You might have heard the term before, but what does it really mean?
Well, it's a different way of looking at and building a road bike. It's really almost crazy to think that it was only four or five years ago that that only option for a road bike was either a heavy and slow touring bike and super-light, aggressive road bike with 23c tires. That's changed, and with good reason. Most cyclists don't race criteriums, or road races, and would rather trade extreme lightweight and aerodynamics for more comfort and bigger tires. Road plus is the next step in the slow move to offerings bike that do more things well (pavement, gravel, trails, touring, etc.) rather than one thing perfectly (win bunch sprints).
First, more and more bikes have fork and frame clearance to fit 28, 30, or even 32c tires in what we'd consider a traditional 'road' frame. The emergence of gravel bikes, which are a hybrid of road and cyclocross bikes, have wide tire clearance and a longer, road geometry. Bikes of that ilk can fit up to 40c or even 42c tires, plenty of floatation for even Michigan's sandy gravel roads and two tracks.
But for riders looking to really open up all trails, roads, and adventures, road plus goes even further. The idea is to replace the 700 wheel with a mountain bike style 650b wheelsize, which has a small diameter. Pair that with a 47c or wider tire, and you've turned a road or gravel bike into a rigid mountain bike. Companies are starting to offer new bikes with these wheelsets stock, like the Kona Rova NRB. Many riders have opted to run the WTB Horizon or Byway 47c, which offers nearly twice the width of a traditional road wheel, but a slick center tread that reduces rolling resistance.
The question you hear most often isn't about the actual numbers, though. People are less likely to ask what it is as they are who the wheel size is for. Well, we think it's for most people. Unless you're doing fast group rides and races all the time, the flexibility of the 47c tire means you get a lot more out of one bike. The perfect set-up might be to have a set of road tires on traditional road wheels for hopping into a big grand fondo or Grattan, and riding your 'mountain' wheels for training, trails, gravel, and every day. They're wheels for gravel grinders, bike packers, commuters...really anyone that doesn't care about winning the town line sprint on Tuesday nights.
You can check out the Kona Rove line-up here, with all Road Plus bikes denoted by the NRB tag. Kona won't say officially what NRB, but they do say it isn't necessarily 'New Road Bike'...we'll leave you to guess.