3 min read

Older Bikes & ULEZ

London’s extended Ultra Low Emission Zone has now been in force for six months. Any vehicle used within the North and South Circular Roads falls into one of three categories: exempt, compliant or subject to a daily charge of £12.50. It’s now proposed to extend the zone to cover the whole of Greater London, which will affect many more motorcyclists , both residents and those needing to travel into or through the zone.

Those exempt include those registered as Historic Vehicles, so my 1976 400/4 is exempt. Since the ULEZ charge was introduced (initially in the Congestion Charge zone only) I’ve been relieved to have a vehicle that gives me a charge-free option for travelling in the zone, but when it was decided that the ULEZ zone was going to be extended to my front door, I thought that I’d better investigate compliance for my other bikes.

The National Emissions Test Centre, run by Riverbank Motorcycles in Bow, offers the only route to compliance for pre-Euro 3 bikes for which there is no manufacturer’s data to demonstrate it. The test measures average NOx emissions over a set rolling road route and, including the related TFL admin, costs £175. That’s 14 daily charges. At my current rate, I might not use any of my bikes 14 times before the rules might change, but that’s not the point: if using my 400/4 instead of any other bike would save me £12.50, it might become the only bike that I’d ever use.

First to step up was my Honda NC35. Riverbank had tested Japanese market 400s and they had generally passed, so I had reason to be hopeful. I swapped in an old air filter (lean running raises combustion chamber temperature, which increases NOx emissions) and tanked up with Super Unleaded. The bike failed anyway, but Riverbank welded a catalyst into the link pipe and it passed on retest. Total cost around £400.

Next was the 1994 Ducati 600ss. Its fuel efficiency indicates that it runs pretty lean, so I thought that I'd fit a catalyst before the test and save the retest fee, but investigation with Riverbank showed that there was nowhere convenient to fit one. Riverbank had seen 600 Monsters pass without work, so I took a chance and the ss passed. Cheap at £175.

That left my 1998 Ducati 1078ss - that’s a 600ss with a 1078 Hypermotard engine. The Hyper is Euro 3 compliant, so it should be able to pass, but the ss has a one-off exhaust, and I knew that the front cylinder was running rich and the rear running lean. A good reason to visit BSD in Peterborough for some ECU mapping before the test. The mapping made the bike much nicer to ride, but when I took it to Riverbank the tester pointed at the RSV Mille silencer and indicated that, in his experience, Aprilia catalysts are unpredictable in their effectiveness. I must have got a good one, because the bike measured 0.01 g/km against a compliance limit of 0.15 g/km. Relief, for a total cost of around £600 including my trips to Peterborough.

So, at last, my choice of which bike to pull out of the garage is unfettered by cost considerations, and once again based purely on whichever I fancy out of those that will start. It’s not been cheap, but compliance must surely have added to the bikes’ market value in fair proportion to my outlay, and it’s good to know that their effect on London’s air quality is near-benign.

Tests can be booked online at the National Emissions Test Centre website, and at the time of writing the wait for available slots is relatively short.

Tony White – Morini Riders’Club


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