Dynohub for Tandem

[pwa]

But you can't get the balls out on both sides, or can you?

Yes you can. A bit of care needs to be taken not to damage the wire or its insulation in the course of removing the various parts, but the video shows that it's not difficult.

Well I learn something every day.

[iandusud]

I'm considering building a new front wheel for our tandem with a dynohub. I don't have unlimited resources so I'm looking at cheaper hub options if poss. Obviously I'm aware of the extra loads imposed by a tandem which is why I'm seeking advice. We currently have 26" 48 spoke wheels, which is probably overkill, particularly on the front. Cheaper hub options (compared to Son) that I've looked at are Shimano and SP. As I don't use a disc brake up front I would prefer a non-disc hub for a stronger wheel. 36 spokes adequate? I suspect it is (we don't as yet carry luggage on the front but would like to have that option). Spa list an XT hub rated at 1.5W whereas most others are rated at 3W. Is this adequate? Alternatively they list a DH-3N72 rated at 3W. How does this compare to the XT hub. They list SP-PV8. How does this compare. One other consideration is that we regularly cycle up a steep unlit path where our speed drops to around 4mph. Will we still get decent light output at this speed. This is a new area for me so the benefit of your experience much appreciated.

Ian

Weirdly I might have one for sale, has only seen a few 3 seasons worth of use before a small child came a long and put tandeming on hold a while - PM me if you are interested (700c SP-PV8 hand build)

Thanks for the offer but I run 26" wheels.

[iandusud]

Decathlon are still selling their cheap 26" front dynohub wheel.

I bought 2 of these a couple of years ago; one at 26" for the daughters paper round bike, and one at 700C for my utility bike.

The 26" version still works great and is on its 2nd winter. Installed straight out of the box. The bike is basically only used for a paper round so doesn't do any great distance.

The 700C version dynohub was taken out of the decathlon wheel and built up into a sputnik rim with decent spokes. Again, still working great.

Maybe worth considering if you're after a functional dynamo hub.https://www.decathlon.co.uk/p/wheel-26- ... mc=8131687

Is it too much to hope that it is built with SS spokes? TBH at that price it's worth it just for the hub.

[Brucey]

DH-3N72 is a good hub. It will need the bearings adjusting (they have been set too tightly in all the new examples I have seen) but it will build into a stronger wheel than an SP hub (the DH-3N72 flanges are wider spaced than the SP hub and slightly wider spaced than a shimano hub which takes a disc brake). 36H with a decent rim (eg sputnik) and a decent build ought to be strong enough for a tandem.

I wouldn't use a 1.5W hub. The only hub which might offer a real (but small) advantage or a tandem is the widebody SON; this has wider flanges again and it also has a better low speed output too. At a cost though!

cheers

[NickJP]

Why not consider a modern rim dynamo, and you can keep your existing wheel: https://www.cyclingabout.com/rim-dynamo ... b-dynamos/.

[Mike_Ayling]

I'm considering building a new front wheel for our tandem with a dynohub. I don't have unlimited resources so I'm looking at cheaper hub options if poss. Obviously I'm aware of the extra loads imposed by a tandem which is why I'm seeking advice. We currently have 26" 48 spoke wheels, which is probably overkill, particularly on the front. Cheaper hub options (compared to Son) that I've looked at are Shimano and SP. As I don't use a disc brake up front I would prefer a non-disc hub for a stronger wheel. 36 spokes adequate? I suspect it is (we don't as yet carry luggage on the front but would like to have that option). Spa list an XT hub rated at 1.5W whereas most others are rated at 3W. Is this adequate? Alternatively they list a DH-3N72 rated at 3W. How does this compare to the XT hub. They list SP-PV8. How does this compare. One other consideration is that we regularly cycle up a steep unlit path where our speed drops to around 4mph. Will we still get decent light output at this speed. This is a new area for me so the benefit of your experience much appreciated.

Ian

Our Thorn tandem has 32 spoke front, 26" with a Rigida/Ryde andra rim and we carry 3 to 4kg in each front pannier so no worries about 36 or even 32 spokes for your dynohub especially if there is no disc brake involved.

Mike

[iandusud]

DH-3N72 is a good hub. It will need the bearings adjusting (they have been set too tightly in all the new examples I have seen) but it will build into a stronger wheel than an SP hub (the DH-3N72 flanges are wider spaced than the SP hub and slightly wider spaced than a shimano hub which takes a disc brake). 36H with a decent rim (eg sputnik) and a decent build ought to be strong enough for a tandem.

I wouldn't use a 1.5W hub. The only hub which might offer a real (but small) advantage or a tandem is the widebody SON; this has wider flanges again and it also has a better low speed output too. At a cost though!

cheers

Hi Brucey, Thanks for your comments. Out of interest do you know how the DH-C3000-3 hub supplied with the Decathlon wheel compares with the DH-3-N72?

[Brucey]

not a bad hub per se but it is heavier, draggier and has less good bearings vs DH-3N72

FWIW the decathlon wheel uses a single-wall rim; OK for a solo front wheel but not ideal for a tandem

cheers

[iandusud]

not a bad hub per se but it is heavier, draggier and has less good bearings vs DH-3N72

FWIW the decathlon wheel uses a single-wall rim; OK for a solo front wheel but not ideal for a tandem

cheers

Thanks, Ian

[iandusud]

Moving on to the rim, Spa list a few options in 26" 36h rims. Anyone care to comment on the various merits of the following: Ridgida Sputnik, Exal ML21 and the ubiquitous Ryde Andra 40 (i'm slightly put off this rim by its width and weight). I run 40mm Marathon Supremes. I have no experience of any of these rims.

[Brucey]

sputnik would be first choice for me, unless you need more rim width than that.

cheers

[Carlton green]

Why not consider a modern rim dynamo, and you can keep your existing wheel: https://www.cyclingabout.com/rim-dynamo ... b-dynamos/.

From what I read in the article (link above) Rim Dynamo’s are quite expensive, I can’t see sufficient value in them myself but maybe I’m tight fisted. I’m puzzled as to why a Hub Dynamo rather than a Bottle Dynamo, but the OP might be looking for perfection rather than perfectly adequate; or perhaps he intends to use it through the day for charging electronic devices (rather than just as a source of electrical power for occasional lighting needs).

[francovendee]

Decathlon are still selling their cheap 26" front dynohub wheel.

I bought 2 of these a couple of years ago; one at 26" for the daughters paper round bike, and one at 700C for my utility bike.

The 26" version still works great and is on its 2nd winter. Installed straight out of the box. The bike is basically only used for a paper round so doesn't do any great distance.

The 700C version dynohub was taken out of the decathlon wheel and built up into a sputnik rim with decent spokes. Again, still working great.

Maybe worth considering if you're after a functional dynamo hub.https://www.decathlon.co.uk/p/wheel-26- ... mc=8131687

Simon .. very apposite post. I have literally just ordered one of these from Decathlon.. to save cash I am going to pick it up from the store down the road so £30 total.. less than it would cost for the included Shimano Nexus DH-C3000 dynohub alone. I already have this dynohub and its near identical predecessor the Shimano DH3N31 on my solo commuting bikes and both hubs have been faultless - the older one covering c.10,000 muddy commuting miles so far... I have a couple of 36 hole 26" Ryde Sputnik rims stashed so my reasoning was to buy the Decathlon wheel and then re-lace the hub and spokes into a Sputnik rim.

That said though I am considering trying the Decathlon single wall wheel out "as is" on the tandem. its a symmetric wheel with 36 spokes and the single wall (a.k.a. dual channel) rims I have used in the past were pretty robust - typically with a pretty thick spoke-bed. Tony Oliver shows a few for tandem use in "Touring Bikes" after all. I was thinking of using it for a while and then swapping the rim out if it needed a lot of re-trueing in use.

Anyone got a view on using the Decathlon single wall rim as is ?

Just took a look at this, a good price but in the UK.
I need it in France so looked at Decathalon France website. Over double the price!! I'll think I'll pass.

[zenitb]

Decathlon are still selling their cheap 26" front dynohub wheel.

I bought 2 of these a couple of years ago; one at 26" for the daughters paper round bike, and one at 700C for my utility bike.

The 26" version still works great and is on its 2nd winter. Installed straight out of the box. The bike is basically only used for a paper round so doesn't do any great distance.

The 700C version dynohub was taken out of the decathlon wheel and built up into a sputnik rim with decent spokes. Again, still working great.

Maybe worth considering if you're after a functional dynamo hub.https://www.decathlon.co.uk/p/wheel-26- ... mc=8131687

Simon .. very apposite post. I have literally just ordered one of these from Decathlon.. to save cash I am going to pick it up from the store down the road so £30 total.. less than it would cost for the included Shimano Nexus DH-C3000 dynohub alone. I already have this dynohub and its near identical predecessor the Shimano DH3N31 on my solo commuting bikes and both hubs have been faultless - the older one covering c.10,000 muddy commuting miles so far... I have a couple of 36 hole 26" Ryde Sputnik rims stashed so my reasoning was to buy the Decathlon wheel and then re-lace the hub and spokes into a Sputnik rim.

That said though I am considering trying the Decathlon single wall wheel out "as is" on the tandem. its a symmetric wheel with 36 spokes and the single wall (a.k.a. dual channel) rims I have used in the past were pretty robust - typically with a pretty thick spoke-bed. Tony Oliver shows a few for tandem use in "Touring Bikes" after all. I was thinking of using it for a while and then swapping the rim out if it needed a lot of re-trueing in use.

Anyone got a view on using the Decathlon single wall rim as is ?

Just took a look at this, a good price but in the UK.
I need it in France so looked at Decathalon France website. Over double the price!! I'll think I'll pass.

Wow!!! Thats a first...something more expensive abroad than here in Britain!!! From the same chain as well. The underlying reason for the cheapness in the uk is, I think,that its actually a spare part for one of their Elops commuter bikes..hence it not coming with a QR skewer. Someone somewhere in Decathlon must be wondering why the Elops front wheel is so unreliable

[zenitb]

Moving on to the rim, Spa list a few options in 26" 36h rims. Anyone care to comment on the various merits of the following: Ridgida Sputnik, Exal ML21 and the ubiquitous Ryde Andra 40 (i'm slightly put off this rim by its width and weight). I run 40mm Marathon Supremes. I have no experience of any of these rims.

I am using ML21 rims on my tandem Ian. Looking back at my blog (http://zenit-b.blogspot.com/2016/11/tan ... build.html) I built the rear four years ago and its been pretty solid since then. I recently got some chain damage to the spokes and had to replace two spokes and retrue the wheel but that is the first time I have attended to it, and it was only due to my incompetence with the gear setup. See the blog for the build details.

More recently I also built an ML21 rim into a Sachs-Maillard front hub (sold to me by Brucey ) and that has been pretty solid in use as well, although I have only been using it for a year or so now.

We take the tandem out most weekends (tarmac), and put moderate loads on on holidays (some off road/tracks etc), but have not cycle camped with it (yet:-)) so no really heavy use to report back on.

One thing is to check for fit. My Marathon Extremes did not initially seat well on the front rim. I subsequently pumped the tyre up to 75psi and with three frighteningly loud cracks it seated. If you do get ML21s then maybe a quick initial check that your selected tyres fit ok (or measure the actual ETRTO bead seat diameter) before spending the time building up the wheel (I suppose that's good practice anyway)