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hello from NY! just joined-- attempting a 2007 gary fisher X-caliber 29er w/ BBSHD

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    #31
    First of all, tire pressure. I can guaranee that if you continue to add higher pressure than the conditions warrant you WILL have a serious control problem. Now as to stability/traction. A test is to find soft sand material to ride on. As the material gets deeper the higher pressure tire will do a few bad things. 1st, it will cut an ever deeper furrow. 2and, it will slow down really quickly. Weight will transfer forward and problem gets worse. Your back tire will loose traction while your balance on the front goes to hell. Next stop is a crash. Now reduce pressure to 25 or 20 psi. depending on tire width. Approach same soft deep conditions and tire will ride comfortably on the surface. It will NOT build a wedge sort of dam in front of it. The bike will remain in control and with a bit more powe you can ride on comfortably. I have often rode on the beach with 26x1.5 at 18/20 psi. The same applies to off road vehicles. Or snow driving. The easiest way to maintain traction and control is to lower tire pressure. 18 psi on sand with wide tires is ideal. PERIOD.
    NOW, pavement. At speed with higher then design pressure you are going to get hurt. As long as the pavement is clean all will seem well. Then a little something like sand or water is on pavement. This is bad. The tire is so rigid it has no copliance to absorb the sudden loss of traction. It will tend to skid on top of the material. A sort of lubrication. Trust me keep pressures in normal range. Oh and yes E- Bikes can haul ass. Be careful my friend.

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      #32
      Let me know how that tubeless setup works. I just had a flat last night. Slow leak so 2x CO2 cartridges got me within 1/4 mile of home. Discovered the low rear tire in the middle of an intersection making a fast S turn. My first flat with the Schwalbe Big Ben Plus. They (Schwalbe) don't make a tubeless E bike rated tire in 26". I had a spare tube with me but didn't feel like breaking down a tire in the dark. So it looks like you're way ahead of me there.

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      • Retrorockit
        Retrorockit commented
        Editing a comment
        Actually with that bike you're ahead of me in several areas.
        I found a tubeless tire plugging tool for bikes.
        https://www.notubes.com/dart-tool
        Last edited by Retrorockit; 07-27-2021, 07:28 AM.

      • chem
        chem commented
        Editing a comment
        got the knobbys off and the road tires on yesterday. the noise difference-wow. and the drag loss--i can now do a proper range test. the max rim pressure is 40 for 2.4's these are 2.2's so i upped the pressure to 42. 42 in back, and the tire deforms acceptably with my whole weight on it. (doesnt look like its going flat) i figure for a >90% pavement bike going 20 mph,..3 or 4 over isnt going to explode my rims i think those #'s are for washboard logs downhill death trip riding style.

      #33
      I'm all about running as low a pressure as I can and still maintain good cornering on hard surface - I've found this pressure to be very different on different make/model tires even if the same size

      Tubeless is often about running a lot lower pressures since they don't get pinch flats - at least not easily

      YMMV

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      • chem
        chem commented
        Editing a comment
        been running tubed tires all my life--my kneejerk reaction to see-ing a low tire is to stop everything and get the pump. the sound of tires going way over in a turn on pavement gives me the willies bad. that sound meant crash time was near
        Last edited by chem; 07-30-2021, 03:11 AM.

      #34
      I saw you have those nice red hubs. I found this 203mm red Hope floating brake rotor. High end, but a good match for that bike.
      http://www.bikerecyclery.com/all-pro...mnisend&page=2

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      • chem
        chem commented
        Editing a comment
        i did a quick check for bearing replacement kits for those hope pro 2 hubs and apparently i need to buy at least another 40 in tools they need special socket-like bearing "presses". of course a socket wont work

      • Retrorockit
        Retrorockit commented
        Editing a comment
        A lot of things have been pressed together with sockets and a piece of threaded rod run through the middle of them. There are so many sizes of sockets you can almost always find something that works. But GF was known to go outside the Trek parts bin if he thought something was better. A Trek would have had Shimano there. Looking at the reviews the rear hub is tough as hell. That will probably pay off on an E bike."Poor man's Chris King".
        My 2004 GF comfort bike had a coil and oil Rockshox fork that Trek never had on their Navigator series.I tuned it up with a heavy rider elastomer stuck down inside the coil for a 2 stage spring rate and it rides smooth, and rails the turns on a 60# E bike. The Trek stuff wouldn't be up to that.
        I see the tool here for $18
        https://www.chainreactioncycles.com/...ir/rp-prod8032
        It seems those hubs are convertible to different axle standards. But the fork it came with should be more than good enough for street use.
        Last edited by Retrorockit; 07-30-2021, 05:54 AM.

      • chem
        chem commented
        Editing a comment
        schwing!!!!

      #35
      When the Scwalbes arrive, either wash them or ride some tight figure 8s to get the mold release compound off of them. In the good old days they used talc which wasn't a problem, but now they use some slick spray lube which is very slippery. I hope not hearing from you is because you're too busy riding to talk about it. That should be a very nice conversion.

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