Cycling UK Forum

tim-b wrote: ↑13 Aug 2024, 7:04am The problem with "Whatabout car drivers? They should wear helmets too..." is that some bright spark sees that as a good suggestion.

They then develop a private car helmet standard, which will differ from racing car standards, due to multiple airbags, etc.
They realise that their niche career can be extended by "improving" cycle helmet standards and, in a similar manner to Audax67 and his Metabo saw, make them unusable. Except that unlike the saw in private use, it's now the law

In the meantime the even better protected car drivers are even more invulnerable and become even worse drivers

Well done, everyone!

Use constructive arguments, based on the evidence, not whataboutery

Certainly helmet manufacturers & government departments looking to justify their existence will think its a good idea.

The main function of the check valve in a track pump is to ensure that all the air compressed in the hose is not released back into the pump cylinder thus rendering half the stroke useless. Therefore it is positioned as close as practically possible to the cylinder base leaving as little air as possible between the plunger and the bottom of the cylinder.
The primitive frame pumps that clip straight onto the valve head and have no hose don't need a check valve unless they fit schrader valves which have to be held open as the air pressure in the pump won't open them. I think the type that had a hose stored in the handle used to have check valves in the hose head if they were meant for Schrader valves.

If your in hilly terrain the amount of time a none racing snake gets over the charging speed is vastly reduced, the downhills usually being wasted by being over to quickly and producing too much current to be useful.
In flat terrain its possible to charge steadily all day.

Thanks all.
Job now done, I removed them and after fiddling around with a small screwdriver decided to blast them out with compressed air. Which worked fine apart from the shed wall got splattered with black spots. I did not expect them to be all one moulding.

I put a tiny bit of grease on the bush, not sure if this is a good idea but time will tell.

Do they run on ball bearings or bushes?

There is a non return valve in the base of the unit that should be accessible, take the non return ball or plug out clean it and put it back with a touch of silicone grease if you have any.
Any air that gets past the valve connector should not pass the non return on the pump base.

Brucey wrote: ↑25 Jun 2024, 4:55pm . I think it should not be difficult to replace (with better) any worn material on steel chainrings via welding, if it is done in the right way. If the weld-repaired chainring is then remachined it should be possible to end up with a much-improved chainring, with harder, more wear resistant material added only where it is really needed.

Are you suggesting this as a service offered by a specialist?
Even those with a home welder would struggle to re-machine the teeth correctly.

The following is, in my opinion, the only way. To meaningfully test a cycle chain & coincidentally the reason why it will never bee done.

Fill a small open top tank with straight mineral oil.
The tank will incorporate a small agitator.
Mix a quantity of carborundum powder in with the oil.
Arrange for a shaft connected to a constant torque device to straddle the tank. A new sprocket of about 17t is fastened to the shaft.
A chain wheel is then connected to a motor gear box to give a constant speed similar to the average cycling speed.
A brand new chain is then rigged between the two, also going via a chain tensioner to give a constant tension.
The sprocket dips slightly into the oil bath.
The motor is then run for the equivalent of say 5000 - 10000 miles.
The agitator is then run to keep the mix even throughout the trial.
Motor power is monitored at beginning and end and also the chain wear.
This is then repeated with new sprockets and chain rings for every chain on the market.

The results wouldn't tell you how long a chain will last but it will tell you which chain resists wear the best and which chain loses least power and is probably the only meaningful results that could be given.
It does ignore chain strength and build quality but there is a negligible difference between respected brands on these points.

Once the best chain has been selected the whole trial is then repeated for different lubricants mixed with carborundum. For dry and wax lubes the carborundum would need to be blown around the tank with an air jet mixed with a little water mist.
This would then show up any differences in the effectiveness of the lubricant.

This would give people the information needed to choose the genuinely best chain and lube with regard to cost.
However the time involved and the amount of chains and lubricants would probably ensure it never happens at least not by an independent source.

Once these have been selected the cleaning and lubricating regime is up to the individual as trials could run into the hundreds for every method.

Or, just buy a decent chain and oil it now and then.

As components can be 'badly worn' in many different ways it's unlikely.

simonineaston wrote: ↑2 Jun 2024, 1:30pm What is the benefit of adding extra indexing marks? I can see why Shimano chose to place their single index point at gear 6, ‘cos its mid range, but what extra information would I see if I added a mark at all eleven?

A piece of grit in the pulley would not necessarily show a fault on the yellow mark but misalignment could show up as the cable rides over the offending piece of grit in a higher/lower* gear.
*(corrected for model type)

toontra wrote: ↑1 Jun 2024, 10:53am

jb wrote: ↑31 May 2024, 10:37pm It's a bit like Einstein showing the theory of how to make an atom bomb but then saying nobody should actually make one cos there too dangerous.

There are too many problems with that analogy to list.

I know there's problems with it but the fact is if you make something with the capability of higher performance then its fairly naïve to not expect people to use it and get round any token restrictors. Just the same as when 60mph mopeds were restricted to 30mph for learners and then telling youths it was very naughty to remove the piece of plate restricting them.
People have after all being making home made electric bikes with huge power for decades before they were even a thing, but now mainstream manufacturers are bringing it to the masses.

It's a bit like Einstein showing the theory of how to make an atom bomb but then saying nobody should actually make one cos there too dangerous.

Same castings , different windings probably.
At least until weight becomes an issue then it will be worth making lighter bodies for smaller motors.

I recon the bike shop has done the OP a favour by subtly suggesting the bike is not worth repairing unless he does it himself. If he had the absolute necessary work done he'd be back next week with the next thing and the next until he'd spent more than a new bike.
I've repaired worn out bikes for non cyclists and it's a thankless task when you know they are going to baulk at paying out more than fifteen quid and that's without owt for thi sen.

You can use any chain checker, just stick to using it and eventually with experience you learn at what point on your particular gauge the chain needs replacing at. The numbers are a bit meaningless but most gauges are accurate as comparisons. Even the gauge which excludes roller wear can give a reasonable indication so long as your aware of the roller error.