SHIMANO Internal Geared Hub Nexus 5-speed for E-Bikes

[Sid Aluminium]

I purchased my two (!) SA RX-RF5s because
1) I got a really good deal on them.
2) I have fond memories of riding thousands of joyful, trouble-free miles using an S5-1 hub many decades ago. (I know, seems unlikely, but there it is.)

Sid these look CHUNKY !!!

I read the specifications before purchase but was still surprised at their mass when I hoisted the first one out of the box. You could anchor a Clyde puffer with one of these. With a trebuchet and a crate of RX-RF5s, you could batter down a castle wall in short order.

Ref the SA 5 speed, there's been much debate over the gear shifter quality, which one do you use and has it proved reliable?

I will apologize that I do not have many miles on the RX-RF5 bikes. I'm using the TSC50 grip twist shifters that came in the box and while they have performed flawlessly to date, they were clearly manufactured to a price point. I see SA also offers a thumb shifter, the SLC50, and a DLC50 dual lever trigger (a push-push) shifter. In a fantastically unlikely case where I left on a long tour - hmm - I'd probably switch to an SLC50 beforehand.

Except for the weight I rather like these hubs. 2kg for 243% gear range! I suppose that the weight would not be a significant concern on an ebike (with which I have no experience). On a pushbike, you can get more gearing for less weight with another hub - in fact, any other hub.

[chesini]

In practice the Nexus5 is doing well in terms of handling and riding.

Also contacted Shimano technical service. This Nexus5 is specially designed for e-bikes with a more powerful motor. The bearings and gears are noticeably thicker and firmer. That is why the hub only has 5 gears. The Nexus7 and 8 are actually not intended for the more powerful e-bikes. If the bicycle manufacturers were to follow the specs carefully, they would be best not to mount a 7 or 8 on the power e-bikes.

The technical service of the bicycle manufacturer itself also provides similar information. The installation of the Nexus5 on a number of their bicycle models is a well-considered design choice that is independent of any shortage of certain parts.

NB: calling the technical service gives a little more guarantee that you receive more objective information from technicians on the field, which is by no means the case when calling the sales / marketing.

The dealer himself indicates that he has already delivered quite a few bicycles with Nexus5 without having had any problem so far. With the Nexus 7 and 8 there have been cases of defective hubs.

The general advice is to always start in 1 and Eco mode and only then increase. Just like a car. You also do not start in 3rd or 4th gear.

[Greystoke]

I'd say based on that reply that gearing it down below what Shimano recommend and using it on a conventially powered touring bike would be ok.

[Bonzo Banana]

In practice the Nexus5 is doing well in terms of handling and riding.

Also contacted Shimano technical service. This Nexus5 is specially designed for e-bikes with a more powerful motor. The bearings and gears are noticeably thicker and firmer. That is why the hub only has 5 gears. The Nexus7 and 8 are actually not intended for the more powerful e-bikes. If the bicycle manufacturers were to follow the specs carefully, they would be best not to mount a 7 or 8 on the power e-bikes.

The technical service of the bicycle manufacturer itself also provides similar information. The installation of the Nexus5 on a number of their bicycle models is a well-considered design choice that is independent of any shortage of certain parts.

NB: calling the technical service gives a little more guarantee that you receive more objective information from technicians on the field, which is by no means the case when calling the sales / marketing.

The dealer himself indicates that he has already delivered quite a few bicycles with Nexus5 without having had any problem so far. With the Nexus 7 and 8 there have been cases of defective hubs.

The general advice is to always start in 1 and Eco mode and only then increase. Just like a car. You also do not start in 3rd or 4th gear.

Again should be pointed out if you have a hub motor your points are invalid. In fact a more powerful front hub motor would take even more load off the Nexus hub gears making the Nexus hub gears last even longer again. The more power delivered away from the normal gearing system the less those drivetrain components will wear out. These upgraded Shimano components are designed for mid-drive ebikes not ebikes in general most of which out there in use are using hub motors as those dominate entry level ebikes and ebike kits so most ebikes in the world use hub motors. Mid drive motors are a large niche of the ebike market but their high pricing means the volumes of such bikes sold is much lower. Amazon sell a huge amount of ebikes and you'd struggle to find a mid-drive ebike on there, same situation with ebay and Halfords who have up to 40% of bike sales in the UK sell a huge amount of ebikes with hub motors. Real e-mountain bikes are dominated by mid-drive motors but that is still a niche of the overall ebike market.

Same situation with freewheels as Nexus geared hubs. A low cost entry level component use it on a conventional bicycle and it will last a reasonable amount of time but don't expect to get a very long life out of it. However stick it on motor hub and suddenly they last ages because going up a hill is made much easier for the rider so the wear rate of the drivetrain is massively reduced including the freewheel. You can expect to get 3x as long out of the freewheel possibly longer. Hence a large number of entry level ebikes have freewheels but its not a problem at all.

Just gets a bit weird when people write about ebikes as if mid-drive is the norm if anything all the data points to it being a premium end product with a much smaller percentage of overall sales. There is a debate about which is better but surely no debate about which dominates sales and forms the basis of more ebikes sold. You can pick up a hub motor ebike for as low as £400. The cost of entry into the ebike world is much lower with a hub motor and therefore much greater volume of units are sold. I mean if you made special ebike grade components for hub motor ebikes those components could actually be lighter, weaker components, you could make chains and cogs a bit thinner and maybe crankarms a bit thinner too. The Shimano NEXUS 8 is a super strong geared hub for a ebike with a front hub motor.

https://www.parkersofbolton.co.uk/colle ... ding-ebike