Touring - Shimano Dynahubs...

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russ_substance
05-13-08, 10:20 AM
would anyone recommend or warn against the shimano dynahubs for heavy loaded touring?
i'm thinking of using one with mavic rims on a LHT frame... pros, cons, value for money?
my main concerns are with strenght over a long distance with a heavy load, and ease of fixing / replacing in remote areas...
any thoughts would be appreciated!
positron
05-13-08, 10:56 AM
Hi,
As a long time dynamo user, If I were to get a dynohub, I would only really consider the most efficient one i.e. the Schmidt. This advice being based in the fact that hubs are so integral to the bike, and dynohubs are constantly providing a small amount of resistance, regardless of whether the light is on or off. The schmidt is very durable (shimano likely is as well..) but also provides only negligable resistance during daytime riding. This is not the case with he shimano hubs as far as i know.
What I would reccomemend most, given that the schmidt is so spendy, is the Busch and Muller dymotec 6 bottle dynamo, which is about 50 bucks (peter white, velo orange) and can be removed entirely from the system during the day. Additionally, the bottle dynamo does not require a switchable light (cheaper, ~ 18 bucks). The electrical qualities of the Band M bottles are identical to the schmidt, and will readily power a 6v 3w light. I have two, I use them regularly, and they are very, very durable. I have not had them slip, and when there is snow i use the wire wheel instead of the rubber wheel. The resistance is indiscernable to me - there is just the whirring sound.
I know that bottle dynamos do not have the je ne se quois of the dynohubs, but are cheaper, easier to deal with, and provide just as much light.
http://www.bikeforums.net/archive/index.php/t-385983.html
Also look at Sheldon Brown pages and Peter White pages.
For myself I wouldn't have a Shimano on a touring rig for what I do. Hub drag is there, and I don't find night riding practical on a touring bike. It's a lot different trying to ride a known route in the city with all kinds of light polution, vs. riding in the dark in completely unknown setting.
I don't have problems with Nav, most times I loose the track it's just failing to see a change in the route, or being in a position where there are two paths and neither can be identified by map, wear, direction, etc... as being the obvious route. Add in poor light and it's curtains.
If I get caught out in the dark, that's a perfect opportunity to do a stealth campsite. LEDs work fine for small amounts of night riding I do on tour.
But everyone's needs are different.
"I know that bottle dynamos do not have the je ne se quois of the dynohubs, but are cheaper, easier to deal with, and provide just as much light."
+1
That "Je ne sais quoi" would be drag during daylight riding.
Whenever I look over all the options, and pick what I want (virtual brake lights!) the bill comes out to 500 bucks and lots of custom braze ons! The cat eye looks pretty good then.
wahoonc
05-13-08, 11:44 AM
The drag difference between a Schmidt and a Nexus is minimal...yes I know it adds up to 200 miles over every 10,000 miles of riding (or whatever the number was) All of my tour bikes have used the bottom bracket mount generator. The only issue I have ever had with any type of tire driven dynamo is the slippage that occurs occasionally in heavy rain. If you plan on minimal use, want a light that is ready to go at a moments notice, get the sidewall or bb mount generator. If you are going to be riding a lot at night and want dependable lighting go LED with the hub generator. FWIW I have at least one of each style on my different bikes. I don't have a Schmidt, but I do have a Nexus, an SA Dynohub, a B&M sidewall and a Union bb mount. They all perform pretty much the same.
Aaron:)
Ericx25
05-13-08, 12:12 PM
I use the Schmidt dynahub on my touring bike.
Sometimes in the morning I forget to switch off the front lamp, there so little drag I don't notice the lamp is on....
I've got a Shimano 3N-71 on one bike, a Schmidt on another. I've toured with both units. The Shimano is excellent value for money, drag is lower than the Nexus, but higher than the Schmidt. Both are good, durable units.
The Schmidt is lighter and has sturdier wiring connections.
If money is a concern, get the 3N-71 or the new 3N-80, it'll give you perfectly good service. If you just want the best and don't care about money, the Schmidt is awful nice to have.
Generator lights are great for commuting and randonneuring where you routinely ride at night, but not so hot for touring where most people only use lights occasionally. You might be better off with something like a Cateye EL-530 headlight and a Cateye TL-1100 taillight. Cheaper than a generator set up, lighter, no drag at all, and you can take the headlight off the handlebars and use it as a flashlight.
wahoonc
05-13-08, 02:19 PM
I don't particularly like battery lights...seems they are always dead when I need them most and it doesn't matter how often I check them. I have used a small mount on my handle bar to hold a small flashlight as emergency lighting.
Aaron:)
brotherdan
05-14-08, 05:49 PM
I'm rocking a shimano 3n71 on my touring bike. I've only had it for five months, so I haven't toured with it yet. But I'll be getting tons of use out of it on future tours. The drag is absolutely unnoticeable. Compared to the additional effort that it takes to haul thirty pounds of gear strapped on to your bike, the drag of the hub is absolutely negligible and should not be a concern. I would never tour or commute with a bottle dynamo. It isn't even an option as far as I'm concerned. I had one for six months but it basically stopped working once winter came around and it was never reliable in even slightly wet conditions. If you want to ride at night a dynohub is the only option, as far as I'm concerned, and that goes doubly for touring at night.
Personally, the only time I ride at night on a tour is because someone in the group had a breakdown that took a long time to repair and we had to resort to lights to make it to the next scheduled stop. Hauling disposable batteries and having to stop and purchase them is another harassment you don't need considering how fast a good bright headlight can chew through them. I use a hub dynamo on my road bike when I am going to be doing a night ride but for touring I use a bottle type sidewall dynamo. Not only do I use it to power a DIY LED headlight I also employ it to recharge the batteries in my cell phone and a GPS unit. Both are designed to be recharged by plugging them into the USB port of a computer. I discovered quite by accident that Ni-MH batteries have a very nice ability to regulate the voltage produced by a bicycle dynamo. As the voltage produced by the dynamo approaches the voltage limit of the batteries there internal impedance increases or loads the dynamo to the point it simply can't produce more voltage. Connect anywhere between 2 and 5 Ni-MH batteries in series to a bridge rectifier and a dynamo and they will automatically regulate the voltage to a safe level for recharging. Most all dynamos produce 500mA at speed which happens to be the suggested rapid recharge current for Ni-MH batteries. I now use this very simple circuit to recharge my phone and gps unit when required as well as my LED headlight.
http://i143.photobucket.com/albums/r154/n4zou/DynamoUSB.jpg
Even though I use my dynamo to recharge my electronics a hub dynamo would still not be used enough to warrant it's drag when disengaged, extra weight, and expense. Here is a photo of the bridge rectifier I use.
http://i143.photobucket.com/albums/r154/n4zou/HPIM0363.jpg
Here is a drawing showing the required parts and how to solder them to a terminal strip.
http://i143.photobucket.com/albums/r154/n4zou/rectifier.jpg
Here is a photo of my LED headlight.
http://i143.photobucket.com/albums/r154/n4zou/tourlight.jpg
It has two SSC P4 U-BIN LED's, one 10 degree narrow lens, one 15X30 elliptical lens, and is built into an aluminum box which is also a heat sink.
positron
05-15-08, 07:21 AM
N4zou, we need to talk... This is exactly what I have been planning to build for my sidewall setup. Do you have any advice regarding suppliers, part numbers and the like? Also, roughly how much would a setup like yours cost to build, assuming that I have the tools required to assemble? Finally, are there any potential improvements that you would make to the circuit? I am a biologist, not an electrical engineer, but I could build this provided you think its kinks are worked out... I will be in your debt.
MichaelW
05-15-08, 11:56 AM
I use a sidewall generator on my tourer (Nordlicht 200 with rubber cap). The key to effeceint use is to mount to a braze-on, not a clamp.
I use it in fog, rain, evening trips into town or when I get caught late. Ive used it for several miles of dirt road in the dark and it works fine. Ive been using the tourer as a commmuter since Jan so it has had 3 months of daily use 1hr in all weather.
The hella FF lamp is small neat and mounts to the fork crown beneath a bar bag. You can get really efficient LED dynamo lamps with mounts so unless you enjoy DIY electronics...
N4zou, we need to talk... This is exactly what I have been planning to build for my sidewall setup. Do you have any advice regarding suppliers, part numbers and the like? Also, roughly how much would a setup like yours cost to build, assuming that I have the tools required to assemble? Finally, are there any potential improvements that you would make to the circuit? I am a biologist, not an electrical engineer, but I could build this provided you think its kinks are worked out... I will be in your debt.
Diodes
http://www.mouser.com/Search/ProductDetail.aspx?qs=Ro3gc6G1sTn2FJZwyBNNRg%3d%3d
Go ahead and buy 10 at 17 cents each.
terminal strip
http://www.mouser.com/Search/ProductDetail.aspx?qs=YQdJuhbLKuTghxhMBXFd3w%3d%3d
65 cents each or 10 at 44 cents each
I would sugest purchasing a cheap USB extenshion cable cutting off the part that connects to the computer discarding that end and soldering the wires to your batterys. Dollar stores have them for a dollar.;)
Autotparts parts stores will have the wire you need.
Purchase solder tab batteries from a good online battery supplyer. mouser.com has them but there very expencive. Other retailers like batteryspace.com has them at much better prices Such as this pack.
http://www.batteryspace.com/index.asp?PageAction=VIEWPROD&ProdID=2478
http://www.batteryspace.com/productimages/aa/20060317/P7180083.jpg
pasopia
05-15-08, 06:52 PM
http://www.hiawathacyclery.com/cart/index.php?main_page=product_info&cPath=9&products_id=224
These guys have a 700c wheel with a salsa delgado rim and a shimano DH 3N70, seems like a good deal.
Ken Wind
05-15-08, 08:34 PM
http://www.hiawathacyclery.com/cart/index.php?main_page=product_info&cPath=9&products_id=224
These guys have a 700c wheel with a salsa delgado rim and a shimano DH 3N70, seems like a good deal.
That's from the QBP catalog, so most (just about any in the U.S.) bike shops can order that for you. It is cheaper at AEBike (http://aebike.com/page.cfm?PageID=30&action=details&sku=WE7500). If I were going to use it for touring, I would want (at least) a 36 spoke wheel.
pasopia
05-15-08, 10:58 PM
Which shimano dynamo is that though, it doesn't say? I suspect it is the cheaper, less efficient one, due to the price. I would love to be wrong though.
mrbubbles
05-15-08, 11:22 PM
That's from the QBP catalog, so most (just about any in the U.S.) bike shops can order that for you. It is cheaper at AEBike (http://aebike.com/page.cfm?PageID=30&action=details&sku=WE7500). If I were going to use it for touring, I would want (at least) a 36 spoke wheel.
Only if they built it with disc compatible DH-3D71. It is a killer deal though.
Which shimano dynamo is that though, it doesn't say? I suspect it is the cheaper, less efficient one, due to the price. I would love to be wrong though.
Your not wrong. The more you spend the less drag when the lights are off. Shimano
dynamo hubs exhibit much less drag when lights are on than tire driven types and are not subject to slippage. If you do a a lot of night time riding they are worth the slight drag when disengaged. If your not going to be using it for more than a couple of hours at night they just do not make economic since in both cost and drag when off. I use a hub dynamo on my road bike when doing rides of 4 hours or more in the dark but for daylight rides it gets removed and my non-dynamo wheel and tire goes on. When you do spend lots of hours riding at night drag with lights off is a non issue because you'll be running with lights on most all the time anyway.
Ken Wind
05-16-08, 09:37 AM
I just called. It's the Shimano 3D70 Nexus dynamo hub.
pasopia
05-16-08, 11:37 AM
I just called. It's the Shimano 3D70 Nexus dynamo hub.
Wow, thats awesome, I may buy one. Thanks.
I got a front wheel with a Shimano hub dynamo a few years ago. This is on a quite heavy bike (15kg) so that might be a factor, but I can't feel any drag (I know there *is* drag, just not enough to in any way affect my riding). The convenience of knowing I have a light if I need it is very nice. Last year I toured the Croatian coast in the later half of September and so the sun set before 7pm, we usually arrived well before that time but again - it's nice to have the light just in case. This summer I'll be spending a few days in the Alps and a light is always necessary when hitting tunnels.
So far I have about 6000k of heavy touring on it, and about the same unloaded. No problems.
I don't think I'll get a touring bike without a hub dynamo (unless battery capacity increases substantially).
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