I have a Schwinn Willy (single speed).

My commute is 6 miles each way on flat road with a bike section. There's only one 'hilly' section. A single speed bike is too slow. Everyone keeps passing me. I need gears.

I don't want to spend money on a new bike since I like my current one so much. I thought I can upgrade it to have gears using a Shimano Nexus 3 internal gear hub.

My understanding is that I can fit it in. I can even mount the cable through to the steering bar. But I can't find anything on how to install it into the wheel itself. So my questions are:

  1. Will it fit?
  2. Do I need new spokes? If so, what size? I can't figure out what size my wheels are. They measure 27.5" including the tires.
  3. The hub only gives 33% boost in gear. If I want more than that can I put in a new crankset? What size? I can't figure out what size I have and what's bigger than that.
  • That first link says 700c wheels. It is not worth putting a new crank and hub on a $300 bike. It would me more cost effective to just buy a multi speed bike.
    – paparazzo
    Commented May 13, 2015 at 8:09
  • No. You might do it just for the heck of it, I suppose, but you'd spend more than the bike is worth. (You can only reuse the rear wheel if the spoke count matches, and you'd have to learn how to build wheels. And you'd need to add a rear brake.) Commented May 13, 2015 at 11:29
  • Why would i need to add a rear break? The nexus 3 had a coaster break, so I can pedal backwards to stop, right?
    – McTrafik
    Commented May 13, 2015 at 16:03

1 Answer 1


It is possible -- you can either find a 36 spoke internal gear hub (since you have a 36 hole rim) and have the wheel re-built with the new hub and bodge on the cables for the IGH shifting. Alternatively, there are automatic shifting hubs (e.g. the SRAM Automatix) which will also have a coaster brake and no shift cables. That being said, its probably going to be cheaper to get a new rear wheel than have someone building the wheel up with a new hub.

But, in the end, on a 300 dollar bike, you're going to be better off economically just buying a new bike with gears.

As for the crankset, you can swap that out, but you'll still have only one gear ratio unless you add a front derailleur (which your frame likely doesn't have mounts for, so you'd have to bodge it on). You may also need a different bottom bracket in this case. As in the case of the new wheel, this isn't worth it economically.

Generally, though, swapping the rear cog on a single speed is a better choice. The Schwinn ships with a 19t rear cog. If you're willing to work a bit more on the hill, you can swap that out with a 16t or 14t or something. This is quite economical (probably 20 bucks for the cog and a bit for labor at your local bike shop). If you want to do anything to this bike, this is likely the only thing you can do that is economical.

The end of it is: if the cog swap isn't favorable, get a new bike with gears.

  • I thought nexus 3 had a coaster brake as well. Please correct if wrong. Can you answer the crankset part of the question so I can accept your answer. Thank you.
    – McTrafik
    Commented May 13, 2015 at 16:17
  • Theres more than one nexus 3 hub. Some of them will have roller brakes or something, but there is a coaster version. I've updated the answer with the crankset -- in any case, the economical thing to do is buy a new bike (or stick with the existing one and pedal harder).
    – Batman
    Commented May 13, 2015 at 16:24

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