Saturday, 16 July 2016

Life with Di2


Battery Life

One of the main questions about moving to electronic shifting is battery life. You definitely don't want to be worrying about whether you have enough battery to get you home. Shimano claim excellent life from the Di2 battery. My findings definitely confirm that. Where I normally ride, which requires regular shifts as gradients change frequently, I estimate that 10% of the battery lasts in the region of 150 kilometers. I typically top up the battery no more than once a week.

Recharging the battery for Di2 is also fast. You'll need a mains adapter that can charge devices that use a micro USB port. I use the one for my mobile phone. Di2 uses a small interface box that has a micro USB socket on one end and a cable to the special connector for the bike on the other. The connector socket, which is protected by a waterproof cover, is on the control unit, which sits below the handlebar stem.

The interface can be used to charge the battery, or to connect a PC, of which more later. A light on the interface glows while the battery is charging, and goes out once it's finished. The interface seems to remain cool throughout the charging process.

The control unit on the bike also has a couple of lights on it. One of these provides a quick check of battery status. If the front mech is in the small ring, pressing the down shift lever for a couple of seconds will provide battery status. If the light glows green, you're good to go.

Configuring Di2

With PC software that can be downloaded from the Web, it's possible to configure various aspects of Di2. For example, I swapped the function of the shift levers so that the larger one on the right bar moves to a smaller sprocket on the rear. This is to match another bike I have with a Shimano rear mech that has reverse springing.

This software also allows updates to be applied to the firmware in the Di2 components on the bike.

Size Matters

Tubes and Valves

Mavic supply their Cosmic Pro Carbon wheels with their own Yksion Pro tyres and tubes. One small challenge is that, presumably for aerodynamic reasons, the tube's valve only protrudes a little beyond the deep section rims. I found it essentially impossible to get any of my pumps to grip the valve to allow inflation. I was able to attach a CO2 inflator, because that screwed onto the valve. But I couldn't make any normal, mini or track pump attach properly.

The obvious solution was to change the tube for one with a longer valve. The trouble is that the next size up in valve length protrudes a very long way. They're also pretty expensive. In the end, I went for short stem Continental tubes, which have removable cores, and some Topeak presta valve extenders. These can be used with tubes with fixed or removable cores. I also have one long stem tube, which I carry as a spare.

The valve extenders come with a small tool for removing the cores, and replacing them in the extenders. The cores themselves simply screw in. They have a small O ring to ensure a good seal. I chose the standard extender length that leaves about 3cm of valve protruding above the rim on the Mavics.

Tyres

The 883 with Cosmic Pro Carbon wheels comes with 23mm Yksion Pro tyres installed. Over many years of riding my local, north Hampshire roads, I've concluded that only the toughest tyres will survive the local mix of poor surfaces, pot holes and flinty debris. Currently I use Schwalbe's Durano Plus tyres. As I was going to change them anyway, I decided to experiment with 25mm wide tyres.

I'd suspected that the clearances on the 883 might be quite tight, since the Ribble BikeBuilder doesn't include a 25mm option on the wheels, though it is available when buying the wheels separately. It turns out that there is just enough room for 25mm wide tyres, but they need to be deflated when attaching and removing the wheels, to clear the brakes, even when fully backed off.

The Verdict

So far so good. The Duranos perform well around here, as always. The Cosmic's are affected more by cross winds, due to their deep section, than other wheels I've ridden. but that was expected and it's easy to control. The one thing I hadn't bargained for, when choosing a deep section rim, is that they are noisier than conventional wheels. They're not as noisy as a disc wheel, but even so, it can sometimes sound as though you're being followed by a car, even when you're not.

Friday, 15 July 2016

Shake, Rattle and Roll

It takes a while to get to know a new bike. In the case of my new Ribble, this is especially the case. It has a Shimano Di2 Ultegra groupset, and Mavic Cosmic Pro Carbon wheels, which have deep section rims. Both of these are new to me. The 883 also has a very stiff frame. It's by no means uncomfortable and gives great feedback about the surface of the road. But it has an interesting and unexpected side effect, when it comes to diagnosing little creaks and rattles. It almost rings!

I've had a couple of rattles to diagnose. They've both turned out to be minor, but they sounded as though a major failure was imminent. My conclusion is that the wheels and the frame amplify the sounds to some extend, making them sound much worse than they really are!

The first sound developed after I'd been riding the bike for a couple of weeks. It sounded like a combination of a creak and a pinging noise, that was intermittent but that gradually seemed to get louder. I couldn't correlate the sound with the way I was riding. Sometimes it would happen while freewheeling, sometimes while climbing seated, sometimes while standing and sometimes when cruising. In the end I decided that it was probably coming from the front wheel. It sounded like something was about to collapse. To confirm that it was the wheel, I swapped it for the front wheel from my Willier Izoard. The result? Instant peace!

A Google search for odd noises from Mavic wheels revealed an adjustment about which I had no idea. Mavic's have a bearing adjustment built in. It turned out that my front wheel bearing had worked out of adjustment. With the wheel installed, it was possible to rock it from side to side a little. The side to side movement was triggering various pings and creaks within the wheel, which was amplifying the sound to alarming levels. A simple adjustment of the wheel bearings restored silent operation. Phew!

The second sound developed a couple of weeks later. This was just as mysterious. It occurred when seated or standing. So not a creaking saddle then. Sometimes it was quite loud, other times almost absent. It seemed to be louder when riding harder. Also, it only seemed to occur when on the small ring at the front. On the large ring, everything was fine.

The penny finally dropped, and I checked the bolts that hold the small and large rings together. Bingo. They had all worked loose. I've never seen this happen before. Application of a little thread locking compound and re-tightening the bolts cured the noise. Once again, a relatively small movement generated a noise amplified to alarming proportions by the resonance of the frame.

These were tiny faults that were frustrating to track down. But it was a great learning experience, and I feel I know the bike a lot better now.