Any question answered...

The unwanted lovechild progeny of a sordid menage a trois between R2D2, a Dalek and Henry the Hoover.

Is there an abbreviation for neutral?
i.e.
negative (-ive)

Thanks all for the answers. Sounds like there isn't a definitive one and it is context dependent.

Maybe I should have been clearer with its use. It's for a shorthand notes / comments in relation to whether statements are negative or positive. Fwiw just went for "neutral" in the end.

Yup, a laser level. Might be this one: https://www.aliexpress.com/item/32954469985.html

Good find. Some good potatoshopping going on with the images on that page.

Hello.
I am after a 26 inch (rear wheel, rim brake, 7 speed) for a turbo trainer.
Does anyone have anything,local to SE26, in their shed they don't need/want?

Slightly odd question...

(For an ecology experiment) I need to create a temporary airtight seal between two lengths of pipe with an external diameter of approximately 4 inches*. The seal does not need to be strong, just sufficient to prevent air seeping in for a period of a few minutes at close to atmospheric pressure, but it does need to be easy to attach and remove repeatedly.

My current idea is to use a length if inner tube as a sheath over the join. Do MTB/Fatbike inner tubes come in sizes that could be relatively easily stretched over such a pipe?

*Slightly longer explanation: The experiment, being conducted by my GF, is measuring soil respiration (gasses emitted from a known volume of soil in different environmental conditions). I mention joining two "lengths of pipe", one of these will be a length of 4in diameter plastic sewage pipe that has been sunk into the soil... there will be about 100 of these scattered around a forest and my GF needs to measure the gasses emitted from each one on a regular basis. The second "length of pipe" is actually a portable gas respirometer and is used to measure the gasses given off by the soil, it just so happens to be shaped a bit like a length of 4in diameter pipe. The gas respirometer will be carried around the forest to each section of sewage pipe where it will be placed on top of the pipe to measure the soil respiration. The respirometer is designed to work with c. 4in diameter pipe but the manufacturing tolerances on sewage pipes are such that the seal is usually pretty leaky so we just need a way to make doubly sure no extra air is getting in (and while portable, the gas respirometer isn't really designed for the messy tolerances of ecology experiments in the wild...). My simple suggestion is to cut a section of inner tube and slide it over the end of the gas respirometer and tape it in place, the inner tube could then be rolled up onto the respirometer and out of the way during transport, and then rolled down over the join between the respirometer and the pipe, creating a temporary seal while the machine is in use. Does this sound like a reasonable solution, or are there better alternatives? I have considered something a bit like this but the gas respirometer has some screws and other plastic knobbly bits on it's external surface that I imagine an inner tube would stretch over whereas I think this would not.

@mdcc_tester you usually have a pretty good eye for problem solving... any thoughts?

Motorcycle or even car inner tube is more likely to come up to an optimal circumference.
The bin of your local tyre-changing place is going to be your best friend for this.
ETA - cable tie the inner tube in its position - the more cable ties - the slimmer chance of leakage.

Google Toilet soil pipe fittings will bring up lots of variations of a 4" tube with a flexible seal at one end.
Fix the other end to the respirometer?

like this from screwfix?

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Thanks, Yes I'll give the local tyre place a call to see if the have anything lying around.

I like the look of those pipes with flexible 4" seals but from the look of those options I'm unsure how I would attach the respirometer end. If I can find something that will work they could be a very good solution.

Wheelbarrow inner tube?

I would be concerned with off-gassing from the plastic pipe let alone an inner tube - think how much they smell. Food grade materials might be worth looking at instead.

I've literally just replaced a burst wheelbarrow innertube, so can post the broken one to you if you want? This is what I replaced it with, if you need the measurements:
https://www.amazon.co.uk/gp/product/B0848TX9ZB

Just asked and apparently it's only measuring CO2, so hopefully that is less of a problem.

As an aside the baseline concentration of CO2 in our garden is around 417ppm!

@Pifko that would be ace, just as an experiment - will pm.

baseline concentration of CO2 in our garden is around 417ppm

That will do the flowers good.

When a shop or manufacturer describes a frame size as being something "square" (or 54x54 for example) is that c-c measurements for both top and seat tube?

Is the 54x54 size in the attached chart really a 56cm frame in common parlance?

Does anyone have experience with v-brake Travel Agents? Do they suck?

IME yes. Extra friction on your brake cables doesn't feel nice.

Bugger.

I can't get on with Cane Creek's v-brake drop bar levers; way too narrow and hard. I don't get why they didn't replicate their short pull version (SCR-5); those are great.

And there aren't many other options out there, unfortunately. Only ones I know are Dia Compe EVO-V, which don't look great either:

What this?

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Do you need SCR-5s? I have a pair in the parts box

Do you need SCR-5s?

I have them, and they are short pull, so they won't work with v-brakes.

Hence my question about Travel Agents. Thanks though!

I'm sure that you are aware that the Tektro ones are the same as the Cane Creeks.

If you do decide to go travel agent, I can recommend the SRAM S-500 road levers which are comfy. Or hit me up for the SCR5s for mad forum bargainz.

I'm sure that you are aware that the Tektro ones are the same as the Cane Creeks.

The v-brake ones? Yeah.

If you do decide to go travel agent, I can recommend the SRAM S-500 road levers which are comfy.

Thanks. If I go Travel Agent, I think I'll go with STI levers though. The brake situation is basically the only thing preventing that at the moment.

Or hit me up for the SCR5s for mad forum bargainz.

Already got a pair, thanks. :)

Does anyone know of an iPhone map app that lets you put in a specific route and then gives audio route instructions?