Better Braking?
I've been looking only at the advertisements for direct mount brakes.
Looking at them it appears a bit strange to me. The cables appear to come in at a 90 degree angle to the frame and while I can see the cable guide, I can't see where the inner cable is affixed. I suppose that it is obvious if you have a set in your hands but it isn't at all obvious in the pictures of them I've seen. I will go with the idea that since they are connected on both sides instead of through a center bolt that they are stiffer and have a more "direct" feel it seems a little ridiculous that you have to have a frame specifically built to take the new kind of brakes. Though the same can be said of disk brakes. I rode in the rain yesterday and while I was being careful I was taken somewhat aback by the amount of time it took the wheel to go around a full revolution to clean the rims of water so that the rim brakes would work. This was worrying enough that I continued to put them on time after time to keep the rims clear of water as much as possible. But all it took was not putting the brakes on for a quarter of a mile and "Look Ma, no brakes". These were carbon rims with special carbon brake pads. I don't remember this much trouble with aluminum rims but then what do I remember? Since it requires the same amount of time for a wheel to make one revolution and clean a disk off just like a rim brake I'm wondering why they make the claim that disk brakes work better in the rain. If you jump on the brakes in the rain the disks allow you to somewhat break the water layer with sheer force. But as soon at the disk makes a full revolution doesn't it greatly increase the braking force? The only time this occurred to me was going down a hill and hitting a bump which jerked the disk brakes on and locking the wheel up and throwing me off the bike in a very uncomfortable manner. |
Better Braking?
On Wed, 29 Jan 2020 17:30:02 -0800 (PST), Tom Kunich
wrote: I've been looking only at the advertisements for direct mount brakes. Looking at them it appears a bit strange to me. The cables appear to come in at a 90 degree angle to the frame and while I can see the cable guide, I can't see where the inner cable is affixed. I suppose that it is obvious if you have a set in your hands but it isn't at all obvious in the pictures of them I've seen. The pictures I have seen show the cable entering the brake exactly like a sidepull brake, but the pivots are reminiscent of Mafac Racers with brazed-on posts. https://www.cyclingweekly.com/news/l...-future-193731 I have Mafacs with braze-on posts on my randonneuse and they work excellently with very good modulation and power; the Racers are paired with modern Campy Record brake levers and it is a good combination for me. The centerpulls offer excellent clearance for fenders and moderately fat tires (700 x 31). The design also allows the brake pads to have some clearance from the rims in case the wheel gets slightly out of true. I've not tried the direct mount brakes, but they do remove the straddle wire from the equation. That ought to improve efficiency, if greater flexibility wasn't created in the brake arms. |
Better Braking?
On Thursday, 30 January 2020 17:18:31 UTC-5, Tim McNamara wrote:
On Wed, 29 Jan 2020 17:30:02 -0800 (PST), Tom Kunich wrote: I've been looking only at the advertisements for direct mount brakes. Looking at them it appears a bit strange to me. The cables appear to come in at a 90 degree angle to the frame and while I can see the cable guide, I can't see where the inner cable is affixed. I suppose that it is obvious if you have a set in your hands but it isn't at all obvious in the pictures of them I've seen. The pictures I have seen show the cable entering the brake exactly like a sidepull brake, but the pivots are reminiscent of Mafac Racers with brazed-on posts. https://www.cyclingweekly.com/news/l...-future-193731 I have Mafacs with braze-on posts on my randonneuse and they work excellently with very good modulation and power; the Racers are paired with modern Campy Record brake levers and it is a good combination for me. The centerpulls offer excellent clearance for fenders and moderately fat tires (700 x 31). The design also allows the brake pads to have some clearance from the rims in case the wheel gets slightly out of true. I've not tried the direct mount brakes, but they do remove the straddle wire from the equation. That ought to improve efficiency, if greater flexibility wasn't created in the brake arms. I haven't used those but I did put old school Alivio V-brakes on my dropbar MTB with Tecktro dropbar V-brake levers and I find the braking FAR superior to what I had with my cantilever brakes. This is even more so in snow or rain. Cheers |
Better Braking?
On Thursday, January 30, 2020 at 2:18:31 PM UTC-8, Tim McNamara wrote:
On Wed, 29 Jan 2020 17:30:02 -0800 (PST), Tom Kunich wrote: I've been looking only at the advertisements for direct mount brakes. Looking at them it appears a bit strange to me. The cables appear to come in at a 90 degree angle to the frame and while I can see the cable guide, I can't see where the inner cable is affixed. I suppose that it is obvious if you have a set in your hands but it isn't at all obvious in the pictures of them I've seen. The pictures I have seen show the cable entering the brake exactly like a sidepull brake, but the pivots are reminiscent of Mafac Racers with brazed-on posts. https://www.cyclingweekly.com/news/l...-future-193731 I have Mafacs with braze-on posts on my randonneuse and they work excellently with very good modulation and power; the Racers are paired with modern Campy Record brake levers and it is a good combination for me. The centerpulls offer excellent clearance for fenders and moderately fat tires (700 x 31). The design also allows the brake pads to have some clearance from the rims in case the wheel gets slightly out of true. I've not tried the direct mount brakes, but they do remove the straddle wire from the equation. That ought to improve efficiency, if greater flexibility wasn't created in the brake arms. I have direct mount brakes on my Trek Emonda SLR -- great bike, nice OE brakes, although I'm not crazy about the cable routing. They need some Koolstop pads and are rim-lathes in wet weather, like all rim brakes. -- Jay Beattie. |
Better Braking?
On Thursday, January 30, 2020 at 2:18:31 PM UTC-8, Tim McNamara wrote:
On Wed, 29 Jan 2020 17:30:02 -0800 (PST), Tom Kunich wrote: I've been looking only at the advertisements for direct mount brakes. Looking at them it appears a bit strange to me. The cables appear to come in at a 90 degree angle to the frame and while I can see the cable guide, I can't see where the inner cable is affixed. I suppose that it is obvious if you have a set in your hands but it isn't at all obvious in the pictures of them I've seen. The pictures I have seen show the cable entering the brake exactly like a sidepull brake, but the pivots are reminiscent of Mafac Racers with brazed-on posts. https://www.cyclingweekly.com/news/l...-future-193731 I have Mafacs with braze-on posts on my randonneuse and they work excellently with very good modulation and power; the Racers are paired with modern Campy Record brake levers and it is a good combination for me. The centerpulls offer excellent clearance for fenders and moderately fat tires (700 x 31). The design also allows the brake pads to have some clearance from the rims in case the wheel gets slightly out of true. I've not tried the direct mount brakes, but they do remove the straddle wire from the equation. That ought to improve efficiency, if greater flexibility wasn't created in the brake arms. I was looking at the one's mounted on various bikes that hadn't the cable mounted yet and they looked really strange. So I today looked at the advertised versions and they look like normal brakes to me except they are mounted at the sides which reduce the flexing which causes brake shudder. |
Better Braking?
On Thursday, January 30, 2020 at 3:11:17 PM UTC-8, Sir Ridesalot wrote:
On Thursday, 30 January 2020 17:18:31 UTC-5, Tim McNamara wrote: On Wed, 29 Jan 2020 17:30:02 -0800 (PST), Tom Kunich wrote: I've been looking only at the advertisements for direct mount brakes. Looking at them it appears a bit strange to me. The cables appear to come in at a 90 degree angle to the frame and while I can see the cable guide, I can't see where the inner cable is affixed. I suppose that it is obvious if you have a set in your hands but it isn't at all obvious in the pictures of them I've seen. The pictures I have seen show the cable entering the brake exactly like a sidepull brake, but the pivots are reminiscent of Mafac Racers with brazed-on posts. https://www.cyclingweekly.com/news/l...-future-193731 I have Mafacs with braze-on posts on my randonneuse and they work excellently with very good modulation and power; the Racers are paired with modern Campy Record brake levers and it is a good combination for me. The centerpulls offer excellent clearance for fenders and moderately fat tires (700 x 31). The design also allows the brake pads to have some clearance from the rims in case the wheel gets slightly out of true. I've not tried the direct mount brakes, but they do remove the straddle wire from the equation. That ought to improve efficiency, if greater flexibility wasn't created in the brake arms. I haven't used those but I did put old school Alivio V-brakes on my dropbar MTB with Tecktro dropbar V-brake levers and I find the braking FAR superior to what I had with my cantilever brakes. This is even more so in snow or rain. Cheers I'm in total agreement. The TRP 9.0 V-brakes I put on my Ridley Xbow worked every bit as well as a disk brake. |
Better Braking?
On Thursday, January 30, 2020 at 3:28:24 PM UTC-8, jbeattie wrote:
On Thursday, January 30, 2020 at 2:18:31 PM UTC-8, Tim McNamara wrote: On Wed, 29 Jan 2020 17:30:02 -0800 (PST), Tom Kunich wrote: I've been looking only at the advertisements for direct mount brakes. Looking at them it appears a bit strange to me. The cables appear to come in at a 90 degree angle to the frame and while I can see the cable guide, I can't see where the inner cable is affixed. I suppose that it is obvious if you have a set in your hands but it isn't at all obvious in the pictures of them I've seen. The pictures I have seen show the cable entering the brake exactly like a sidepull brake, but the pivots are reminiscent of Mafac Racers with brazed-on posts. https://www.cyclingweekly.com/news/l...-future-193731 I have Mafacs with braze-on posts on my randonneuse and they work excellently with very good modulation and power; the Racers are paired with modern Campy Record brake levers and it is a good combination for me. The centerpulls offer excellent clearance for fenders and moderately fat tires (700 x 31). The design also allows the brake pads to have some clearance from the rims in case the wheel gets slightly out of true. I've not tried the direct mount brakes, but they do remove the straddle wire from the equation. That ought to improve efficiency, if greater flexibility wasn't created in the brake arms. I have direct mount brakes on my Trek Emonda SLR -- great bike, nice OE brakes, although I'm not crazy about the cable routing. They need some Koolstop pads and are rim-lathes in wet weather, like all rim brakes. -- Jay Beattie. I am using the carbon rim specific brake pads and they work well on aluminum rims too. They are not showing rapid wear. Of course they also aren't the sort of brake that I would slam on. I usually feather the brakes to slow wherever necessary. |
Better Braking?
On 1/30/2020 5:18 PM, Tim McNamara wrote:
On Wed, 29 Jan 2020 17:30:02 -0800 (PST), Tom Kunich wrote: I've been looking only at the advertisements for direct mount brakes. .... The pictures I have seen show the cable entering the brake exactly like a sidepull brake, but the pivots are reminiscent of Mafac Racers with brazed-on posts. https://www.cyclingweekly.com/news/l...-future-193731 I have Mafacs with braze-on posts on my randonneuse and they work excellently with very good modulation and power; the Racers are paired with modern Campy Record brake levers and it is a good combination for me. The centerpulls offer excellent clearance for fenders and moderately fat tires (700 x 31). The design also allows the brake pads to have some clearance from the rims in case the wheel gets slightly out of true. I first heard of centerpulls with brazed on posts about 40 years ago. I considered them when modifying the frame of my old Raleigh, but went with cantilever bosses instead. But I suspect the braze-on centerpulls would have worked about as well. I've not tried the direct mount brakes, but they do remove the straddle wire from the equation. That ought to improve efficiency, if greater flexibility wasn't created in the brake arms. The straddle cable isn't a source of flexibility (if that's what you're implying) if you shape it ahead of time to run in a straight line from the saddle to each brake arm. Most of the lost motion occurs because straddle cables are naturally straight, and when installed, are bent into a curve to reach from brake arm to saddle to brake arm. If there's no curve, there's negligible lost motion. Somewhere, I've seen photos of rigid links used to replace the straddle cable. I suppose that might be even better, but I don't know of a supplier. They might not be hard to fabricate, if you're into that thing. Another source of flexibility with center pulls or classic cantilever brakes is the hanger that stops the brake housing. Especially on front brakes, that's often a thin steel or aluminum stamping that flexes a lot. A rigid hanger greatly improves the brake's feel, IME. About the website linked above, I have some agreements and some disagreements. I agree that the chainstays are a terrible place to mount any brake. Like the guys quoted, I don't doubt that some of the other purported benefits (aero, rigidity) exist, but I think the differences are likely negligible. Especially, there are other ways to get rigidity. But I strongly agree with the statement near the end: "However, we think many brands that fit direct-mount brakes at the chainstay are doing it for trend or marketing reasons." Because, fashion! Fashion is weird and powerful. -- - Frank Krygowski |
Better Braking?
On Thu, 30 Jan 2020 19:11:13 -0500, Frank Krygowski
wrote: On 1/30/2020 5:18 PM, Tim McNamara wrote: On Wed, 29 Jan 2020 17:30:02 -0800 (PST), Tom Kunich wrote: I've been looking only at the advertisements for direct mount brakes. ... The pictures I have seen show the cable entering the brake exactly like a sidepull brake, but the pivots are reminiscent of Mafac Racers with brazed-on posts. https://www.cyclingweekly.com/news/l...-future-193731 I have Mafacs with braze-on posts on my randonneuse and they work excellently with very good modulation and power; the Racers are paired with modern Campy Record brake levers and it is a good combination for me. The centerpulls offer excellent clearance for fenders and moderately fat tires (700 x 31). The design also allows the brake pads to have some clearance from the rims in case the wheel gets slightly out of true. I first heard of centerpulls with brazed on posts about 40 years ago. I considered them when modifying the frame of my old Raleigh, but went with cantilever bosses instead. But I suspect the braze-on centerpulls would have worked about as well. I've not tried the direct mount brakes, but they do remove the straddle wire from the equation. That ought to improve efficiency, if greater flexibility wasn't created in the brake arms. The straddle cable isn't a source of flexibility (if that's what you're implying) if you shape it ahead of time to run in a straight line from the saddle to each brake arm. Most of the lost motion occurs because straddle cables are naturally straight, and when installed, are bent into a curve to reach from brake arm to saddle to brake arm. If there's no curve, there's negligible lost motion. Somewhere, I've seen photos of rigid links used to replace the straddle cable. I suppose that might be even better, but I don't know of a supplier. They might not be hard to fabricate, if you're into that thing. Another source of flexibility with center pulls or classic cantilever brakes is the hanger that stops the brake housing. Especially on front brakes, that's often a thin steel or aluminum stamping that flexes a lot. A rigid hanger greatly improves the brake's feel, IME. About the website linked above, I have some agreements and some disagreements. I agree that the chainstays are a terrible place to mount any brake. Like the guys quoted, I don't doubt that some of the other purported benefits (aero, rigidity) exist, but I think the differences are likely negligible. Especially, there are other ways to get rigidity. But I strongly agree with the statement near the end: "However, we think many brands that fit direct-mount brakes at the chainstay are doing it for trend or marketing reasons." Because, fashion! Fashion is weird and powerful. I've installed center pull, cantilever, single pivot caliper, double pivot caliper and vee brakes on the same bike at one time or another and it seems to me that the determining factor, brake pad composition aside, in braking power is the ratio between the brake arm, pivot to cable attachment, and the arm on which the brake pad is mounted, pivot to pad mounting, i.e,, the mechanical advantage of the brake, and in reality nothing else seems to matter. The most powerful brakes I ever had on that bike were cheap old vee brakes which, mounted on the previous canti lever studs, had the brake pad at the lowest possible position on the brake arms and thus the highest mechanical advantage between the cable attachment and the pad. Note that brake arm length and ratio also effect the cable pull necessary to apply the brakes and I am talking about only the effectiveness of the brake itself. And the brake levers themselves have a mechanical advantage that will also effect braking. While I never installed disc brakes on that bike I have brake tested bikes with discs and if the ability to stop the wheel from turning is a measurement of braking efficiency then any of the more efficient rim brakes were equal in braking efficiency to the discs. -- cheers, John B. |
Better Braking?
On 1/30/2020 6:11 PM, Frank Krygowski wrote:
On 1/30/2020 5:18 PM, Tim McNamara wrote: On Wed, 29 Jan 2020 17:30:02 -0800 (PST), Tom Kunich wrote: I've been looking only at the advertisements for direct mount brakes. ... The pictures I have seen show the cable entering the brake exactly like a sidepull brake, but the pivots are reminiscent of Mafac Racers with brazed-on posts. https://www.cyclingweekly.com/news/l...-future-193731 I have Mafacs with braze-on posts on my randonneuse and they work excellently with very good modulation and power; the Racers are paired with modern Campy Record brake levers and it is a good combination for me. The centerpulls offer excellent clearance for fenders and moderately fat tires (700 x 31). The design also allows the brake pads to have some clearance from the rims in case the wheel gets slightly out of true. I first heard of centerpulls with brazed on posts about 40 years ago. I considered them when modifying the frame of my old Raleigh, but went with cantilever bosses instead. But I suspect the braze-on centerpulls would have worked about as well. I've not tried the direct mount brakes, but they do remove the straddle wire from the equation. That ought to improve efficiency, if greater flexibility wasn't created in the brake arms. The straddle cable isn't a source of flexibility (if that's what you're implying) if you shape it ahead of time to run in a straight line from the saddle to each brake arm. Most of the lost motion occurs because straddle cables are naturally straight, and when installed, are bent into a curve to reach from brake arm to saddle to brake arm. If there's no curve, there's negligible lost motion. Somewhere, I've seen photos of rigid links used to replace the straddle cable. I suppose that might be even better, but I don't know of a supplier. They might not be hard to fabricate, if you're into that thing. Another source of flexibility with center pulls or classic cantilever brakes is the hanger that stops the brake housing. Especially on front brakes, that's often a thin steel or aluminum stamping that flexes a lot. A rigid hanger greatly improves the brake's feel, IME. About the website linked above, I have some agreements and some disagreements. I agree that the chainstays are a terrible place to mount any brake. Like the guys quoted, I don't doubt that some of the other purported benefits (aero, rigidity) exist, but I think the differences are likely negligible. Especially, there are other ways to get rigidity. But I strongly agree with the statement near the end: "However, we think many brands that fit direct-mount brakes at the chainstay are doing it for trend or marketing reasons." Because, fashion! Fashion is weird and powerful. If you pull the lever hard and observe, you'll see the greatest loss in a CP is the brake plate- the aluminum thing which connects the two arm pivots. Pivot bolts will visibly move outward with even moderate lever pressure. That's minimized with brazed posts and the other losses are negligible by comparison. -- Andrew Muzi www.yellowjersey.org/ Open every day since 1 April, 1971 |
All times are GMT +1. The time now is 12:54 AM. |
Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
CycleBanter.com