Nirve Beach Cruiser to Mountain Bike Conversion

A while back, I found a great deal on a Nirve Night Owl Beach Cruiser. The first thing I did was to replace the giant cruiser seat with a mountain bike seat just to give it a little more style. With those BMX-style bars, I knew I had something out of the ordinary.

I found a post online from a guy that swapped out the tires and then tried his Nirve Night Owl on some local dirt trails here. Needless to say, I was inspired. So after a few months of collecting parts, I finally turned my cruiser into a single speed mountain bike. I swapped the BMX-style bars for regular mountain bike bars and put some locking grips on them. I realized though that even with the seat pushed as far forward as possible on the rails, I was still stretched out on the bike, so I switched out the stem with a 90mm 30 degree adjustable angle stem. I also swapped out the crank set with a Shimano LX set with a single 34 chain ring, added clipless pedals, and of course, removed the chain guard. (Not to drop weight persay as the bike is still a bit heavy, but more more or less so I didn’t have to listen to the chain slapping against it.) The hardest thing to do was to remove the kick stand, which requires a special tool. I took it to a local bike shop to have that done. And finally, I swapped out the front rim so that at least that would be quick-release and I could then get the bike in the car without tools! I would have swapped the rear rim as well to match them up, but the hub in the rear isn’t a standard width (it’s much more narrow). Oh well, one all black, one all silver – no biggee! I guess I could put my all black Mavic CrossTrail on the front. Hmmm…

So here we have it folks, my single speed Nirve beach cruiser conversion, which I’ve named “The Beach Bruiser”. Oh, and in case you’re curious, the gearing is 34×20 (I counted the teeth on the rear sprocket).

After my first ride on the Beach Bruiser at Irvine Park, I have to say, it’s not easy to climb with, but it does climb and I didn’t have to walk anything! I look forward to taking this bad boy out to all the other local parks. It’s like starting over with mountain biking again since it’s so different than my Trek Fuel EX8 full suspension XC bike and so much harder. I’ve always wondered why people like single speed bikes. Now I’m inspired to build up a light weight single speed bike as well! For now though, I’ll tough it out and build some strength on the Beach Bruiser because it’s FUN!

Garmin Stats:
Most surprising was that I was able to keep pretty much the same overall pace as I normally would at this park. Check out the Garmin stats from my first single speed ride: