clasher

I dunno if I would use IGH on a long brevet (a 3 speed on a 200 might fun). I've found my derailleur bike to be reliable enough and even if the shifters break or the derailleur gets smashed one could still shorten the chain and single-speed it. Also at PBP most of the controls have some mechanics you can pay, though I have no idea how many spares they'd have or what kind of experience they have but I doubt they'd be able to fix IGH issues... I had zero bike issues so no reason to talk to them. I don't recall seeing any of them swamped with people.

My hands were sore at the end of PBP from shifting so much, I run a 3x10 setup, that was when I decided I'd be open to electronic shifting. Seems like some of the ultra crowd are going that way. Cables are the weakest part of the shimano shifters IME, I just had to change out my cable after ~6000km on a brand new brifter, it had started to fray and would stop shifting onto the smallest sprockets, I was glad to get that warning sign before the cable broke. They are tiagra 4703, which have otherwise been a solid setup. I think Dura-ace jockey wheels having bearings, and maybe ultegra is bushing on top and bearing on the bottom? Not sure if I am remembering that or not. Tacx used to make some good bearing jockey wheels.

GhostRider62

Tourist in MN.....I was not criticising your choice. Just a discussion about using the least energy in the most reliable way to get to the finish. I do think many randonneurs use bikes that make it harder to finish but that is their choice

Clasher....I can't shift all that well anymore, I love my e-Tap but I am not a SRAM fan.

unterhausen

I have thought about working on this, since my ftp seems to be inexorably falling. Although the security of dyno lights is hard to give up. What headlights are you using? What do you do about headlights on a 1200k?

I wish there were lower power dynohubs that weren't high drag like the Shimano 1.5 watt. But I guess Schmidt doesn't agree.

Tourist in MSN

My preference for cables is that I can fix that.

On the touring board it has also been commented that Shimano brifters go through cables faster than you would expect. I have never used Shimano brifters, I have two bikes with Campy brifter in back, one bike with Campy brifter in front. I have not had any cable trouble but it makes me ask if anyone has an opinion on those for failure modes?

My derailleur touring bikes use Shimano bar end shifters. I am quite happy with them and my hands never get that tired, but I am probably riding one third or one fourth as many hours in a day as you on PBP, so that is not really a fair comparison.

clasher

The trouble for me is that I'm on a carbon roadie that has internal routing so a roadside fix in the dark would take a lot of luck to fix. My older bikes at least have external cables so much easier to fix on the roadside. At least with a triple if I lose my rear cable I still have a 3 speed , or if the front broke I could leave it in the middle ring and probably finish most any ride. I guess with these shifters I have it'll just be new cables every 5000km to try and stay ahead of that problem... I usually just did it in the spring with my older brifters but they were rumoured to be especially bad at eating cables but I got ~30,000km without having any frayed cables.

unterhausen

Clasher, make sure your derailleur limit screws are just a tiny bit loose when it's in the largest sprocket -- front or rear. Someone told me that's why they fray and it seems reasonable since they don't always fray.

It's a real pain to get that little remnant out of the shifter.

GhostRider62

The Schmidt deluxe is lighter and lower drag if I am not mistaken. I think it was originally for 20 inch wheels.

If you are not riding much at night, the Schmidt has low drag during normal use and not too much of a penalty. I was just saying that mechanical friction items like tires, chain, bearings, and others added together can be significant. I rode with latex tubes, topping them up once. For lights, I use an old BT 20 Fenix that runs on 18650 batteries. It has a crude manner of directing the beam that is helpful but nothing light the German lights. It is broad up close with a long throw, which I like. I also carry a small Fenix spare light that runs on one 18650. I carry a spare set of batteries. I also had some batteries in my drop bag. I have not found something that I like better, yet.

Fast riders are often on Continental GP4000 or 5000 tires in 25 or 28 mm width. I have bought a ton of the much loved supple tires from Seattle. I have also tested them. They are not slow but they are also not fast. They are comfortable.

It seemed to me and my Garmin that PBP had more climbing in 2019. I really noticed it on the bent.

unterhausen

I thought it had more climbing in 2019 too, but the parts I didn't like were essentially the same. I really don't remember the westbound climb up le roc'h being quite so long. The last stretch before Loudeac on the return seemed a lot different.
All the climbing was harder than 2011, since many of us had a tailwind both ways that time. I was in my big chainring going east up le roc'h, that was fun.

antimonysarah

[QUOTE=GhostRider62;22156980]I doubt anyone could feel the 6-8W of a dyno hub of 3-5 watts of a Rohloff hub. Imperceptible doesn't mean irrelevant

I am a low power, efficiency minded rider.
/QUOTE]

Me too, and I absolutely can, in some conditions, feel the dyno hub. Two stories: one, I was on a training ride (had intended to do ~200k) a little while before my first 400k. I headed out a a familiar way, but going further out it than I had in past, and was like "man, either I am not recovered enough from my last wind, or there's more headwind than was predicted. So I decided to turn around earlier than planned, aided by a roadside ice cream stand. Got in the ice cream line, and glanced over at my bike, and, where I'd leaned it in the shade, I could see the standlight still faintly glowing. Turned it off, ate my ice cream, and got back on: there was, in fact, basically no wind, as expected. Though I did turn around anyways, since 85 miles was going to be plenty.

Second story: we're about 500k into a 600k, I'm riding with two other guys. One skinny, one not (I am also not skinny). As we descend the rollers, us two larger riders quickly pull away from our thinner compatriot, and then I, slowly, start to take the overall lead. The other big guy asks me what I'm doing to get more aero. I ask him if he minds sharing what he + his rig weigh -- he and I weigh about the same, he's maybe got a few pounds more stuff loaded on his bike but it's very close. On the next couple of rollers, I match his posture -- tucked if he's tucked, fully upright if he is, and the same thing keeps happening. So I tell him to turn off his lights, match his posture once more, and we go down the next hill in perfect unison.

Tourist in MSN

This is the first I have read of someone that could see the difference riding with a dyno powered light on.

If I lift my front wheel off the ground and give it a spin, if my light is off it will spin the same as if it was a non-dyno hub. Turn the light on and give it a spin, and the wheel slows much more quickly. The extra draw from the headlight clearly adds drag when I do that.

I could readily see that with a SP PV8, the difference on my Shimano hub it was less obvious but still apparent.

So, not only have I read about the wattage losses, I have seen the difference on my own bike. But, when I am riding I can't feel the difference.

unterhausen

For the 200k that you might do someday, the drag from even the worst dynohub, plus an IGH, plus rubbing brakes is mostly academic. Because who cares if you take an extra 15 minutes on a 200k? Over a longer ride it starts to add up. I feel like I recall that Shimano's hubs perform poorly with the lights off, so you may as well leave the lights on. That's what I do. I need to do the work to get my SoN wheel that's hanging from a hook in the garage ceiling working.

GhostRider62

If one trusts Hamibini and many do not, there is 2-3 watts to be gained per wheel from average bearings to top of the line Japanese bearings.

Before PBP, I tore my bike down completely. I replaced all of the bearings with low friction seal NTN bearings in the front hub and I also tore down the Powertap G3 hub and freehub. The Powertap used really mediocre bearings. I put in a properly run in new chain (three chains....on my recumbent) that was waxed. I put on new tires and new latex tubes. Cleaned and lubed the idler (pulley that is heavily loaded by the chain on my recumbent). I put on the rebuilt Rotor RS4X crankset.

Two stories related to friction.....

I went out and did a hard training ride some weeks before PBP with the fresh bike. I beat all of my personal bests and took a considerable amount of time off my 10 mile TT. Some of this was fitness, some of it was the honeymoon effect of cleaning up the bike, but some of it was lower friction. My power levels were considerably higher. I think one can feel 10 watts. I know I can measure it very easily.

On PBP, I started with some GI distress from something bad I had eaten. I know how much power I make at certain heart rates and I ride a a planned level and do not ride harder. At my planned power (measured at the rear wheel), it was taking my heart 140 beats per minute when it should have been 120 BPM. It was very perplexing. I also could not shift off the big ring. I did not figure it out until I got home. The bottom bracket is pretty complex on that crankset. It developed around 5-7 mm play. Based on HR, the extra friction was sucking up a lot of power. If I had pedal power meter in addition to the hub power meter, I could say for sure how much frictional losses were happening. But, I could clearly feel that something was wrong. I mean the diarrhea all the way to Brest might have also contributed. When I got home, I swapped out the crank and sure enough, the bike was faster.

I think it is really easy to save 10 watts at 16 mph just with tires and although this only earns you 1 km/h, it is free money in the bank. Most of the rolling friction tests are on drums and the relative ranking of the tires is accurate but they fail to give a real indication of actual frictional losses on real roads. I learned this lesson because I spent hundreds of hours doing aero testing on my bent using the chung method. It helps to also have the Crr measurements or good estimates. I was getting pretty high numbers for Crr using the best of the best racing tires. I asked Dr. Chung by email and confirmed that my measured Crr was pretty typical or actually pretty good for real roads. I am too cheap to throw 10 watts down the toilet and even 2-5 watts on an IGH is too much for this miser, especially if I have to live with 14% jumps in gear ratios......at that point, I would just go fixe. Apologies for the rambling

himespau 

Yeah, I wonder if that's a hub-specific difference. Do some have less friction. And is it better to use the shimano with wiring that allows you to charge your garmin during the daytime if it's going to be putting out the drag no matter what.

unterhausen

Shimano hubs aren't particularly efficient on or off. If you want to charge something, you're better off with an SP or SoN. It seems like test results differ on which of those is better. Everybody gets about the same answer with SoN, some people measure the SP as being more efficient. I have come to the conclusion that I should buy SoN. For one thing, the price difference is less between disc through axle. But I use my dynohubs long enough that $100 isn't worth worrying about. OTOH, Shimano hubs seem to come my way for very little money, that's why I have so many of them.

randallr

Two thoughts:
1) Numerous folks have spoken about the need for a durable wheel on PBP. A rear wheel with a Rohloff hub is symmetric (no dish) and thus inherently stronger than a dished rear wheel with cassette (just like your typical front wheel is stronger than your typical dished rear).
2) A couple of days ago ascending Lookout Mountain (on the paved road to the top) I met a roadie with a bike upside down waiting for service. I asked if I could help, he said, "I don't think so, it's a broken derailleur hanger." I agreed with him that I couldn't help.
It's impossible to break a derailleur hanger on a Rohloff hub.

Tourist in MSN

I think the consensus is that Son is best, SP PV series is close behind, Shimano after them.

That said, there have been many models of Shimanos over the years, some much better than others. And I am leaving out some of the rare ones like Panasonic.

This is almost a decade old, but it has some good comparisons of the models available at that time. This link is a google translate link:
https://translate.google.com/transla...00242,15700248

I do not read German, if you do, this link may be better for you:
https://fahrradzukunft.de/14/neue-nabendynamos-im-test

While a lot has changed in the world of LED lighting and USB chargers since that was published, the hubs have changed very little. That comparison was one of the pieces that I looked at before I bought my first dynohub in early 2013. I bought an SP PV8 at that time. I could not find a seller in USA, I ordered one from Asia on Ebay so I might have one of the first SP hubs in USA.

This being the rando forum, I suspect most dynohub users here are only using the hub for lighting, with some also using it for battery charging. Realistically from a cost standpoint it would make more sense to carry a powerbank for your GPS than use a USB charger off of your hub.

I primarily bought the hubs for bike touring where I use it for charging every battery I have, camera, phone, GPS, headlamp (for my head in the campsite), batter taillight flashers, etc. When I tour on my S&S coupled bike, the disassembly and re-assembly of the bike at each end of the trip is enough of a hassle that I do not use dyno powered lighting on it when touring, the dynohub is only for battery charging on that bike. If I need a headlamp on the bike, I have a small one that is powered by USB cable, plug that into my powerbank.

Initially I did not plan to have a dynohub on my rando bike, but when I bought a cheap Shimano hub from the charity four years ago, that Shimano hub went on my light touring bike and the SP hub was moved from that touring bike to the rando bike. Earlier this year I finally got around to wiring a fender mounted taillight on the rando bike.

Tourist in MSN

Some Rohoff hubs are on bikes that were not designed with a way to adjust chain tension, they will have a chain tensioner that hangs from a derailleur hanger. So, while unlikely, it is possible to break a hanger on some Rohloff bikes.

unterhausen

What tires are you using now?

GhostRider62

GP5000 in either 23, 25, or 28 but mostly 25 mm. I can't get 28 mm right now. I also can't fit 30 or 32 mm on my bikes. I would probably run a 32mm on the rear if it fit and a 25 mm on the front because the recumbent has a lot of speed, so, the front tire fit to the rim is important but the rear tire is shielded and width matter nothing for aero effects back there. I used 28 mm GP4000 a lot on my uprights. I used 25 mm GP 4000 on PBP 2015. I rarely get flats although I did get one on PBP as Bijorn Lennard and Fiona Kolbinger came by me dragging a whole train of riders behind them. I only had one other flat that year in the middle of the night on lousy roads I ran over a chunk of metal. Butyl vs latex does matter. I am considering trying tubeless once more.

randallr

Thanks for the qualification, you are correct. I was thinking more of bikes built from the ground up for Rohloff

GhostRider62

I always fly with a new derailleur hanger. If riding my Cervelo, I have one in my tool bag.

A carbon rim goes a long way towards wheel reliability

Tourist in MSN

Nice looking bike, but it is too clean. You need to go get it dirtier. Mine has an eccentric bottom bracket for chain tension adjustment.

randallr

Well, that photo is from when it was new 4 years ago. So it's looking more used now ;o)

Tourist in MSN

It took me some time to find it, is that the Co Motion shifter?

randallr

Yep. Oh, and the stem is now flipped so there's not such a huge spacer stack. That's the only possible downside for an old guy for the Crosshairs frame - top tube could be longer.