Originally Posted by big chainring

I dont ride bikes newer than 1975. Euro parts only. 5 speed freewheels...6 speeds are cheating. Sew-ups preferably. Reynolds 531 or french gaspipe. Centerpull rim brakes for the win.

Originally Posted by Rolla

I recently rode a mountain bike that had been set up with friction thumbshifters -- what a fun throwback to the old days! My issue was that with 11 speeds, it was hard to precisely hit the desired cog on the first try, and "trimming" the derailleur to dial it in was a fairly exacting task, due to the narrow gaps. If it had only seven or eight speeds, it would have been more fun.

Originally Posted by rekmeyata

Back in 2018 or 19 I actually tested my Lynskey road bike with rim brakes against a guy who bought a brand new bike with hydro disk brakes to see who would stop the fastest. I had 23mm tire on the front and 25 on the rear Vittoria Rubino tires, he had Conti 4000s 25 mm tires all round; I had Shimano 105 rim brakes, my pads were Kool Stop Salmon, and he had DA Hydro disks with factory pads; the total weight of our bikes and body weights were within 5 pounds of each other; we inflated our tires according a tire calculator for a our size of tires and weight; the only rule we had was that we had to stay on our seat and not slide our butts off the back of the saddle to put more weight on the rear this way there was no ability of one person being able to slide further off the rear than the other person could. The test was going to be 3 sets of 3 runs, 1st run was at 15 mph, the 2nd at 20, and the third at 25. The results were interesting, on the first 2 sets we stopped within a foot of each other, sometimes I stopped a tad faster and sometimes he did, that was probably due to reaction time variance; the last set got interesting, the first stop I stopped about a foot and half faster, not a big deal but the second stop I stopped about 3 feet faster, and the last stop I was nearly 7 feet shorter. What happened we asked ourselves? so he touched his front disk rotor and singed his finger and left a whitish burn mark, but didn't singe his finger when he touched my rim though it was hot. What we determined was that the smaller rotor could not dissipate the heat as fast as the much larger rim could and thus he suffered brake fade. The reality is that all a rim represents is a disk, thus rim brakes are actually disk brakes, but the size of rim allows for more surface cooling and thus less chances for brake fade.

Supposedly the problem with using rim brakes on a touring bike is that you can wear out the rim pretty fast, but people have been touring all over the world for over 100 years on rim brakes and they didn't have a lot of issues with rim failures, so not sure if there is a huge advantage there, but if you run into mud disk brakes are more advantageous.

Originally Posted by Kapusta

Something is really off here, because if you were stopping as hard as you could in dry pavement without moving your weight back, the limiting factor would not be power or heat buildup: It would be going over you bars. This would be true for rim or disc.

If there was a difference in total stopping time/distance, it was due to how hard each of you were willing to brake without risking going OtB.

People can armchair analyze this all they want, but it only took one ride with disc brakes to appreciate the improved control and consistency they offer.

The difference in shear power is debatable and IMO rather beside the point.

Originally Posted by 63rickert

Over the bars excursions are a matter of where your center of gravity is. On flat ground you should never be at risk of OTB. Downhill you must get behind the saddle or you just can’t brake very hard. If at risk of OTB on flat ground you will need to be waaaay back and maybe back and down to brake on descents. If at risk of OTB on flat ground it is only a matter of time and miles before it happens. Just put the saddle down and be safe.
.

Originally Posted by Kapusta

This is true, but I have no idea if you are agreeing or disagreeing with me.

Look at the post I was responding too. He was describing an experiment where they did NOT shift their center of gravity. Any brake worth a damn is going to put you OTB long before any disk vs rim differences come into play if you don't shift your weight back.

Originally Posted by 63rickert

On any normal bike with the rider in the saddle, on flat ground, no amount of brake application will send the rider over the bars

Originally Posted by Kapusta

I wholeheartedly disagree. Any one of my road or street bikes would put me over the bars if I clamped down hard enough with my butt in the saddle on dry ground. Leaning back when braking hard is cycling 101.

Originally Posted by indyfabz

Actually been there, nearly done that. Was going maybe 10-12 mph tops on my Colnago while on a rec path popular with walking tourists, hence the going slow part. Some people were approaching. All of a sudden one of their children ran out from behind the adults right into my path. I slammed on the DA brakes. I went forward. Back of the bike went up in the air. I was able to shift my weight back just in time to save myself.

Originally Posted by rekmeyata

Back in 2018 or 19 I actually tested my Lynskey road bike with rim brakes against a guy who bought a brand new bike with hydro disk brakes to see who would stop the fastest. I had 23mm tire on the front and 25 on the rear Vittoria Rubino tires, he had Conti 4000s 25 mm tires all round; I had Shimano 105 rim brakes, my pads were Kool Stop Salmon, and he had DA Hydro disks with factory pads; the total weight of our bikes and body weights were within 5 pounds of each other; we inflated our tires according a tire calculator for a our size of tires and weight; the only rule we had was that we had to stay on our seat and not slide our butts off the back of the saddle to put more weight on the rear this way there was no ability of one person being able to slide further off the rear than the other person could. The test was going to be 3 sets of 3 runs, 1st run was at 15 mph, the 2nd at 20, and the third at 25. The results were interesting, on the first 2 sets we stopped within a foot of each other, sometimes I stopped a tad faster and sometimes he did, that was probably due to reaction time variance; the last set got interesting, the first stop I stopped about a foot and half faster, not a big deal but the second stop I stopped about 3 feet faster, and the last stop I was nearly 7 feet shorter. What happened we asked ourselves? so he touched his front disk rotor and singed his finger and left a whitish burn mark, but didn't singe his finger when he touched my rim though it was hot. What we determined was that the smaller rotor could not dissipate the heat as fast as the much larger rim could and thus he suffered brake fade. The reality is that all a rim represents is a disk, thus rim brakes are actually disk brakes, but the size of rim allows for more surface cooling and thus less chances for brake fade.

Supposedly the problem with using rim brakes on a touring bike is that you can wear out the rim pretty fast, but people have been touring all over the world for over 100 years on rim brakes and they didn't have a lot of issues with rim failures, so not sure if there is a huge advantage there, but if you run into mud disk brakes are more advantageous.

Originally Posted by Kapusta

I wholeheartedly disagree. Any one of my road or street bikes would put me over the bars if I clamped down hard enough with my butt in the saddle on dry ground. Leaning back when braking hard is cycling 101.

Granted, all of my bikes have good brakes (v-brakes, dual pivot road calipers, or disc). I am sure there are plenty of bikes with without that much stopping power, but the post I was responding to should be comparing good brakes of each variety, not crappy ones.

Originally Posted by Wildwood

, except for the gaspipe. Even metric gaspipe sucks. But then I consider Hi-Ten well above gaspipe.
Altho' i have some cheater 6-speed freewheels (non-euro, too), , nothing vintage is indexed.

for the ethic. All my 70's bikes take me where I want to go just as well as anything new.

New can be great as well - if you require the additional features or for modern glitz.
But then I prefer manual shifting in a sporty automobile over an automatic. As in manual shifting with a clutch. How stupid is that!

Originally Posted by 63rickert

The designers, manufacturers, and sellers of bicycles have a fiendish plot to kill off all their customers. They sell death machines because they want to see their paying customers in the grave. Good business.

It is always the bicycle that is at fault. It is never rider error.

Originally Posted by Kapusta

I thought there was some accepted norm that when replying to someone in a forum that your comment be in some way related to the post or conversation you are replying to.

I guess not.

Originally Posted by livedarklions

Was the topic of the thread the validity of a test of the heat dissipation of rims vs. discs and their comparative effectiveness? I must have missed that.