diary @ telent

I bought a motorbike#

Wed May 8 12:46:56 2024

Topics: motorbike

I bought a motorbike. This was a slightly more drawn-out process than I expected it to be, but the upshot was that I bought a motorbike with a working speed sensor, which might not have been the case if they hadn't serviced it before letting me collect it.

2002 honda cbr600f faired motorcycle in red white and blue, parked next to some grass.

Anyway. Collected it on Saturday. Sat on bike, started it. stalled it, started it again, rode three times round the block by the dealership hitting the horn button every time I went for the turn signals, and then forgetting to cancel the turn signals afterwards, then took off towards the A40 and the A406. Mostly 40/50 limits, lots of stop and go, but more stop than go. I mostly chose to use that as an opportunity to get a feel for the clutch rather than filtering: will upgrade to filtering when I've had a bit more time on the bike. Haven't been past 5000 revs yet.

Very grateful for the Mod 1 manual handling training but I do wish it had included how to go up kerbs, because getting the bike from the street into the back garden was hard work. The turning circle when pushing is ... not great.

I have the CoC from Honda but it looks like I'll have to wait for the V5 to be sent to me (I only have the new keeper slip) before I can do ULEZ registration.

First ride#

Thu May 9 17:16:47 2024

Topics: ride-report motorbike

Yesterday I went out for my first ride not counting riding home from the dealership.

tl;dr didn't drop it didn't crash, so it met the basic success criteria. But not an unalloyed pleasure.

For the longer-form report ... the plan was to go to a garden centre about 20 miles from home and buy a coffee to sit in the sunshine with. I perhaps foolishly decided to try navigation using Kurviger. Foolish (1) because Kurviger's idea of a "curvy" route in London turns out to be a route that eschews all major thoroughfares in favour of 20mph residential roads, and foolish (2) because Kurviger "Follow mode" is not terribly (at all) clear on a smartphone screen when the sun's shining directly on it.

I spent 20-30 minutes riding around Chingford and South Woodford before deciding I was lost enough to stop and look at the map properly, and when I did, I appeared to be on a long straight road that would have passed under the A406 (London's "North Circular Road") and rejoined the route. So I set off again Unfortunately, when I reached the A406 it turned out to be not a bridge but an on-ramp. Downside: I was now pointing in the wrong direction; upside: I knew exactly where I was and it was about 5 minutes from home. So I went home and had a coffee in the sunshine there instead.

Lessons learned: get some miles from home before engaging wiggle mode.

ULEZ registration#

Fri May 10 19:17:31 2024

Topics: motorbike

Result, indeed. My fuel-injected CBR600F (2001 and later years) meets the ULEZ standard for Euro 3 NOx emissions despite not being officially a Euro 3 vehicle, but you have to do some paperwork to get it registered as such.

  1. Get the Certificate of Conformity from Honda. This is free if no previous owner has applied for it already: in my case it was sent by DHL from Bosch in Seville, causing much puzzlement when I got the SMS notification of a package. "Don't remember ordering anything from Bosch, what can that be?". Took about four or five days https://www.honda.co.uk/motorcycles/owners/documentation/certificate-of-conformity.html

  2. The TfL process is all done on the internet https://tfl.gov.uk/modes/driving/compliance-registration/before-you-start and requires scans of the CoC and the V5C. I attempted on the day I collected the bike (Saturday of May Bank Holiday weekend), not yet having the V5C, to register using the new keeper slip, the CoC and a copy of the purchase receipt ...

  3. and had a response from them by email on the next working day (Tuesday) saying they needed the full four page V5C. My subsequent attempt to persuade them otherwise (I was polite) was unsuccessful.

  4. Today the V5C arrived in the post, so I scanned it, attached it to the email thread and sent it to them, and had a reply before the end of the day saying my application was successful.

Overall the process was pretty painless, faster than I'd feared it might be, and cheaper than taking the bike to one of the approved testing stations. I'm out £25 for the two days I rode in the ULEZ zone while paperwork was pending (can't claim that back) but that was the only cost involved.

A is for Aeroplane#

Sat May 18 17:00:03 2024

Topics: dashcam ride-report motorbike

A small propeller aeroplane of some kind: mostly grey with blue section of fuselage forward of the wings, and a red tip on the tail My motorbike, with a plane in the background that you can't see unless you zoom in A is for Aeroplane. The plan for this ride was to go to Stapleford Airfield and then on to Finchingfield. The ride as performed went to the airfield (as you can see) and then roughly northwards until the petrol light came on, then back the way we came then ... then I confused myself with the gps due to setting it for Abridge when I thought I'd set it for home. Went to Abridge twice, took in Chigwell (although no part of it that I recognized), then I saw a sign for Buckhurst Hill and it was more or less plain sailing after that. Phone battery died at some point between Buckhurst hill and home, so probably a good job I didn't need it by then.

I've done something to the wiring at the back while wiring the dashcams, resulting in the right indicator flashing at double speed. So that's a bit annoying but hopefully its just a loose ground.

Haven't actually looked yet to see if anything was recorded

The camera is made by "Vsysto" which sounds like the typical Amazon made-up name ("WISZUA") but has reviews from some reputable web site so I thought I'd take a punt on it (half the price of an Innov). By means of ejecting the microsd card and sticking it in a computer, I can verify that it did successfully record, that the rear camera was mounted upside down, and the footage is just as boring as you'd expect dashcam footage to be.

The front camera footage has a weird ripple effect, but i think that's because it's stuck to a piece of plastic that wobbles when the bike is moving. There aren't many options for mounting a camera on the front of a faired bike that aren't fairing

B is for Bunker#

Sat May 25 20:09:41 2024

Topics: ride-report motorbike

B is for Bunker, but sadly there are no photos as I was unable to actually find it. Rode out to Nazeing via some twisty turny up and downy NSL roads, which was fun at times and slightly scary (gravel) at one point, and also slower than necessary at other times due to cars travelling 35 in a 50. Though perhaps if it hadn't been a 50 I'd have spent more time looking for the bunker I was there to find.

Nazeing' was a World War II airfield decoy controlled by RAF North Weald some four miles to the east. The decoy was both a daytime K' site and a night-time Q' site. K' sites included grassed runways, defence positions and plywood aircraft amongst their simulations; Nazeing was equipped with dummy Hurricanes. `Q' site deceptions included runway lighting, obstruction/recognition lights and moving headlamps.

Why we lean#

Mon May 27 17:47:26 2024

Topics: motorbike

I think I have mostly figured out, in my own head, why lean and why counter-lean and when. This may be one of those subjects where once you understand it you lose the abilty to explain it but here goes anyway.

You can turn a bike by steering it (turning the front wheel by moving the bars), or by leaning it, or by a combination of the two.

Steering is like in a car: the wheel is pointing at an angle to the direction of travel. The tyre sticks to the road a bit instead of sliding smoothly over it, so the wheel is exerting a force on the rest of the vehicle. This force is acting partly against the direction of travel (providing a "drag" force) and partly at right-angles to the direction of travel (providing a "slip" force). Per Newton, the sideways slip force changes the vehicle's direction of travel to make it go round the corner. On a bike, trying to turn using steering alone will result in falling over. Suppose you're turning left, the bottom of the wheel is being going left slightly, but the bike has mass - and therefore inertia - so this will cause it to rotate rightwards. Once the centre of gravity is no longer over the tyre contact patch, it will topple. The faster you're moving, or the sharper you turn, the greater the sideways force.

Leaning is not like in a car. The diameter of your tyre is largest measured around the centre of the tread and gets smaller as you go off-centre - so if you tilt the tyre then you're rolling on a section of a cone, not a cylinder. That will naturally go round in circles. Here's the thing, though: the radius of the turn depends only on geometry. The shape of the tyre and the angle of lean say how sharp the turn is going to be; the speed you're going at has (approximately) no bearing on that.

So we're rolling a cone and it's turning. Per logic and Newton's first law of motion, we know that to be turning it must have a force acting on it, otherwise it would be going in a straight line. Wikipedia says that a centripetal force has an acceleration of v squared/radius.

So there's a sideways force pushing leftward on the bottom of the wheel, and this is going to tend to rotate the bike rightward. But, the motorbike is already leant over to the left, so there's a competing force from gravity which is going to try to rotate it leftwards. Which one wins?

(This is the bit I haven't figured out: if we're looking at rotation then we should be comparing moments not just forces, but about what point do we measure the moment? The "hinge" is at the ground, but that means the centripetal force would have zero moment; the other obvious point would be the CoG. but that means the gravitational force (which acts at CoG) has zero moment. Anywhere else we can pick seems kind of arbitrary. Anyway, we can handwave the next part ...)

The gravitational force is greater when you're leaning further, and the camber force is greater when you're leaning further (sharper turn) or going faster. We assume you don't go so fast that the tyre loses grip. So there should be some speed for a given turning radius where the two balance. If you want to go around the corner at some other speed, either you can change the sideways force by adding/removing slip (turning the bars) or you can change the turning effect from gravity by shifting your bodyweight to move the overall centre of gravity nearer or further from vertical.

fear my poor inkspace skills. diagram of a motorbike tyre showing its contact patch looks like a conic section when leant over Thus: WSBK riders get their knees and their elbows down, but Motogymkhana riders shove their Harleys sideways and stay upright. And Fortnine is a clickbait merchant. Ryan YOU'RE DOING IT WRONG, for any value of "it" equal to "explaining things".

It does feel kind of magical in an "anthropic principle" way that the sideways force we need to go around a corner can be provided by leaning the bike onto the rounded part of the tyre - and that changing the bike's CoG by leaning it is also providing the balancing force that stops the cornering from throwing us off to the outside. God is ~~an astronaut~~ ~~a DJ~~ ~~a cyclist~~.

C is for Coal-tax obelisk#

Thu May 30 13:13:34 2024

Topics: ride-report motorbike

stone obelisk bearing City of London coat of arms, by a railway track C is for Coal-tax obelisk

In an early example of the City of London's approach to democratic principle, they erected a series of pillars of various kinds at a 20 mile radius from London to mark the boundaries at which coal brought into London would be taxed. The tax was spent on rebuilding bits of central London (mostly churches) after the Great Fire. The practice ceased in 1890.

This particular obelisk I went to visit is in Wormley, just south of Broxbourne. It took a bit of finding, too, mostly because I saw something that I thought was it on OSM but that turned out to be a completely different coal tax marker. It is entirely possible that I also found (or at least, looked past) that marker and didn't register it because I was expecting to see something taller than I am.

The ride there was speed-limited, first to 20/30-in-places by speed limits in Waltham Forest, and then to around 40 by the van in front of me and the solid white "no overtaking" lines in the middle of the road. It took ~ 40 minutes longer than I'd planned, most of that spent wandering around Wormley woods looking for the wrong thing in the right place.

(My other clue was http://www.coaldutyposts.org.uk/today/list.html which says "E side of railway, N side of Slipe Lane at level crossing". This is all true except for the bit about the level crossing: there is no level crossing there.)

I suppose the lesson is that if I want to do motorcycle treasure hunts for random listed monuments I should expect to spend time hunting, not juist ride there and back and tick off another box,

The ride back was straight down the A10, not a lot to say there.

Anyway, D is - unless I have a better idea by the time of my next ride - for Duck Pond, which should be a much more straightforward endeavour.

carved into obelisk, the Corporation of London shield: "rgent a cross gules, in the first quarter a sword in pale point upwards of the last". That's how wikipedia describes it, anyway Inmscription on base reads "14 & 15 VIC. C 146" Close-ups