Fabian
Well-Known Member
But you can be saved if you repent and make disk brakes your new "God" !!!
In the name of the disk brake pad and the disk brake rotor and the disk brake caliper.
One day you will thank me for changing religions...
Brakes brake pads or v brake
- Thread starter oldpot
- Start date
But you can be saved if you repent and make disk brakes your new "God" !!!
In the name of the disk brake pad and the disk brake rotor and the disk brake caliper.
One day you will thank me for changing religions...
grinningremlin
Active Member
OK, that WAS funny!So was Profs comment, though he may be on to something if you ride a faired bike.I'll stick to my suicidal ways, no helmet, V-brakes; life is a calculated risk,... and no one gets out alive.
HeadSmess
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i do 70km/h.
i have front brakes only cus i couldnt be bothered whacking a new cable on the rear.
cantilevers work fine. there is an art in setting them to operate effectively. arm angle, strapping cable length and included angle, approach angle of shoes/pads, and toe-in angle. the leading tip of the pad should hit the rim 1mm or 1/16 before the rear! and not run off the rim either into the tyre or into the spokes... then tweaking the side screws so the whole assembly works symmetrically.
i do back sidepull/caliper brakes up with some coasters after having a cable snap just before a hairpin. overtook that motorbike! weeeee! had to jump off at 50! left a dent in the guardrail the bike hit that hard
i would have taken that corner if the motorbike hadnt been there
magura hydralics crush standard rims
discs on pushbikes are just bling. bling bling bling. yet to see a pushbikes disc start glowing like my motorbikes does after a good ride.
on a car...they can be slotted(internally, not just crossdrilled), for heat. the large surface area with small contact area makes for a big heat sink. they are lightweight(ha ha...not really). they are maintenance free when adjusted correctly. they(usually) are easy to service and maintain. they dont get waterlogged so easily. they stay relatively clean. mechanically they are simple.
a drum brake...large contact area, with minimum surface area, and bad ventilation. hard to adjust, annoying to maintain, and they catch/hold water,oil and road grit and brake dust. useless if you have to use them for extended periods. look at the size of the hub and the vents used in the 70's-80's! they also have a habit of locking on at times.
they are still common on a lot of cars, at the rear, because one, the handbrake is a lock, not a stopping device. heats no issue. nor is wear. and at the rear, they take 40% braking load, they dont get as hot as the front brakes.
(funniest label ive ever seen on a car? "WARNING!!! THIS VEHICLE IS FITTED WITH GIRLING HYDRALIC BRAKES". a bentley. thats the best way to describe some british engineering...WARNING!!!!)
if you are stuck with having to use caliper brakes...find some bulldogs or similar. the type used on freestyle bmx. they are one finger flippers when ADJUSTED CORRECTLY, just like v-brakes can do. the ones that sorta look like vbrakes in many regards, with twin pivots and a cross pulling cable, they are the bomb
spend the money, and do not get stingy on brakes! if you ride like a girl
personally, im more worried about chains coming off and locking up wheels at speed than having to stop. spent my whole life practising how to stop got it down to an art, i does
im with gremlin. ride to the conditions, remain alert and prepared, and you barely NEED brakes.
and no. i CANNOT ride one of these bmx bikes with no brakes. that feels WRONG.
i have front brakes only cus i couldnt be bothered whacking a new cable on the rear.
cantilevers work fine. there is an art in setting them to operate effectively. arm angle, strapping cable length and included angle, approach angle of shoes/pads, and toe-in angle. the leading tip of the pad should hit the rim 1mm or 1/16 before the rear! and not run off the rim either into the tyre or into the spokes... then tweaking the side screws so the whole assembly works symmetrically.
i do back sidepull/caliper brakes up with some coasters after having a cable snap just before a hairpin. overtook that motorbike! weeeee! had to jump off at 50! left a dent in the guardrail the bike hit that hard
i would have taken that corner if the motorbike hadnt been there magura hydralics crush standard rims
discs on pushbikes are just bling. bling bling bling. yet to see a pushbikes disc start glowing like my motorbikes does after a good ride.
on a car...they can be slotted(internally, not just crossdrilled), for heat. the large surface area with small contact area makes for a big heat sink. they are lightweight(ha ha...not really). they are maintenance free when adjusted correctly. they(usually) are easy to service and maintain. they dont get waterlogged so easily. they stay relatively clean. mechanically they are simple.
a drum brake...large contact area, with minimum surface area, and bad ventilation. hard to adjust, annoying to maintain, and they catch/hold water,oil and road grit and brake dust. useless if you have to use them for extended periods. look at the size of the hub and the vents used in the 70's-80's! they also have a habit of locking on at times.
they are still common on a lot of cars, at the rear, because one, the handbrake is a lock, not a stopping device. heats no issue. nor is wear. and at the rear, they take 40% braking load, they dont get as hot as the front brakes.
(funniest label ive ever seen on a car? "WARNING!!! THIS VEHICLE IS FITTED WITH GIRLING HYDRALIC BRAKES". a bentley. thats the best way to describe some british engineering...WARNING!!!!)
if you are stuck with having to use caliper brakes...find some bulldogs or similar. the type used on freestyle bmx. they are one finger flippers when ADJUSTED CORRECTLY, just like v-brakes can do. the ones that sorta look like vbrakes in many regards, with twin pivots and a cross pulling cable, they are the bomb
spend the money, and do not get stingy on brakes! if you ride like a girl
personally, im more worried about chains coming off and locking up wheels at speed than having to stop. spent my whole life practising how to stop
got it down to an art, i does im with gremlin. ride to the conditions, remain alert and prepared, and you barely NEED brakes.
and no. i CANNOT ride one of these bmx bikes with no brakes. that feels WRONG.
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Fabian
Well-Known Member
And this is why you do not ride a motorized bicycle with rim brakes, because even the largest available disk rotor (9" Hayes V9 Rotor) still doesn't have enough surface area to get rid of the heat from a downhill run. If the same decent would be tried with rim brakes, you would be dead.
I had to modulate the brakes on the way down to try and prevent the pads from totally over heating.
Even so, there was a column of smoke rising from the caliper when i came to a stop.
I had to modulate the brakes on the way down to try and prevent the pads from totally over heating.
Even so, there was a column of smoke rising from the caliper when i came to a stop.
HeadSmess
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http://www.engineeringtoolbox.com/thermal-conductivity-d_429.html
stainless steel... 16@25C
aluminium...205@25C
which one can conduct the heat away faster?
cant find a section of brake rotor...2.5mm?
what has more volume to conduct heat away?
the fact that larger rotors increase braking power just shows that a 26" "disc" is a lot more effective at stopping than even a 9" rotor.
therefore a lot less pressure at the pad required, therefore less heat generated?
wet doesnt bother good pads set properly. oil does
anyone can ride down a steep hill with the brakes on
the trick is to do it without them disc brakes...that model is obsolete and pads are no longer available but for $650 we can upgrade for you sir... oh, vbrake pads are $10. but really you should upgrade to these new brakes... and you will need new forks. oh, yeah baby
almost easier and cheaper to buy a new bike when something needs replacing! meh. its personal taste.
wheres the hill? ill take it on with just a rear coaster brake!
(ill go down and take some more pics one day. dont have any good ones. i think this one was where i stacked and snapped the bars. on the way up!)
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Fabian
Well-Known Member
I will agree that the hill you have shown is a nice looking hill, but does it decend for 6 kilometers (3.7 miles).
Your description of heat transfer between aluminium and stainless steel is precisely the reason why disk brakes are the optimal solution because rim brakes conduct all of the heat into the rim; heating up the air inside the trye, then causing the tyre to explode if the rim is heated in sufficient manner.
This is also the precise reason why people who cycle up the mountain (as depicted by the results from my trip down it) only travel up the road, but take their bicycle down the hill on their car (if they have rim brakes) because the rim gets so hot that the tyre bead explodes off the wheel rim from overheating.
At the end of the day rim brakes are marginal on a normal bicycle and in some cases simply dangerous, but they are a lethal combination when used on a motorized bicycle, for more reasons than simply the notion of stopping power.
Your description of heat transfer between aluminium and stainless steel is precisely the reason why disk brakes are the optimal solution because rim brakes conduct all of the heat into the rim; heating up the air inside the trye, then causing the tyre to explode if the rim is heated in sufficient manner.
This is also the precise reason why people who cycle up the mountain (as depicted by the results from my trip down it) only travel up the road, but take their bicycle down the hill on their car (if they have rim brakes) because the rim gets so hot that the tyre bead explodes off the wheel rim from overheating.
At the end of the day rim brakes are marginal on a normal bicycle and in some cases simply dangerous, but they are a lethal combination when used on a motorized bicycle, for more reasons than simply the notion of stopping power.
Fabian
Well-Known Member
and you are correct in saying that upgrading a bike with rim brakes to disk brakes is an expensive affair.
It's much better to throw your bike with rim brakes on the scrap heap and start from scratch - spend $500 on a basic base model 24 speed mountain bike with front and rear disk brakes then upspec the front rotor to a 9" Hayes and replace the standard caliper with an Avid BB7.
Job done.
It's much better to throw your bike with rim brakes on the scrap heap and start from scratch - spend $500 on a basic base model 24 speed mountain bike with front and rear disk brakes then upspec the front rotor to a 9" Hayes and replace the standard caliper with an Avid BB7.
Job done.
HeadSmess
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i really wanna try this hill! where where where so i can gooooooooogle it!!!!!! coming down that kossywotso or summink?
no. mines only about 2km but the track in total is a good 12km...past the gates
right down the bottom...
is pretty
i dont go down on a pushy much nowadays due to these lurking around...
im not worried about the brakes! im worried about getting the $^% outta there!
no. mines only about 2km
but the track in total is a good 12km...past the gates right down the bottom...
is pretty
i dont go down on a pushy much nowadays due to these lurking around...
im not worried about the brakes! im worried about getting the $^% outta there!
Fabian
Well-Known Member
Mt Baw Baw
grinningremlin
Active Member
One neat thing about GEBE and friction is when you bomb a hill you can use engine braking, barely a need for the hand brakes at all.When we used to bomb the fireroads with Bendix, we would buy a snap on heavy leather watch band, strap it to the hub, wet it before our descent, and evaporative cooling would keep us from losing brakes, the band was steaming at the bottom.
