I bought an old French randonneur with the primary intention of doing a 70 mile charity ride, the ebike being unethical for the purpose and also not having the range. Ended up spending a stupid amount of money upgrading it but now I love it to bits, principally beause of the Shimano Alfine 8-speed I had fitted. Without doubt the best gearing I have had on any bike and when the time comes to replace my beloved Oxygen, hub gears will be a pre-requisite.
I was talking to the guys at NuVinci a couple of weeks ago, they told me that Shimano were not going to apply their warranty to hub gears when being used with the Bosch system and this may extend to all crank motors. This was due to hub gears collapsing due to the extra stresses caused by the torque exerted by the rider and the crank drive system working together.
Has anyone else heard this or were the NuVinci guys getting over enthusiastic?
All the best
David
Has anyone else heard this or were the NuVinci guys getting over enthusiastic?
All the best
David
I agree Bob, I have just emailed them for clarification but they did seem professional and on the ball.
Hub gears was the question Eddie! I don't try to keep track of derailleurs since they don't keep fixed ranges and ratios.and my 27 speed XT please
(how could you forget me)
Well they are Americans David, noted for over-enthusiastic selling!
That said, even the 24 volt old Panasonic system caused Shimano to withdraw their Nexus Inter-4 gear hub completely and never replace it due to them failing frequently in the Giant Lafree. Therefore there is history, and since the Bosch is very much more powerful, I could well understand them getting nervous even with their tough newer hub gears.
Tonaro crank driven bikes would be much better fitted with the Nuvinci. The forces on a derailleur or hub gears are considerable with crank driven bikes and if I could find a cheap nuvinci for my Tonaro I'd fit it in a second. They are currently sold in Australia sensibly prefitted with the nuvinci so its a shame there are warranty issues.
Two things,
1 With hub gears you can have the old standard heavier chains and sprockets.
2 I still don't understand these percentages.
Take the Nexus 3 for instance with a quoted 200% range. What does this mean?
Does it mean that if bottom gear is 33 inches, second will be 66 inches and third will be 99 inches
or does it mean that bottom is 33 inches and top is 66 inches (ie 200% of 33)
What does the Nexus/Alfine at 307% actually offer if bottom gear is 33 inches?
To try to illustrate the problem, the old Sturmey Archer 3 speed offered a drop from 2nd to first of 25% and a rise from second to third of 33%
Take an example of a bike with a standard SA,
for ease let it have a 100 inch middle gear, 75 inch bottom gear and 133 inch top gear. But its range from first to second was 133% (100 is 133% of 75) and from second to top was also 133% (133 is 133% of 100). However, top gear was 177% of bottom gear!
1 With hub gears you can have the old standard heavier chains and sprockets.
2 I still don't understand these percentages.
Take the Nexus 3 for instance with a quoted 200% range. What does this mean?
Does it mean that if bottom gear is 33 inches, second will be 66 inches and third will be 99 inches
or does it mean that bottom is 33 inches and top is 66 inches (ie 200% of 33)
What does the Nexus/Alfine at 307% actually offer if bottom gear is 33 inches?
To try to illustrate the problem, the old Sturmey Archer 3 speed offered a drop from 2nd to first of 25% and a rise from second to third of 33%
Take an example of a bike with a standard SA,
for ease let it have a 100 inch middle gear, 75 inch bottom gear and 133 inch top gear. But its range from first to second was 133% (100 is 133% of 75) and from second to top was also 133% (133 is 133% of 100). However, top gear was 177% of bottom gear!
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The one I've highlighted bold Mike.
The 8 speed Shimanos have this range, 1 (i.e. 1 to 1 ratio) being the direct drive gear roughly in the middle, the other figures being the proportion relative to that direct drive:
1 = 0.527
2 = 0.644
3 = 0.748
4 = 0.851
5 = 1.000
6 = 1.223
7 = 1.419
8 = 1.615
You can see that the 8th gear at 1.615 is about 307% of the 1st gear of 0.527. (The exact percentage figure depends on the way it's worked out)
.
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Maybe so but it offers a much smoother alternative to the harsh and noisy derailleur system and maybe the better solution for a crank driven bike. I dont know about Shimano or Rhollof systems having never tried them but clearly there are issues here with the Bosch drive.
With respect Hech, we don't know that yet, we only know what was said by a rival sales team. I won't be surprised to hear that Shimano deny or qualify this.
The Shimano hub gear systems are the best for quiet and smooth operation, the Rohloff is noisy in the lower 7 gears. I agree about derailleur noise, but they are far, far more efficient than any other cycle gears so a must for competition. The NuVinci is certainly quiet and, apart from the midway changeover point from geared up to geared down and vice versa where there's harshness, smooth as well. I just don't like the drag, but for someone not bothered about that it's a good choice.
The Shimano hub gear systems are the best for quiet and smooth operation, the Rohloff is noisy in the lower 7 gears. I agree about derailleur noise, but they are far, far more efficient than any other cycle gears so a must for competition. The NuVinci is certainly quiet and, apart from the midway changeover point from geared up to geared down and vice versa where there's harshness, smooth as well. I just don't like the drag, but for someone not bothered about that it's a good choice.
For the first sixty years of my life, I firmly believed that the SA 3 speed hub gear was the answer. I thought that derailleurs must be useless because the principle on which they worked was fundamentally flawed. Then I found a bike on the dump with a ten speed derailleur. I gave it a dose of oil, and pumped the tyres up. What a revelation, I was amazed. A gear for every purpose, smooth gearchanges, and light weight. Derailleurs need a bit of regular maintenance, but I love them. I did briefly own an 8 speed hub in a Batavus recumbent, and although it was nice , I still prefer derailleurs.
I am not an engineer nor even a gifted cyclist, however I don't have to be either to see potential for failure in a transmission system designed specifically for personal pedal power. None of the crank manf so far as Im aware have upgraded their derailleur systems to cope with the additional demands of electric assist and I mean only to relate my personal concerns in that regard and suggest the nuvinci as a sensible alternative. You dont have to be a francophobe traindriver to dislike derailleurs.............
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