Tyre width

[sojournermike]

Always funny to see how t'internet turns a cheery discussion into a hard argued battle;)

On discs, there are fairly clear advantages and disadvantages. In my mind they make sense off road and are not particularly necessary on (although I accept the case with carbon rims and long descents where discs may also over heat?)

I use tubeless for reasons explained above - not because changing/repairing a tube bothers me, nor for outright speed, but because it does lower the risk of a sudden complete deflation. I've had no problems with road tubeless set up or use, but I also don't have a problem riding tubes tyres and would likewise ride tubs if I had the rims. Perhaps that should be the next project...

In terms of speed and comfort from a clincher, Vittoria Corsa's are lovely and I'm looking forward to riding the tubeless set I have when the weather is finer;)

[rogerzilla]

Punctures aren't much of an issue if there is a team car just behind you with a spare bike on the roof.  Pros would probably choose the best tubs and the lightest rim brakes if they could, because that's the fastest and lightest option.  You can also ride a flat tubular for a bit until the team car gets to you. Amateur needs are different, of course.

[quixoticgeek]

Always funny to see how t'internet turns a cheery discussion into a hard argued battle;)

On discs, there are fairly clear advantages and disadvantages. In my mind they make sense off road and are not particularly necessary on (although I accept the case with carbon rims and long descents where discs may also over heat?)

This evening I switched my bike over from Ryde DP18 rims to some Pacenti TL28 rims. The former had 28mm Schwalbe Marathon's, the later have a pair of 42mm Schwalbe Marathon Winter spiked tyres. The tyres on the DP18's before the Marathon's were some 23mm slicks. Being able to easily swap between a variety of rims and tyre widths for the conditions is, IMHO, a major advantage of disc brakes. That and the stopping power in the wet. For some of us riding in the wet is common...

I am a big fan of disc brakes and can't really see any reason to use anything else.

J

[Kim]

I am a big fan of disc brakes and can't really see any reason to use anything else.

Weight, where weight matters.  Which is on bikes that are getting raced up hills or folded up and carried non-trivial distances.  Similarly for aerodynamics, where it matters (again, racing I suppose).  Or because a brake is fitted for reasons other than as a device for slowing the bike^[1], where mechanical simplicity beats performance.

And boring real-world things like the frame/fork/hub/etc you want to use for more important reasons requires rim brakes.  Or because for the intended application drum brakes are even better.

But generally, yes, discs.


_{[1] Legal requirement, parking brake.}

[mattc]

Being able to easily swap between a variety of rims and tyre widths for the conditions is, IMHO, a major advantage of disc brakes.

Losing that resource is a major reason for me sticking with rim brakes!


[but yes, I do know what you mean ... ]

[Brucey]

disc brakes are not practical brakes for all kinds of utility bikes, because they simply get knocked and damaged too easily.  A disc that is much more than 0.25mm out of true will rub so badly it is practically useless, and may not be trued easily (an LBS near me usually just replaces them).  Almost the slightest knock when the bike is parked will produce that amount of deformation or more.

I live in a town with lots of bikes in it that are used for transport and I can clearly hear the brakes rubbing on about half of the bikes I ride past that are fitted with disc brakes.

cheers

[quixoticgeek]

disc brakes are not practical brakes for all kinds of utility bikes, because they simply get knocked and damaged too easily.  A disc that is much more than 0.25mm out of true will rub so badly it is practically useless, and may not be trued easily (an LBS near me usually just replaces them).  Almost the slightest knock when the bike is parked will produce that amount of deformation or more.

The disk rubbing and keeping it true is something that I think has come on considerably with recent iterations of the disk brake calipers. My old hybrid had avid brakes of some iteration (it/s over 10 years old). And it was a right pain in the but to get the disk to be true and in the right place whilst also having enough braking power.

My new bike has TRP Spyre, and it's been very simple to get set up and working. I've had to true the discs on the rear once, but that's an easy enough thing to do with an adjustable spanner, takes about a minute.

I live in a town with lots of bikes in it that are used for transport and I can clearly hear the brakes rubbing on about half of the bikes I ride past that are fitted with disc brakes.

I'm in a city with more bikes than people. Nearly all of them utility bikes. I can hear most of them coming from the squeak, or the rattle, or the grinding, or the combination of all three. And if you ever have to do an emergency stop, hope that there's no local on a bike too close behind you, as their brakes probably wont work and you are their crumple zone...[1] Badly maintained brakes are not unique to any one type of brake, what ever you fit you need to be aware of the quirks of it, and that you may need to true the disk every once in a while is some idiot knocks it is hardly a major difficulty.

J


[1]Learnt that the hardway on day 1 of commuting here. Idiot stopped in front of me on the cycle path. I slammed on the brakes and stopped safely, then 5 locals ploughed into the back of me cos their brakes sucked. The torrent of robust anglo saxon that the guy who caused it all got did not impress him...

[Brucey]

.... Badly maintained brakes are not unique to any one type of brake...

true enough, but some are more likely to give trouble (that won't be attended to by the average owner) than others.

cheers

[Kim]

.... Badly maintained brakes are not unique to any one type of brake...

true enough, but some are more likely to give trouble (that won't be attended to by the average owner) than others.

Which would be all rim brakes on poor quality factory-built wheels.

[mrcharly-YHT]

Blimey brucey I know you don't like disc brakes but that is really stretching it.

If that were true of disc brakes then MTB bikes would be unrideable after every crash. Come on, the first widespread adoption of disc brakes was in MTBing and you are suggesting that they are susceptible to the slightest knock in general cycling!

[Brucey]

Blimey brucey I know you don't like disc brakes but that is really stretching it.

If that were true of disc brakes then MTB bikes would be unrideable after every crash. Come on, the first widespread adoption of disc brakes was in MTBing and you are suggesting that they are susceptible to the slightest knock in general cycling!

I have used disc brakes on MTBs for about 20 years and they are quite good for that purpose. Yes I have seen very many MTBs rendered unrideable (with both brakes working) by virtue of bent discs.  But the worst that happens is that playtime is prematurely over for today, and the cost of occasional new discs is lost in the noise, what with the blizzard of expenditure to keep thing in decent tyres, transmission and suspension components....

Discs on utility bikes get bent by all kinds of stupid parking knocks; some bike racks look as if they were designed to bend discs, and even if your bike is leant against a wall or something, it just takes someone else leaning their bike against yours and their pedal will soon put a disc out true. Such knocks  happen often.

  For years I have habitually leant derailleur geared bikes with their right side against a wall, so that the rear mech, chainrings etc don't get similarly knocked. But with a disc braked utility bike I wonder if it isn't better (on balance) to lean it the other way, so the discs are less likely to take a knock.

cheers

[Kim]

For years I have habitually leant derailleur geared bikes with their right side against a wall, so that the rear mech, chainrings etc don't get similarly knocked. But with a disc braked utility bike I wonder if it isn't better (on balance) to lean it the other way, so the discs are less likely to take a knock.

Lean the side you don't naturally wheel a bike from against the wall.  You're more likely to knock things rotating the bike or wheeling it incompetently from the 'wrong' side.

[PaulF]

disc brakes are not practical brakes for all kinds of utility bikes, because they simply get knocked and damaged too easily.  A disc that is much more than 0.25mm out of true will rub so badly it is practically useless, and may not be trued easily (an LBS near me usually just replaces them).  Almost the slightest knock when the bike is parked will produce that amount of deformation or more.

I live in a town with lots of bikes in it that are used for transport and I can clearly hear the brakes rubbing on about half of the bikes I ride past that are fitted with disc brakes.

cheers

That’s totally at odds with my experience. I’ve had disc brakes on 4 different bikes for about 8 years now and never had to replace a disc. Bikes get used and abused for all purposes.

There may be some sound arguments, weight aside, against discs brakes but the vulnerability of the is not one of them. 

[citoyen]

Apparently Michelin and Continental have do not produce tubeless.

With Michelin especially, I get the impression that's mainly because they don't really care about bike tyres as it's such a small part of their overall business. Not that there's anything wrong with the tyres they do produce but they don't have the impetus to invest in new technologies for the cycling market in the same way as, say, Schwalbe.

[LittleWheelsandBig]

That isn't quite correct citoyen. Michelin developed ultra-low rolling resistance bicycle tyres that aren't available to the general public but are quite coveted by HPV and solar car folk.

I still remember walking an early disk braked MTB tandem out of the bush when the front rotor warped because of heavy braking. On a separate occasion,  I also remember kicking the front rotor of a snot-nosed MTBer specifically so that he had to walk out of the bush.

[Brucey]

chances of discs surviving this sort of parking every day = zero

(and no, you don't have much choice)

cheers

[PaulF]

Not exactly typical of how the majority of bikes are parked though is it?

[fuaran]

With that parking, I'd be more worried about bending the rims, or breaking spokes etc.

Most disc rotors are pretty tough, it would take a lot of effort to bend them (unless they are superlightweight, or worn out, or just rubbish).

[Kim]

The only way I've ever succeeded in bending a disc rotor has been by losing control of the unbalanced bike (heavy recumbent) while refitting the wheel.  A couple of minutes with an adjustable spanner sorted it out, but it was still ridable if you ignored the rubbing noises.

Not to say that it couldn't happen to a parked bike.  I'm sure it could.  The bike I tend to park in busy racks has V-brakes.

IME the most common form of damage to parked bikes (other than scuffs to paintwork from the lock itself) is bent mudguard stays.  You wouldn't say that a utility bike shouldn't have mudguards on that basis.

[dim]

chances of discs surviving this sort of parking every day = zero

(and no, you don't have much choice)

cheers

well  .... i very much doubt that I will be parking my £6000 Canyon aeroad with Dura Ace Di2 and £2000 wheels at my local Cambridge train station .... I'd park my vintage commuter bike there (and even then, I'm a tad nervous)

I think that people on this thread are talking about wheels and tyres for 'faster bikes' that won't be locked up in public places ?

[Brucey]

in response to the claim that there are  'no downsides to disc brakes' I pointed out several things that are downsides and added that IMHO they are not really suitable for utility bikes because they are liable to get knocked.

 They also don't always survive the neglect they typically receive in that service either.  For that service (and for various reasons) I'd choose drum brakes, roller brakes, and even rim brakes over discs.

I had discs on my commuting bike for a while (one that I didn't have to park in hazardous areas) and the brakes were ones that would only take organic pads. The brakes were great for most planned braking, but when it was tipping with rain, there was an enormous amount of lag (a bit like with chrome steel rims and rim brakes) that made any unplanned braking a real lottery.  I came to the conclusion it was only a matter of time till I skittled some dozy sod staggering off the pavement in front of me. 

With different brakes, fitted with sintered pads, that would have been better. But TBH drum brakes work so well for that purpose that it'd be daft to choose something other than those.

cheers

[citoyen]

That isn't quite correct citoyen. Michelin developed ultra-low rolling resistance bicycle tyres that aren't available to the general public but are quite coveted by HPV and solar car folk.

OK, maybe it's just the mass consumer market they're not interested in. Maybe the more experimental stuff is of interest for R&D purposes.

[Samuel D]

You don’t think Michelin’s long-running Pro range (e.g. Pro4) and now Power tyres reveal a fair interest in bicycles?

The Michelin company is probably the most capable tyre maker in the world, but with that competence comes caution. Tubeless bicycle tyres are a Wild West of standards, bodges, and guesswork at the moment. I think Michelin and Continental see no reason to dive into that mess, with all the risk to reputation that comes with it, while their tubed tyres still capture most of the high-performance market.

[quixoticgeek]

Not exactly typical of how the majority of bikes are parked though is it?

Round these parts, yeah, it is. There's a reason I don't lock my bike up here. I take it into the office at work, I store it inside at home. That picture could be anywhere in Amsterdam or a University city in the Netherlands.

I would never consider parking a bike there, no matter what the config.

J

[quixoticgeek]

in response to the claim that there are  'no downsides to disc brakes' I pointed out several things that are downsides and added that IMHO they are not really suitable for utility bikes because they are liable to get knocked.

My quick search suggests the phrase 'no downsides to disc brakes' is used exactly once, prior to my typing it just now, which is in your post to which I am replying...

I do not think that your statement is as true as you think.

I carried a pair of 700c disc wheels with discs attached, strapped to a 65L backpack on a Eurostar and on trains across 4 countries, then installed them on a bike, the disc on one wheel needed to be trued, and this took me exactly one "bend" with an adjustable spanner, and they worked perfectly.

 They also don't always survive the neglect they typically receive in that service either.  For that service (and for various reasons) I'd choose drum brakes, roller brakes, and even rim brakes over discs.

Then don't neglect bikes. There's a lot of 'solutions' out there for making it such that a bike needs less servicing, but in my experience what that does is just make the servicing harder when it's needed. A Dutch friend with a Dutch city bike was espousing how their bike was really low maintenance and they hadn't needed to oil it and the chain guard protected everything and the hub brakes just work and and and... It took bloody ages to just get the chain guard off so we could try to fix it. With hub brakes you only know that they are wearing out when they fail on you. It's not something you can easily see if the shoe is wearing, unlike rim and disk brakes where you can see the wear level by looking at them.

I still can't understand why anyone would choose back pedal brakes, I've used them a few times, they never have the stopping power even close to other brakes, and it restricts what you can do with the pedals... oh and the usual stuff above regarding checking wear...

I had discs on my commuting bike for a while (one that I didn't have to park in hazardous areas) and the brakes were ones that would only take organic pads. The brakes were great for most planned braking, but when it was tipping with rain, there was an enormous amount of lag (a bit like with chrome steel rims and rim brakes) that made any unplanned braking a real lottery.  I came to the conclusion it was only a matter of time till I skittled some dozy sod staggering off the pavement in front of me.

Sounds like you had just poor quality disc brakes... in which case you get what you pay for. The TRP Spyre's that I'm running on my current bike are a world away from the cheaper disc brakes out there.

With different brakes, fitted with sintered pads, that would have been better. But TBH drum brakes work so well for that purpose that it'd be daft to choose something other than those.

Right up to the point where they fail, at which point you're gonna need a proper work shop to do anything with them...

J