The Velodrome

MaplePanda

00:10

@Szabolcs Interesting. A bleed might be the way to go then. I'm not familiar with Magura, but they should be similar to Shimano I'd imagine...bicycle hydro brakes are all related

I don't think the noise is unusual when you push the pistons back in. Provided you don't feel any sponginess in the lever (signifying the presence of air), it might just be cavitation caused by pushing the piston back a little too quickly

Criggie

00:41

a bleed sounds like the right process here.

Nathan Knutson

03:32

apparently the NES zelda script writers are in the bike biz now

Criggie

04:12

heh I recognised your tool shelf in the background immediately.

Renaud

05:23

@gschenk In Belgium infrastructure is a regional competence. Flanders (north, dutch speaking) is way behind the others regions and between Denmark and Netherlands in term of bike infrastructure. Wallonia is bad in cities, but has a network of long distance roads (that started from abandoned railways and towpaths). Brussels had a "boost" of conversions because of COVID, and has now reached the critical mass.

Maybe too late to mention, but if you happen to bike in the low countries, an interesting way of doing it is through the "knooppunten" networks. Short version, each crossing is numbered (2-digits), and at each crossing (in the network, not all crossings are in the network) you have arrows pointing to the other nodes. Then when you plan a route, you just need to write down the sequence. Super convenient for those not having navigation devices.

Numbered-node cycle network

The numbered-node cycle network (Dutch: fietsknooppuntennetwerk; German: Knotenpunktbezogene Wegweisung/Knotenpunktsystem für Radwanderern [formal] and Radeln nach Zahlen ["bike-by-numbers", informal]) is a wayfinding system. It spans the Netherlands, Belgium, parts of France and Germany, and parts of Croatia, and is expanding rapidly, as of 2017. Each intersection or node is given a number, and the numbers are signposted, so the cyclist always knows which way to go to get to the next node. Numbers are not unique, but nodes with the same number are placed far apart, so that they can't be confused...

2

MaplePanda

06:10

@NathanKnutson The way the supplementary washers are arranged is annoying me LOL

Andy P

08:30

https://bicycles.stackexchange.com/a/84436/14027
@MaplePanda I believe on a road tyre the interlocking is supposed to occur at a molecular level - hence schwalbes assertion that rubber compound is what matters.
If the road surface is rough enough where a tread pattern would help, then the correct answer is actually lower tyre pressure so the tyre deforms to the surface better.

Take for example the new michelin power cup: https://www.bicyclerollingresistance.com/road-bike-reviews/michelin-power-cup-tlr

gschenk

08:49

I trust continental more in this matter. According to them as soon as lubricants like water, dust, slicks come into play edges at the thread provide most friction.

Reason for this trust, from car (winter) tyres they have pretty good understanding what happens at the tread-road interface, and they have the means to actually test it.

Michael

if their bike tyre division actually works together with the car guys ...

I have colleagues who build GPUs, but don’t trust anything I say about GPUs :D

Andy P

Have you got a link with the info from Conti?
Michelin also make very good car tyres and they never include tread on their road bike tyres

Andy P

09:10

Did some digging and found this:
https://www.michelin.co.uk/bicycle/tips-and-advice/tips-and-advice-bicycle/what-is-grip
Michelin also believe its all about the rubber compound for a road tyre

Renaud

@AndyP Note that the question you linked to asked for road and city. And Michelin seems also to think that threading matters in the second case (and their city tires are threaded). So there's clearly a split about road (sport) and commuting.

Andy P

As a 'genre' city riding includes crappy gravel paths etc (and as mentioned in both my answer and criggies answer) the banks of micro gravel that build up.
In every other way a road is a road.

Michael

does tread help on a road covered with sand?

or on gravel?

gschenk

@AndyP unfortunately not. Read it some years ago. Tried to find it again but cannot.

Erlkoenig

@Michael Considering that gravel tyres are treaded... yes

gschenk

09:20

@AndyP city riding also usually requires long lasting and cheap compounds, very good breakers.

Andy P

In theory it should. Some of the sand/gravel will fall into the tread pattern giving a better chance for the rubber to penetrate to the road surface and grip.
Whenever you have a situation where the tyre can penetrate a 'soft' surface then you have mechanical advantage from tread blocks

gschenk

cannot count on the tyre tread conforming to grip the road's roughness.

Andy P

Long lasting and good breakers yes.
Cheap i disagree with - for example conti's black chilli compound is known to have excellent durability considering it's speed and grip.
For me tyres are a terrible place to cut corners on cost. They are the main thing that determines your speed, grip and comfort = buy a terrible bike if you must, but budget to put great tyres on it

gschenk

@AndyP I shan't put 60 EUR tyres on a 100 EUR bike that might be stolen within the year.

I think the price of a pair of Schwalbe Marathon is exactly what most people are willing to spend for their city bikes.

Michael

@Erlkoenig it's such a tiny tread that I’ve always wondered if it's actually useful

Andy P

09:29

I don't like my marathons.
They do the job I bought them for (being bomb proof), but the wet grip is horrendous

I'm open to the possibility the compound hardens in cold and in warmer countries they perform better in that regard though

gschenk

I am not fond of them either. Especially as they tend to crack. Don't ride them with low pressure when they are about two years old.

Erlkoenig

@Michael I think so, the G-One grip pretty well

Michael

@AndyP I think that’s true for pretty much all city tyres. I also crashed twice on my Vittoria Randonneur Hyper in wet weather

gschenk

@AndyP i find it immensely annoying that every time bike press writes anything about winter tyres they leave out the most important thing of a proper winter tyre: compound that stays soft when cold.

Andy P

@Michael Yes, I have some voyager hypers. They are indeed really fast as the reviews say. But they have exactly 0 wet grip. Not crashed on them, but coming down this in the wet on them was an undesirable adventure: climbbybike.com/profile/…

Michael

09:37

@AndyP I managed to lock up the front wheel on wet tarmac

Andy P

My sister likes her G-Ones and says she finds them really grippy.
Which I guess is good considering they roll like squares otherwise they would have nothing going for them

gschenk

G-Ones are surprisingly noisy for such a small pattern.

It is gone quite soon though. It really show's on bikes here who's inflating their gravel tyres too high.

With a bald strip along the centre on an otherwise pristine tyre.

@AndyP terra speeds grip as well, or better. They are faster and cost 20% less.

Andy P

Yes, unless you are going to be encountering mud I don't see much reason to run anything other than a terra speed with 2 exceptions.
1) if you want some more puncture protection you might want the specialized pathfinder.
2) if you have clearance for a race king/thunder burt then run those

Erlkoenig

10:04

@gschenk The low pressure dampens the noise. Only on very smooth tarmac are they louder than Pro-One

@AndyP Which ones does she have? I have the Allround ones and I don't think they roll bad

Andy P

10:16

@Erlkoenig She also has the allround (35c v-guard version iirc)

schwalbe have the correct technology, but they have made some very odd choices with their off road lineup recently. (such as putting the speed grip compound on tyres that clearly should have the speed compound)

gschenk

12:22

@Erlkoenig I've ridden G-One for a few years. When switching to Terra speed I did a direct comparison. Rode a short round on G-One (tubeless), then swapped tyres, rode Terrra Speed (inner tubes).

tubes vs tubeless was a small bias towards G-One, but still terra speed were much quieter on tarmac, and that's no surprise grippier on lose ground.

Since G-one are only marginally better protected, but much slower and more expensive, there's no reason to stick to them any more.

I think they were the best choice for most in Europe about five years ago. Gravel kings did cost about twice as much. But today other manufacturers caught up, and Schwalbe cost as much as any other brand.

Andy P

12:37

First generation of G-One was indeed an easy choice - there was basically no competition.

Andy P

13:08

Anyone else finding the main site is spamming them with review queues and half the time they are empty when you click on them?

Swifty

@AndyP in the top right, yeah always have. But I log straight into the review queue page each time, so clear the queues first thing and then don't get spammed

Andy P

Interesting. Only started for me ~2-3 weeks ago

Before that it was very rare for me to see the red notification dot up there

Swifty

Hmm, bit odd that it started suddenly but doesn't sound unusual

Should I be more surprised I got an upvote, or sad that I got a downvote?

Andy P

13:26

I assume for the comedy answer on the rear light question? :D

Swifty

yassss

Andy P

I think the other way round.
Sad that some folks thought it was worthy of an upvote and surprised anyone was mean enough to downvote it

Swifty

haha that's fair

it's ok though it's now +1 so I am restored

Andy P

Really though, what has the world come to when you need to ask the internet how to attach a bike light. Especially when that model of light comes with such a versatile fitting

Or ask what model of bmx you have when it has the brand and model name clear as day on the frame.....

That surely had to be a troll question

Swifty

I had a cheapy rechargable that came with a plastic clip for clipping onto the saddle bag, that worked really nicely

but I don't see one for the lezyne

oh yes that bmx, I think it was a valuation request really

Andy P

13:35

Lezyne had a combination clip + silicon strap on the old version of the KTV drive.
But the clip wasnt clippy enough and it would bounce off and get lost on rough surfaces.
So I guess they had enough bad feedback on that and abandoned it

Swifty

oh shame

Andy P

it was a pretty genius fitting if it had actually worked

Swifty

mine was a rsp, which was a raleigh brand reboot I think. cheap but effective

you need it to stay attached!

Andy P

i need to find some little blinky lights that will fit to a really deep aero bar and seatpost for going to the alps this summer (for the tunnels). although may just see if I can fit them on my helmet

Renaud

@AndyP And it looks like your quest to bring their reputation to 0 is compromised, on top of that.

Andy P

13:50

Yeah. I guess it's a sort of ok question.
Only requires about 30 seconds of common sense to solve, but I guess most of us have been there at some point = its relevant to many people

Railway union in the UK doing their best to prove why cars are still king.
As a sector they are really quite well paid and going on strike claiming pay is bad.

Rory Alsop

14:49

@AndyP They really aren't. It's only drivers that get anything decent - the rest are massively overworked and underpaid. Not as badly as nurses, but still.

I mean, I'd still always prefer to drive or go by bike, motorbike or aeroplane, or even a boat, than take the train, as I'm really not a fan of trains in this country.

Andy P

Define decent.
The folks wandering up and down checking tickets are earning more than many young engineering graduates.
I'd call that more than decent

Rory Alsop

@AndyP ah - there's the problem. "Wandering up and down" is not really their job. Being able to cope with emergencies including death, major injury etc is - for that they get paid terribly

Most engineering graduates never have to worry about death and maiming. In my entire career I the worst thing that can happen in my area is someone has to spend a bit more money. And yet I get a decent salary. I am of the firm belief that anyone who has to deal with those sorts of things should be recompensed rather better

(Married to a nurse who was cardiothoracic intensive care for a few years - my new interns earn more than she does after 30 years in nursing - doesn't make it right)

Andy P

Indeed.
Nurses have a harder job and are paid worse than those in rail industry.
And yet nurses arent going on strike demanding more (which would be much more understandable)

Michael

here in Austria everyone earns a ton of money but they still complain

Rory Alsop

@AndyP they can't easily - people tend to die rather faster if nurses strike

@Michael I tend to argue my industry earns too much (but I also complain it pays better in the US... ;-) )

Andy P

15:06

I don't think anyone can be a fan of trains in this country.
The infrastructure and rolling stock are mostly terrible.
Whoever at Scotrail thought resurrecting intercity125 was the solution to problems definitely needs to be found another less demanding job

Swifty

19:09

@AndyP sorry I was writing an answer to suspension already

Andy P

Don't worry, I did exactly the same thing to someone else a couple of weeks ago. Didn't notice they had posted whilst I was writing and made an almost identical answer 1 min later

Erlkoenig

19:57

@AndyP Make sure blinking lights are legal in the respective country. They aren't in Germany!

DavidW

So what tyres would people recommend for a road bike that is at worst going to be ridden on maintained gravel? The ones that the shop put on last fall both failed identically within a hundred km of one another yesterday.

Fortunately the people I was with had a couple of spares among them, but now I've got a 23mm Schwalbe on the front and a 25mm GP5000 on the back, and I'd like to swap the front for a 25mm.

(And I owe a couple of people dinner, but that's not a hardship.)

Michael

@DavidW failed? How?

crushed beer bottles is not gravel :D

DavidW

The casing failed under the main tread and tore a 10-15mm hole; the tube promptly exploded.

Michael

o.O any idea why it failed? Did you ride with extremely low pressure?

DavidW

I was running them near max sidewall pressure (thin tires, fat rider) but not over and it wasn't particularly hot.

Michael

20:10

okay, that’s really strange

so the casing’s fabric simply tore apart? No sign of a cut or anything?

DavidW

Thinking back when I got the bike back from the shop it was winter and I just stored it. Kept the tyres from completely deflating through the winter, but not at full pressure either; maybe 4bar. But when I rolled it out in the spring I noticed that both tyres hadn't been centred when they were mounted.

Michael

anyway … tyre recommendation depends on your priorities. GP5000 is a great all round road bike tyre

DavidW

It's hard to tell a cut, which is actually what we suspected the first time, even if we couldn't see anything. But the second time it happened one of the guys walked back down the road while I was swapping on the new tyre and didn't see anything suspicious in the previous 100m.

Michael

if you are heavy you might want to go wider than 25mm (maybe put the 25mm GP5000 on the front and go for 28mm in the rear)

DavidW

It's a 10+ year-old bike; I was looking at the clearances in the fall when I bought the crappy ones and I didn't think 28s would fit.

(At least I'd have to partially deflate them to get the past the brakes.)

Michael

20:16

and unless you are >90kg I really wouldn’t go for the 7.5bars or so of maximum pressure at 25mm

I think this is the tyre pressure calculator my sister recommends: silca.cc/pages/sppc-form

Andy P

If you can fit a 26mm, the pirelli p zero race could be a good option.
It's still a fast tyre, just trading a little speed for a little more protection vs gp5000
https://www.pirelli.com/tyres/en-gb/bike/tyres/catalogue/p-zero-race

Michael

GP4 Seasons also has a bit more protection (especially on the sidewalls for occasional gravel use)

at 25mm width I think road bike tyres are your only option anyway. Gravel and cyclocross start around ~32mm

Criggie

There are far too many Continental tyre options IMO.

Andy P

lol, you should see schwalbe's lineup, they have 2-3x as many as conti

Criggie

Schwalbe's not really a tyre brand locally. Tubes yes but not tyres. Its odd.

@Erlkoenig Are throbbers permitted? They don't blink but they do cycle from on to off over a second or two.

Michael

20:24

@Criggie nope

here in Austria a flashing rear light is allowed but the front light has to be steady

Criggie

Shame - I rather like them for night rides.

Michael

why does your light not have a steady mode? o.O

Criggie

They are more visible than a steady light, but without that brain-pain that comes from STAB STAB STAB blinking

Michael

IMHO the advantage of flashing is that it usually only consumes half the power

Andy P

honestly, call me a rebel, but i'm not THAT concerned about the legality (or not) of a 5lm light that i'll be using for a grand total of 5-10 mins over ~36hrs of riding

Criggie

20:26

yeah - lower power useage means longer runtime. I have a light that can't even cover one commute home when left on solid.

Michael

on the nice road bike I also have my daylight lights in illegal flashing mode. They do have a light sensor and automatically switch to steady light when it gets dark.

so far only one older gentleman has stopped me to point out that it’s illegal

(interestingly enough he didn’t notice the lack of spoke reflectors)

DavidW

@Michael cough

Most of the people I ride with have gradually adopted daytime use of blinking rear lights.

Michael

I just found a paper with this nice title “The Respiratory Exchange Ratio is Associated with Fitness Indicators Both in Trained and Untrained Men: A Possible Application for People with Reduced Exercise Tolerance”

DavidW

If the group breaks up it's definitely easier to see the blinking red lights way up the road than make out cyclists in a lot of conditions.

Michael

“People With Reduced Exercise Tolerance” aka weak and lazy :D

Andy P

20:36

lol

That's such a 2019 solution.
Now we are ALL supposed to spend £500 on a garmin 1040 and have it track movements of the entire group

DavidW

@AndyP And share it with anyone that Garmin feels like, no doubt. :-P

Andy P

That and whoever hacks them and gets all their data next :P

MaplePanda

Molecular level interlocking--do you mean like intermolecular bonding between the tire and road? If we are talking about mechanical effects still, I'd imagine a tire with a textured surface inherently has more "domains" to interlock with the road. I do agree the tread isn't too important, if only because it wears off after <500km.

As supple as modern road tires are, I'm not convinced they are able to effectively conform to the <1mm bumpiness on a road surface purely by pneumatic means.

MathCubes

Hello everyone

Criggie

Garmin being the company that paid the ransom for their encryptionware attack because they had no backups or other solution ?

3

Just making sure that's never forgotten

@MathCubes Hello!

MathCubes

20:45

Hey

Is anyone in here that is knowledgeable with saddles?

DavidW

No, we never use them. :)

Michael

@MathCubes it’s not the saddle

MathCubes

huh?

You ride on one of those layback cycles?

MaplePanda

What's up with your saddle

Andy P

Not intermolecular bonding.
But even a 'perfectly' smooth new asphalt and a slick tyre are not smooth at the surface when you reach the molecular level.
If I recall correctly that's one of the reasons some newer compounds are using graphine and carbon

MaplePanda

20:47

Is it saddling you with problems?

MathCubes

I just have a very large sit bone and like I need help to finding an comfortable one for my touring bicycle.

My sitbone is 18cm measured at a bicycle shop

Criggie

@MathCubes actually yes, I own two recumbent bikes, which have "seats" not saddles... but that's beside the point.

MathCubes

and I can not really find one that is wide enough

Michael

time for bed, good night!

MathCubes

The bicycle shop let me borrow an Brooks C17 and that burns the inside of my butt because its still too norrow.

Criggie

20:48

@MathCubes yeah wide saddles are a good idea if you need them.

Andy P

@MathCubes Look at ladies saddles, they are typically wider than mens saddles because they have wider sit bones

MathCubes

Could I used an upright one on my bicycle or like how would I go about that.

I have but they still do not make them wide enough or atleast I haven't found one wider than 16.5 cm but my sit bone is at 18 cm

Does the angle matter that much?

I do not have experance in this

MaplePanda

Good point. Perhaps the macroscopic tread is not significant then.

Carbon has always been in tires for abrasion resistance and UV protection I believe. I wonder whether the "graphene" part is legit or just more carbon nanotube magic handwaving

Michael

@MathCubes in a more leaned forward position you usually need a narrower saddle

MathCubes

But shouldn't it be base on your sit bone width?

Michael

20:50

they get narrower in the front

MathCubes

Oh

How about an noseless saddle?

Criggie

@MathCubes You could consider those weird non-traditional saddle shapes, but they're not common and might just be throwing away money.

You'd want to try one before committing to purchase

MathCubes

NIOSH No Nose Saddle Explained

►

Criggie

No-nose doesn't mean wider, does it ?

MaplePanda

I don't think there's a correlation

Andy P

20:54

some cheap low end saddles designed for leisure bikes are wide enough. I find it hard to recommend such a thing though:
https://hollandbikeshop.com/en-gb/bicycle-saddles-seatposts/selle-royal-bicycle-saddle/selle-royal-hybrid-bicycle-saddle/selle-royal-saddle-nuvola-royal-vacuum-light-ladies-black/

MathCubes

No, it doesn't but I am bringing it up that there is science behind them

MaplePanda

Perhaps chatting with a saddle manufacturer might be the way to go.

They'd obviously know their inventory best.

Andy P

21:10

No nose is certainly an interesting concept.
If someone gave me one i'd be willing to give it a go, but suspect it only works for very upright positions and wouldnt work too well on drop bar bikes

MathCubes

True

Andy P

21:46

That is a tiny biy unfair.
They had backups, they just let those get encrypted too!

Andy P

22:03

@MaplePanda I didn't have much else to do this evening so wasted an hour researching tyre grip a bit more. I found this nice article (or at least the 2nd half of it is nice): formula1-dictionary.net/most_important.html

Criggie

@AndyP -grin- I'd rather use pencil and notebook than Garmin, personally.

Andy P

OK, I did it, i reached maximum nerd levels.
Here's everything you ever wanted to know about tyres - and probably things you didnt want to know too!
http://www.dimnp.unipi.it/guiggiani-m/Michelin_Tire_Grip.pdf

Kudos to Michelin for actually writing such a document

gschenk

23:03

@AndyP carbon black is being used since the great war. When they tried to stretch the little rubber they had with anything that might do as a filler.

Criggie

@NathanKnutson Wondering about your thoughts on the spoke tensionmeter question at bicycles.stackexchange.com/questions/84455

gschenk

23:20

Be super careful when it comes to graphene. Carbon black is roughly speaking soot. Carbon black producers burn heavy oil (Like freight ships). Depending on the process there may be a considerable amount of graphene (and carbon nanotubes) in that stuff. Might depend on sulfur content and whatnot. There is also a whole zoo of different graphenes. (Allotropes, size, oxidised, bonded to other stuff.)

The carbon black off one company may be equally good or better than the mix off carbon black and pure graphene of another mfg, or batch.

It might be actually better, might as well be the combination of unrealised high hopes by R&D and marketing hype

I've talked with some experimental post docs who did stuff with nanotubes, Bucky balls, and graphene at molecular level: it is a right bitch to work with cause these things contaminate everything, mix up, and degrade. Likely isn't that much of a problem with three large quantities used in industrial products. Yet, might still be challenged in analytics: what does actually end up in product.

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