Drama Rebuilding a Trike Wheel

[redsonic]

I finished rebuilding one of my Mum's recumbent trike wheels the other day; boy, what a drama.
The spokes had broken mid body with the trike just stationary in the house, unused for months. They did have some corrosion from a coastal environment, but spontaneous fracture?

I ordered replacements from Custom Cut Spokes (thanks for the recommendation, Duck), but they were too short. A combination of me measuring a slightly bent original spoke, plus the originals being shorter than ideal to start with.
Another batch of spokes arrived from overseas, and on to building the wheel.

Hmm. How to use a truing stand with a wheel with only 1 axle (spindle)? I made a second axle anchored into the hex hole on the outside of the hub. The new axle had a very slightly smaller (0.6mm) diameter than the real one, so I placed a shim in the truing stand "V" that holds the axle.
Hmm. Small wheel, high spoke count; my favourite spoke key only just turns between the adjacent spokes.
Hmm. Small wheel, 2X pattern; my tensiometer has no chance of taking measurements. Being tone deaf, I relied instead on the feedback from turning the nipples to even out the tension.
Hmm. Disc brake, only 1 axle. How do I determine the dish? Decided to centre the rim between the hub flanges & ignore the brake disc (irrelevant with just one axle), but unable to use my dishing tool properly because the wheel was so small, and there was a long blimmin' axle sticking out from only one side.

There was further sweating and cursing adjusting the cable disc pads to avoid any rub (nothing is easy working on a large recumbent trike without a stand), then pumped up the tires, lubed the chain, and took Mum for her first ride since a serious health scare 12 months ago.

The smile on her face as she slowly pedaled along the waterfront made it all well worth while.

[elantra]

Great outcome. Huge kudos !

Amazing how these jobs never go exactly according to plan.
There’s always some complication, just a matter of whether it’s big or small….

[warthog1]

You are a good son, nice work
"the smile on her face made it all worthwhile" gave me a smile too, thanks.

[redsonic]

You are a good son, nice work
"the smile on her face made it all worthwhile" gave me a smile too, thanks.

Time with Mum these days is precious. An inspirational lady who doesn't deserve what life has dealt her.

[foo on patrol]

Foo

[skyblot]

I’ve done quite a few trike wheels, what you have done sounds fine. (On a 20” wheel with 32 or 36 spokes you could just do the spokes up finger tight and it would work. I had one trike come in with the rear wheel missing 7 spokes and the rest were all loose and the owner hadn’t noticed…)

Definitely centre the rim between the spokes flanges on the front wheels, and also do so on the rear if there is enough room between the chainstays, 10mm offset makes no difference at all. (Tadpole trike here, reverse for delta.) 1 cross or 2 cross is fine, 1 cross on large diameter hubs or 16” wheels.

You’re experience with spokes just breaking is not unheard of, I’ve seen trike wheels where the spokes have cracked mid length with the trike just in storage. Expensive brand name too.

[redsonic]

I’ve done quite a few trike wheels, what you have done sounds fine. (On a 20” wheel with 32 or 36 spokes you could just do the spokes up finger tight and it would work. I had one trike come in with the rear wheel missing 7 spokes and the rest were all loose and the owner hadn’t noticed…)

Definitely centre the rim between the spokes flanges on the front wheels, and also do so on the rear if there is enough room between the chainstays, 10mm offset makes no difference at all. (Tadpole trike here, reverse for delta.) 1 cross or 2 cross is fine, 1 cross on large diameter hubs or 16” wheels.

You’re experience with spokes just breaking is not unheard of, I’ve seen trike wheels where the spokes have cracked mid length with the trike just in storage. Expensive brand name too.

Thanks for the tips, Skyblot. Reassuring about the tension; I figured the wheel will be super strong without racking up too much tension on those spokes.
This trike was an expensive European brand. Bought second-hand though, so I don't know its full history. I was surprised the factory (house branded) wheel build used such short spokes though.
What sort of truing stand have you used for single axle wheels? My plan B was to somehow anchor/clamp the axle to 1 of the V's of the stand and use it that way, but I doubt I would have been able to remove all play/wobble. I suppose those working on Cannondale Leftys have the same issue.

[skyblot]

I have a simple home made truing stand, and with a small machine shop I make whatever adapters I need to mount the wheel in it. Trike wheels are easy, they are simply not critical on wheel dish or centering!

You will probably find the axle will come out of the hub, though maybe not without a fight. The outer end (away from the trike) is most likely a machined cap and a countersunk bolt so that it is a nice flush surface. This will be loctited in place with a high strength threadlock...heat will soften it, plus brute force and ignorance will remove the bolt and then you have a simple front hub to work with.

If the trike is going to be ridden enthusiastically (read: aggressively), high spoke tension is recomended. Trike wheels cop large side loads that bicycles never experience!