Search found 1656 matches

by tim-b
17 Apr 2021, 7:13am
Forum: Does anyone know … ?
Topic: Cycling Camera... and a ****
Replies: 54
Views: 2489

Re: Cycling Camera... and a ****

Hi
PM sent
I've felt your pain!
Regards
tim-b
by tim-b
31 Dec 2020, 6:35am
Forum: The Tea Shop
Topic: If you were an MP how would you vote on Brexit Trade deal?
Replies: 266
Views: 5170

Re: If you were an MP how would you vote on Brexit Trade deal?

Stevek76 wrote:I'd say the following was of interest:
https://www.politico.eu/article/5-reaso ... xit-talks/

Learning lessons from Jonathan Powell?
On the so-called 45 minute warning, "Some people – including both Jonathan Powell and Alastair Campbell – regard (or portray) this as pure coincidence. Others may feel that, far from being coincidental, it was part of a deliberate strategy designed to emphasise the immediacy of the threat from Iraq and so justify military action if and when the latter was deemed necessary. " ( https://www.barder.com/alastair-campbell-jonathan-powell-and-the-45-minute-warning/ )
On legality of military action in Iraq, "In his statement released tonight, Goldsmith described how Jonathan Powell, Blair's chief of staff, was one of those who discouraged him from giving his advice on the legality of military action. "I was told that I was not being called on to give advice at this stage [October 2002]," Goldsmith says." ( https://www.theguardian.com/uk/2011/jan/17/blair-ignored-goldsmith-chilcot-inquiry )
And we all know how that action ended, or rather hasn't almost 20 years later.
Regards
tim-b
by tim-b
25 Dec 2020, 7:25am
Forum: Does anyone know … ?
Topic: Memories of the Dawes Galaxy
Replies: 88
Views: 6053

Re: Memories of the Dawes Galaxy

Hi
Here's my Super Galaxy Tandem, bought second-hand to get our (then) small boy out on longer bike rides. I bought it from an elderly couple who delivered the tandem in their Volvo estate, it wouldn't fit either in or on our car :)
Totally original apart from Bontrager tyres, I added SIS indexed levers on the handlebar stem and split the front, rear and drag brakes (I wasn't confident in the peculiar double-cabled brake lever and went for a more conventional set up). A ratchet gear lever on the end of the pilot's handlebar restored the drag brake and gave a bonus parking brake
My abiding memory was riding uphill for the first time and realising that the stoker wasn't stoking. We got to our destination, I was cream-crackered, and I reached into my back jersey pocket for a snack only to realise that small boys can't pedal because they're eating. We enjoyed a gentle, energy-conserving ride home
The tandem was eventually sold to another cyclist so that he could take his son out, the circle complete
Regards
tim-b
Sm-Tandem.jpg
by tim-b
14 Dec 2020, 7:43am
Forum: Bikes & Bits – Technical section
Topic: yet another brake thread; not all about discs
Replies: 111
Views: 3964

Re: yet another brake thread; not all about discs

Hi
This means if they won't do a particular job I am likely to say so, and I may have little time for those with more blinkered views.

Is that meant as an apology for the totally unnecessary and insulting comments used by you about mental capacity?
I don't expect you to answer, I'll let others judge that https://forum.cyclinguk.org/viewtopic.php?f=5&t=142842&start=75#p1560001 (and source https://forum.cyclinguk.org/viewtopic.php?f=5&t=142842&start=60#p1559873 )
As for "those with more blinkered views", I don't think that my comments are blinkered; they're factual and reflect personal experience in rain and winter commutes in the context of the topic under discussion
Everyone has their points of view and mine are backed up by practical, personal experience
Regards
tim-b
by tim-b
13 Dec 2020, 9:34pm
Forum: Bikes & Bits – Technical section
Topic: yet another brake thread; not all about discs
Replies: 111
Views: 3964

Re: yet another brake thread; not all about discs

fastpedaller wrote:I was about to ask (before Brucey posted the above) whether inverting the bike could cause a problem. If it's difficult to see whether the pads are worn without inverting the bike (or if this appears to be the easy way for someone without more knowledge of how the system works) this should surely by pointed out as a safety warning with any bike using hydraulics?

It is in some of the user manuals, e.g. https://si.shimano.com/api/publish/storage/pdf/en/um/07X0A/UM-07X0A-004-ENG.pdf
It's also mentioned in the dealer manual https://si.shimano.com/api/publish/storage/pdf/en/dm/GADBR01/DM-GADBR01-02-ENG.pdf
Regards
tim-b
by tim-b
13 Dec 2020, 5:33pm
Forum: Bikes & Bits – Technical section
Topic: yet another brake thread; not all about discs
Replies: 111
Views: 3964

Re: yet another brake thread; not all about discs

Hi
Brucey, how many bikes with disc brakes do you own and ride regularly?
snip...Of all the brakes in my 'fleet' the ones which -without warning- provide the worst wet weather braking are a set of disc brakes. When the disc is actually wet, they provide almost zero retardation; this can persist for a second or two (much as it does with chrome plated steel rims and rim brakes). Not all disc brakes are as bad as that but many are...

Of course wet bicycle brakes don't work well, but given the choice of wet rim brakes and wet disc brakes I prefer disc brakes. I'd have a look at the set up on your disc-braked bike(s) if I were you because you might not have it quite right
In the winter the whole bike gets dirty. The small amount of extra grot arising from rim brakes is literally a drop in the ocean. The grot gets into caliper bores and the consequent corrosion causes the most popular (shimano) hydraulic disc brakes to become unreliable, leaking oil from the caliper seals

If the unpressurised grot is getting in through the caliper seals then the pressurised fluid will already have leaked out
Some riders accept that these brakes are effectively consumables on their winter bike and expect to have to replace them every year or two.

Your source for this assertion?
Re rim wear, only folk who are mad enough to buy the thinnest-walled rims for winter use, fit them with the hardest-wearing tyres and then ignore all common sense regarding the use of rim brakes need worry about the rim wearing out before the tyre

The context of my sentence isn't clear; I didn't mean that you would wear a rim out in a "couple of months", merely that you will be wearing the rims out. In another topic I stated that it might take several winters and another poster replied with their experience of only eight months.
You can argue all that you like, but a disc brake is much easier to assess for wear than a rim fitted with a tyre and doesn't need any sort of mechanical intervention to take a measurement
Rims are not that pricey and are not that difficult to change either.

How much is a rim compared to a disc of comparable pedigree? Half a dozen screws (or a centre-lock), I know which I think is less difficult, needs less experience and which doesn't need a jig
If you learn to do this then you will have another skill and you can even use it on your (heavily dished, likely to be weaker) disc brake wheels when they fall apart or the rims crack

I learnt to build wheels in the 1970s, for money, in a bike shop
(both of which are depressingly commonplace).

Your source for this assertion?
Discs of course can get contaminated, bent, and wear out too

And rims don't?
In some standard brake setups (eg current shimano 'road' setups) you should expect the (expensive) disc itself to last no longer than two sets of pads and that the pads and or discs may need to be replaced before the tyres wear out

Is this your own experience, or that of a legion of anonymous chums?
Hydraulic systems come with a whole new swathe of maintenance obligations, and as implemented on bicycles, they have many pitfalls for the unwary; it literally beggars belief that the most simple tests (e.g. which ensure that you are unlikely to run out of brake fluid before you run out of pads) appear to be absent from both the manufacturers and third party service instructions.

I suggest that you discuss that with the manufacturers and their expert engineers
Bottom line; unless you are a bit daft, a bit wet behind the ears, (or riding offroad perhaps) you shouldn't have big problems with rim wear; it should just be another planned maintenance item

I've never implied that you would have big problems, but you will have more expensive problems
There, a whole post without using insults except where it's been necessary to quote you
Regards
tim-b
by tim-b
13 Dec 2020, 2:19pm
Forum: Bikes & Bits – Technical section
Topic: yet another brake thread; not all about discs
Replies: 111
Views: 3964

Re: yet another brake thread; not all about discs

Hi
Brucey wrote:
tim-b wrote: ...but IMHO you're missing the point. There are various advantages and disadvantages to any kind of brake, but discs are better in the constantly wet conditions of the UK in the last couple of months than rim brakes; they'll stop you :wink: , you won't wear your rims out, and your bike won't be covered in black brake clag....


speaking of missing the point...

When it is wet and braking performance isn't at its best you need to ride within the limits of your bike/conditions in relation to tyres, brakes, visibility etc. The kind of brakes that cause you to have accidents are the ones that don't behave predictably; otherwise -assuming that you are not a complete moron- you ride within their limits. Of all the brakes in my 'fleet' the ones which -without warning- provide the worst wet weather braking are a set of disc brakes. When the disc is actually wet, they provide almost zero retardation; this can persist for a second or two (much as it does with chrome plated steel rims and rim brakes). Not all disc brakes are as bad as that but many are and I'd describe that as being 'unacceptably poor' in relation to urban riding (although the same brakes might be very good offroad). This of course does not worry folk who don't actually ride in the rain, or live in some fantasy world where no-one steps out in front of you, ever, or you keep dragging the brake in the rain 'to keep the disc dry' once every ten yards.

In the winter the whole bike gets dirty. The small amount of extra grot arising from rim brakes is literally a drop in the ocean. The grot gets into caliper bores and the consequent corrosion causes the most popular (shimano) hydraulic disc brakes to become unreliable, leaking oil from the caliper seals. Some riders accept that these brakes are effectively consumables on their winter bike and expect to have to replace them every year or two.

Re rim wear, only folk who are mad enough to buy the thinnest-walled rims for winter use, fit them with the hardest-wearing tyres and then ignore all common sense regarding the use of rim brakes need worry about the rim wearing out before the tyre. Otherwise all that is required is that you glance at the rim whenever you inspect the tyre (which should be often, in case you are wondering), and to make some attempt to assess or measure the remaining rim thickness whenever the tyre is replaced. Neither thing is difficult and the rim is literally staring you in the face whenever you are doing anything with the tyre.

The most common outcome of excessive rim wear is that the braking goes 'pulsy' before the rim actually fails. I don't think it is a good idea to rely on this alone (unless the rim is designed for this; some are) but it has been a saving grace for many riders who were not previously in the habit of assessing their rims for wear.

Rims are not that pricey and are not that difficult to change either. If you learn to do this then you will have another skill and you can even use it on your (heavily dished, likely to be weaker) disc brake wheels when they fall apart or the rims crack (both of which are depressingly commonplace).

Disc brakes do generate (highly abrasive) pad wear debris and this tends to contaminate the workings of mechanical calipers, or nearby hub bearings etc if they are not sufficiently well sealed. If you run mechanical disc calipers I recommend that you overhaul the caliper each time you wear the pads out; otherwise you may find that the adjusters seize up and/or the thrust bearings inside the caliper wear/corrode. IME this overhauling is most conveniently done 'offline' by having a third caliper 'ready to go' with new pads in it. Discs of course can get contaminated, bent, and wear out too. In some standard brake setups (eg current shimano 'road' setups) you should expect the (expensive) disc itself to last no longer than two sets of pads and that the pads and or discs may need to be replaced before the tyres wear out. Hydraulic systems come with a whole new swathe of maintenance obligations, and as implemented on bicycles, they have many pitfalls for the unwary; it literally beggars belief that the most simple tests (e.g. which ensure that you are unlikely to run out of brake fluid before you run out of pads) appear to be absent from both the manufacturers and third party service instructions. In other words (as is usual in bike parts) everything is made cheaper, worse and/or lighter, more expensive (and more maintenance intensive) until it is actually pretty hopeless and this sort of stuff is (for various reasons) what most people end up buying.

Bottom line; unless you are a bit daft, a bit wet behind the ears, (or riding offroad perhaps) you shouldn't have big problems with rim wear; it should just be another planned maintenance item. If you want a heavier brake which works better in foul conditions (but won't ever be a panacea for all ills, there is no such thing in bike brakes.... :roll: ), you might want to use disc brakes or (better still in many respects) drum brakes.

cheers

A bit tetchy this afternoon?
Regards
tim-b
by tim-b
13 Dec 2020, 8:36am
Forum: Helmets & helmet discussion
Topic: Helmets for cricketers, footballers, motorists, not cyclists
Replies: 124
Views: 7771

Re: Helmets for cricketers, footballers, motorists, not cyclists

Hi
mattsccm wrote:"Surely professional exposures to hazards of that nature should be properly assessed and regulated by the HSE".
Page 1
Surely just the opposite. No one but the individual should have any decision what so ever in that individual's safety.

In any context your decisions on safety mustn't impinge on my safety, whether you manage me or work alongside
In the context of football if I can be better at the game by heading the ball and earn more money than people who choose not to then I might be influencing their choices and desire to further their career. Everyone who wants a good career either heads the ball or becomes a goalkeeper
If FIFA make the right self-regulatory H&S choices, and individuals comply, then the HSE won't need to be involved. Win-win?
Regards
tim-b
by tim-b
13 Dec 2020, 7:49am
Forum: Bikes & Bits – Technical section
Topic: yet another brake thread; not all about discs
Replies: 111
Views: 3964

Re: yet another brake thread; not all about discs

Hi
Cowsham wrote:I love hydraulic disc brakes but I have experienced brake fade which is scary. It was with 160mm front 140mm rear. Long steep descents really need 180mm discs in my opinion.

Darragh rd on the isle of man drops down from Cregneash down into port Erin. There's a few bends on the way down. The first bend I slowed for was just about OK but the heat had started to accumulate in the disc and caliper so when the next bend came I was pulling harder on the brakes to get the speed bled off. I ended up letting the brakes off completely between corners to let them cool then on hard nearer the bend releasing them at the bend so that the tyres had the best chance of sticking. I finally got the speed bled off enough to keep the speed low as I reached port Erin. The length of the drop caught me out.

Was it a temporary change in the brake pads or a brake fluid problem due to heat?
[egg-sucking]New brake pads can suffer more from fade, use moderate braking to generate a bit of heat and bed them in before working them hard
Water vapour causes problems for both DoT and mineral oil in all vehicle types
Bigger discs are likely to be better[/egg-sucking]
Regards
tim-b
by tim-b
13 Dec 2020, 7:18am
Forum: Bikes & Bits – Technical section
Topic: yet another brake thread; not all about discs
Replies: 111
Views: 3964

Re: yet another brake thread; not all about discs

Hi
I'm certainly not capable of testing a brake with that kind of stopping power to its limits of performance, and I doubt many on here would be either...snip...Ducks and awaits flak :wink:

No flak from me, but IMHO you're missing the point. There are various advantages and disadvantages to any kind of brake, but discs are better in the constantly wet conditions of the UK in the last couple of months than rim brakes; they'll stop you :wink: , you won't wear your rims out, and your bike won't be covered in black brake clag
If I want to change from 50mm tyres to 32mm tyres for a particular tour then I can drop a 700c wheel in in place of the 650b wheels and not have to change my brakes, mudguards or any frame geometry such as bottom bracket height
In terms of maintenance I've never had to bleed one and I haven't greased/replaced a single brake cable in the three sets that I've owned :D
The fronts are a bit of a pain to check pad thickness (I have to look from underneath, I could probably do it with a mirror but I've never tried), but the rears are simple. I can check disc wear a darn sight more easily than I can rim thickness, and discs are way simpler (and cheaper) to replace than rims. Replacing pads is simple enough, different but no more difficult than rim brake pads
Rim brakes still have a place in the fleet, but not on my winter bike
Regards
tim-b
by tim-b
12 Dec 2020, 1:40pm
Forum: Helmets & helmet discussion
Topic: Angi Helmet crash sensor
Replies: 2
Views: 993

Re: Angi Helmet crash sensor

Hi
"What happens if I want to gift or sell my helmet to someone else?
Activation codes are not transferable. This means that, if you want to pair a device to a different phone, the new owner will need to buy a new activation code or pay a one-time fee of $29.99 with the Specialized Ride App." ( https://www.specialized.com/us/en/faq/angi )
Regards
tim-b
by tim-b
12 Dec 2020, 9:16am
Forum: Bikes & Bits – Technical section
Topic: yet another brake thread; not all about discs
Replies: 111
Views: 3964

Re: yet another brake thread; not all about discs

Hi
b) 'squealers' on brake pads (which only start to make noise when the pads are worn past their service limit)

I think that this is fulfilled by what Shimano describe as the "brake pad presser spring"
Inadequate filling of bicycle MCs is a common problem and one that isn't tested for in maintenance procedures.

Shimano give various checks to complete before riding the bicycle in their user manuals. These include checking for fluid leaks, pad wear and correct brake operation and say that you should consult the dealer if there's a problem. Tragically this advice isn't always followed
Shimano acknowledge in the dealer manual that air may be in the reservoir and say, "...be sure to depress the brake lever a few times to
check that the brakes operate normally before riding the bicycle. If the brakes do not operate normally, adjust them according to the following procedure." (from DM-GADBR01-02) This implies to me that a certain air volume is acceptable within the fluid reservoir and the dealer manual advises when to top the reservoir up and when to bleed.
The other essential check is for brake disc wear, which is easier to see and to measure
Regards
tim-b
by tim-b
8 Dec 2020, 6:26am
Forum: The Tea Shop
Topic: crackle, fizzzzzzzzz - ouch! (big amp fuses)
Replies: 14
Views: 523

Re: crackle, fizzzzzzzzz - ouch! (big amp fuses)

Hi
A 13A BS1362 fuse won't blow at 20A, and a 3A needs to get to almost 5A
1 sq.mm copper cable has a rating of approx 10A, so get a 3A (max) in there if that's what you have. The house lighting circuit could be 0.75 sq.mm (older), 1 sq.mm or 1.5 sq.mm (more recently) and will have its own protection (5 or 6A), as a comparison
Regards
tim-b
by tim-b
7 Dec 2020, 7:05am
Forum: Campaigning & Public Policy
Topic: 48 tonnes HGV's for road-rail freight - good or bad?
Replies: 48
Views: 3338

Re: 48 tonnes HGV's for road-rail freight - good or bad?

Hi
Even more so if the hidden subsidy for HGVs in the tax regime...snip

Diesel trains have been powered by red diesel for decades and currently pay 11p per litre duty (~10%?), road vehicles currently pay 58p per litre duty
I'm the first to admit that I don't know how many goods trains are diesels, but there are lots of infrastructure and tax issues that could be ironed out so that objective comparisons can be made on a level playing field
Regards
tim-b