Hill climbing ability and range

[flecc]

There have been different 8 speed versions of the Shimano hub gear.

First launched as a standard version with a promise of a premium one to follow, the standard one soon started to give trouble so it was upgraded, but it since seems to have largely disappeared so it may have been discontinued.

The name Alfine actually belongs to the system, a homogenised relationship of a set of components aiming to give the best possible integrated performance, and it was generally believed to use the premium 8 speed hub from the outset. There was a rumour of the Alfine hub being fitted with stronger spindle, but I've seen nothing from Shimano about that or any evidence of it.

So in terms of hub strength, the 8 speed premium Nexus and it's Alfine marketed form should perform similarly.
.

 

[Mussels]

so you cant change down as necessary when hill climbing without stopping peddling? I think I wil stick with derailleurs in that case.

are alfina hubs really a good idea on an E Bike??

That concerned me when considering the 906 but derailers need a lot of maintenance and I think it's a good trade off with the mileage I do. A good reason to have the Alfine hub on an ebike is the ratio between top and bottom gear, on a bike that can't be fitted with a front mech that is very useful. As the 906 is hub powered I won't have to stop all the power to change gear, I'll let you know how it goes.

 

[Patrick]

Is it the hub's fault?

so you cant change down as necessary when hill climbing without stopping peddling? I think I wil stick with derailleurs in that case.

It occurred to me this morning that you could have much the same problem with derailleurs on any bike that put power through the gears (such as a Panosonic type system that drives the chain or a Gruber Assist type system that powers the chainring and pedals). Although you don't stop peddling when you change gears on deralliers, you do have to ease off the pedals to allow the change to happen smoothly. So when accelerating or going up hill you could end up having to wait for the motor to ease off before you could change regardless of whether you have hub gears or derailleurs.

 

[eddieo]

I was not thinking straight and did not realise until Mussels post. with a 906 or a front motor kit the alfina should be OK? it seems the crank drives are more problematic?

 

[Blew it]

As I understand it, both the Panasonic and Yamaha crankdrives have a very useful feature built into the system.

Flecc mentioned the need to anticipate which road gear would be needed to climb an approaching hill before the ascent begins. On occasions, when the rider gets this wrong, the machine will stall. On a hub motored bike, restarting on a steep hill can be a knee-crunching affair while waiting for the motor to join in. The redeeming feature of the Panasonic system is the instantaneous response to pedal pressure. With the correct gear selected, restarting on a steep upslope would be a doddle compared to a hub motored bike. In fact, if my memory serves me correctly, one owner of a Kalkhoff expressed a little concern about the way his machine surged forward when restarting on a hill. Remembering the problems I had when riding The Ridgeway Route, I would dearly have loved that kind of instant response.

I never thought the day would come when I would consider a crank drive machine, but this appears to be changing. If the Gepida MTB Sirmium was available with disc brakes front and rear, and providing it could be fitted with the 10 ah battery option, I would seriously consider adding it to the collection!.

To clarify my preference for disc brakes. When riding rural trails after recent rain, particularly limestone hardpack, rimbrakes suffer badly from the highly abrasive paste that finds it's way onto the rims. Even after hosing the machine down this grit is still embedded into the brake blocks and continues grind away at the alloy braking surface. Likewise, when negotiating muddy sections, It's not unusual to stop and select a suitable stick from the hedgerow to poke the mud out of V brakes.

 

[Gepida uk]

Hi,

We can equip the MTB Gepida with a front disc brake; this can be done in house.

 

[flecc]

On a hub motored bike, restarting on a steep hill can be a knee-crunching affair while waiting for the motor to join in. The redeeming feature of the Panasonic system is the instantaneous response to pedal pressure. With the correct gear selected, restarting on a steep upslope would be a doddle compared to a hub motored bike.

Absolutely right, full power is available with a high pressure pedal thrust from a standstill so a hill take-off is always easy, much better than nearly all hub motors in this respect. That said, an eZee Quando will pull my 65/70 kilos away from a standstill on a 1 in 7 with it's hub motor only, so a few are not too bad.
.

 

[Blew it]

Hi,

We can equip the MTB Gepida with a front disc brake; this can be done in house.

One down....two to go!

Thanks for the reply.

 

[Mussels]

On a hub motored bike, restarting on a steep hill can be a knee-crunching affair while waiting for the motor to join in.

Not if you use the right gear, assuming the bike has a suitable range of gears.

 

[Blew it]

I don't think you have the foggiest idea what either of us is talking about!

Have a nice day little one!

 

[Mussels]

I don't think you have the foggiest idea what either of us is talking about!

Have a nice day little one!

Can you elaborate on what a 'knee-crunching affair' is then. I've done lots of starts on steep hills on a hub driven bike and never crunched my knees. Not all hub driven bikes have a delay.

 

[Andrew harvey]

I use an old 7 speed Nexus of my old Lafree, now fitted to a front hub motored bike. I've also done a fair bit of testing on the Gepida Reptillia with an 8 speed hub.
The 7 speed once worn in changes gear fairly smoothly, deraileir users riding it always comment on how smooth it is. The 7 speed changes up slicker than it does down, having said that it's probably time to change the selector cable after all the salt and grit has got into it.
The 8 speed hubs I've used have all being new or very nearly so. They change up the gears much faster than they do down, there is minimal need to ease pedaling to get a smooth shift unless your standing on the pedals. Down shifts are different, and are eased with a marked relaxation of pedal force, on a hill with a crank drive motor this amounts to stopping pedaling, but only on steeper gradients, just for a fraction.
As Flecc says if you can change gear before you get to an incline this will ease any burden on the hub gears greatly.
The people who have most problems with hub gears tend to be those who like to race about, crunching through the shifts, these people wear deraileirs down quickly to.
The Yamaha unit fitted to the Gepida definitely has a sharper power cut of than the Panasonic, but it doesn't lose as much speed on shallow hills.
Riding fast around country lanes it feels a lot faster despite it's looks.The motor does seem to turn on and off at speed, on nice sweeping roads that allow you to enjoy yourself, in a way the Panasonic doesn't. Thats just a feature of having more power available at speed, not a criticism.

 

[Blew it]

That's a very interesting direct comparison with the two systems. Over the past few weeks, I've been reading around for a better understanding of the subtle differences in the Panasonic and Yamaha systems which is now much clearer.

Thanks for posting your personal experiences with them.

Regards
Bob