Cycling UK Forum

Brucey wrote: ↑20 May 2024, 5:59pm

jb wrote: ↑20 May 2024, 12:41pm If your going to remove the cage and add more balls its wise to check they are exactly the same size with a micrometre. Having one ball that is slightly but significantly larger will wear the bearing races out or cause the one overstressed ball to fracture prematurely.

i agree, adding balls to an extant set is fraught with danger. The 'one oversized ball' outcome is the one you really want to avoid, although the 'one undersize ball' outcome is not that much better. Unfortunately even with a good micrometer most people would struggle. It is very good policy to keep steel balls in sets, with each set from the same packet.
This way there is no need to set yourself an unnecessarily hard metrological challenge.

Yes, unfortunately that means discarding the balls it was fitted with and only using balls from a packaged set, providing they are of a high grade suitable for ball races. Not that that's going to break the bank.

If your going to remove the cage and add more balls its wise to check they are exactly the same size with a micrometre. Having one ball that is slightly but significantly larger will wear the bearing races out or cause the one overstressed ball to fracture prematurely.

CA is used where using electricity would be inconvenient or dangerous. Or where a stall can happen without damage, not because it's particularly efficient. It's also good at running spindles at high speed without overheating. None of which is much use for a cycle motor, and generating compressed air is very expensive.
It's a lot safer to tamper with than electric though - mostly.

The difference between steam and compressed air is that steam has energy stored within it other than the potential energy of a compressed gas. Thus it will expand to many times the volume of a similar amount of air.
And storing liquid air has its own complications.

Compressed air has no where near enough energy to propel a cycle for any distance. Unless you had a tank the size of a lamp post. It's just a storage method anyway it has no chemical energy.

JerseyJoe wrote: ↑7 May 2024, 2:29pm

jb wrote: ↑7 May 2024, 12:20pm

JerseyJoe wrote: ↑6 May 2024, 11:08am It does seem pretty bizarre that we live in the era of graphene reinforced everything and new materials coming along all the time and no one has yet solved the problem of punctures. I absolutely hate them. When!?

They have invented new materials for tyres, they don't puncture anywhere near as much as they used to.

I suppose my point is we have developed materials that can stop micrometeoroids in space travelling at 45,000mph, graphene nanotubes which have a tensile strength 80 times that of stainless steel, and have developed carbon and Kevlar aircraft and submersibles that can withstand enormous pressure and continuous abuse, yet we can't produce a bicycle tyre which is invulnerable to punctures? Doesn't that seem odd?

I think you misunderstand the huge amount of pressure of a sharp point pressing on a tyre that has the full weight of the rider on it. modern materials can reduce the amount of artefacts penetrating through to the tube but for a sufficiently rigid item (i.e. a nail) a sufficiently strong material would be either too thick or too expensive or too heavy. Having one or two punctures a year, if that, is a small price to pay for a balance between a good ridding quality and cost.
Plus, since punctures can be unavoidable for other reasons (failed valves etc.) its a good idea for people to keep their hand in at being able to remove a wheel and tyre on the roadside.

JerseyJoe wrote: ↑6 May 2024, 11:08am It does seem pretty bizarre that we live in the era of graphene reinforced everything and new materials coming along all the time and no one has yet solved the problem of punctures. I absolutely hate them. When!?

They have invented new materials for tyres, they don't puncture anywhere near as much as they used to.

Cowsham wrote: ↑4 May 2024, 3:41pm Not a cheap bike though

I paid £400 for my Dawes Super Galaxy in the mid nineties, they are now about £2000.00 and are crap compared to my hand built frame. I can't imagine a bike sold for £900 being anything more than an off the peg bike with most of the money going towards midrange components.

It's at the cheaper end of the market for okay bicycles, bang the wheels in and ride it, if it's okay keep it , if it gives problems send it back but don't expect perfection.
If you want perfection go to a reputable small bike shop and pay a little premium for their experience.

531colin wrote: ↑1 May 2024, 8:21am

jb wrote: ↑28 Apr 2024, 7:08pm

CJ wrote: ↑27 Apr 2024, 4:35pm
I appreciate your agreement, but DFC? Would that be Northern Ireland's Department For Comunities, the USA Development Finance Corporation, or the Distinguished Flying Cross?

As an engineer I'm guessing FC stands for Full Complement rather than Football Club. (And as I was born in the city of Derby I know it couldn't be Derby FC because proper name of 'the Rams' is Derby County...) Deep perhaps?

Please don't use a arcane TLAs (Three Letter Acronyms) without explanation.

Here here, it's a PITA to keep googling every acronym. The military we are not.

Took me about 6 key strokes, for goodness sake!

Its bad practice, what ever anyone says. sometimes posts are so full of acronyms its like wading through treacle trying to read the article. They should only be used when everyone involved is thoroughly familiar with the terms involved, and even then the first use should be in full.

CJ wrote: ↑27 Apr 2024, 4:35pm

Brucey wrote: ↑19 Apr 2024, 10:52am what CJ says is pretty much why I think that most cartridge bearings on a bike would be improved by conversion to DFC specification. On a bike, not only are DFC bearings stronger and longer-lasting, but when they fail, they should fail gracefully, much like a cup and cone bearing in fact. Ideally, a DFC bearing will either have no retainer or a plastic one.

I appreciate your agreement, but DFC? Would that be Northern Ireland's Department For Comunities, the USA Development Finance Corporation, or the Distinguished Flying Cross?

As an engineer I'm guessing FC stands for Full Complement rather than Football Club. (And as I was born in the city of Derby I know it couldn't be Derby FC because proper name of 'the Rams' is Derby County...) Deep perhaps?

Please don't use a arcane TLAs (Three Letter Acronyms) without explanation.

Here here, it's a PITA to keep googling every acronym. The military we are not.

My old Hope closed brakes were a pleasure to use and there was no faff except perhaps when renewing the fluid. all adjustment done on the fly and the ability to back off the pads when crudded up in order to stop annoying disc rub was a most useful operation. Fitting new pads was easily achieved without having to force the pistons back in and still 'strangely' find that the rotor will not fit in the gap with the new pads fitted.
Possibly the old Hope callipers would give the weight weenies a heart attack now with their sheer size ho hum.

I have a 'Lion' bell which can, under the right circumstances cause the obstruction to jump into the canal or adjacent ditch giving a warm feeling of love to all humanity. Unfortunately it doesn't have the same effect on sheep or dogs.

Were struggling to recycle a good many consumer goods but chain sprockets are probably the easiest thing on earth to recycle. just chuck them back in the furnace - no degradation of the material either. there is of course the carbon released by doing it but that's another issue better addressed by reducing plastic waste.

I used to grind down the hooks on the teeth with partial success. I now realise it's the ramps that need addressing (and dressing ). With a dremmel or a die grinder it could possibly be quite a quick process to knock back the ramps without to much precision needed. However I'm now far to rich to be buttocked to do such jobs - as I suspect are the majority of folk hereabouts.