Converting 2012 Rover8

Hey Folks,

My Sturmey-Archer Hub broke yesterday, so now I'm trying to plan the cheapest way to get back riding again.  My current plan is converting to an external solution.  Money is a real issue, but the other complication is preserving my existing gear inch range since the newer hub solutions are geared pretty low. (SA is roughly 25-79 GI)

I'm normally riding on 8th gear, especially on the trails. It's pretty much my cruising gear. In fact I'd prefer more if possible, especially on the downhills. :)  I do use 1st and 2nd on every ride as well.  I absolutely can't have my new low gear inch be any higher than my current 2nd (~32 GI), but for comfort/safety reasons would prefer it to be 28 GI or lower. Also, a 26 inch wheel is not an option for me. Aside from the extra costs, my huge size 14 feet would be hitting the ground. (There are other disadvantages  as well.)

In another thread $181 was roughly the price for getting external components. There are two issues for me, though.  One is that the GI range listed for the external Rover is so low I'd have a hard time riding it.  The other is that I wouldn't even get that much.  The External Rover has a larger front ring than the other Rovers (38 vs 32), so my actual GI would be more like 21-58.

The fix for that is to get a larger crankset/ring, which should be easy enough.  I'd just need to get a square taper crankset, right? Is that pretty standardized now, or are there still different taper sizes? (I'm not referring to teeth # or crank arm length.)

I'd prefer getting a cassette with 11-34 teeth instead of the default 11-30. Combined with a 48 tooth crankset I'd have roughly 28-87 GI, which gives me higher gear without sacrificing much lower gearing.  Has anybody run an 11-34 tooth cassette on a Rover? I'm thinking it'll work ok, with enough space for the derailleur.

Speaking of derailleur, is the drop out derailleur hanger universal?  Meaning can I mount a scavenged 8 gear derailleur on it, or do I need a specific derailleur?

I'd need to get a hold of some tools (cassette lockring tool, crank puller), and I suspect I'll need to add chain as well given the big increase in sprocket sizes.  Anything else I'm missing? Any comments or questions?

- PaulNM

Comments

  • The main problem with the Nexus approach is that it's too expensive for me. The Utah Trike listing doesn't include a shifter, I don't think I can reuse the SA one. Also it looks like the gearing would still be too low with a 16t sprocket, so I'd still be looking at a new crankset on top of that. That pushes the cost close to ~$350, verses a little over $200 for the external approach.

    Money is a major limitation with this project, even the external approach is really high.  I'm seriously considering picking up a freehub/longer spokes and relacing my existing wheel myself. There are a couple of things I may be able to pick up second hand as well.

    Elrique64: There's a earlier thread in which Goldmember breaks down the parts needed and costs for converting a Rover to external.  One of those is a $6 drop out derailleur hanger. I'm hoping a scavanged/second hand derailleur would work with it.


    You'll notice I chimed in on that thread as well, mostly out of curiosity.  Never expected I'd be forced to deal with this less than a month later. :(

    - PaulNM
  • Interested in selling your broken hub?  What kind of broken is it?
  • Sorry, I haven't been online for a while.  What is the difference between the xrf8 and the xrk8?

    For that matter, how is the nexus8 different (better for the knees)?  Does Shimano have that much less internal friction than SA?
  • edited July 2016
    Hey Folks, 

    I never really did an explanation of what I ended up doing, aside from some mentions in other posts. I've been meaning to do so for awhile, a private message from someone (via BentRider's forums) who is in the same boat finally pushed me to get this done. Bear in mind this happened just over a year ago, so any prices I mention may have changed.

    I ended up deciding on an external setup. I could have tried replacing the broken ring on the old hub, but taking it apart found other issues and I didn't want to risk being stuck again with a re-failed hub. I was *really*, *really* lucky my breakdowns happened when and where they did.

    Of the "replacement" options, an external setup was the cheapest and most flexible. I would have had to replace the front crankset even if I went with an internal hub, in order to try and keep my current gear-inch range. I was also really attracted to the idea of replacing one very expensive part with several inexpensive ($30-ish) parts.

    I picked up a new 20 inch wheel with an 11-30 tooth cassette.  Along with a 48 tooth front crankset, that put my gear inches at 32-87.2. (SA hub was ~25-79).  Actually, the front crankset I got was a triple (48/38/28). In a pinch I can use the chain tube tube to switch the front down to the 28 tooth sprocket and get as low as 18.7 GI. 

    Parts I got and approximate costs below. I did all labor myself:

    From Utah Trikes:
    $60 TerraTrike OEM 20 inch rear wheel with freehub 
    $25 11-30 tooth cassette (ordered 11-34, but they were out)
    $13 more chain
    (Wheel was on sale since they were trying to unload what little TT stuff they had)

    From TerraTrike:
    $30 8-speed rear derailleur
    $15 8-speed twist shifter
    $5  derailleur hanger (as the Rover frame has no hole to mount a derailleur)
    $7  shifting cable and cable housing

    Via Amazon:
    $32 Front triple crankset (48/38/28) with 175mm cranks (wanted longer than the stock)
    $14 Park Tool Compact Crank Puller
    $7  Park Tool Cassette Lockring Removal Tool

    All in all I spent about $220 USD with the parts and shipping. I already had a chain breaker and wrenches to use for removing/installing my pedals. Utah trikes actually shipped my wheel assembled, with a CST tire and a tube, so I never actually needed the  Cassette removal tool, though I'm glad I have one.

    Oh, and I also needed a rear skewer. Fortunately I have an out-of-town friend's old road bike, so I'm using her quick-release rear skewer.

    If you're doing this, I strongly suggest removing your pedals *BEFORE* removing the old crankset. You'll desperately need the leverage. :)

    If I were doing this all over again, I'd likely try getting a crankset with 52 teeth (or more if possible). At the time I wasn't sure how well using the chain tube to front shift would work. I do eventually plan to build up a front derailleur, but can deal with things as they are for now.

    - PaulNM 


     
  • I think you will need some type of derailleur someday.  I can't imagine using a 48T crank all the time, even in the flats down here.  How hard is it to start out from a complete stop?

    Going from a 32T to a 38T crank made a significant difference in my hill climbing ability.  But, I have short crank arms which makes it harder.  Guess I could make that change if I added an electric motor to get me started.  I think I'll try a Patterson Crank instead.
  • Yeah, 32 gear inch is pretty much what my old 2nd gear was, so I didn't mind having it as my new 1st gear.  That said, I'm living in *very* hilly Manayunk (Philadelphia) now, so I do need to switch the front ring to get the last few blocks home. Knowing about the chain-tube-shifting method was good enough for me. I definitely wouldn't have gone to 48 teeth if it was only a single cog. 

    Using the chain tube "works" fairly well for downshifting. Going back up is a pain because it keeps jumping past the 48 tooth cog into the guard. Fortunately I only "need" the lowest gears for occasional steep climbs. It would be nice to automate it though.  Even if the front post was still being sold, it was pretty expensive. I'd likely end up building my own anyway.

    - PaulNM 
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