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Dynamo hub durability

20K views 38 replies 18 participants last post by  Johnny Chicken Bones  
#1 ·
I am building up a new wheelset for my rigid Krampus and I've been toying with the idea of doing a dynamo hub in the front. I weight about 175lbs. My only concern is how they hold up riding rocky/rooty singletrack. If I'm honest with myself, I probably would only need the dynamo a small handful of times a year when I'm able to sneak away for long trips. The other 95% of the time it would be just riding regular trails in eastern PA. Ideally I would have two front wheels, one with a regular hub for everyday riding and one with the dynamo for long trips, but I don't have the money for that. Am I going to ruin a nice expensive dynamo if I use it often on singletrack?
 
#3 ·
I guess if you are extremely rough on your gear. Or ford creeks and streams that will submerge the hub. I believe that dyno hubs, like internal gear hubs, have been proven by bicycle tourists the world over to be a winner.

Here is my Schmidt SON 28 dyno hub and gear (B&M IQ-X front headlight and Schmidt SON tailight) and two shots on the D&L Trail, at the Chain Dam Lock House and further up at Allentown at Canal Park. Completely reliable and lights always made available. (click photos to enlarge)



 
#7 ·
I haven't done much single track. Mostly commuting and rail-trail-type rides. But my Shutter Precision hub has been going for 3 years, which probably adds up to around 10K miles. I have overloaded that bike on occasion for sure, but haven't subjected it to seriously rough riding at the same time. I built a 2nd set of wheels two years ago. Considerably less miles on that set, but, again, no problems with my Shutter Precision.
 
#5 ·
To add some more anecdata, I've been riding several dynamo wheels for the last few years with basically no problems. And the stuff I ride is absurdly chunky, I have skinny tires, and no suspension. If something was going to break, it would have.

That said, I did damage one of my dynamo hubs, but not in the way you are concerned about. I purchased a used SP-PD8X (so I don't know its history) and it worked great. But when I was returning from a trip and re-attaching the disc rotor, two of the rotor bolts stripped before they hit the torque spec. I've now demoted that wheel to my commuter. As long as I don't take the rotor off EVER again I think I'll be fine.

But again, that has basically nothing to do with what you are concerned about, and getting a centerlock version would avoid that problem entirely (that's what I did with the replacement).
 
#6 ·
Durability does not seem to be an issue: the SON dynamo hub has been through quite a bit, and keeps on spinning. It has been through some harsh environments and I can't say that I'd wished that I put another hub on it. I will admit, as you indicated, that it does not see alot of use powering a headlight. Let's face it, the vast majority of riding for fun is done during the day. Commuting and racing sees more need for lighting. Good Luck!
 

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#8 ·
Spend the money on SON. The SP hubs are mostly OK; but every now and then there are reports of bearing issues. The SON hub is more expensive; but it will last a very long time and endure a multitude of conditions. My SON hubs have seen years and many miles of bikepacking on road, singletrack, dirt roads, through mud and water almost every trip. The hubs have been submerged numerous times through water crossings and tons of rain. They'll last a very long time with no maintenance at all. They also provide optimal power output and matched with a good light and charging system like K-Lite and/or Sinewave, will create a tough power and lighting system that will always be there on your bike.
 
#9 ·
Also, if anyone is wondering about a dynamo hub/light/charging set up vs a battery setup. I've done a few spreadsheet comparisons and even though the hub is like 400+g, the dynamo setup ends up being slightly lighter weight when you factor in you'll want/need a larger cache battery and larger/additional light batteries, Garmin batteries, etc.
 
#10 ·
Night riding is very popular in Az during the summer for obvious reasons. Yet, I have not found a single user of any brand dynamo hub. Everyone here uses rechargeable devices. I think if you were commuting, it would be a good choice. But for night riding, why not just use rechargeable lights? They last for several hours and recharge while you sleep or work.
 
#13 ·
I have a Shimano 3D72 hub in the front on my touring/commuter bike. I will hit the 20tkm/12,5tm marker Monday morning on my ride to work after 4y3m. I did not so much touring but my commute includes gravel and bad roads as well and I am not the slimmest guy either. A bearing nut loosened twice, I adjusted it again, that's it. I ride the bike all year round, it is always outside and I clean it seldomly....

In a German touring forum there are several threads on the lifespan of dynamohubs. In general, the Shimanos and SONs almost no failures are reported. On the Shutter, some bearing issues are reported after 10tkm/6,5tm. Shutter seems to replace those without much hassle, but still you are without the wheel for a while and also, the wheel will need to be relaced and if you can not do that yourself, it will cost something.

Taken on the lifespan, the SON will probably be the best for this reason. Once it fails after over 60tkm or so, bearings can be replaced and a new rim/spokes can be justified anyway.

A Shimano hub will most probably also provide you with all you need for a very good price/performance level. The only thing is, at the moment Shimano does not have any models for tru-axle standards, only the 100mm bolt-on/Skewer standards are available.

For an SP hub, you could think of replacing the bearings with better ones from SKS or something before lacing it to increase the lifespan. I've seen it done but no longterm report available yet. If you can do that yourself, this might deliver the best price/performance level, since the performance is pretty close to a SON.

If you are in for some funny english, you can check here:
https://translate.google.com/translate?hl=en&sl=de&tl=en&u=https://rad-forum.de/topics/1303639
 
#16 ·
Does any dynamo hub have Front Hub and Wheel Conversion Kits, 9mm quick release too 15 mm through?
No. The "rotor" assembly and its electrical windings are fixed to the axle; there is no way to replace the axle. You could probably use a 9mm QR adapter to convert a 15mm TA hub for use in a standard fork, but you cannot replace a QR axle with a thru-axle in any dynamo hub.
 
#19 ·
I have a 12mm x 100 through-axle Shutter Precision running happily on my non-TA bike thanks to an quick-release adapter. I'm also wondering if it's possible to adapt that to a 15 x 110 set-up, but I'm not certain. But, as has been stated, you can't start with the 9mm quick release and go to a thru axle with any method I've seen.
 
#20 ·
From the pics of the SP 15x100 and 15x110, it seems they share the core axle and make up the difference with the end caps (but I suspect the body of the hub is different to account for the disk mount).

But, since you've got the 12mm SP hub, take out the QR adapter and see if it has a sleeve inside the axle to bring the inner diameter down to 12mm (i.e. 15mm OD, 12mm ID)...if so, you should be able to remove the sleeve, find appropriate end caps and space the rotor mount to fit the 110mm width. OTOH, if there is no removable sleeve inside the axle (i.e. it's ID is fixed at 12mm), then you're stuck with it.


Note: I've been trying to figure out how to modify a dynamo hub for my RS-1 fork...the major hangup is that none of the manufacturers produce even a long-enough axle so that I could fabricate endcaps to sufficiently reinforce the connection between the two legs of the fork.
 
#21 ·
I have a KASAI Dynacoil D6 front hub (9mm) that powers a Busch and Muller IQ-X LED headlight. I attach the wheel to the rigid steel fork with a Halo bolt-on skewer. Hasn't shaken loose or bent yet (I've had issues with other front and rear skewers).

This setup has clicked off 1,650 miles so far... works like a champ. It is so much nicer not having to think about battery charging or riding in the dark when you out "energizer bunny" your lights LOL
 
#24 ·
That MikeSee guy laced up a 29+ wheel for me over a year ago.
Like the OP is guessing- it gets used less for light than I would like.
The rest of the time it's just getting used like a normal mountain bike hub.

It's a SON.
It's unnoticeable when in use. Noticeable when you heft the wheel by itself.
THe lighting is plenty (Supernova Triple) bright.
It's set/forget.

I also use a Shimano hub plenty. It's fine. More flicker at low speeds. Prob not as durable but it's on a cross bike so doens't get to beat up.

-JCB
 
#25 ·
Like the OP is guessing- it gets used less for light than I would like.
The rest of the time it's just getting used like a normal mountain bike hub. .....
There are several devices on the market that you can use to charge phone, gps etc with the power from your dynamohub. Its not just for having a light.
 
#28 ·
Yep- there are ways to charge while pedaling.
The light I run on a cross bike (the Luxos U) has that feature though I haven't put it to use much. More to test it than depend on it.

Headed to Spain for a few weeks to tour- decided to skip a dyno and not even bring the small solar panel we've used elsewhere.
Instead am bringing a portable battery. 13,000mha. Should be enough to fill some gaps as we need it.
Guess I'll know soon how that plan goes.

And as for Cycling About?
Alee is pretty sharp. Guy sure has been some places and writes it all up in great way.
Much more entertaining than the more common drone footage of a kitted out rider scorching his way across the hinterlands of Iceland.

If you use a gadget that'll charge an iphone off your dyno- how long do you ride to go from a dead phone to about oh... say 50%?

-JCB
 
#29 ·
nd.

If you use a gadget that'll charge an iphone off your dyno- how long do you ride to go from a dead phone to about oh... say 50%?
Too many variables for anyone's answer to have much meaning.
How fast are you going?
How efficient is your charging method?
How big is your phone's battery?
How much is your phone being used while you ride?

I try to charge an external battery rather than the phone itself. I found that my phone's screen would come on every time there was a significant change in the amount of energy it was getting, and the constant on/off of the screen was draining power faster than it was gaining power. But if you maintain a good speed, that's less of an issue. I found myself without a battery and heading home with my phone starting out at around 25%. 50 miles and probably 7 hours later it was at 18%, but somewhere along the way it hit 40%. As long as I maintained a decent, constant speed, it charged pretty well, but varying speeds made it discharge faster than normal.
 
#30 ·
Good info. Thanks Rob.
As I guessed, you can eek phone charging out of a Dyno but note without some hurdles.

I like the idea of pumping it into a battery instead of the phone for a handful of reasons. One being that the phone can charge all night as we sleep.
Thanks for that idea.

-JCB
 
#31 ·
Good info. Thanks Rob.
As I guessed, you can eek phone charging out of a Dyno but note without some hurdles.
I wouldn't consider them hurdles as much as issues to be aware of. Charging a battery instead of directly charging the phone solved all my problems. Spent a week biking around not too long ago and kept everything charged using my Shutter Precision hub and a solar panel. Ended every day with everything topped off.
 
#34 ·
y'all have any thoughts about whether 110mm TAs or 100mm QRs are better for long term durability? just got a salsa fargo and it sounds like a 110mm TA SON 28 would work best on it if I don't replace the fork (carbon firestarter)... but I'd really like a steel firestarter fork, which would put me in 100mm QR territory. not a decision I have to make anytime soon, or really at all given how good a reputation the carbon firestarter fork has, but still curious.
 
#35 ·
My (questionable) 2 cents-
It won’t be the axle configuration that makes either fork more durable.
The Son I have is a hand me down from bigger and farther flung rides- and it’s perfectly bullet proof.
I’d get the fork you most want, then get which ever Son matches it.
Then go ride a few billion miles.

But- if you’re a clever one, can you tell me why we can’t come up w/ some way to integrate the capability to generate into a disc rotor?
Sure, there are ample hurdles (first off, I don’t know anything about such things and surely dirt/water would have to be considered) but a converted rotor w/ some armature attached to the caliper could be swapped from bike to bike.
Now... how do we make one?

-JCBs
 
#38 ·
But- if you're a clever one, can you tell me why we can't come up w/ some way to integrate the capability to generate into a disc rotor?
The biggest problem is that you don't want to make the disc out of magnets since that's probably a poor braking surface, and also, magnets don't like too much heat. Brakes, needless to say, can generate a lot of heat. Likewise, it's not like you can put windings in the disc either.

Maybe you can place the magnets closer to the axle, but then I'd go another few paragraphs about that, and I don't want to put that much effort into typing up an explanation of the pros and cons about it.

Anyway, maybe the discs could be used for an eddy current style generator such as the Magnic lights. There are probably pros and cons to mounting those lights by the disc vs rim, but again, this is something that I don't want to chase down a rabbit hole (especially when typing in my phone). Feel free to research that avenue, or just buy some and play with them.

Maybe consider a bottle dynamo. Either mount it conventionally against the tire sidewall or rim, or figure some way that it can rub against the edge of the disc. Either way, it's probably going to be pretty noisy.

Or consider mounting a bottom bracket dynamo so it hits the edge of the disc, like with a bottle dynamo. The bottom bracket version might be quieter because of the bearing placement.
 
#37 ·
KaSai?
I had to look them up. Never heard of them.
Always good to have other options.

So there's what?
-Sturmey Archer (or at least there used to be). Fine for townie use, ours has a drum brake.
-Shimano (Not gucci but tried and true. Only QR)
-Son (gold standard? Every option of axle I suppose?)
-Shutter Precision (also great reviews. Many axle options)
-KaSai (first I've heard of them. Ah- lots of axle options)

Any others I'm forgetting?

-JCB
 
#39 ·
Yeah-
All good points. I wasn’t considering the braking surface changing, just something additional to the rotor.
More along the lines of the braking surface staying the same, and the spokes of the rotor being the coils. The armature could be mounted to the caliper mounts.

One idea was something along the lines of a bottle generator that would actually be run by the narrow edge of the disc. Mount to the fork or perhaps uses the caliper mounts.
But yes- I get it. Rabbit hole indeed.

We have several dyno hubs. Love them. But, would love a solution that could swap from bike to bike more easily than lacing up a new F wheel.

-JCB