Spokes for rear wheel folding bike.

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Keezx
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Spokes for rear wheel folding bike.

Postby Keezx » 7 Jan 2021, 6:13pm

Recently bougt an older folding bike 16" Buzbike made in Taiwan.
General in remarkable good condition (original tyres and brake pads) with 1 exception: 6 spokes of the rear wheel are missing.
At close examination quite clear why: the spokes are interlaced (2 cross) and the nipples are not in line with the spokes.
So planning to rebuild it with new spokes (all 28 new) and spoke head washers (elbows too long for the steel flange of the Nexus 3 speed hub), and not interlacing the spokes.
The rims has holes for 14 G nipples, but the spokes are 13G stainless steel plain gauge, so special thinner nipples are used.
My observation is that most folding bikes have 13G rear wheels (Brompton too), but that's apparantly no guarantee for staying unbroken....
My question: shall I use 13 G spokes again, or will 14G spokes work for at least a couple of years with a light person on it.

PS, I'm a quite expirienced wheelbuilder, but no reference to small wheels.

Brucey
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Re: Spokes for rear wheel folding bike.

Postby Brucey » 7 Jan 2021, 6:27pm

IME x28 14G spokes which are fitted properly (i.e. with the nipples in line, spoke washers at the head end where necessary, uniform tensions and good stress-relief) in a small wheel will be more than good enough.

If you want more of a comfort blanket, (especially if the spokes have been breaking at the hub end), consider using 13-14G single butted spokes such as Sapim 'strong', or the ACI or DT equivalents (any of which can be cut to length and threaded using 14G threading kit). You will still need to use spoke washers at the head end but the net result ought to be a bit stronger. [NB a potential snag with such spokes is that the loading required for good stress relief at the 13G J bend is somewhat higher than will stress-relieve a 14G J bend.]

cheers
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Cyckelgalen
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Re: Spokes for rear wheel folding bike.

Postby Cyckelgalen » 7 Jan 2021, 6:31pm

Bear in mind that you will always have to interlace the spokes on the drive side of the rear wheel, I have seen several rear wheels on folders with radial lacing on the non drive side. They are sturdy enough provided that the hub flanges can withstand radial lacing. Being steel you are probably OK.

Keezx
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Re: Spokes for rear wheel folding bike.

Postby Keezx » 7 Jan 2021, 7:05pm

Sorry, do not see the necessity for interlacing the drive side spokes...maybe you can explain dat?
Wheel isn't dished...
Advice from a professional wheelbuilder was : do not interlace on wheels< 20´

Brucey
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Re: Spokes for rear wheel folding bike.

Postby Brucey » 7 Jan 2021, 7:12pm

did Cyckelgalen mean crossing rather than interlacing? IMHO interlacing isn't inevitably bad in a small wheel, but it can be. However interlacing is almost always a PITA to do in a small wheel, so is might be best avoided for that reason, even if it doesn't make the spoke alignment bad or anything like that.

cheers
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Keezx
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Re: Spokes for rear wheel folding bike.

Postby Keezx » 7 Jan 2021, 7:22pm

Yes , probably , with regard of the remark about the radial lacing on NDS....(which I do not intend)

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RickH
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Re: Spokes for rear wheel folding bike.

Postby RickH » 7 Jan 2021, 9:37pm

If by interlacing you mean actually crossing sides inboard/outboard as they coss then I don't think it is necessary & possibly a disadvantage given the short lengths of the spokes.

I have a Circe Helios tandem with 20" (ETRTO 406) wheels which I have had for over 10 years. That came with the spokes 1x but they don't actually touch where they cross, probably a 2 to 3mm gap, & it would need quite a bend in the spokes to interlace them.

Even with a good few thousand miles of riding - & several thousand of those with 2 adults "pushing on", sometimes off road - they have proved robust enough.

I did have dome breakages early on but after respoking with Sapim spokes (I can't remember what gauge) & Polyax nipples plus proper stress relieving there have been no problems.

iandusud
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Re: Spokes for rear wheel folding bike.

Postby iandusud » 8 Jan 2021, 7:55am

My wife and I each have a 17" Moulton the wheels for which I built up over 30 years ago, and which have never needed any attention. Both bike are regularly used and have been used for touring carrying camping gear. They use 14g stainless steel spokes. The rear wheels are very heavily dished and are built up 2x on the GS (not interlaced) and radial on the NGS. Front wheels are radial. Both wheels are 28 spoke. Small wheels are very strong. The potential issue is that because the spokes are short they don't have much stretch along their length and therefore it is vitally important that they built with sufficient tension.

Brucey
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Re: Spokes for rear wheel folding bike.

Postby Brucey » 8 Jan 2021, 8:33am

it is probably fair to say that the suspension gives moulton wheels an easier time of it than many others of that size/configuration. 28 spoke moulton wheels -if built well- seem more than up to the job.

cheers
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fausto99
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Re: Spokes for rear wheel folding bike.

Postby fausto99 » 8 Jan 2021, 8:35am

I've built a fair number of 17" Moulton wheels 1x, 2x and 3x. All interlaced and crossed. Easy to do if you do 4 spokes at a time, (two from each side) probably not so easy using conventional lacing.
I don't like radial lacing at all. I can see it might be more aerodynamic but I've never time trialed. In my book radial spokes should only be used on wooden cartwheels. :lol: :lol: :lol:
Last edited by fausto99 on 8 Jan 2021, 10:12am, edited 2 times in total.

Keezx
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Re: Spokes for rear wheel folding bike.

Postby Keezx » 8 Jan 2021, 9:08am

Brucey wrote:it is probably fair to say that the suspension gives moulton wheels an easier time of it than many others of that size/configuration. 28 spoke moulton wheels -if built well- seem more than up to the job.

cheers


Good point.....
My 16" Buzbike has rear suspension (similar as Brompton, this bike is called "the poor man's Brompton" in NL).
Most likely I will try 14G spokes.

Probably most brands are just lazy wheelbuilders who use 13G spokes, when poperly built 14G would do the job

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Mick F
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Re: Spokes for rear wheel folding bike.

Postby Mick F » 8 Jan 2021, 9:28am

Just a question regarding interlacing or not on 20" (406) wheels.

It won't be long, and I'll need to replace the rims on my Moulton TSR. I already have the rims.
I built the existing wheels (36h rear and 28h front) and interlaced the spokes on them both. Sorry can't remember the spoke gauges but I have replaced a couple on the rear where they broke at the nipple.

Question:
When I next build them up, should I interlace or not?
What's the advantages of one vs the other?
Mick F. Cornwall

alexnharvey
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Re: Spokes for rear wheel folding bike.

Postby alexnharvey » 8 Jan 2021, 10:24am

Mick F wrote:Just a question regarding interlacing or not on 20" (406) wheels.

It won't be long, and I'll need to replace the rims on my Moulton TSR. I already have the rims.
I built the existing wheels (36h rear and 28h front) and interlaced the spokes on them both. Sorry can't remember the spoke gauges but I have replaced a couple on the rear where they broke at the nipple.

Question:
When I next build them up, should I interlace or not?
What's the advantages of one vs the other?


Mr F, if anyone runs a search on this question they will find that you have been a frequent discusser of this very question over the years!

Those discussions suggest there may be small advantages in equalising tension and keeping a broken spoke out of harm's way but that it's not essential and therefore can be omitted when it is difficult or impossible to interlace, e.g. on smaller rims and with stiffer spokes.

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Mick F
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Re: Spokes for rear wheel folding bike.

Postby Mick F » 8 Jan 2021, 10:33am

I have indeed asked a question or two on interlacing spokes, but never considered NOT doing so on smaller wheels. As far as I can remember, I never asked the question when building my Moulton 20" wheels.

Given the absolute choice on any wheel, they would always be interlaced. If the wheel is too small, it would be impossible.

What is the diameter of a 16" wheel as per the OP?
305 or 349?
Mine are 406 so they are only a couple of inches more in radius than 305.

Does that make enough of a difference?
TBH, I don't know.
Mick F. Cornwall

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fausto99
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Re: Spokes for rear wheel folding bike.

Postby fausto99 » 8 Jan 2021, 10:40am

Mick F wrote:... should I interlace or not?...


According to Musson:
"Interlacing spokes has nothing to do with strengthening the wheel but is done to give added resistance to spoke loosening. Under shock loads such as the wheel encounters at speed over rough ground, spokes momentarily become slack at times. The interlacing allows an adjacent tight spoke to pull on the slack spoke to keep it from becoming entirely loose and thus preventing the nipple from unscrewing. The benefit of interlacing is small and as a consequence radial (unlaced) wheels perform fine. Interlacing also pulls the spokes inwards by approximately 1.5mm at the spoke crossing which gives more clearance between a close running rear derailleur or a front disc brake caliper."

As far as I'm concerned, it looks better and feels stronger. I think radial spoked wheels will always "wind up" to some degree and I don't like the idea of that, even though I used to have an AM7 with radial spoking on the front and that felt OK. IMO, you don't want any "wind up" on the rear drive side or with disc brakes so radial there is a no-no.