Dynamo Wheels

[Kim]

Have you considered that you may be overthinking this?? 

She hasn't used pirate-ninjas in any of those calculations...

[vorsprung]

Ok I have some comments I hope will be helpful

Firstly, if you want to go the dynamo wheel route then there are 3 choices of makers for hubs.  SON, Shutter Precision and Shimano. 

I have all three but I would guess as an introductory grade part probably the Shimano is best.  The performance /price/ reliability ratios are good

Next, the light.  There are several makers but here's a choice of two actual models.  The Cyo Premium (80 LUX VERSION) and the SON Edelux II

I don't have an Edelux II but the reputation of it is good, however, it's expensive.  The Cyo Premium is super reliable and much cheaper, so go for that.
If you want to do charging don't get a Luxos-U or a similar light with a built in USB output.  Get an external charge unit like a B&M USB Werk.  The Luxos U seems to break too much and this is due to it doing many things rather than one thing well

I would also advise getting a rear light driven by the generator, such as a B&M Seculite

To source these parts try the German shops bike24, starbike, bike-discount.de or the yorkshire based Spa Cycles

If you don't want to go the dynamo route then the way to go with battery lights are the 18650 based ones.  The Fenix BC30 seems to be the best.  I haven't tried this myself but again, heard nothing but good.  I am all dynamo'd up but I agree with people up thread, battery lights are fantastically good now and are probably a better option for what you want to do

[quixoticgeek]

Have you considered that you may be overthinking this?? 

Maybe.

Yesterday I forked out €500 for a flight to the start, and the balance of the £350 entry fee, the hotel for 4 days in Burgas is about €200. Over €1000. Just to get to the start. Not including the bike, kit, etc...

I built my bike in 2017 with the goal of starting the TCR. As part of the training, I've literally gone to Hell and back. I cycled in headwinds, in snow, ice, rain, sunshine, and hail. I've had sunburn, hypothermia, frostbite, and dehydration.

I've put a heck of a lot into being able to line up on the start line in Burgas in July. And when the flag goes up and we all start rolling, I want to be in the best position to make sure that the odds are stacked in my favour of getting to Brest. RatN has made me realise that Brest is going to be an epic ask, the best I can hope for is to get as far back into Western Europe that a train home isn't too difficult.

But that means I don't want to find myself half way up a mountain in Slovenia with a dead battery in every device. So how do I avoid that? I work out a power budget, I work within it.

If I scratch, it should be because I as a human have not been upto the task, not because my planning wasn't up to it. Plan your ride, ride your plan.

But yes, it does appear to everyone else that I'm over thinking it.

J

[caerau]

Ah, oops, I got you confused with the original poster who was just talking about a 200 km RRTY, for your case, no I think you're thinking it through.  Apologies.

[Dtcman]

Ok I have some comments I hope will be helpful

Firstly, if you want to go the dynamo wheel route then there are 3 choices of makers for hubs.  SON, Shutter Precision and Shimano. 

I have all three but I would guess as an introductory grade part probably the Shimano is best.  The performance /price/ reliability ratios are good

Next, the light.  There are several makers but here's a choice of two actual models.  The Cyo Premium (80 LUX VERSION) and the SON Edelux II

I don't have an Edelux II but the reputation of it is good, however, it's expensive.  The Cyo Premium is super reliable and much cheaper, so go for that.
If you want to do charging don't get a Luxos-U or a similar light with a built in USB output.  Get an external charge unit like a B&M USB Werk.  The Luxos U seems to break too much and this is due to it doing many things rather than one thing well

I would also advise getting a rear light driven by the generator, such as a B&M Seculite

To source these parts try the German shops bike24, starbike, bike-discount.de or the yorkshire based Spa Cycles

If you don't want to go the dynamo route then the way to go with battery lights are the 18650 based ones.  The Fenix BC30 seems to be the best.  I haven't tried this myself but again, heard nothing but good.  I am all dynamo'd up but I agree with people up thread, battery lights are fantastically good now and are probably a better option for what you want to do

Agree with all the above.  To add to it:

Have you got disc brakes? This limits your choice of hubs. Alpkit do a rebranded Shutter Precision disc hub for £75 and I've found it good. https://www.alpkit.com/products/love-mud-juice

the The Cyo Premium 80 lux is good (used one for a few years) but if all you want is a lot of light look at the IQ-X (100 lux)

Rear light is personal choice. Personally I've never bothered with running a cable to a rear light as battery powered leds last forever.

 

[quixoticgeek]

If you don't want to go the dynamo route then the way to go with battery lights are the 18650 based ones.  The Fenix BC30 seems to be the best.  I haven't tried this myself but again, heard nothing but good.  I am all dynamo'd up but I agree with people up thread, battery lights are fantastically good now and are probably a better option for what you want to do

I have the Fenix PD35, I use it with the exposure joystick helmet mount. I used it a little on RatN, along side my dynamo. Tho it would be plenty on it's own. I have the 3500MAh and the 2600MAh(this one came free with the light) batteries, both have built in µUSB charging.

I may have to investigate a handlebar mount for the light as well.

It does have quite a hot spot in the centre, helmet mounted I can put this exactly where I want. On the bars, that may not be possible. It's gonna be well up the obnoxious stakes for oncoming vehicles.

It's not a CE approved bike light, this may be a problem in some jurisdictions.

Oh, and things that probably don't need saying, but erm, I learnt the hard way. When you screw the battery cap on, don't accidentally hold the on switch, esp don't do this when the light is pointed at your face. This light is bright...

J

[Frank9755]

.

But that means I don't want to find myself half way up a mountain in Slovenia with a dead battery in every device. So how do I avoid that? I work out a power budget, I work within it.

If I scratch, it should be because I as a human have not been upto the task, not because my planning wasn't up to it. Plan your ride, ride your plan.

Apols to the op for digression, but I'd give you a higher chance of getting to Brest in time if you didn't have a dynamo.

[quixoticgeek]

.

But that means I don't want to find myself half way up a mountain in Slovenia with a dead battery in every device. So how do I avoid that? I work out a power budget, I work within it.

If I scratch, it should be because I as a human have not been upto the task, not because my planning wasn't up to it. Plan your ride, ride your plan.

Apols to the op for digression, but I'd give you a higher chance of getting to Brest in time if you didn't have a dynamo.

I'm listening. Please show your working.

J

[simonp]

I did the last PBP with battery lighting and a single German-approved light (IXON IQ Speed Premium) did the whole ride without recharging.

I've made up my own battery this time which has more capacity and is lighter. The weight of the new battery is roughly the same as the difference in weight between SON Delux 12 and a DT Swiss hub - and with zero drag. Clearly this is going to be faster. You also get way more light than with an Edelux II.

[zigzag]

dynamos have some major drawbacks*, so apart from trying it out i've never really used them on long rides. the extra drag especially on hard rides like tcr would drive me nuts (not as much physically as mentally). battery lights are more than adequate these days, brighter and possibly more reliable than dynamo lights.

*flicker at low speeds (i.e. anytime you crawl up the mountain), no light when stopped, draaaaaag, possible wiring failure - to name a few.

[S2L]

True, however, I think it's best to start in the winter months and get them out of the way... the most annoying thing is when you are 10 months in and the beast from the East arrives, wiping out all your efforts... 
I would start in December, by the time it's April, you've got it in the bag.

Conversely, if you have 3-4 months of summer stuff done, you're more likely to stick the winter ride, rather than can it cos you can restart your streak as you've less to lose... Depends on your thought processes.

As you said, it depends.. you seem to have a lot of time in your hands, but I am a bit more average, meaning I can probably find a couple of days each month (at a push) to ride a 200. In winter those two days might well turn out to be icy, snowy or maybe it's raining with 6 degrees and simply I can't be arsed to spend 9-10 hours in that.
So best to get them out of the way and if I fail, I haven't lost much.

For the record, I have tried RRTY once, failed in February (month 9 or 10 can't remember) and won't be trying again

[Frank9755]

There are two issues with dynamos.

The power loss, which is trivial for a strong rider on a short ride, but not so for a less strong ride on a long ride. What was your power at the end of ratn? If you don't know the figure, you have omitted the key input from all your power budgeting. I would guess it might have been around 70W.  Can you really spare almost 10% of it?   Take the cube root and it's only 3% of your speed. that's 3% more time, you might say, so instead of, eg 15 days, it would be 15.45 days. But it's the marginal power, the difference between getting up a hill and walking, between getting to a town or having to stop short, between reaching the shop before closing time and not, etc. And if you go a tiny bit slower all the time, you end up having to go into the next day, so suddenly it has cost you an extra 6-8 hours that werent in your calculations.

The other one is what do you need the extra power for?  Ime there are two things people use it for, neither contributing to their speed. The first if extra-bright lighting. This is nice to have but actually you get used to the lights you have and don't need anything specialy bright.  The second is messing around on d social media which is a form of faffing.

I reckon a dynamo would cost you at least a day, and it only takes a tiny bit of organisation and planning to ride without one.

[Phil W]

Certainly for SON hub the power loss is no more than 1W when the light is switched off.  So let's go with the 7W (which is the figure for riding at 30km/h) when switched on, being riding when it is dark.

Let's say 14 hours riding per day of which 10 is during daylight and 4 when lights are required. So 3% slower at night means what would take 4 hours now takes 4 hours 7 mins. During the day, with the light switched off, the loss at between 0.25W to 1W is pretty close to normal loses in a hub.  So difference in time is by the by, but let's call it 3 mins over 10 hours for arguments sake.

So for the sake of 10 mins or about 3-4km (for a rider averaging 18-24km/h) per day. You now have a battery light you need to keep charged enough to deliver at least 4 hours of light every day. If you are stopping in hotels every night probably a worthwhile trade to go for a battery light.  Only using hotels every so often then it begins to favour the Dynamo setup.

Besides you'll probably lose the 10 min advantage taking battery lights on and off the bike every time you stop and fishing out a charging plug and plugging them in to charge each day.

[Frank9755]

It's those kind of errors which lead people who to use a dynamo setup! 

As I read it QG is planning to run her dynamo all the time she is riding - to charge her batteries - so it would be 14 - or however many hours she rides, not 4, so c.18 minutes per day, not 7, which adds up to 4.5 hours over a notional 15 day period (chosen to keep maths simpler, not as a forecast - realistically will probably be more days).  That is a bigger loss than from carrying an extra 5kg of weight!  But, as I said, it will be more than that as it is marginal power so would lead to walking a few hills that the extra few Watts might have made rideable, etc, and a few extra hours at the end (and it sounds trite but the extra hours always do come at the end when you are at your slowest and least able to cope effectively with them!) means there's a very good chance of forcing her into an extra day, which would obviously involve a night.

In 10 years of audaxing and longer of other riding I'm yet to see anyone take their lights off their bike when they stop!  Most people don't lock their bikes so why would they remove the lights?

Not using a dynamo is not an excuse for faffing.  You need to have an efficient process for what you do when you get into a hotel room and a good charging setup.  With that, it takes you less than a minute to set it all up and put it away again in the morning.

My real world experience is that I have managed three nights bivvying on battery power without needing a recharge.  I could have done another night but would then have needed to re-charge.  I think Zigzag has done longer with similar setup.  Very few TCR riders stay in a hotel less often than once every fifth night.  Bigger batteries could extend the range further.

[quixoticgeek]

It's those kind of errors which lead people who to use a dynamo setup!

It's a mistake I appear to have walked into.

As I read it QG is planning to run her dynamo all the time she is riding - to charge her batteries - so it would be 14 - or however many hours she rides, not 4, so c.18 minutes per day, not 7, which adds up to 4.5 hours over a notional 15 day period (chosen to keep maths simpler, not as a forecast - realistically will probably be more days).  That is a bigger loss than from carrying an extra 5kg of weight!  But, as I said, it will be more than that as it is marginal power so would lead to walking a few hills that the extra few Watts might have made rideable, etc, and a few extra hours at the end (and it sounds trite but the extra hours always do come at the end when you are at your slowest and least able to cope effectively with them!) means there's a very good chance of forcing her into an extra day, which would obviously involve a night.

(My bold)
That is the magic number I needed. If I have to add 1-2kg of battery kit to be able to go 3 days between hotels without a dynamo. What is the penalty? You've answered that.

In 10 years of audaxing and longer of other riding I'm yet to see anyone take their lights off their bike when they stop!  Most people don't lock their bikes so why would they remove the lights?

Not using a dynamo is not an excuse for faffing.  You need to have an efficient process for what you do when you get into a hotel room and a good charging setup.  With that, it takes you less than a minute to set it all up and put it away again in the morning.

My first night of RatN, the hotel routine took me just under 40 minutes, from arriving, to being in bed, including checkin, washing shorts, shower, etc... By the last night, it was under 15 minutes...

My real world experience is that I have managed three nights bivvying on battery power without needing a recharge.  I could have done another night but would then have needed to re-charge.  I think Zigzag has done longer with similar setup.  Very few TCR riders stay in a hotel less often than once every fifth night.  Bigger batteries could extend the range further.

What light did you use?

J

[JonJo]

Will you be doing DIY routes? If so plan them so that navigation is easy at the start and end when it will likely be darkest. It reduces the need for a backlight on your navigation device and means you can get by with a 'be seen' light rather than a 'see by' light setup and so minimise your power requirements.

Use devices with compatible batteries to cut down on the need to carry lots of spares. After a lot of experimentation my setup is for two Fenix ld10 lights at the front and a Garmin etrex 30 gps. These both use AA batteries. Then I have an Alpkit headtorch and rear light both using AAA batteries. All the batteries are Eneloop rechargeables and I carry two spares of each size. I've never had to use the spares, including on an overnight 300. Make sure you start with fully charged batteries. Dead easy with the Eneloops cos you can charge them when they're partially discharged without degrading performance.

Charge your phone before you set off and the job's a good 'un. No need for a dynamo to do RRtY really.

[Zed43]

One thing not mentioned with regards to winter riding is that low temperatures can have a dramatic effect on the run time of batteries. I've once had a Garmin 820 giving up after 2 1/2 hours of riding at near 0 degrees C.

[Kim]

One thing not mentioned with regards to winter riding is that low temperatures can have a dramatic effect on the run time of batteries. I've once had a Garmin 820 giving up after 2 1/2 hours of riding at near 0 degrees C.

GPWM.  I got fed up with seemingly fine batteries (particularly in rear lights) conking out as soon as they reached ambient temperature in winter.  Again, more of a day-to-day thing than audax, but it's one of the major advantages of a dynamo.

[vorsprung]

There are two issues with dynamos.

The power loss, which is trivial for a strong rider on a short ride, but not so for a less strong ride on a long ride. What was your power at the end of ratn? If you don't know the figure, you have omitted the key input from all your power budgeting. I would guess it might have been around 70W.  Can you really spare almost 10% of it?   Take the cube root and it's only 3% of your speed. that's 3% more time, you might say, so instead of, eg 15 days, it would be 15.45 days. But it's the marginal power, the difference between getting up a hill and walking, between getting to a town or having to stop short, between reaching the shop before closing time and not, etc. And if you go a tiny bit slower all the time, you end up having to go into the next day, so suddenly it has cost you an extra 6-8 hours that werent in your calculations.

The other one is what do you need the extra power for?  Ime there are two things people use it for, neither contributing to their speed. The first if extra-bright lighting. This is nice to have but actually you get used to the lights you have and don't need anything specialy bright.  The second is messing around on d social media which is a form of faffing.

I reckon a dynamo would cost you at least a day, and it only takes a tiny bit of organisation and planning to ride without one.

I assume the "at least a day" is for a distance of several thousand km?

Prompted by your calculations I looked at this topic again

According to https://www.cyclingabout.com/dynamo-hub-drag-lab-testing/ if the Dynamo hub is on and if you have a best in class SON28 the drag is 5 to 7 watts.  Helpfully, it is lower if you are slower

It's really difficult to relate things like this to real-world courses.  Maybe I need to write some software that can?  Anyway, using this site https://www.gribble.org/cycling/power_v_speed.html and faffling about with the controls- if I increase the "drivetrain drag" from 2% to 7% then it seems to approximately DTRT.  This is all on the flat and assumes no headwinds

On that basis the average speed for 140W is 28km.  With the drag cut back to the usual 2% the speed for 140W is 28.5km.  Now that might not sound much but if you are doing 600km that difference is 22 minutes
At lower speed/power of 100W, the difference is more like 33 minutes

Half an hour doesn't seem like much out of 80 or 90h (in the context of getting to Brest) and it isn't unless you are a) trying to get a good time or  b) so slow that getting time in hand to sleep is difficult

[cygnet]

Staying resolutely off topic

Flatness and Power input make huge differences

Adding in some relatively gentle gradients (5% max, 1250m over a 200km distance) at 200W there is negligible time difference over about 4.5hrs

At 100W that becomes c.15 minutes over 6.5 hrs and drop that to 70W, 30 minutes over 8.5hrs.

(2kg weight saving, 7W power loss, 0 wind)

[vorsprung]

Staying resolutely off topic

Flatness and Power input make huge differences

Adding in some relatively gentle gradients (5% max, 1250m over a 200km distance) at 200W there is negligible time difference over about 4.5hrs

At 100W that becomes c.15 minutes over 6.5 hrs and drop that to 70W, 30 minutes over 8.5hrs.

(2kg weight saving, 7W power loss, 0 wind)

I dunno, that's why it's a pity that there isn't a "simulator" to follow a particular route with added lag as the rider gets tired, headwinds etc etc

My previous thoughts (see Stressing over the Mille Cymru) is that these sort of differences make little difference even on a hilly course

[LittleWheelsandBig]

OP, just pick some nice battery lights. With current technology, battery lights are plenty for what you want to do, though most of the audax bikes in this house have dynamo lights.

For everybody else filling this thread, I can't be bothered with whether or not an extra 3-5W are consumed during a long brevet by a dynohub or not. The speed I travel at during long brevets isn't really limited by my actual maximum power output but rather by how much effort/ pain I think the ride deserves at that point (or the speed of whoever I am riding with). The more motivated I am, the more power I can sustain for longer periods (5W just gets lost in the noise), though there are still periods of "Ah, bugger it; let's stop for an icecream/ coffee/ whatever!"

[The Wheeler]

I done 2015 PBP and all qualifiers x 2 using a battery setup.
A one2one with 4 spare batteries and I only used 3 on PBP.
I brought the light 2 years before PBP and3 extra batteries for the PBP
I am still using all the batteries in rotation now . After use I always completely drain batteries.
The light and 2 batteries were £60 and £9 for each spare battery.

[The Wheeler]

The make is one23!!

[S2L]

One thing not mentioned with regards to winter riding is that low temperatures can have a dramatic effect on the run time of batteries. I've once had a Garmin 820 giving up after 2 1/2 hours of riding at near 0 degrees C.

true