Saturday 26 February 2022

The XS Triple sidecar says bye bye - a comparison of sidecar concepts

 So the mighty XS Triple sidecar is sold. 

This gave me the chance to do something that I already did the last time, when two of my sidecars were parked side-by-side. As some will be quick to point out, I went (again) from one extreme to the other. From a very powerful (some might say overpowered) to a very light and small sidecar. The thing is, the size difference is rather hard to grasp, unless you see both bikes next to each other.

Even though the trackwidth only differs by 120mm, the weight difference (the XS Triple weighed in just shy of 400kg, whereas the SR500 with its fiberglass Velorex in under 200kg, both with a full tank, etc.)

The last ride was lovely though. Sunshine, not too cold and the mighty triple sang its song. Do I regret the sale? No not really, it turned out that it was just too much sidecar for me and my use cases. Too thirsty, too loud and only vaguely usable during the Winter months due to a lack of weight on the rear wheel and just too much power, yet not quite the kind of the torque that would be necessary to make good use of it.

Saturday 19 February 2022

Unholy unions - XV750 with 1290 SuperDuke running gear

When it comes to building bikes for myself, I am a bit of a traditionalist. Also, I am cheap and old and tatty bits are a lot cheaper than new and shiny stuff. That being said, my mate Andi, well he prefers to go down a different route.  And as a result, he got himself "da good" stuff. KTM/WP 1290 suspension all the way and asked me to make it fit. 

We started off with the rear shock, which was pretty straight forward and just needed a few bushings to reduce the internal diameters and to locate the shock properly in the bike. 

Front forks are dead easy, press out the stem out of a set of XV750SE triples, turn it to size and press it back in, into the SuperDuke triples. 

So what was in it for me you ask? Well there's this little 790/890 Duke shock, which looks like it could turn out be a VERY good replacement for the current XT600 1VJ rearshock I currently run in my TR1...

Thursday 17 February 2022

Bye, bye Rhino Lathe

 ... you will be missed. But, as much as I would have loved to, there simply isn't enough room for a big and a small(er) lathe. Even though I borrowed an engine hoist, in the end, we mostly did the lifting by hand and as much as I wouldn't recommend doing it that way, we managed to scrape by without any substantial injuries.

And yes, you can fit the lathe and the cabinet in just one family size station wagon. (I am not going to say, with no problems at all, but...)

So ends the story of the old girl. Now why swap a bigger lathe for a smaller one? Mostly because the Matra just has got a lot more ooomph to her and in general is just that useful bit more rigid. Yes, there will undoubtedly be moments, where I'll miss the bigger work envelope of this old girl, but for the most of the time, I do work that could be done on a much smaller machine than Martha II.

Friday 11 February 2022

The SR500 sidecar - she's a (rock 'n') rolla (part 12)

 Two unexpected, but very pleasant events greatly ate into the amount of time I had lately to make progress on the SR500 sidecar. First the new to me Matra lathe on the one hand and on the other hand the fact that "ye olde XS Triple Sidecar" was sold rather unexpectedly, which again meant going through all the usual work involved with that of getting it to the buyer, deregistering it and so on... 

First things first was to primer (and later paint) the modified sidecar frame and then throw a decent amount of paint onto the actual sidecar body. 

A lick of filler to cover the worst spots on the sidecar. Which was sort of the point, where I realised that the gel coat had cracked in so many cases that this was a noble yet entirely futile attempt.

So on with primer and paint. But isn't that snow I hear you say? Absolutely it is. But if you heat the inside of a grp sidecar with a bathroom heater or a hot air gun and it's a windy day, so the fumes are extracted quickly enough one can do an a lot nicer job than even I anticipated.

With the scope of the project so hopelessly out of the window, I decided to go ahead and make my own swingarm for a long-stroke shock. I did this for two reasons: first the stock velorex shock is somewhere between garbage and junk and I have plenty of 320-330mm shocks (stock shocks of SR500s and XS750ies) and finding a decent replacement down the line shouldn't be too hard. Spoiler alert: already been given a very nice Koni 7610-1303 so the old girl will roll in style like it's no one's business. Initially I had this idea of taking the stock swingarm apart, but as it twisted when undoing one of the bolts, I realised starting from scratch might be the MUCH smarter idea. 

One of the neat side effects of making my own swingarm was that it allowed me to lower the sidecar wheel spindle by 40mm. This meant that the sidecar would now sit level and have an extra 40mm of ground clearance, which undoubtedly will come in handy at some point when playing in the snow.

With a wheel attached to the sidecar swingarm, I mean it would be rude not to roll it out I guess?

A quick test fit of the stock Velorex mudguard indicated that with a bit of tweaking the position and arch should still work fine. At least for a start.

I totally had the plan to fit a 4.00x18 onto the XS400 wheel shown above, but due to a lucky coincidence a friendly fella on the German SR500 forum promised me two SR500 rear wheel for shipping, so my (currently only) spare SR500 rear wheel went onto the sidecar, which also meant redoing the axle as the SR500 wheel is a quite a bit narrower on the hub.

Originally I had planned to make my own (emergency) seat from some builder's wood plate, but after looking at the matter more closely, I am not a wood guy and it most likely would have caused some issues, when getting the sidecar approved, so I bit the bullet and got a new seat and also a tarp.

It is a very good seat as I would like to point out. The sidecar is a bit tight for a full grown European about half a century later than the Velorex 562 was designed. Honestly I think I wouldn't be able to get my feet in there with the stock handrail installed.

Well she's a roller, everything is snugged up. First start and a little testride to let the neighbours know that there's a new thumper in town. After a quick warm up checked the battery voltage: charges nicely both with the light off and then with the lights on.

 Uh oh... but she might be a bit on the lean side, if I may say so.

One of the few actual problems that surfaced during the testride was that I had forgotten to fully tighten the rear lower sidecar mount. Milled in a pair of flats and this will certainly NOT happen again. 

Best way to fight a lean condition? Fit the bigger airbox of a later model SR500. Downside: rearwheel and inner mudguard have to come off. 

With the rear wheel out, the time had come to do finally tackle a job I had postponed more than once. Fitting tyres isn't too bad with normal tubed stuff, but if you deliberately fit a set of "weal seasoned" Avon Sidecar Triple Duty Mk. IIs, named this way because of their extra thick sidewalls... 

Admittedly the TKC80ies looked a lot cooler, but these are really durable and I plan to use the sidecar and clock up some miles on it. Also passing inspection on worn tyres is rather unlikely. 

So what's the next steps: Not that much left anymore to be honest. The rear upper mount needs reinforcement to prevent it from twisting under load. Then the sidecar mudguard has to be put back into shape and installed. Once the frame has got some reinforcements the whole lot needs to be dialed in correctly and then I am at the engineer's mercy.

Saturday 5 February 2022

Martha II - a Matra MDR2A for every need

If you feel like you suffer from a deja vu, well you're not entirely wrong. There used to be a Matra MDR2A in my life before, which thanks to a typo of the seller was called "Marta". As a result it only seemed apt to call the new Matra, Martha the second. 

A bit of backstory to those Matra MDR2A lathes. They were heavily influenced by the American Regal LeBlond 10inch lathes, which were found as standard equipment on American WW2 vessels. The Matra with her 240mm swing over bed is a bit smaller. Now these weren't found on ships, but inside tank repair/service trucks. This also explains why a German made lathe can produce a stupidizillion of imperial threads, but only some of the most basic metric thread pitches. (To be fair, those cover about 90 percent of what's out there anyway.) With the step-by-step replacement of the WW2-era American M41 and M47 tanks, the tank-repair trucks also started to become obsolete and by the early 1960ies the German army retired these lathes and sold them off. There is also a civilian version of this lathe, but it doesn't carry the motor on top, but in a more conventional position behind the headstock and thus the casting is notably different.

So what I did is exactly what I tell everyone not to do. I bought a lathe sight unseen and asked a mate to pick it up and deliver it to me. (Luckily said friendly fella, who goes by the name of Torsten, also bought my old Rhino/Coronet and after about a week or two of arranging everything and a very friendly seller, everything worked about as smooth as one could hope for in a deal like this.)

As should be rather evident by the picture above, the lathe came without a suitable cabinet. For a plethora of reasons I chose the approach more akin to a certain Swedish furniture house.

In this picture the reinforcement bar was still missing, because I had to build the cabinet, whilst the lathe was still about 400km away from my workshop.

There's no pictures of the lathe being put up on the stand as that involved three people and a bit of swearing and as a result there was a distinct shortage of spare hands to take photos. Due to the nasty surprise with my last Matra, I checked the spindle nose and it is in pristine condition.

The following morning a slightly more in-depth assessment of the situation was undertaken. Just as the seller told me, it was used for woodwork the last few years. Overall the condition wasn't bad, but very dry. A bit of scotchbrite quickly dealt with the surface rust and a plenty bit of oil made sure it wouldn't come back quickly.

Especially the Norton box needed a lot of penetrating oil and then some regular engine oil to become movable again. Still not entirely sure, whether it wouldn't be a smart move to take the box off and clean it in some diesel.

Speaking of which, the lathe came with two lovely vintage Arowa chucks, a #3 and a #4. Unfortunately a mix of rust and wood-dust locked them up tight. A few days in diesel made them loose enough, so at least the jaws could be removed and the ways derusted and polished with a brass brush.

You can just about make out the amount of rust and crud stuck in those ways and this picture was taken after the first cleaning...

 Now a lathe is not really much good without a motor. I chose a 2.2kW single-phase motor running at 2800rpm, mainly because I had two of them and I thought it would not give me much trouble... In comparison to the original switches backplate, this 3mm steel plate is almost flimsy, with the original being made of a casting with at least 6 or 7mm of thickness. In case you're wondering, why the switch is so much to the right, that's because I will need room for the direction-selector-switch later.

Looking good, eh? Well that electric motor wasn't. No matter how it was wired up, it would always trip the breaker.


Luckily I still had a Soviet-era Polish-made 1.5kW Wefamel single-phase motor sitting on a shelf and just as the paper said: "Made by the proud socialist workers of Poland to the highest standards". Not entirely sure what those standards actually are, but it works and is about twice as heavy as a modern electric motor with the same power rating. 

 ... and as I did all the wiring I made sure that the motor and lathe are actually grounded, you know healthy and safety and all that, because electrocutions really spoil the day. 

And there she is... in full glory...

... and running too!

All nice and good, but how well does she do her spinny-turny-thingy?

Any further questions? Because I don't. That is some lovely performance, the surface finish is almost like it's been polished, the swarf that came off was almost perfect and subsequent attempts that the old girl is not in the taking prisoners business. 

So what's the plan in the near(-ish) future: First I have to get the thread-cutting gears set up for metric and then fabricate two new backplates for new (not yet bought) chucks. Nothing against those lovely Arowa chucks, but they've had their best days probably somewhere around 50 years ago. Other than that, the cabinet still needs some actual trays to put stuff in currently there's just a few planks resting on the bars to get some of the tooling out of the way. And lastly, the motor has to be rewired (again) for a direction-selector-switch so I don't have to turn the lathe back by hand, when thread cutting. Other than that it will see some more cleaning and an oil-change and mostly simply be used because it is in lovely condition and I see no reason to tear it apart just for curiosity's sake. 

 Oh and last but not least: Special thanks for Torsten for the logistics and quite literally "the heavy lifting", Raffi for even more lifting and Ralf for putting up with all the hassle that was involved to get the lathe from Germany to Austria without even exchanging a single word face to face.