Not a grinder, but I recently bought a Bodum Travel Press mug (basically a French press built into an insulated travel mug) and a Portland Design Works handlebar cup holder. They fit together perfectly and the mug stays securely on the bike. After drinking instant all down the Pacific coast and through Mexico, when I reached Guatemala I realized I shouldn't waste this time in prime coffee country. I'm very happy with this addition to the bike. The mug makes a decent cup of coffee and I can pick up freshly ground local coffee when I need it.