When it comes to cargo bikes, geometry is everything! You’re carrying a heavy load, get the weight distribution wrong and you’ll have trouble keeping your bike upright!
When we developed the Tribe Evamos, this was front and centre in our thinking. Starting from wooden prototypes in the backyard to specialist bike engineer drawings, prototype bikes and finally our production release. It was 18 months in the making to ensure a bike that handled well and could carry up to 80kg on the rear rack without feeling like it.
The Mullet was born
It was during this prototyping that we landed on one of the most key features of the Evamos, the 24″ front wheel and 20″ rear wheel. In bike design, the same size front and rear wheels are the norm, but somewhere in the 2000’s in mountain bike innovation, the idea to have a smaller rear wheel than front came about.
Nicknamed ‘the mullet’ (business up front, party down back?), the design didn’t take off in the world of mountain bike, but a few years later would find its home in the world of cargo bikes.
What’s the advantage of a mullet design?
Starting with the rear wheel
It’s in your interest to have cargo on your rear of the bike as low to the ground as possible. Why does a low sports car handle better than a high SUV? Its low centre of gravity. The same applies to a bike, the lower you can get your cargo the lower the centre of gravity and the easier for your bike to handle.
The Evamos has a 20″ rear wheel. Once reserved for kids bikes, a 20″ wheel gets you about as low to the ground as you can go. Paired with wide balloon tyres (2.4″ on the Evamos), it makes for a super comfortable ride.
Compared to a bike say with 24″ wheels, your cargo on the rear bench will be 10cm lower with a 20″ rear wheel. 10cm might not sound like a lot, but when you’re holding up 40 or 50 extra kg of weight, it really makes a difference!
And the front wheel
Many modern cargo bikes adopt a 20″ front and rear wheel. This makes them nice and compact but un-nerving when you hit a pot hole or speed hump!
The Evamos has a 24″ front wheel, this gives it a larger contact point on the road for safer handling, and if you’re used to riding a ‘normal’ bike, feels much more like what you’re used to.
By not going any larger, to say a 26″ front wheel, we’ve helped keep the total length of the bike as low as possible, at just 195cm in total length, the Evamos is barely bigger than a large men’s mountain bike and with 2.1″ front balloon tyre, it cushions all but the biggest road bumps!
Safer for kids
Not only does the 20″ rear wheel get your centre of gravity down, there’s plenty of safety benefits associated with it too.
Firstly, it gives less distance between the seat and the side boards (foot boards) or footpegs on the Raha, meaning your kids legs don’t dangle around at the back of the bike. This extra contact point is incredibly important for safety, both ensuring feet stay away from spokes and brakes and to have your child more stable.
Secondly it makes it easier for kids to climb on and off, without the extra height of a larger 24″ rear wheel.
The distance from the top of the bench, with seat pads installed on the Evamos is just 40cm, meaning kids as young as 4 can safely place their feet on the sideboards.
Where else does the unique geometry of the Evamos make a difference?
The Evamos is fitted with a split top tube, which wraps right around to the rear rack. This split top tube is an important design feature. It stiffens the frame, so at speed with a heavy load ‘frame flex’ is limited. Flex makes your bike feel less stable, and as a result of this feature the Evamos feels super stiff and stable even at speed.
Rider comfort is also important, The adjustable stem allows you find the perfect spot for the handlebars for your comfort, and the saddle can be adjusted both forward and back. Adjusting both of these will ensure you are not having to ‘reach’ further than comfortable.
Finally, the low step through frame makes getting on and off a breeze. just step your leg through to get going, no having to do the hurdles while holding up a fully loaded cargo bike!
Evamos and Raha share the same geometry
Most of the discussion above has been centred around the Evamos. We make no secret in the fact that the Raha is simply a shorter version of the Evamos, so anything you read about the Evamos holds true for the Raha.
Get your geometry right for safe and fun riding
No matter what cargo bike you choose, the number one thing you should get right is your frame geometry. We’ve tried a lot and reckon we’ve landed on the sweet spot with the Evamos and Raha.
Happy riding!
