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I have an Electra Townie 8i with Shimano Nexus components. Every time I remove the rear wheel it is a major PITA to adjust the chain tension when putting back the wheel again. Is there some smart way to do this I am not aware of?

Currently I put the wheel back but let the chain remain off, that is not running on the rear chainring (it is still on the front chainring). I then have to "bend" the chain and rotate the front chainring to make it "enter" the rear chainring (similar to how you restore a chain that has fallen off a bike with multiple chainrings and a derailleur). This makes it hard to know when the wheel is in the right position. It is a very small adjustment between "easy to make the chain run on the rear chainring but too loose" and "impossible to make the chain 'click on' the rear chainring because it is too tight".

It seems this is a known problem: according to this video (at 6m00s), other versions of Shimano Nexus have some special kind of washers that you can use to adjust the tension after you have put back the wheel, but I don't have them. Could I buy these "washers" and use on my setup?

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Stock photo of Electra Townie

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    No idea how to properly change chain tension here. But to get the chain on a non-derailleur, it should usually be easier to first put in on the rear chainring, then rotate the front chainring to 'wrap' the chain around it.
    – Berend
    Commented Jul 28, 2022 at 15:26
  • Here's a video (in dutch, but pretty self explanatory) youtu.be/ReWjorphc9Q it's a matter of wiggling the wheel left, tighten the left nut, wiggle right, tighten right nut. Repeat until you have proper tension and the wheel is centered.
    – Berend
    Commented Jul 28, 2022 at 15:38
  • @Berend "it should usually be easier to first put in on the rear chainring, then rotate the front chainring to 'wrap' the chain around it." - that! Much easier indeed! Never thought of it before. Thank you.
    – d-b
    Commented Jul 29, 2022 at 16:26
  • @Berend Any smart ideas on how to make sure the wheel is centred? I used a caliper and measured the distance between the nut/bolt and the dropout but it doesn't feel exact.
    – d-b
    Commented Jul 29, 2022 at 16:28
  • I don't think centering a wheel is an exact science, usually I do that by eye, or I place my index fingers between the tire and the frame to feel if there's equal space left and right. You could also look at the bicycle from behind, and check if the wheel is in line with the frame.
    – Berend
    Commented Jul 29, 2022 at 18:15

2 Answers 2

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  1. Get the chain tension adjusted properly one time.
  2. Using a Sharpie™ (or other permanent marker) of a contrasting color to your frame paint, make a mark where the bolts hit the dropouts.
    1. You'll want to mark the dropouts on both sides.
  3. Remove the wheel.
  4. Reinstall the wheel, lining up the bolts with the Sharpie marks.
  5. Tighten bolts knowing that the chain tension will be as correct as it was in your initial setting.

Bob's your uncle!

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  • chains elongate with wear, so this works for e.g., replacing the wheel after fixing a flat. But it's not a general solution.
    – Paul H
    Commented Jul 28, 2022 at 17:56
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    When the chain is too loose at the previous marks, @PaulH, it's time to replace it! At a minimum, it allows you to easily measure the stretch and gives you a reference for when it's time to replace. Desperately tries to salvage credibility...
    – FreeMan
    Commented Jul 28, 2022 at 18:00
  • I have actually removed a (double) link because the chain had become stretched. That was two years ago and it still works fine.
    – d-b
    Commented Jul 29, 2022 at 0:11
  • @d-b When the chain streches so much that you can remove the double link, the pitch is no longer exactly 0.5 inches. This means instead of being driven by/driving all teeth on the chainring/cogs, it only tightly engages with a single tooth, which will greatly accelerate wear of the cogs and chainrings, especially when pedalling with some force, like going uphill. The cost saved by replacing the chain later is easily more than amortized by the cost of replacing cogs earlier. Commented Jul 30, 2022 at 8:58
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I would say your bike frame wasn't designed to be used with an IGH, and the nexus hub was added later.

Option 1 is to add a chain tensioner. This will take up the slack regardless of where your wheel ends up in the dropout.

Downsides, this prevents the use of a coaster/back-pedal brake if your hub has one. It also requires a little more chain, and makes wheel changing fiddlier. There's a little more friction and noise because you have one or two jockey wheels to go around.

Advantage: you can pull the axle back hard against the top of the dropout slots and it should be fairly well centered and aligned.

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Option 2 Change your method for re-mounting the rear wheel.

  1. Physically put wheel in bike so the axle is in the dropouts. Make sure your anti-rotation washers are both pointing forward but don't tighten nuts yet.

  2. Fit the chain around both chainring and sprocket.

  3. Pull back on the rear wheel which applies tension to the chain. If your axle bottoms out in the dropout and the chain is still slack, then the chain is too long and one link/pair needs to be removed.

  4. Tighten the right-hand/drive side nut while maintaining tension. Three hands helps here, or you can sometimes wedge a foot in front of the wheel, push the frame forward with one hand and use the other hand on the spanner.

  5. If you have rim brakes, then from the left side of the bike, activate your rear brake with your left hand. Use your left foot to nudge the front of the wheel sideways till it is centered between chainstays. Then use your right hand to tighten the left-side nut whereever it sits.

  6. Check for frame rub and that your rim brake pads hit the right part of the wheel. Check the chain has a little slack but not too much. Pack up tools, wipe hands on grass, and ride on.

Side-note: Do carry a 15mm ring spanner in your toolkit. An adjustable spanner can't generate the required torque and risks rounding the expensive nuts off. To save weight you can cut off the open-end.

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Option 3 Use puncture-resistant tyres and tubes. These minimise the number of times you need to remove the rear wheel for punctures.

Downside, they can be hard to fit/remove, and an additional drag when riding.

Upside, fewer punctures meaning less stopping.

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