Mailbag #14: Unicorn troubles

I ride a Honda Unicorn. I do ride my bike fast but prefer to be very safe unlike others my age (I turned 20 just a few days ago). What I wanted to know is that earlier, however hard I rode my bike in the traffic it would return 50 kmpl. But off late (for the last 2,000 km or so) I have been getting 45 kmpl. I don't want to ask you how to get better fuel economy, not at all. In fact, I am not really bothered about the fuel economy, but I was baffled by the drop in mileage especially since I don't think my riding style has changed a lot. How does one analyze things like that when most of the magazines claim 55+ kmpl in the city? Is it possible that there could be something wrong in my bike (suddenly)? The authorized service station is a dreaded place to go to, most of the days they have more bikes to service than they can, so my guess is they just wash it (not even properly sometimes) and give it back. I would also like to point out that my bike has run close to 24000 km in about 22 months, previously I was running MRF Zapper-Q 100/90-18 at the back and very recently shifted to Michelin M45 3.25x18 and I do keep a check on the tyre pressure regularly. And ever since I bought my bike I have been filling up at the Shell stations only, which sell unadulterated petrol, to the best of my knowledge.

Secondly there's this frequent problem with the wheel alignment cropping up, I spoke to a few other Unicorn owners on a popular biking forum and they too seem to have the same problem. The only solution is frequent wheel bend removal and re-alignment. My query is, is it harmful in anyway if the wheel bend is removed and aligned frequently? Like every 3000 km or so.. awaiting an early reply eagerly..

C Hooligan K (no kidding)

Service
On the contrary, I think Honda's service is the best in the business. In Mumbai, at least, they promise and deliver one hour service, without fail. And to the best of my knowledge, they cut no corners.

Bent wheels
I assume you have a spoked wheel Unicorn. Spoked wheels and their bending is a normal thing especially if you ride hard. When riding hard, we tend to go over potholes and stuff at speed, which seems to transfer no shocks to the bike, but it does bend rims. Quality alloy rims, especially the OEM-spec stuff, is better at handling this, and usually will not show any wear from this kind of bashing. Removing the bend itself and realignment is the only way around it, but again, bending this often usually points to a problem with the riding style – not enough mechanical sympathy – than really a problem with the bike. If your rim is bending so often that at every service you have to unbend it, the problem lies with your riding style and you need to reconsider your choices when it comes to broken roads.

Fuel economy
Fuel economy unfortunately is a fairly nebulous thing. It's hard to replicate numbers you've read and harder still to remotely diagnose a ten per cent drop in economy. I'm certain that your tyre change has something to do with it. The Michelin is stickier than the Zapper, that will definitely push down your economy. As far reported figures go, the figures are designed to be comparable across tests, rather than hundred per cent replicable on the street. So a magazine would design a test cycle that can be used on the largest number of machines and produce a representative number. In your case, you see 55+ kpl. Plus you have to consider the rider's weight, ambient temperature and a whole host of other figures (including the fuel load during the test cycle) befre you can replicate that number. You indicate that you ride hard, this will automatically put you in a place that returns lower economy than the test results. Performance testing is one part of road testing, fuel economy test cycles tend to be gentler by design. There's little point in reporting fuel economy off a throttle-wide-open test cycle – no actually rides like that for long.

Shell, I've heard, is good fuel and accurately dispensed too, so that's not a factor. Other reasons could be smaller stuff, like your spark plug gap, chain tension and lubrication, dirt in the air filter... all of which alone make only minor deductions from the economy, but together can add up to 5 kpl.