Thank you all for turning up - in the end we had about 8 (I never bothered to do a proper count - that wasn't the point). Mostly on Bromptons, with a couple of big bikes to leaven the mix. I had a lovely rest from my desk!
I must apologise for my inability to find Bevis Marks synagogue - I had a little lecturette prepared on the way in which Britain has opened its doors to immigrants over the years and adopted them in our own particularly spiky way (BM was built by a community chucked out of Spain and Portugal to a British non-conformist church design; the mosque was originally a chapel for Huguenots chucked out of France, then taken over by jews chucked out of Russia; Christchurch Spitalfields was built by the Brits to convert the Huguenots to Anglicanism). When I realised we'd missed it I was tempted to take a detour into Devonshire Square for a photography session (see P&Lite a few months ago for the reference).
I'll take a look at my diary and suggest another date. There are plenty more roads in the City and East London to potter around, as well as a few parks (being optimistic about the weather). Alternatively, we could aim in a particular direction - 20 minutes north/east/southeast/south. I'm only not suggesting west because that's the direction I come from.