Woooosh

Just before heading to Bintan I got myself a new bit of kit to play with.

This isn't actually a disc, but rather a wheel cover, produced by these guys.

Dyma Wheel Covers

That is just my standard race wheel under that disc.

Dyma is a small company that has recently started making covers in Melbourne. Despite the small size, the advice and service that I have got from them was good and very prompt. Certainly no complaints.

The cover arrived the day I was getting ready to leave for Bintan. I took it with me and was very tempted to use it for the race, but in the end I decided against it. There are a couple of reasons why I decided against racing with it. Firstly, with 700m of elevation gain, the Bintan course is not particularly disc friendly. Secondly, I only really had one chance to try the wheel cover before the race. I wasn't comfortable using new gear in a race without having a chance to get familiar with it first. The cover seems great and solid etc, but I thought a fault from an unfamiliar piece of equipment was a stupid reason to get an dnf.

So how is it? Well first off it looks awesome.

P5 with disc - fast standing still

I have only had one ride on it, but during the ride it seemed pretty good. It certainly didn't cause any problems. The cover is only a thin flexible layer of laminate, but once it is fastened in place it is solid, it doesn't move around. My cover is the Dyma CL version, which has a carbon finish. The finish on the cover is very nicely done and it looks great.

 

Where I was riding in Bintan wasn't really a good place to judge any speed changes, but I will give it another spin on Sunday on familiar roads which should give me a better idea.

 

I am reasonably confident that I will be getting most of the aerodynamic benefits that you get with a proper disc. The aerodynamic principals around a disc are not as complicated as with a spoked rim. No spokes, less drag, simple. I can imagine this has slightly more drag than a proper disc, the surface isn't quite as clean, there are bumps from the fastening screws etc. But I think I will be getting the vast majority of the drag benefits that come with a disc.

 

Installing the cover is very straight forward, only takes 10 minutes or so. The two wheel covers are fixed in place by a series of plastic screw type things that attaches the two halves together. Due to the shape of the cover, you don't even have to remove the wheel to put it on.

 

So the downsides. Well this particular cover adds 400g to the weight of the wheel (and it is the lightest one in the Dyma range). That makes my wheel weigh about as much as a clincher disc. It is approximately a 30% increase in the weight of the wheel, which is not insignificant. In the bigger picture of the weight of the bike, water bottles, me etc perhaps it isn't such a big deal though, but that really is up to the individual. I have decided it is a weight increase I can live with for certain courses.

 

The other downside? No whomp, whomp noise. But not every disc makes that anyway.

 

The big upside, this cover costs about $260, and it is the expensive version. Not bad considering I now effectively have two back wheels.