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    Brake cable mods.

    I have a couple bikes that were either built from parts or converted to disc brakes. I always just let my LBS do the cables for these since I didn't have the parts or cable cutters to do it myself. This resulted in a lot of long flex cables flapping around. By mistake I bought some road bike disc brake calipers that needed special levers, and the higher leverage of these exposed the weakness of my cable system. I decided to upgrade my cables and see what could be learned from this.
    The first thing I did was apply the brakes and see what was going on. When the brake pads first touched, the next thing that happened was the cables moved around, only then was pressure was applied to the brakes. So less flexy cables, and less slack was desired. The long cable runs were the result of bikes designed for rim brakes having cables reaching to the calipers.
    The next question was, does a hardtail with disc brakes really need a flex cable at the rear anyway? Not really!

    I ordered some Jagwire Elite solid metal brake cable kits. List$73, but I got 2@ $50 each for 2 bikes. Seems like a lot but you don't need to buy cable housing cutting tools to use them. Be aware that they are intended for Vee brake bikes and you will need the hardline mod for them to work.

    To reduce the length of flex line to the calipers I got some 1 foot lengths of metal tubing. For the inside I used 3/16x.030" (maybe .028") stainless steel. This allows the Jagwire teflon liner to pass through. For the outside to get the right O.D. I added 7/32"x.014" aluminum tubing. With the stainless inside it becomes possible to bend the aluminum tube without breaking it. This runs up the rear wishbone, or the fork up to where the old brakes would have been. A couple rubber bits to keep the tubing off the frame and some zip ties so it doesn't move around. I tried this on my XC Softtail so some flex line was needed at the rear for suspension movement. The length was perfect, and it looks like hydraulic lines going to the TRP Spyre 2 piston cable brakes. Did exactly the same thing on the fork.

    Now to install the Jagwire stuff. The Elite kit has aluminum beads instead of wire cable housing. My hard lines probably eliminated any weight advantage. But tighter bends, and easy to work with still apply. I made sure I had enough cable to turn the fork 180* for transport and built from there. The front brake was simple since the fork turns with the bars. Suspension motion was all that needed to be accounted for. When I was done I had solid metal housings from end to end (except the bare cable run along the top tube). The Jagwire kit comes with a couple cable connectors. The hole inside is for the bare cable to go through. I drilled it out so the liner would pass through, and it joined the flex section to the hardline perfectly. FWIW Jagwire says don't use their stuff on powered bikes. If you want to try some other brand that's up to you.

    Using as little cable as possible resulted in very little wiggle when the brakes were applied. This was eliminated by using the figure 8 connectors to attach the cables to each other where they crossed.
    It actually makes a difference. The hardlines resulted in my having a lot of the aluminum beads left over. Without that I may not have had enough.

    Brake response is immediate, and for the first time ever I'm having to think about adjusting the reach setting on my brake levers. The Jagwire cables are smoothed, and polished. They are also pre- stretched so should be more rigid. But it's still a small cable in tension. So I'm not going to claim it's as good or smooth as hydraulics with a non compressible fliud in compression, and no friction.

    I'm waiting for a set of TRP Spyke calipers to arrive, and see how this cable setup works with those. I will probably try the higher leverage setup also just to see what happens. The old BB7s will be in the mix also.
    I didn't do the hardtail E bike yet. this will require more than a 1 foot run of hardline at the rear. I will just use the same tubing and offset the cut in the inner tube from the cut in the outer to eliminate a joint there. I will have to be careful to put the joint in the inner tube in a straight section of pipe.
    Last edited by Retrorockit; 4 weeks ago.

    #2
    I'll get some photos up soon. I need to recharge my camera battery.

    Comment


      #3
      Click image for larger version  Name:	003.JPG Views:	0 Size:	1.39 MB ID:	125927 Click image for larger version  Name:	004.JPG Views:	0 Size:	1.42 MB ID:	125928 Click image for larger version  Name:	005.JPG Views:	0 Size:	1.33 MB ID:	125929 Click image for larger version  Name:	006.JPG Views:	0 Size:	1.44 MB ID:	125930 Click image for larger version  Name:	007.JPG Views:	0 Size:	1.08 MB ID:	125931 Click image for larger version  Name:	008.JPG Views:	0 Size:	1.12 MB ID:	125932
      Last edited by Retrorockit; 4 weeks ago. Reason: I've got some photos of the hardline brake cable mod.

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      • Retrorockit
        Retrorockit commented
        Editing a comment
        There are no E bike pics. because The TRP Spyke MTB calipers seem to be lost in transit. Last update to the tracking form USPS was 4/5/21. They should have been here 4/8/21. The TRP 2 piston calipers are a completely different experience than the BB7s, both in setup and feel.

      #4
      I had a college student across the street who owns a modern 29er with hydro brakes test the TRP Jagwire setup. He had no complaints with the feel or the braking of it. There is so little compression I has to run the reach screws almost all the way in. I did go up to a 185mm front rotor. The TRP calipers don't bend the rotor so they engage right away. Any slack in the cable and they hit too hard.
      The proper MTB calipers have finally reached Florida (mailed 4/4 from OR) I should have them sometime tomorrow but maybe late in the day. The brake levers I have are convertible from road to MTB ratio so I'll see what difference that makes. I ordered some metallic pads for the TRPs because that's what I'm used to running in the BB7s. By the time they get here I'll know my way around these well enough to put them on the Ebike. My experience with BB7s is that you just hook up the cable, and twist the knobs and you're read to go, but even with Jagwires they don't feel like the TRPs. The TRPs want good cables, and good adjustment but they're a much more precise brake setup.
      On the Ebike while ordering brake parts I added a 200mm front rotor. The old 185 rotor went back onto the XC bikes offroad wheelset.
      Last edited by Retrorockit; 4 weeks ago.

      Comment


      • Retrorockit
        Retrorockit commented
        Editing a comment
        The 200mm rotor is way beyond spec for my fork. But really it's the tires that determine maximum torque applied, and I'm at the high end for that also. I may go back to the 180mm. But with the very high CG of my bike OTB is the actual limit. I need something that can absorb the heat of 35mph runs.As the bike slows I back way off on the levers. I have an old 85mm Marzocchi fork . If I can get it pulled down to 65mm I will probably run that. I can't find anyone around here who does that. But it's just been sitting in the closet for 10 years so I may DIY it. I really like the feel of offset rotor sizes.
        I got 2 sets of the Jagwire Elites. I ran that all the way to the front BB7 and it didn't seem to make a lot of difference. The Spires are a bit touchy with full metal housings but they sucked with what I had before. I'm in R&D mode so extra parts are going to happen.
        I went with EBC metallic pads on the BB7s, they cut way down on the adjustment interval. I've ordered some for the TRPs also. It's what I'm used to.
        Last edited by Retrorockit; 3 weeks ago.

      • Dshue
        Dshue commented
        Editing a comment
        I know certain Marzocchi forks have a cult following, maybe yours does and parts are easily obtainable.
        I haven't tried any full metallic pads yet. My go to is semi metallic. Maybe when it's time for new rotors I'll get a set of full metallic pads and try it out.

      • Retrorockit
        Retrorockit commented
        Editing a comment
        The EBC metallic pads are pretty quiet. Adjustments are about 1/5 what they were before
        .My Zoke is the MX Comp Coil. There is a spacer to go from 85mm to 100mm, but IDK about the other way. It can be converted to an air fork also.My bike needs a very long headtube also. Plenty of skilled pipe welders around here due to the marine industry. Bicycles not so much.

      #5
      It looks like the post office plans on taking 3 days to deliver my TRP calipers just from N. Miami to Ft. Lauderdale area. It seems they can only move about 10 miles per day. Better than Oregon where they didn't move at all for 1 whole week!
      Spoke too soon. Received notice this morning they were received in Hollywwod FL PO @ 7:16AM
      Just received new notice they were received in Hollywood FL PO @ 1:26PM
      At least they're consistent.
      Last edited by Retrorockit; 3 weeks ago.

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      • Retrorockit
        Retrorockit commented
        Editing a comment
        Moron this: Last night they were sent from Hwd.#2 back to N.Miami, and then to Ft.Lauderdale this morning. But they're supposedly "Out for Delivery"now..
        They were originally shipped 4/4/21 from Oregon.

      #6
      Finally got the TRP Spyke MTB calipers. I'm kind of glad I got the Spyre Road /CX and matching Tektro disc/canti convertible levers first to compare.
      First thing I should say is I've had BB7s with metallic pads for years. They work, i Like them, and I'm used to them.
      I put the Spykes on the XC bike and tried them with the high rim brake leverage setting. The lever didn't feel as firm, and the travel was longer, but just about what I'm used to with the rotor flexing BB7s. Braking felt about like the BB7s also which is good stopping power, and good modulation.
      Then I tried them with the levers at the correct ratio. It was more like the Spyres felt. Firm high levers (like hydro) but a solid first engagement, and not very linear as you added pressure. "Felt" good but but i don't like to have to ask twice for full braking power. I guess the skinny tire, and offroad guys aren't looking for the same thing in braking that I am.
      I'll see if i can find some flat bar Ebike brake levers with the cantilever ratio.
      The Tektro levers are nice, but again they're trying to sell me some 2 finger braking, Rapidfire only, MTB racers setup. I need long levers for long rides, and room for E bike throttles, and gripshifts for urban situations.
      I'll put the Spykes on the Ebike after I get the metal pads, harden up the cable housings and find some canti type E bike levers I like. I think they're very good brakes. Other people might be happy with them as is.

      If I'm being an old retro grouch, well that's just the way it is

      Comment


        #7
        FOR THE TLDR KIDS- AVID BB7, METAL PADS, AND BIG ROTORS WINS


        To be fair TRP doesn't sell these calipers for E bikes. They have downhill, and Ebike offering and they're all 4 piston hydraulic. The 2.3mm thick rotor and 223mm rotor options look good.
        So this is just me exploring some new and interesting braking hardware. Learning as I go. The XC bike, flat ground, and 67 years old is a pretty safe space to do this. That's why no BBSHD E bike yet.

        So the TRP Spyres are aimed at road bike racers. The rule in the peloton is "don't touch the brakes". They're also used in Cyclocross. basically road bikes with knobby tires. When the going get's tough, pick your bike up and run away. They feel like hydros when set up with good cables and the power builds slowly. I bought them by mistake thinking the Spykes were a lower tier plastic caliper, which they're not. I can make these work on the XC bike so that's where they will end up. 185/160mm rotors and metallic pads. Definitely need some different levers for them.

        The TRP Spykes got my attention when I saw they were offered as an option for tandem bike rear brakes. Those are fast and heavy bikes. The improvement over Avids is their 2 piston desing that doesn't flex the rotors. They are sold as MTB brakes. With the levers set to the correct ratio they perform similar to the Spyres. Quick response, firm feel, and build power slowly. I don't have metallic pads yet. But if you want power from these big rotors will be required.
        The "design" could work with the thicker rotors, but I guess the rotors came later so they won't fit. So same rotor choices as BB7.

        So far cable brakes for an E bike still consist of Avid BB7s with big rotors, and metallic pads. This is an old school DH racing setup. Tool less adjustment. Attach any cable, tighten the knobs and back them off and you're good to go. Go long, and go hard if you want. There's a reason they're still around.

        Now to the experiments. I ran the MTB Spykes with the Tektro Eclipse levers set to cantilever ratio. It was step too far, but not by much, and this made the lessons obvious.
        1- The firm high "hydraulic" feel was gone. I had to add back in the lever travel I had removed with the Spyres.
        2- The "sharp" response was gone. The pads which contact the rotor squarely and both at once were moving slower as they landed. But the smoother response was easier to modulate. It might be an advantage in slick conditions.
        3- Braking power was there like the BB7s had. For my kind of riding (fast. flat, urban) you want braking NOW. At high speed with wide street tires it's hard to have too much. It's faster to modulate to lower levels than to build up slowly to a high one, and the lower hand pressure makes it easier to modulate.

        When braking from high speed it's normal to apply a lot of braking force at first, and modulate lower as the bike slows and less is needed. If a brake requires you to apply a lot of strength at the start, this wastes time, and while the braking force is building up the bike is also slowing reducing what's needed. So it becomes a juggling act right when you probably have other things to worry about. So that's my response to worrying about how your cable brakes" feel" vs. hydros.

        I may have the solution to this in my spare parts. Avid used to make brake levers with a feature called "Speed Dial" which allowed you to increase the ratio incrementally. Not quite enough to run the CX Spyres ( I tried it) but pretty good. My SRAM 9.0 XC levers have this and are gripshift compatible. No brake switches though. But it's old tech so probably not available for E bikes. I'm seeing high prices for old Avid Speed Dial canti levers on Ebay so it's not a secret. I'll try these with the MTB Spykes on the XC bike which I think will be a good setup, and no obvious mismatch of parts.

        Here are my 67 year old thoughts on brake lever length. 2 finger braking has become fashionable. The problem for people like me is that on long rides it gets old (painful) having 2 fingers on the brakes, and 2 on the grips. I like to have room to stretch out and have all of them on the brakes, or all on the grips when the situation allows. I can play 2 finger braking games with the longer levers any time I feel like it. This is what Luna sells with their kits and I think they've got it right. It might take a while to find some long levers with Speed Dial and add brake switches to them.

        So for now the MTB Spykes will stay on the XC bike for testing with the Avid SD levers, and metal pads when they arrive. If I think they're good enough for E bike use (and I can get some levers for that application) I'll take it to the landfill and run it down the hill a few times. Since they require a 3mm allen wrench to adjust them, I feel the harder metal pads are mandatory to avoid roadside tinkering.
        But really too much modding and trickery required compared to BB7s to advise using the TRP MTB Spyke cable discs for E bike use.
        Last edited by Retrorockit; 3 weeks ago.

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          #8
          I did a little more on the Spyke MTB calipers. Went back to the SRAM 9.0 Speed Dial XC levers set to max. leverage. Now the brakes feel just about right. No sharp initial engagement, and good gain and modulation with normal hand pressure. This is something I could put on the Ebike, but there are no 3 finger, Speed Dial, E bike levers that I'm aware of. No metallic pads here yet either. I could also dial them back towards how the CX Spyres felt if I wanted to.
          These calipers are a better design than the BB7, but if all they intended is a replacement for Cantis on a road/CX bike, or a back brake for tandems (talk about a niche market!) it's kind of wasted.

          Comment


          • Retrorockit
            Retrorockit commented
            Editing a comment
            The Speed Dial feature has been around for years, and most reviewers (and myself) found little use for it. The brakes already had the correct ratio.
            But in this case they proved their worth.
            I'm having a hard time finding more metal tubing to do the hardline cable mod on the Ebike. I did the front with Jagwire beads all the way. Automotive 3/16" brake pipe has a thick anti corrosion plating on it and won't fit into the outer sleeve. I have brass tubing I can use for that. A nice steam punk look until I paint it to match the bike.
            Last edited by Retrorockit; 3 weeks ago.

          #9
          I found some CuNi unplated automotive metal brake line I can use (with some sanding). So I can move forward with the cable mods to the Ebike.
          When putting the Speed Dial levers on the XC bike I had a hard time pulling enough cable out to change the levers, and it was hard to push the slack back in. It turns out the cheap clamp on the the TRP calipers smashes the shit out of the Jagwire brake cables. I may see this through and get them on the E bike, but without the thicker rotors I'm not sure there is any real advantage to the 2 piston design
          Last edited by Retrorockit; 3 weeks ago.

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            #10
            It will be a little while before my EBC metallic pads get here. The vendor I ordered them form waited about 4 days to ship them. I guess they had to order them form someone else. So it looks like another week to get any further with this project.

            Comment


            • 73Eldo
              73Eldo commented
              Editing a comment
              Was it a vendor that talked about how fast they ship everywhere you looked in their web store?

            • Retrorockit
              Retrorockit commented
              Editing a comment
              Not particularly. They sell EBC products for cars and motorcycles also. Bicycles are probably not their main interest.But they didn't say they weren't in stock either. I've had other vendors where it wasn't clear they weren't in the USA. But they had things I couldn't find here so sometimes that happens. I'm usually looking for things that aren't that popular for my research projects.

            #11
            I did a little tuning of the Speed dials on the XC bike. Turning the rear all the way to normal ratio and leaving the front on high, even with offset rotor sizes seems to be about right.
            Tectro sells mostly to OEMs for pedal bikes. There are lawsuits going back and forth with Shimano and some bike builders over who is to blame for OTB incidents due to front lockup of their roller brakes. Shimano says the OEMs didn't follow instructions and use a "modulator" in the front brakes to limit braking power. So I guess brakes are being designed to please lawyers, and people who don't know how to ride bicycles, and not people like me.
            So here it is. Ebike ABS systems.
            https://blubrake.it/

            Comment


            • Dshue
              Dshue commented
              Editing a comment
              Litigation is the reason all SR
              Suntour suspension forks have a big yellow warning sticker. OEMS don't always apply the sticker on these forks. It's also what makes cheap bikes heavier. And it's why many cheap bikes use bolt on axles. Mainstream stores don't want the easy lawsuits. Many chea bikes come fitted with an item know as a "lawyer tab" to keep the front wheel in the fork in the event that it comes loose. High end stuff gets the "lawyer lip" front and sometimes rear.

            #12
            The EBC metallic pads finally came in. The seller took 10 days to even ship them. I'll try and get them on the XC bike tomorrow and haul it out to the landfill. If I ride way out there I might not get a lot of braking runs accomplished. I don't want to go on the weekend because then they charge admission to the ex-dump/park.

            Comment


              #13
              I made the test runs and everything was OK. No grabbing to find extra braking power, and good modulation as the bike slowed. I probably should have named this thread "Cable Brake Mods" but it's too late to change that now. So my finding are that the TRP Spykes are short on leverage as is for E bike use. There are 3 places that brake leverage changes. The levers, the calipers themselves, and the rotor diameter.
              Levers from high to low leverage are Cantilever road type, Avid Speed Dial (adjustable), and linear pull MTB. Only the last are easily found with Ebike brake switches.
              Calipers are Avid BB7 (DH rated), TRP Spyke (MTB), TRP Spyre (road)/canti).
              For cable brakes on an Ebike I would go straight to metallic pads. DH rated, good grip, no fade, good modulation, long wear, and much less frequent adjustment. I like the EBC Gold series.
              I will do the brake cable upgrade on the rear of the MTB that TRP suggests. I've done the Jagwire Elite cable mod on the front BB7, and 200mm rotor upgrade. I didn't do the hardline mod there yet.

              So I now have enough confidence in the TRP Spyre/ EBC Gold braking power to try them on the Ebike. But be clear I'm relying entirely on the 200mm front rotor to provide the missing leverage I need. The 26" wheels and 200mm rotors are going to be producing some high surface velocity at the pads on the Ebike. I wouldn't try this w/o metallic pads, or on larger wheels. The lightweight AVID 9,0 Plastic SD brake levers are staying on the carbon fiber handlebars where they belong. TRP makes a 223mm rotor, but it's in the thicker 2.3mm format that unfortunately won't fit these calipers. I tested with a 185mm front rotor on the XC bike at the landfill, and it needed the SD levers to work. At the end of the day I don't expect to find better braking than the BB7/EBC pads provided. Maybe the fancy cables and dual piston calipers will give a more modern "feel" or something. But the cables are already doing that with the BB7s.
              I have a modification in mind to improve the leverage of the Spykes. But I won't show any photos of it because I will be relying on my 50 years experience as a mechanic to make it work. I'm too lazy to fabricate stuff that doesn't work. But others might take a shortcut, or miss a trick somewhere, and then blame me for their bad result.
              Last edited by Retrorockit; 1 week ago.

              Comment


                #14
                A friend of mine just bought a used bike that has a TRP cable brake of some sort on the front. I didn't look for a model number but the original owner said its a dual piston meaning both sides move. It worked really well, made the back brake which was a BB7 seem like a rim brake. I didn't get a chance to investigate if there was maybe a pad issue on the rear because it seemed really weak like to the point I could not lock it up. I didn't try too hard because when I was on it it was still a pre buy test ride and didn't want to do that to the sellers ride.

                Comment


                • Retrorockit
                  Retrorockit commented
                  Editing a comment
                  Pre-2008 BB7 were Avid's original design and smaller/lighter than the later SRAM ones, and had smaller rear adjuster knobs. The later ones got the bigger BB5 rear knob. I've never seen the road version in the flesh so IDK what's going on there. But Ultegra is a road racing groupset. The gravel bike may have the road parts. The braking requirements of a skinny tire gravel bike are a lot different than a 1500w BBSHD with street tires on asphalt.

                  There are a lot of serious riders on serious bikes who have relied on BB7s over the years. 29" wheels, and 160mm rotors looks like they were trying to save weight on the brakes.Not a good idea with a BBS motor and battery if any street riding is planned. II the TRP caliper had a polished stirrup lever then it's the Spyre road version.That's what's in the photos above.
                  I could live with either set of TRP calipers on the XC pedal bike.On the BBSHD they're going to have to prove themselves.
                  Last edited by Retrorockit; 1 week ago.

                • ncmired
                  ncmired commented
                  Editing a comment
                  I've got flat mount TRP Spyre road/CX calipers on all of my bikes, clamped by the standard Bafang silver color padded brake levers. The rotor diameters are160mm rear and 180mm (BBS02) or 203mm (BBSHD) front.

                  I spend a lot of initial setup time aligning/spacing up the pad contact patch correctly on the rotor. I reset the pad gapping probably twice a year, after the cable bedding in settles down.
                  Last edited by ncmired; 1 week ago.

                • Retrorockit
                  Retrorockit commented
                  Editing a comment
                  Long brake pad life is not what I'm looking for.

                #15
                I see TRP selling the bracket as for 200mm front, but they sell 203mm rotors. Is that what you had to adjust for?
                I'm putting these on bikes that already have BB7s with metallic pads and big rotors. That's my baseline setup. I'm having to tweak them quite a bit to match the braking power of what I already have.
                Back to back testing and honest feedback is all you'll get out of me. I spent a lot of time and money on the TRP stuff. I hope it ends up doing something for me. To pull BB7s off my bike they're going to have to show me something more than shiny finish, and good lever feel.

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