Zel's Fleet Blog - BX, Jag XJ-S, Sinclair C5, Mercedes 208D & 230TE, AC Model 70.

[CitroJim]

Zel, could you perhaps engineer a bike disc brake on to it? They come in both cable and hydraulic...

[Zelandeth]

The tricky part of engineering one is actually the mounting of the caliper on the fork. Attaching the disc to the wheel is pretty easy.

Forks made for fitting of disc brakes are usually reinforced to handle the forces involved. So adapting things for that really requires you to weld brackets on and some additional reinforcements. There's a guy down in Kent who charges £50 all in for this service - you send him the whole fork and your front wheel and he does the whole lot - so I'll probably be doing that shortly.

The rear brake is drum based and there's really not much that can easily be done to improve it. Fitting discs on the rear is quite tricky given the hub and axle design. It can be done, but is quite a lot more work. Unless you're running some crazy 24V conversion that will do 35mph odd, having a standard disc on the front will generally serve you perfectly fine.

[CitroJim]

For the work involved, £50 is not bad at all... Try to get a hydraulic disc if you can. they're seriously good..

[Zelandeth]

The £50 includes a standard off-the-shelf cable operated caliper - a cheapie obviously, but by all accounts on the forum is man enough for the job. Probably a bit on the heavy side for a push bike, but given how much of a brick the C5 is to start with a few hundred grams isn't going to make a huge difference! Forks will come back with a standard disk brake mounting on anyhow, so if I wanted to upgrade to a better quality caliper at a later date there wouldn't be anything to stop me. A basic disc compared to what's on there at present (standard cantilever brakes - on a plastic wheel rim) which are essentially completely useless. The front brake with a ratchet strap holding it on will just about hold the thing still on a moderate slope, forget using it to slow down/stop. You're at the mercy of the puny drum on the rear for that!

Did stumble across a bit of a surprise when I was out and about today getting a replacement inner tube for one of the other bikes. The Sinclair unsurprisingly has moderately oddball tyre sizes (at least these days), with 16x2" rubber on the back, and 12x2 1/4" on the front. Mine still has the original tyres on, and to be honest they are utterly shot. Perished to the point that I'm staggered none of them have actually come apart on me, and so hard that the ride is shocking, and grip is nigh on non-existent. Especially annoying when the already well discussed rear brake likes to snatch when it does actually do something useful. I'm sure their original "low rolling resistance" characteristics are also rather impaired...

The general consensus seems to be that Schwalbe City Jets are the best current replacement for the original Sinclair branded tyres (made for them by Vee Rubber). They aren't tyres you tend to see in these sizes "on the shelf" though, so I was rather surprised to find a 12x1.95" one at Go Outdoors. Was a reasonable price too, so grabbed it (it's a slightly narrower tyre, but is still a perfectly suitable fit). That's also poked me into ordering a pair of matching 16" tyres for the back which will hopefully arrive towards the end of the week. Be interesting to see what difference they make, and see whether just changing the front one has had any appreciable effect. Will see if I can get it out for a while tomorrow to find out.

Here's the state of the tyre that came off. I think it's fair to say that this is past its best - but for a 30 year old and well used tyre ain't that bad really!





This is an improvement I think...



Then had to wash a heap of bird muck off the Xantia as one had manaded to in one shot get the bonnet, windscreen, roof and rear windscreen. The joys of having a car waxed to within an inch of its life though resulted in the whole lot just rinsing straight off.

Then got around to finishing off the wardrobe in our master bedroom. Curtain rail and curtain installed, the plinth at the top to hide the rail also installed, along with a light tucked in there to provide some nice indirect light at that end of the room when it's in "Spa mode." I've got a 2500K tube for it rolling around somewhere once I can find it which will make it a far warmer light more suited to its role. Photo below actually makes it look far brighter than it actually is.



Excuse the board in the window! One of the things I deal very, very poorly with these days is any temperature north of about 20C - and our house is very thermally efficient, so an air conditioner is a must in there - portable one for now, our plan being to get a proper split air con system installed either next year or the year after. Big issue we had though was that it just tended to suck warm air back in from outside when the window was open. Hacked off with this issue one evening I stumbled across a conveniently window-shaped sheet of chipboard and made a snugly fitting baffle that resolved that problem. More than halved the time the compressor is running on an average evening anyway. It is ugly though. Keep meaning to at least paint it and add a couple of handles to make it easier to manhandle...Have dropped it on my toes enough times already as it is. Or I could be sensible and go get myself a thinner sheet which would be about 5kg lighter. That seems like giving in though.

[CitroJim]

That tyre has done well to last this long like that Zel.. They must have been very high quality to start with!

Aircon? I've been needing a bit of heat recently in the evening up here!!!

[Zelandeth]

The C5 tyres were of really good quality originally (I know a few people who are still running originals which have been stored better than mine and are still showing little or no signs of perishing). The original tyres were of a special compound made for Sinclair, as nobody (as far as I'm aware) made low rolling resistance tyres with wider cross sections like these back at the time, the intention being to get both a comfortable ride *and* low rolling resistance.

Having spent a good number of years in a damp barn however, mine were pretty rotten externally by this point in time (the main motor control relay being full of water required a bit of remedial work too). Rears were a bit worse than the front one - and the offside one was completely bald as well, though credit to them they were still structurally sound, it was just the surface rubber that was perished. The replacements for the rear arrived today from Germany (including the postage, still cheaper than I could find them in the UK...go figure), and are now on.



Haven't had a chance to take it out properly yet, but a quick trundle around the house has revealed that it certainly seems to roll more freely - though how much that's just me expecting it to I don't know. We'll see once I get it out for a proper run when the speedometer will tell the story.

Would really like to do a LiPo battery conversion, as you can easily fit a 60Ah pack in the bottom of the luggage compartment. That knocks about 7kg off the weight (and centres the mass better), and gives you a useful battery range of something like 50 miles. Unfortunately you're looking at a bill of a few hundred quid for the batteries alone, which is kind of hard to justify!

Had planned to do a bit of cleaning up work on the Saab this afternoon but while looking for something else in a box, re-found this...



...and proceeded to lose the next few hours playing with it. It's alarming how often that sequence of events seems to happen around here.

My internal thought processes seem to spend far too much time going something along the lines of:

"I promise that whatever I do, I will not get distract...Ooooohshiny..."

[CitroJim]

Tyres, as I have found on bikes Zel, can have a heck of an effect on rolling resistance.. Those new ones almost look like small motorbike tyres.. What are their primary application? A small scooter?

Long time since I've seen one of those Psions...

Up in the attic I have an old original Palm Pilot...

[Zelandeth]

I think their main intended audience is for city commuter bikes. They're kind of a cross between a conventional mountain bike style tyre and a road bike's. The unusual profile is down to the deliberate designing into the structure a degree of suspension to deal with typically potholed city roads. There seems to be quite a bit of vertical give in the sidewalls, but the tread surface doesn't seem to deform nearly as much as on the likes of a normal mountain bike tyre, deliberately keeping the rolling surface actually touching the road to a minimum for efficiency. At least that's my theory based on me poking and prodding them and trundling around the side of the house while peering at the tyres. I believe they have a kevlar type material layer built in as well to aid in puncture resistance.

Curious to see how they work to be honest, will report back once I've had a chance to take it out for a run.

Been a while since I'd seen the Psion as well, and to be honest I'd forgotten that I even had it (if memory serves, it was a five quid impulse buy from Cash Converters, which I used to live a 30 second walk away, which was rather dangerous). Sadly this one is starting to show signs of the usual screen ribbon cable failure, so I'll need to do some surgery at some point. Screen still works fine on this one, but the backlight doesn't (it's often the first thing to go as its conductor is one of the nearest ones to the usual failure point). Still cannot help but see how advanced a little device the Series 5 and 5MX were for their time. To be honest, had it wireless networking abilities I could see me still having a use for it today.

I really do need to properly inventory my old tech at some point. Between stuff like that, several old Palms, a quintet of 386 Toshiba "portables" at least three or four 486 desktops, a handful of Amigas, more Archimedes machines than you can shake a stick at (the RiscPC still eludes me though), a Macintosh SE, and an Atari 520STE that I found about a week ago that I have no memory of ever owning...I really need to actually keep track of what's where! Then actually try to get the relevant section of my website updated. Suffice to say, I'm one of those people for whom floppy discs are a valuable commodity as I always seem to need more. Especially as in my more active years I was primarily an Amiga user, so the vast majority of my stockpile are 720K double density ones.

[CitroJim]

Sounds more like a museum of computing Zel Very interesting..

Next time you're here I'll show you a processor box I have from an old mainframe that holds special memories for me - a beast I worked on for 20 years...

[Stickyfinger]

You guys !

Here is some Retro VALVE P~O~R~N to keep you going on a cold wet late autumn night.....

[CitroJim]

Love it! State of the art when I first started work...

The one I spent a load of my working life working on was a Ferranti Argus 700 complete with CDC Cartridge Disk Drives the size of fridges Loved them...

[Zelandeth]

That's quite an installation!

I'm still waiting to stumble across any really old computing hardware, don't think I've got anything earlier than the 80s. TVs back to the 50s and radios to the 30s though mind you...

Still need to make a proper visit to the National Museum of Computing down at Bletchley Park. Had to cut it short last time as we were running massively late on account of how much more stuff there was in the place in general compared to when we were last there. The Harwell Dekatron/WITCH is quite a machine to see in action. I think in a lot of ways, machines from that sort of era (and Colossus of course) are even more interesting these days now that I have a reasonable understanding of *how* they work. Before I got into vintage tech, it was a bit of a mystery as it was so alien to what I was used to from college and my own experiments.

Had the Sinclair C5 out for a run today to see what the new tyres have done. Definitely has cut down rolling resistance quite a bit. By far the biggest changes though are ride and handling characteristics. Both are vastly improved, surprised it made much difference to the way it corners as it was already pretty good (they're a lot more stable than you would think - though two wheeled moments do happen if you're being silly).

[Hell Razor5543]

A friend once passed me a mess of wires and ferrite rings, and bet me I could not identify what it was, and how it was made. He lost the bet (much to his chagrin!), as I had seen something like it before (and how it was produced). It was a chunk of early computer memory (with X, Y, and sense wires passing through each ring), and it was produced by knitting!

A colleague once told me of an occasion he had seen the aftermath of, when a computer storage drum had had a bearing fail. These units were very large cylinders mounted horizontally, weighing tonnes each (not sure how many, but it was measured in tonnage!). As you can imagine, the frames and bearings for these were massive, and spinning them up to or down from speed was a 2 day job each (so they were not switched off very often!). On this occasion (fortunately the climax was at the weekend) the lubrication system failed, and so one of the main bearings ran dry. When it did fail the whole cylinder went for a wander around the basement (where it and its' siblings were located), and destroyed everything it encountered (fortunately it didn't manage to convince its friends to leave their frames and join in!). When the first technician went in there on the following Monday he left in a hurry, and got the building evacuated. It took building inspectors a few days of very careful (and nervous) inspection before the building was pronounced safe to enter!

[Zelandeth]

Goodness, that must have made a mess. Remember seeing a photograph where one of the early disc based systems had a similar incident. In that case though it had exited the cabinet, sliced a desk clean in half and then vanished stage left via the exterior wall. Must have been quite the event to see, obviously provided nobody got in the way! Do wonder how far it went before it stopped...

The thought of an early drum system doing the same is downright terrifying!

Best I can compare was one day when I had a DVD escape from my first DVD ROM drive at full chat (think it was an 8x speed drive from memory). I got it free because the tray was knackered, but being resourceful I stuck a hinge on the case lid, linked out the tray interlock, routed cables as needed and ran it as an external drive. One day though I didn't put the little magnetic "hub" in place quite right, and being lazy had left the lid open. About five minutes later, the disc ejected itself from the drive, left a couple of millimetre deep skid mark/gouge in the side of my monitor, did two complete circuits of the room at ceiling height before getting captured by the bookcase. I was rather glad that the first thing it hit was the side of a hulking great CRT monitor rather than my head. ...never left the lid open again after that!

[CitroJim]

Gosh, yes I've watched a CD make a bid for freedom from a CD duplicator... It's scary...