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My flat & fast gearing setup

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    My flat & fast gearing setup

    This might be of interest to commuters in flat terrain. BBSHD 50T x 11-13-15-18-21-24-28-34 casette made with XTR cluster for 1500W stop light launches, and 30mph cruising.
    The 50x34 is badly crosschained and only used at low power in pedestrian areas. It's just there to give a walking speed gear.
    XTR casette. was 12-28. By removing 14T,16T and putting 15T gained space for 34T in back.  !!t top gear also. 50T surly Stainless steel chainring on Bafang spider. Needs chain guide to keep chain on in lowest gears.
50x34 gives a walking speed gear for pedestrian areas. Carnks are Shimano E6000 175mm with Luna CNC pedals i added reflectors to.
    Last edited by Retrorockit; 10-14-2018, 05:31 AM.

    #2
    I ended up using a different casette for this bike. Sunrace 8 speed 11-40T which needed an extended derailer hanger to work on the 2004 comfort bike. 11-13-15-18-22-28-34-40. I also located an XTR short cage Rapid Rise derailer and Rapid Rise (low normal) gripshifter. This allows multiple gear down shifts while stopped. I've added a roller type chain guide at the top. The 34-40T are walking speed gears and on flat ground don't need any extra power so the crosschain doesn't cause any issues. Wippermann XE8 e bike chain finishes it off.

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      #3
      i have a sram x5/x7 thumb lever shifter/derailleur combo (first 1:1 sram setup i've used, only used shimano type actuation derailleurs before), that functions like rapid rise, on my bike (no motor yet unfortunately) and is able to dump up to 3 gears at once quite easily.
      just a thought if you ever plan on upgrading or changing your setup, you could try sram.
      in my experience grip shifters tend to have a lot of unintentional shifting when hitting a bump, adjusting position, or hitting the brakes to avoid the dumdums in cars. ymmv, but just a thought
      also my sram install was far far less finicky than any shimano setup i have done. not sure why. also i find the shifting to be much less... sloppy.
      Last edited by djp1987; 1 week ago. Reason: most of my post didnt show up when i hit post. just... poof! gone. very strange.

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        #4
        SRAM 1:1 is good stuff. But Rapid Rise is different. SRAM and Shimano both PULL cable for down shifts. If the cable breaks they go to high gear.
        Rapid Rise is called low normal. If the cable breaks it goes to low gear. This is a feature of the derailer and not just the shifter.
        The difference this makes is whether you can downshift sitting still, or not pedaling. I can dump all 8 gears sitting still. Like after a , horn blowing, throttle jamming,panic stop, evasive maneuver. The shift won't actually happen until the cranks turn, but you won't have to take off in high and go down 1gear at a time.
        This does require a gripshift that doesn't ration how many gears you can dump. The disdvantage and why it's not popular with mountain bikers is you can't force a downshift while climbing. Pulling the cable for a downshift is more positive than having a spring do it. For my flat terrain it's a slick setup, but if downshifting under load is part of your routine than it's probably not for you.
        If I wasn't running an actual Rapid Rise setup i would probably try SRAM. They have a reputation for solid shifts. I've used the SRAM Attack Gripshifts for Shimano derailers on my XC bike with Rapid Rise for many years. So this is what I'm used to. All the Shimano Raapid Rise gripshifts do is keep the numbers on the gear indicator from being reversed. But they're very rare parts. Rapid Rise with a SRAM trigger shifter is hopeless. 3 upshifts, but only one downshift at a time.

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