Front gear ring change

A question for you all....I have a stock, 2 yr. old Rover,(except for a 26 " rear wheel and a NuVinci Hub).  I'd like to gain a little more top speed. Wondering if changing the front gear ring to larger one, or one with more teeth would do the trick? Has anyone done this, and are any special tools needed ? Any details would be greatly appreciated !!

Comments

  • Thanks for the input Elrique64 !!  I wouldn't be opposed to just swapping to a single 42T chain ring.  It is the stock 32T ring that is on there now.  Maybe 4-5 MPH more is what I'm looking for.  I noticed it is bolted onto the crank.  Could I just buy the 42T and swap it out ? If so, any special tools needed to get off the crank arm ?  Thanks again.
  • edited September 2015
    You would have to replace the entire crankset, though you could re-use your pedals.

    For the Rover (and I think all of TT's models) you'll need a square taper crank puller. This lets you pop the crank arms off of the bottom bracket. (Basically the axle for your cranks.)  You'll also need a hex set to remove the bolt/hole cover over where the crank arm attaches to the bottom bracket.

    Essentially you remove the bolt & cap covering the hole in the crank arm over where it connects to the bottom bracket.  The hole is threaded on the inside. You then screw in the crank puller nice and snug.  That makes the puller grip hard onto the crank arm itself. In the center of the puller is a freely rotating screw pin. Turning that in eventually hits the bottom bracket, pushing it away from the crank arm. Just apply leverage, then POP it's off.

    Some pullers have handles, others need an adjustable wrench or something similar.

    Pedal wrench is also needed, for pulling and re-attaching the pedals.  Do yourself a big favor and take the pedals off the old crankset *BEFORE* removing the crankset from the trike. :) You'll need the extra leverage.

    The Rover's crankset is 170mm. (Distance from pedal to bottom bracket.) If you're happy with your cadence and pedaling in general, then make sure your replacement crankset is the same. Some people like to go shorter for higher rpms or because they're having heel strike issues. Others (like me) want more leverage, so they go with longer cranksets. (Remember, longer cranksets mean your pedal is farther from the bottom bracket and therefore closer to the ground on the bottom part of your pedaling cycle.)

    Don't be afraid to get a multi-gear crankset. They're pretty much the same cost, and you can easily just size the chain for the one you want.

    In my case, I needed to get a much larger crankset after converting my 2012 Rover 8's rear wheel to external. Otherwise my gearing would have dropped WAY too low for me to be able to do anything.

    The tool I got a few months ago is this one:
    for under $15. This is one of the ones needing a wrench to use.

    I also picked up:
    for ~$30, though it seems to be even less expensive now.

    I needed the 48 tooth cog, and wanted to get a longer crank arm as well (175mm). In the extremely rare case I need an ultra low gear, I can move the chain by hand to a smaller cog until I'm up the hill. I reused my pedals, as I already had the Shimano pedals with one regular side and one clipless side.

    Your needs will be different, but for whatever crankset you get: pay attention to the tooth count, crank leangth, and make sure it's for a square taper bottom bracket.

    - PaulNM
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