Experimental Downhill Bike Is Pushing the Limits of What is Ridable

Longer, lower, and slacker was the trend in mountain bike design for years, and we're finally hitting a plateau, with most modern bikes having pretty damn perfect geometry. However, this prototype DH bike, belonging to Bronson Moore, is significantly longer, lower, and slacker than almost anything I've ever seen. And like many who have seen it, I'm curious as hell.

This truly spectacular experiment is pushing the limits of ridable MTB geometry; some might find the extreme geometry and crazy-looking stem super polarizing. Despite its wild appearance, its creator might be onto something. “I’m going the distance on pushing MTB geo with the Mule DH,” says BeMoreBikes founder, Bronson Moore. “This thing is so long - We will see if this is too far for a 5’8” rider, considering that most traditionally sized bikes would be over 200mm shorter for my height”.

Bronson Moore from BeMoreBikes (BMB) is a loud voice in the choir of riders praising the benefits of taller stack heights and shorter reach numbers on mountain bikes, and it’s not just snake oil. The BeMoreBikes Raised Reversed (RR) Stem has been making waves for a while now, and we’re starting to see more and more brands hop on the trend of taller rise bars - albeit not quite as extreme as BeMoreBikes stems, and they are yet to adopt the “Reversed” component.

But BeMoreBikes is onto more than just the taller stack and shorter reach. Bronson is also really stretching the concepts of bike geometry (pun intended). Recently, Moore teased his BMB Mule DH bike on Instagram, and when I came across the image of this absolute unit of a downhill bike, I was drawn back into the science he’s been pushing. This test bike was updated by blending the BMB Mule TR, which has a longer front-center, and the BMB Mule, with a chainstay length of 530mm, into a dual crown boat that sits on a 1470mm wheelbase, 190mm of rear wheel travel, 200mm of front travel, 59-degree head tube angle, and gearbox. Go ahead and read that again, letting it sink in.

In addition to the impressive geometry numbers, which are staggering on their own, this test rig also features a 150mm tall stem with a -15mm reach, the tallest and most polarizing stem anyone has ever dared to create. However, BMB isn’t just making these stems for fun (all designed and manufactured in Covina, California, BTW); they are also available for purchase at $500.00 USD. A high price tag for a pretty high stem, but Bronson also has a significant amount of testing and rider testimonies to back up the benefits of this wacky-looking stem.

Brian Cahal, a voice of influence on MTB geometry and an advocate of longer chainstays, has a couple of really insightful videos on the BMB stem on his YouTube channel, which are well worth watching if you're curious about real-world use and the theory behind the design.

All the geometry and sizing aside, the pure visual impact of this bike would catch the eye of any mountain biker. It doesn't look like it would ride well, but Bronson has it figured out, although he may be a little biased. “There is something to this super slack headtube angle, along with the RR stem and a long chainstay that seems to allow more steering more stably, especially at high lean angles,” Moore said on Instagram, “The bike is longer, but I can turn it more, so the length isn’t really an issue.”