DIY truing stand

I think I’ve mentioned that I did build several wheels sets for the Sprint in recent time.
A P&K Lie truing stand is slightly out of my reach and I hesitated spending money for a cheap truing stand when I could build one myself.

A length of 25 x 3 mm aluminium tube, a piece of 40 x 60 mm aluminium bracket, a M10 all-thread rod and an old dial indicator where at hand, the piece of water-resistant plywood, a piece of zink-plated steel plate, some washers and some M10 nuts came from the local hard ware shop. Ebay provided the cheap magnet stand for the dial indicator.

The construction is fairly simple. A piece of 15 mm plywood as a base, two pieces of thread rod, two pieces of aluminium tube, two brackets to mount the wheels, three M10 drive-in nuts to screw the thread rods to the plywood base, four M10 nuts, four washers. The steel plate is glued to the plywood to provide a base for the magnet stand. I’ve drilled three holes in the plywood to mount the stands accordingly for 100 mm and 135 mm wide hubs.

Shame on me that I didn’t remember how much I’ve learned to hate these cheap Chinese magnet stands for dial indicators when working with grinding machines. Since you don’t true a bicycle wheel to 0.01 mm I thought I can get away with a cheap €25 magnet stand. It works ok, but next time I’ll get a better one anyway.

It works quite well as a crude hub motor test stand too. Thats my new Bafang BPM2 btw. (and my cat)

Begorett Velomobile

So far the Begorett velomobile only looks like it’s a design study at the moment.
At 40 kg weight and 1.08 m overall width I’d say it’s slightly overweight and at least 15 cm too wide to fit through obstacles if you leave the road.

That critique out-of-the-way, I really like the idea of four wheels and 26″ wheel size in a velomobile. I’ve got a fair share of bad roads as well as multiple train tracks and flap bridges on my daily commute and thus experimented with 24″ and 26″ front wheels on my Sprint again.

here is a 360° view

The Begorett velomobile is build (or better say might be build) on an aluminium tube space frame and the designers focus obviously lays heavily on cycling safety.

here is an other 360° view

All images: Begorett Velomobile

Wrapping the Valve

About three years ago, after one particularly nice but salty winter, I’ve found a very corroded valve hole in one of my rims. Sticking a nickel-plated brass valve in a hollow aluminium rim and pickling it for month creates a perfect example for galvanic corrosion.

The corroded valve hole after some cleaning. It had orginally the same diameter as the spoke holes.

Since then, I was wrapping some tape around the valve stem and used two rubber O-rings to electrically isolate the aluminium rim from the nickel-plated valve stem to see if that prevents corrosion of my rims in the future.

One O-ring goes inside between rim and tube, the other O-ring on the outside between rim and nut.

It really works. No nasty corroded valve holes since then.

Current setup

Thats how my Sprint currently looks like (again):

At the rear, a MXUS 1307 direct drive hub with 140mm disc parking brake, 47mm wide 24″ rim and Schwalbe Land Cruiser 50-507 (my standard winter rear tyre), Givi E21 cases with B+M Toplight Flat S battery lights and a third B+M Toplight Flat S at the head rest.

One 74V/11Ah LiMn battery (200x Sony US18650VT 1.1Ah cells) strapped under the seat, a second 74V/11Ah LiMn battery (100x Sony US18650V3 2.2Ah cells) mounted onto the front boom. While the battery under the seat made from twice the amount of older cells is unfortunately twice the size and weight, it can be loaded with more than 50A without even getting warm and has less voltage sag.

At the front 47mm wide 20″ rims with Schwalbe Big Ben 55-406 und 90mm SA drum brake hubs, the nose mit 2x Myrrycle mirrors and 2x B+M IQ Cyo S-Pedelec 75V head lights.

I’ve recently build 26″ front wheels to try some 28mm Schwalbe Durano tyres, but they felt not better than my old 24″ front wheels with plain old 24″ Schwalbe Marathons. Corner handling of the bigger wheels was actually slightly worse.

Since the 90mm SA drum brakes are a bit strained with the big 24″ and 26″ front wheels, I’ve got an other set of 24″ wheels with 40mm wide rims and disc brakes ready for testing. I think I’ll write a post when they’re on the trike.

Carol of the Spokes

Merry Christmas and a happy new year!

Carl Georg Rasmussen – Inventor of the Leitra

Copenhagenize has an interview of Carl Georg Rasmussen, the inventor of the Leitra velomobile in their Vimeo stream, where he explained why he started Leitra in 1980.

A very interesting man.

The Leiba Record

Since its introduction in the German velomobile forum, the Leiba Record went straight on top of my velomobile shortlist (along with the 2014 WAW).
Designed for speed the Record might not be exactly what I’m looking for, since my daily commute leads over fairly rough roads, but it just looks purely awesome.

The Leiba Record prototype

Leiba went a unique way to construct the rear suspension. Instead of a swing arm, the whole rear wheel well together with the bottom shell moves and is suspended by a suspension strut at the top to provide 3cm of suspension travel. Lateral movement of the wheel well is controlled by two plastic covered screws in the upper seat mount (the horizontal aluminium bar). A bit crude but hey, it’s the prototype!
Time and tests will tell if that construction is simple and genius or, well… not.

Leiba Record rear suspension

A show stopper (for me) would be the current size of the rather slim 26″ wheel well. It is only wide enough to fit a skinny 559×1.35 tyre. I think that’s unnecessary restricting tyre choices.

I’m currently quite fond of the Schwalbe Big Ben for comfort and most importantly its great grip on wet roads. Leiba mentioned in the introductory thread they might build a bigger wheel well to fit 700c tyres if they be faster. Maybe a bigger AND wider rear wheel well isn’t out of the question.

Leiba Record cockpit

The prototype has tiller steering but side stick steering will be available as well.

Some preliminary specs of the Leiba Record:
length: 273 cm
width: ca. 69 cm
track width: ca. 66 cm
height: ca. 89 cm
turning cycle: ?
weight: empty raw shell in glass 8.7 kg, lid 0.65 kg, hood 0.5 kg
price (glass): ca € 6,500
carbon update: ca € 1,200

All images: Leiba