Recent Entries

The 7th London Inline Marathon (my, doesn't time fly?) was last Sunday. Full results have yet to be published, because as usual there are gremlins in the timing chips, but at the moment it's looking like I came seventh.

Which - if correct - is as much of a surprise to me as anyone, because it's the first race I've done this year longer than 10k and I was struggling even at that distance.

The race was held at Hillingdon Cycle Circuit, which is slightly under a mile long and has one longish gentleish uphill leading into a downhill with a hairpin at the bottom and a shorter steeper uphill out of that. Then there's the uninteresting half of the circuit, which is basically a long gentle downhill that goes around some turns and eventually gets back to the finish line. Repeat 27 more times.

It was a UK race, which means that people were playing silly buggers at the front (note: this is not true for Cat 2 track races in the way it used to be, and I for one am suffering in the new actually-trying-hard regime. But that's for another time). The typical lap involved an attack on the first uphill, coasting around the hairpin, walking up the second hill (I exaggerate, but not by much) then waiting around at the top while everyone caught up again until someone got bored enough to lead off and everyone followed them. The common variation, especially in the second half of the race, was basically the same but without an attack. In the atypical lap another skater tried to force his way into the line in front of me and instead tripped over: I then fell over him as well (some road rash on knee) and lost the lead pack as a result. But I caught it again a couple of laps later when they were waiting around on the top of a hill.

Think that's about everything of note. Much more fun than I thought it was going to be, because I thought it was going to be much more like this year's cat 2 races. I think this was the first UK marathon where I finished in the lead pack. (Unless you count LIM 2006, but I was a lap down on them that time owing to a stack on the first lap, so, really, you don't count LIM 2006)

Knee is a bit oozy and a bit sore, but not a big deal.

P.S In completely unrelated news, I have finally written my article on armswing. See sidebar

This seems as good a place as any to describe what we've been doing lately with the Firebrox, LFNS's bicycle-based mobile sound system, and why you haven't seen it out much lately.

The background

One of the system's original design objectives was to get the speakers up high, so that the sound carried further instead of being projected striaght into the bodies of skaters surrounding the bike. Speakers are heavy, so this needs a stable platform, which means a three or four-wheeled vehicle

Well, obviously, most bicycles (the clue is in the name ...) are built with two wheels not four. Back in 2006 when we were specifying it, the chassis options appeared to be the Rhoades Car , the AVD Stablemate and the Brox Compact the decision ended up being based mostly on availability/price: we found a second hand Brox Compact for a sum which left us some cash over for buying the audio equipment.

The problems

There probably aren't many people who have personal experience of trying to ride a 3 foot wide 70kg bicycle in the middle of a crowd of skaters, so you might have to take it on trust when I say that it's hard on the bike. These things are specced for carting boxes around warehouses, riding mobile advertising hoardings around town, or making deliveries - at a sedate pace and steady speed, usually in daylight. Where are we using it? At night, under constant braking and acceleration as skaters cut in front or veer into its path, and through potholes - when boxed in by skaters there's often no chance to go around them by the time they appear. If you have any amount of mechanical sympathy, it would make you cry.

That's one problem. The other is that the bike is both unusual and elderly.

Most bicycles (the clue is in the name) have two wheels not four, so if you want to design a bike which has two wheels controlled from each brake lever and 8 feet distance between the pedals and drive wheel, you have some lateral thinking to do. The rear brakes are connected in series, in a configuration which Hope (the manufacturer) says should work in principle but is actually outside spec. The front brakes are a mix of manufacturers (Sachs calipers, Magura lever) with a T joint in the pipe between them.

Most bicycles have a headset (bearings in the front tube that allows the handlebar/forks/wheel to turn) - this one has three (steerer plus two front wheels).

Most bicycles have hub gears built into the back wheel hub, or derailleur gears alongside it: this one has hub gears under the seat, and derailleur gears attached to it, and a cog on the other side with a second chain that runs to (one of) the back wheels. What am I saying? I'm saying it's more than usually complicated, and being something like ten years old many of the parts are obsolete.

The situation

We took the bike off the road at the start of this year to fix it up a bit because it was beginning to look a bit battered: when duct tape has been used in a structural role that's usually a sign to get the wood glue out at the very least. Events between then and now can be summarised as "everything was unexpectedly complicated"

• There are two standards for 1" headsets, which differ in the internal size of the cups that slide onto the steerer. Learning this (when we observed that the usual ISO 1" standard cups would not fit) came as something of a surprise, so imagine the shock and awe accompanying our discovery that the other standard (JIS) didn't fit either. In the end we had to file the new cups to get them onto the tubes.

• To bleed the front brake calipers requires loosening a bolt on the bottom of the caliper to let the air out. This bolt has an M8x0.75 thread, requires an unfeasibly huge tightening torque to be leak-free, and has an Allen head which is made of cheese. You can see where this is going, can't you?

• To bleed the front brake calipers successfully requires getting all the air out (obviously enough). We managed this once and once only, after trying the lever, calipers and lines in more orientations and relative positions than the Kama Sutra - albeit with mineral oil substituting for yoghurt. Our best success was with the calipers lying on their back, though as it was unrepeatable I think there may have been something else involved too. "Damnit Jim, I'm a cyclist not a plumber"

• and, well, other stuff. Even the new paintwork involved bizarre chemical reactions and blistering (of the paint, not the painter)

The upshot

We have ordered some new front brakes: calipers, lever, cables, discs, the whole caboodle... They're the Magura Big, which is designed for this kind of application (apparently they are made by the "Industrial Controls" division, not the cycle division). They are expected to arrive next week. When they do we will find that we can not mount them directly on the frame and will need to make adaptors from IS mount to strange-obsolete-Sachs-mount: happily we have anticipated this and think our tame Alu expert will probably take a week or so to come up with the goods.

So, possibly a couple more weeks without music on the LFNS if all goes to plan.

Is the end in sight?

From http://groups.google.co.uk/group/uk.rec.cycling/browse_thread/thread/a24b28d1ce4d8296?hl=en&q=#d1dfbfc1476e0e02

So we have a pair of 1990s-era Sachs Power Discs on the front wheels
of our work bike. It's a closed hydraulic system and hasn't needed
any attention in the few years we've owned the bike, until recently
one of the lines broke (probably from flexing during some other
maintenance)

We've established that they drink mineral oil (not dot fluid) and that
the usual bleed procedure is to squirt the oil in from the bottom of
the system until it comes out at the top. There is a hole at the
bottom of the caliper through which one is presumably supposed to
inject the oil. It's covered by a short M8x0.75 bolt, which has a
head made of cheese.

Getting bolt off/pipe in/oil in/bolt on again without letting any air
in looks like it is going to be Extreme Faff. Has anyone who
owns/used to own these things got any tips? The ideal would probably
be to replace the bolt with a bleed nippple like the back brakes (Hope
C2) have, but even ebay is provnig not that helpful for sourcing bleed
nipples with that unusal thread pitch.

Having added twitter automation at work and for the LFNS I went on to look for more toys as well. So, this web site now sports a cute-in-an-ugly-way - actually, I am undecided, it may just be ugly-in-a-cute-way javascript-based sidebar with my recent tweets.

From http://getsatisfaction.com/people/david_needham :

I would like to filter out all replies in the html or flash badge provided by Twitter to be embedded on our personal sites. Facebook currently has some sort of filter in place which does exactly this before posting things (ie. my replies do not get posted while regular posts do). Is there any way that we can choose that option for the provided badges?

Maybe that's just ugly-in-an-ugly-way

The Twitter thing seems to be pressing on my consciousness lately, sufficiently so that I registered with it and spent a little while looking for Android clients. You can find my random spew at http://twitter.com/coruskate

Have been suffering over the last couple of days from unattributable DOMS. The only real contender was my Saturday ride to Crystal Palace and back - was quite pleased to get from Liverpool St to Norwood Junction (approximately) in 35 minutes (it helps to know where I'm going, of course, as stopping to look at the map is never entirely consonant with setting PBs) but I wasn't exactly killing myself even so. Or at least, I didn't think so at the time. Seems to be mostly OK again now, after walking home from the office this evening and then a hot bath.

As hinted last time, the Firebrox is in bits. Many bits. It's off the road for scheduled(sic) maintenance, although some of the bits we're now finding that are worth maintaining were not on the original schedule. Still worth doing them now anyway, while the weather is generally rubbish, to avoid having bits explode unexpectedly in the middle of a big skate in summer.