’s have long and low frames. But they also have 26″ wheels, which turn much more quickly than the 700c wheels that most gravel bikes roll on.
Keep it up. And here’s to more age diversity for the bikes that make it on the channel!
Kevin March 27, 2021 at 4:41 am
Interesting video, however I think a bit disingenuous and misleading. When you discuss frame geometry you use very early mountain bikes(80’s) as the “mountain bike” reference. Mtn bikes were just getting started in the 80s and as such they saw many significant changes that happened at a rather fast pace. The super slack head tubes and long chain stays didn’t last very long. Most folks interested in repurposing an older mtn bike into a gravel bike tend to know at least something about the older bikes themselves, or it can easily be researched. By the early to mid 90’s, a golden age for rigid mtn bikes, the 67 degree head tube changed to more like 71 degrees. The 470mm chainstay had became about 430mm. You’ll note those dimensions are still used today in gravel bikes. An early 90’s mtn bike as a base to modify into a gravel bike is a much more honest (and informed) reference. The Trek geometry charts for this era are readily available. I think it’s pretty safe to assume the Spec jumper models were lockstep with the Trek geometries at the time., as were many other mfgs.
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The Gravel bike is mostly about the tires. Seems that lightly treaded 40-50mm tires that are designed to roll fast on pavement but also hook up well on dirt defines the gravel tire. While road tires only roll fast on pavement and mountain tires only hook up well on dirt, the gravel tire manages to do both. Put a set of 45mm gravel tires on your hardtail and it makes a pretty good gravel bike. I did and I couldn’t believe how fast my hardtail was on pavement and gravel. (It would be better with a rigid carbon fork.) Put a set of 45mm tires on your road bike (If it had clearance?) and you would have pretty good gravel bike. I could see how some might prefer a gravel bike with mountain geometry and flat bars (like myself). Others might prefer a gravel bike with road geometry and drop bars. I don’t think it has to be one or the other. However both bikes would need a tire that rolls fast on pavement while hooking up on dirt to be called a gravel bike because that’s how we/I use gravel bikes. It’s not about the geometry or the handlebars. It’s about the tires!