Weight weenie dream tourer

Any updates on the dream tourer?
Did the cat already ride with you?

Not much progress this week. Been learning to use my new Gopro. The cat's first voyage must be recorded. Have also planned her social media strategy. Got her a username which will work on all platforms. Also got her some catnip to get her acquainted with my bar bag. But she just ate it. She could tell I was planning something and was suspicious that it might be another trip to the vet. She really hated the last time. So she didn't speak to me for several hours. The weather looks good tomorrow, so we shall see. She's such a good mind reader that if I start thinking about it she'll hide.

Check out skintension on Instagram.

Have you thought about a foul-weather cat carrying set-up for travel? A handlebar bag is going to be pretty cramped if it rains the whole day.

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skintension on Instagram

That's a great find!

I've ruled out a bar bag. She needs something she can sleep in and be protected from the elements. Assuming the trials go well I'll make something suitable. It will be aero and ultralight of course. Probably suspended from the tt bar extensions.

I’d imagine the swaying will rock her gently to sleep

Any updates on the tent pole rear rack?

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She had her first ride today, and there was less grumbling than expected, so off we go. The project has a green light. I pointed the Gopro in more or less the right direction so I now need a crash course in editing for youtube. Advice gratefully received. I got talking to a ten year old and he suggested Shotcut.

I'm on the brink of ordering some materials:

• 3mm rod https://www.easycomposites.co.uk/3mm-carbon-fibre-rod for the tent poles, which will double as the major struts of the rack. I have no idea whether this rod is strong enough or agreeably bendy. It's 22 grams per metre. Is that too conservative? Should I try 2mm rod first? https://www.easycomposites.co.uk/2mm-carbon-fibre-rod It's only 4.5 grams per metre. I'm tempted.

• if I get the 3mm rod I'll get a bit of 5mm tube, which has an inside diameter of 3mm, to make ferrules. https://www.easycomposites.co.uk/5mm-pultruded-carbon-fibre-tube If I get the 2mm rod I'll get a bit of 3mm tube https://www.easycomposites.co.uk/3mm-pultruded-carbon-fibre-tube

I can test the poles by using them with my current tent. It's a single skinned freestanding thing and the fabric weighs about 800 grams. It has 2 poles which cross each other diagonally and fit into little pockets.

To join the rack struts to each other and to attach them to the bike, I'm thinking pieces of rubber hose and Sugru.

I've also bought this on a bit of a whim. New rings, used crankset:

My excuse is that these cranks are, according to my Cyclefit file, the recommended length for me, whereas the Sram cranks which came with my second hand bike are 25mm too short. The weight saving will be roughly 200 grams. I think. I don't know what BB is on my bike. Don't know anything about the shell either. But a Clavicula is a badge of honour for any self-respecting weight weenie.

The Clavicula is 104 BCD, so I suppose I'll be needing custom rings for the rest of my life. I'll try to keep wear to the absolute minimum. The chainring instructions say not to put pressure on the pedals when using the FD. I wonder if I should give the teeth a sacrificial layer of nail varnish or epoxy resin?

25mm!? What length are the Clavicula, what what length are your legs?

They’re rad though. What’s the jump in chainring teeth? Looks huge.

Every time I see there is a picture here I get excited thinking it is your cat. More cat photos please.

Carbon chainrings on a tourer hahaha

The Stupid:Awesome ratio gauge is going nuts.

Just upload the raw footage to WeTransfer, I'm sure someone here will oblige you with an edit

At first I thought this was just stupid. Now I know it is. And I can't wait to see it.

The Clavicula is 104 BCD, so I suppose I'll be needing custom rings for the rest of my life.

There are plenty of alloy chainrings in 104 BCD so they look like a replacement option (e.g,. at SJS Cycles) -- you could just drill a lot of holes in the those for a drillium weight-saving finish.

I'm on the brink of ordering some materials:

Been having fun thinking about this rack.

I think you gain very little by using such thin tubes. I would probably use 10mm outer diameter (OD) carbon tubes for making a rack, or 8mm if I was feeling WW. I've no calcs to back that up, but it feels risky to just use 2-3mm tube without doing the calcs. And think of abuse loads, like someone stepping on the rack.

As for the brackets which connect the tubes at corners, you have many options.

Hose might make things a bit flexy depending on geometry - a cube would flex but a pyramid would be fine, so use many diagonal tubes. Triangles good, squares bad. If you took two short sections of hose, drilled at the middle and nut/bolted across each other into an X, you'd have a cheap weather proof 4-way connector. I'd use clear, bendy PVC tube for this.

You could also just drill holes into wooden blocks (or some other material), using ever increasing drill bits - i.e. in 0.5mm increments - to achieve an interference fit (push fit).

Or take fatter sections of rigid tube with ID matching main tube OD (like your ferrules). Join these using epoxy-soaked carbon tow. You'd want to do this with the tubes assembled into a mock rack, with some awkward jig involving tape and swearing.

You can also google "3 way PVC pipe fitting" if you don't mind 90 degree corners. Then spec your carbon tubes to match the sizes to achieve push fit.

With all of these solutions though, you'd need to hold (compress) the assembly under tension so that it doesn't dismantle during use. Like how tent fabric tension holds the poles into connectors. So one or two bungee cords would be an idea, perhaps made from inner tubes (can fasten these using buckles from an old rucksack).

I wonder if I should give the teeth a sacrificial layer of nail varnish or epoxy resin?

I'd have thought that would just wear off the first time you used it (or even in the first couple of pedal strokes)? The strength of a carbon composite material is mostly in the fibres; in any case, I'd not be sure how strong a bond you'd get on the chainrings.

Did I describe this wrong? The Clavicula arms are 175. The Sram ones on my bike are 172.5.

The rings are 34 and 50. The cogs are (or will be) 11-36. Just within the capacity of the mechs, I think. Hopefully OK for climbing with a loaded bike. We shall see. I'm trying to recover from ME/CFS. Am v. weak cos I've hardly been on a bike for 10 years. My touring plan is basically a big dose of Graded Exercise Therapy. I think it's my best (and only) way of beating the ME and having a normal life. I'm getting on a bit, so I fear this may be my last chance. I've tried touring as therapy quite successfully before, but some unfortunate things happened and I had some rather severe relapses.

The weight weenie fixation is both practical and psychological. My steel tourer is 25 lbs or more unladen, and probably 70 lbs with bags on my last trip. I've developed a fear of its weight...carrying it up the stairs at a railway station, or hoiking it over some barriers to cross a road. I live in a third floor flat and it's such a relief to have light carbon bike when carrying it up and down stairs.

Here's my steel bike. 853 randonneur with exery braze-on known to man. I built it on Dave Yates' framebuilding course.

The campervan is another way to prevent relapses. When I'm tired I can pull over and sleep anywhere. Same story having camping gear on the bike.

Extreme measures like carbon rings also have a psych benefit. The gleeful joy of having bits which for decades I've been telling myself are out of bounds...how do I describe it? It's like Father Christmas being real and actually popping out of the fireplace. Of course, if they start snapping and getting me stranded in the middle of nowhere, I'll develop some new fears.

Awesome stuff man. Great looking bike. Just spotted the couplers as well.

The Clavicula arms are 175. The Sram ones on my bike are 172.5.

2.5mm difference, not 25mm 🙂

Hang on, the rack is going to be made of tent poles?