Haibike EQ Trekking, Bosch drive.
- Thread starter o00scorpion00o
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o00scorpion00o
100 kW
4REEE said:
Ah, no. I think that hill was about 8-12% that I'm comparing the mac ( edit: the kind of hill that you would free wheel down about 25-30 mph) to the Bosch, however it's easy to forget that I'm also putting in a lot of effort as the Bosch makes you where I wasn't peddling with the mac so that might save what 200 watts ?
crossbreak
1 MW
I would rather go for better efficiency than lower and prefer a derailleur over a hub, or an even worse CVT hub like the NuVinci. In 2nd IGH gear you should barely see any drag, so just try to use it most times. Have fun in Germany 
o00scorpion00o
100 kW
Hi crossbreak, I'm here now enjoying the weather and the wonderful bicycle lanes. 
Really it's truly wonderful to have such cycle lanes that are far smoother than most of our roads.
Getting back to the bosch bike, I was on the Raleigh again and I noticed it a lot easier to cycle without assistance making my assumptions about the SRAM 3 speed hub correct, it's zapping power.
I wish Bosch used 3 chain rings like a normal bike, surely it can't be that hard ? But Ai guess they assumed people who buy such bikes wouldn't notice the difference and have some motor assistance on all the time.
I'm not saying the SRAM hub Is impossible to peddle but it does make a noticeable difference.
The big difference is the SRAM hub would allow much greater hill climbing, basically anything you can find, while with just a 9 speed cassette would be more limited but I've not being able to find something the Raleigh bike couldn't climb yet, nothing like the 20%+ I was up a few weeks ago back home, but still pretty steep clumps 16-18% ish.
I could just remove the hub and install a normal wheel but then I would be missing a lot of gears,mor I can use some assistance to compensate.
Really it's truly wonderful to have such cycle lanes that are far smoother than most of our roads.
Getting back to the bosch bike, I was on the Raleigh again and I noticed it a lot easier to cycle without assistance making my assumptions about the SRAM 3 speed hub correct, it's zapping power.
I wish Bosch used 3 chain rings like a normal bike, surely it can't be that hard ? But Ai guess they assumed people who buy such bikes wouldn't notice the difference and have some motor assistance on all the time.
I'm not saying the SRAM hub Is impossible to peddle but it does make a noticeable difference.
The big difference is the SRAM hub would allow much greater hill climbing, basically anything you can find, while with just a 9 speed cassette would be more limited but I've not being able to find something the Raleigh bike couldn't climb yet, nothing like the 20%+ I was up a few weeks ago back home, but still pretty steep clumps 16-18% ish.
I could just remove the hub and install a normal wheel but then I would be missing a lot of gears,mor I can use some assistance to compensate.
comradegerry
100 W
I spoke to a bike distributor sellinging one of the 45kmh Bosch EU Fast Pedelec about changing the rear wheel to a Rohloff.
If you tell them in advance, they will change the gearing at the sprocket so that the 45Kmh top speed is maintained.
If you neglect to mention it at the time of purchase and install the longer legged gearing of the Rohlhoff, a little more top end speed may be possible. Probably not much more though as wind resistance is becoming a bigger factor as the speed gets up there.
I will know first week of October when I get mine and will share the stats.
If you tell them in advance, they will change the gearing at the sprocket so that the 45Kmh top speed is maintained.
If you neglect to mention it at the time of purchase and install the longer legged gearing of the Rohlhoff, a little more top end speed may be possible. Probably not much more though as wind resistance is becoming a bigger factor as the speed gets up there.
I will know first week of October when I get mine and will share the stats.
o00scorpion00o
100 kW
4REEE said:
Would this be more efficient than the SRAM ?
Would it give me the same gearing as I have now ?
samsavvas
100 W
o00scorpion00o said:
I've put a lot of km on both the Sachs Orbit 2 speed and the later 3 speed/freewheel or cassette & derailleur set ups - both predecessors to the SRAM rear hub you have. You should experience no noticeable 'drag' from the hub, especially in the 2nd gear which I believe is direct drive. They are less efficient than a cassette/freewheel-only system but only marginally in every-day terms.
I have never seen a Bosch drive but I would suspect that any 'drag' you are experiencing with a brand new unit may well be associated with seals and o-rings wearing in. You may want to investigate this and either wait for further use to alleviate any friction or get some silicon grease and apply to said seals (if they exist).
Savvas.
o00scorpion00o
100 kW
samsavvas said:
I would be 95% certain it's the SRAM hub causing drag.
The Raleigh bike I tested for over 60 Kms in Germany was a lot easier to pedal with no motor assistance.
I am going to put a normal wheel on when the weather gets better to test and report back.
samsavvas
100 W
o00scorpion00o said:
Well make sure you think it through carefully. The Dual-Drive employs the same 3 speed hub that has been in use for generations. It now just has different bearings and a free-hub grafted on to it. There are several reviews around (including ones by the CTC and by Frank Berto et al) that demonstrate quite clearly what 'drag' it contributes - and it isn't much. So the evidence is out there. if using a crank drive andsingle chain ring the Dual Drive makes a lot of sense. And as I have pointed out, 2nd gear is direct so the hub is behaving just like a normal multi-speed cassette unit.
Savvas
o00scorpion00o
100 kW
samsavvas said:
Yes I heard before that 2nd was supposed to be direct and feel if there is no hub present at all but I find it strange that the Raleigh doesn't have that drag feel. But when I replace the wheel I'll know more.
Sure I'll have much less gear range but just the 9 speed cassette got me up a few good size hills in Germany. And for much steeper hills I'll just put pack the Sram again. Just a matter of swapping the two wheels depending on the trip I plan.
I did notice the drag was the same on the 2012 Haibike too and last year when I went between the two bikes even on a trip I noticed the difference between the Raleigh without Gear hub to the Haibike with hub. My Partner's Dad also notices it.
It's not a huge deal but I like to pedal as much as I can on my own as efficiently as possible without any motor assistance when I want to go on a good long cycle. I do wish they could use the 3 chain rings, simple, cheap and it works.
o00scorpion00o
100 kW
4REEE said:
No Didn't get a chance to test them out yet.
They have an internal gearbox of some sort and I'm wondering if there is much resistance when peddling without the motor .
I do notice a bit of resistance in the S-ram Dual Drive III rear hub, that was not in the raleigh without the S-ram hub. But without it I wouldn't be able to climb the steepest of climbs.
I do wish they would find a way to use the good old 3 chainrings as the geared hubs can be expensive and not so efficient.
I may be in Germany in the Summer to test it out, though I might not get a proper test.
Next time around I'd probably aim for a lighter bike. 27 kg is heavy.
I would find a hard time selling the old one here as not many people would be willing to pay so much for a bike.
o00scorpion00o
100 kW
I removed the SRAM dd 3 hub and sure enough it's much easier to pedal without the motor.
So this confirms what I was thinking all along.
I don't know why they can't make these geared hubs more efficient, I would imagine the Nuvinci hub to be a lot worse.
This has turned me off of geared hubs, why couldn't they just use normal front chainrings ? I suppose they think that people who buy the bikes would just use the motor most of the time and not notice it.
So this confirms what I was thinking all along.
I don't know why they can't make these geared hubs more efficient, I would imagine the Nuvinci hub to be a lot worse.
This has turned me off of geared hubs, why couldn't they just use normal front chainrings ? I suppose they think that people who buy the bikes would just use the motor most of the time and not notice it.
samsavvas
100 W
o00scorpion00o said:
Some worthwhile reading (emphasis is mine)!
http://hubstripping.wordpress.com/geared-hubs-vs-derailleur/
“8% efficiency loss against derailleurs (except Rohloff Speedhub). Internal gear hubs have a efficiency of 92% compared to 98% for derailleurs…There are three friction loss sources inside a internal gear hub drivetrain:
a) Inside a internal gear hub are planetary gears. The planetary wheels cogs into the sun wheels and the ring gear wheel at the same time. This system results a friction loss of 4%
b) Also the friction bearings of the planetary wheels are a source of friction loss.
c) Finally the friction loss of the chain which is also relevant for the derailleurs.
This is the most important disadvantage for sportive riders. But compared to the power loss because of air resistance of the system rider + bicycle this is not worth mentioning!”
http://www.rohloff.de/en/technology/speedhub/mechanical_efficiency/
Several excellent & easy to read pages with great graphs!
http://sheldonbrown.com/internal-gears.html
“Internal-gear hubs tend to be heavier than derailer systems, and are slightly less efficient in some gears. The direct-drive middle gear can be more efficient than in a derailer system, as there is no drag from derailler pulleys.”
&
“Middle Gear has the sprocket still driving the gear ring, but has the gear ring drive the hub. Thus, the drive is direct. Although the internal gears are always rotating when the sprocket is in motion, they don't have any effect on the drive in middle gear.”
&
“All current three-speeds except for the Sturmey-Archer S3X fixed-gear hub have a wide range, with big steps between all of the gears. The way bicycle manufacturers commonly set up three-speeds, the middle gear is too low for level-ground riding, to keep the top gear from being completely useless. A 3-speed hub will serve you much better if you install a larger rear sprocket or smaller chainwheel, and use the top gear on level terrain. The low and middle gears are then better for acceleration and climbing. If you spin out on downhills, then you can coast.”
&
“Hybrid gearing uses an internal-gear hub along with derailer gearing. Sturmey-Archer and SRAM make 3-speed hubs with splines for an 8- 9- or 10-sprocket cassette. These hubs are especially useful on bicycles which can't take a front derailler… The stock cassettes sold with SRAM hybrid-gearing systems work OK, but I like other combinations better… With any of these hybrid gearing systems, choose the chainwheel so the smallest sprocket and the hub's direct-drive middle gear give about 75 gear inches (6.0 meters development, 5.5 gain ratio)…”
http://www.ihpva.org/HParchive/PDF/hp52-2001.pdf
Kyle & Berto (definitive read!)
“Hub gears are generally about 2% lower in efficiency than derailleur-type gears. But there are exceptions. This is illustrated by figures 3, 6, 7, and 12. Figure 12 shows that the efficiencies of the Shimano 4, Sachs 7, Shimano 7, Sturmey 7 and the Rohloff 14 all cluster about two percent lower
than the Browning 4, Browning 12, or the Shimano 27. However, two of the 3-speed hub gears did not follow this trend. The grease in the Sachs 3 and the Sturmey Archer 3-speeds was replaced with light oil, and unlike the other hub gear transmissions, the efficiencies of the Sachs 3 and Sturmey 3, compare well with the best of the derailleur transmissions (figs. 7, 9, and 12).”
Savvas