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I'm looking for the name of the cable marked "H", so that I can track down some replacements.

In the photos, the one marked S1 is a Jagwire MTB brake cable, with a standard 6mm deep nipple. The one marked H has been taken from a Xiaomi QiCycle ebike, and has an 8mm deep nipple. I found that the Jagwire cable did not fit into the QiCycle brake levers, as the nipple was not deep enough and rotated inside the cut-out for it.

What is the name of this strange 8mm version of MTB cable?

Photo showing brake cable nipple labels Photo showing brake cable nipple depth comparison Photo showing 6mm nipple not seated correctly in brake lever

EDIT: Closest thing I could find is this, which might be too large in nipple size and wire diameter (2mm)... and it's out-of-stock, so I'm no closer to finding a name or some way of searching for it:

enter image description here

2 Answers 2

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It appears to be an oversize cable. If so they were common on early mountain bikes. The 8mm head size typically goes along with a 2mm wire thickness, and they use 6mm housings. A decent number of hits come up for options by searching "2mm brake cable."

Simple adapter bushings are available to take up the slop if you want to use a normal MTB cable.

enter image description here

Most of the time it's possible to repair bikes that originally used oversized brake cables using by using modern standard MTB cables and housings without modification.

Edit: With your reply I see that it's not a simple oversize MTB cable. Since just searching around for the cable head dimensions isn't coming up with anything, one other place you could look is the notion that this cable and head was made to act as a one-piece unit that does that job a knarp is often used for. If you can make enough of them at a go, presumably a soldered head is cheaper. It's not obvious to me from your images what the brake lever would allow for the clearance needs of the various knarp profiles out there, but what you could do is get one of the motorsports products that just gives you one of each of a bunch of sizes and see if any are a match.

enter image description here

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    The diameter of the original cable is the standard 1.6mm, and it's the nipple cylinder length that is too short; the diameter of the nipple is the normal 6mm. So that adapter wouldn't work for this situation. I tried searching for "2mm brake cable", and it gave me lots of unusual cables to dig through. I added a photo of the closest thing that I found so far. Thanks.
    – Paul
    Oct 9, 2022 at 21:58
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    @Paul Ah, that is a strange animal then. I see now what you're up against better now. See edit. Oct 10, 2022 at 5:07
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I've never seen one like that. Could be this is a proprietary part so the bike-maker has an ongoing income stream from selling spares and consumables?

  1. It may be possible that this ugly-lay of the cable is acceptable even when rotated inside the housing. It's hard to tell from photo, but as long as it doesn't slip out or pull-through then this might be workable. Absolutely test this in safety, first!

  2. Would a pair of 1mm washers glued to the end work to hold the barrel in the lever? You might get away with adding a 1mm thick bushing inside the brake lever.

  3. Could you swap out the levers with normal brake levers? These may have integrated motor-stop functions which would make that difficult.

  4. Looking at your last photo, the original barrel might be subtly wider too - you need to get an accurate measurement with calipers (not a ruler) Does the old barrel-end rattle around in the brake lever too?

  5. As an extreme solution, it is possible to put your own ends on a twisted cable. They are not lead, its some kind of zinc alloy with a low melting temperature. Brake cable end anchor, which metal?

Consider that brakes are safety-critical, and failure can have significant consequences, it may be easier to buy the correct part if you can find it. Try contacting the place you bought the ebike and see what they have to offer.

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    No one has ever advertised cables for QiCycle bikes, at least not in English. 0) It sits pretty firmly. I did a test ride and it did not change position. I changed over the other brake cable and this one sits as you'd expect. I think I will leave as is. 2) You're right, these levers send a stop-command to the computer. 3) I measured diameter and they are exactly the same. The old one sits perfectly. The circle cut-out of the housing is at the top only, so the 6mm nipple doesn't extend enough to engage it, just lucky there is no twisting force in the 2nd cable. Thanks for your help!
    – Paul
    Oct 9, 2022 at 3:00
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    The problem with gluing washers on is that you're relying on the glue. I'd be more inclined to drill the bottom and insert a screw, so the unmodified top engages with the hole. The cable would be about 1mm off but this shouldn't matter - it flexes more in regular use.
    – Chris H
    Oct 9, 2022 at 7:08
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    Note if you do try to cast your own ends, you need to avoid zinc fumes. Lead-free solder should be an alternative, but I'd want to look up the strength compared to zinc
    – Chris H
    Oct 9, 2022 at 7:10
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    I'm fairly certain Tektro's levers with a built in switch to tell the controller to cut the motor use standard cable ends. But I no longer look after the e-bike they're on, and their e-bike specific parts are hard to get hold of
    – Chris H
    Oct 9, 2022 at 15:06
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    I was curious so I looked a little into yield strengths. Common solders, with or without lead, are considerably softer than casting alloys of zinc. Pewter is also rather soft. To cast a zinc-based alloy you'd need to get it to around 450°C or 850°F, which is doable in a hobby context but not trivial.
    – Chris H
    Oct 10, 2022 at 12:15

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