Hub gears v derailleur

[Jimeno]

Hi all.

I have a question about gear systems on an ebike.

I have a Giant Daily which I bought about 6 months ago and I have done about 1000 miles leisure riding.

It has a crank motor and hub gears.

Overall it is a huge improvement over my much-loved previous ride - a Raleigh Array with front motor and derailleur gears.

However I am finding gear changes - particularly changing down while climbing - far more problematical.

With the Raleigh derailleur set-up you continue to pedal forwards in a gear change so the motor continues to run - also the motor was in the front wheel so the power wasn't being transmitted via the chain so was continually delivered through the gear change.

However with the crank drive/hub gears set-up, you have to stop pedaling or sometimes even backpedal slightly, which cuts the power completely which in any case is being transmitted through the chain.

This is much less convenient than the Raleigh system - the bike slows dramatically - and it's a real effort to get it going again.

Does anyone else see this as a problem?

Is it something I've just got to live with?

I'm obviously stuck with the crank drive - but I am considering trying to get the hub gears changed to a derailleur so at least I can still continue to pedal forwards.

Might this help? I don't want to modify the bike if it ain't going to help.

TIA

 

[Ocsid]

With my Nexus 8 there is only a need to take the torque I apply off as I change gear, no need to stop pedaling or back pedal.
The crank drive itself also automatically is powered off for a moment as the gears change, it has a sensor to signal this in the gear change cable.

 

[Nosweat]

Granted, when climbing a hill hub gears are harder as you momentarily lose power unlike a derailleur where you keep the power on throughout the change. They win hands down over derailleurs when changing while stationary e.g. traffic junctions. Possibly better suited to commuting than racing or touring (especially as they are wear much less than derailleurs and are virtually maintenance free).

For people like me who wouldn't be seen dead riding any bike without a hub gear I guess we just got used to that slight ease off of pressure that comes when changing gear - and you have an electric motor to give extra poke up the hills. My XF07 is considered not especially powerful yet I find I rarely need to change gear going up a hill any more (though I might put a bit more on the power setting). I ease off the pressure on the pedals when changing gear but certainly don't backpedal (unless I want to stop - I even chose to have a coaster brake so if I back pedal it stops the bike!)

Not sure you can easily swap to a derailleur in any case due to the drop outs and especialy if you have the belt drive version. Learn to appreciate it for the fabulous bike it is, anticipate when you need to drop a gear ahead of time, adapt your riding style and you ought to get used to it. Yes you have to unlearn some riding habits and change when you plan to change gear, but the motor is your friend on hills.

 

[sjpt]

On our Motus with hub gears (Bosch + Nexus 7) you do have to stop pedalling for a fraction of a second (*), but the power comes back immediately when you push again so it isn't a problem. Maybe the sensor system on the Giant doesn't react quickly enough to the torque as you start pushing again? If so, could be a poor design or could be a slight mis-adjustment somewhere or error in the unit.

I see it has Giant PedalPlus 6-sensor technology; which sounds as if maybe it's being too clever for its own good. Perhaps it is worth checking if there is a firmware update.

(*) just easing off sometimes works, but not reliably.

 

[Artstu]

As the others say a very very brief pause in pedalling is all that is needed, never been an issue for me even on 25% gradients.

 

[Jimeno]

Many thanks for your thought-provoking replies.

I do appreciate the bike for what it is - it's just that in that one area it's so different from my previous one.

My local shop reckon they could change it to derailleur provided Giant can supply a replacement drop out with a hanger - I'll think hard before doing it though.

In fact maybe I'll see if I can borrow a Giant with a derailleur from them first to see if it makes much of a difference anyway.

 

[Artstu]

In fact maybe I'll see if I can borrow a Giant with a derailleur from them first to see if it makes much of a difference anyway.

Or you could actually just follow the advice of the three of us who have taken the time to try and help you. ..

 

[Warwick]

Ignoring the rather blunt last reply, I'd echo those who have advised to stick with things as they are. However, there's no harm in checking out your options, is there?

I've done the following bike journey over the last couple of years: rear hub drive/derailleurs; Bosch Active Line/Nexus 7; Bosch CX Performance/derailleurs. The transition between the 3 bikes took some time. I came to appreciate the advantages of the hub gears. The fact that gear selection can be made at any time - and over the entire gear range, was much appreciated. The latter point might be something for you to consider. You don't have to drop only one gear at a time with hub gears, you can drop as many as you like. Top to bottom gear, if it suits. A combination of forward planning - in other words looking ahead to judge the terrain - and selecting the appropriate gear for the gradient, should reduce the slight drop in power for that split second. Do you have twist or trigger shifters?

 

[Jimeno]

... I'd echo those who have advised to stick with things as they are. However, there's no harm in checking out your options, is there?

I've done the following bike journey over the last couple of years: rear hub drive/derailleurs; Bosch Active Line/Nexus 7; Bosch CX Performance/derailleurs. The transition between the 3 bikes took some time. I came to appreciate the advantages of the hub gears. The fact that gear selection can be made at any time - and over the entire gear range, was much appreciated. The latter point might be something for you to consider. You don't have to drop only one gear at a time with hub gears, you can drop as many as you like. Top to bottom gear, if it suits. A combination of forward planning - in other words looking ahead to judge the terrain - and selecting the appropriate gear for the gradient, should reduce the slight drop in power for that split second. Do you have twist or trigger shifters?

Twist - forwards for change-down.

Yes - I do all those things - I'll probably end up sticking with the set-up - it's so good in every other way.

Point about taking advice (which I really appreciate) is that as far as I am aware - no-one is actually using the combination I am, so no-one actually knows the extent of the 'problem'. Only I know that so I will take on board all your very helpful advice and - together with my experience - make a decision.

...Ignoring the rather blunt last reply...

I am. Don't worry - I'm used to forums. He'd probably had a heavy night.

 

[Warwick]

Moving from hub gears back to derailleurs had its challenges too. I'd got used to coasting up to junctions on the Nexus-hubbed Ortler and deciding which gear to use at the last moment. You can't really do that with a derailleur-equipped Cube, because you need to pedal to change gears. I'd also stop on the Cube and forget to change down, so I'd end up having to start off in an unfeasibly high gear. On the Ortler I could easily select a lower gear. It was the perfect urban commuter.

 

[Artstu]

Point about taking advice (which I really appreciate) is that as far as I am aware - no-one is actually using the combination I am, so no-one actually knows the extent of the 'problem'. Only I know that so I will take on board all your very helpful advice and - together with my experience - make a decision.

Please don't take offence, that's just my way usually given the way this is going.

Is it the bike or is it you? I'd be amazed if the Yamaha behaves significantly different to Bosch and Shimano motors. I guess one way to establish if the issue lies with you or the bike is let someone with experience of crank-drive and hub gears ride it to give a second opinion.

 

[Warwick]

One other response to the issue is to quickly up the power setting. I'm not familiar with the Yamaha set up, but when I start off on the Cube in too high a gear, I respond by upping the power setting a notch. That's easily doable on the Bosch. My Ortler was a Bosch/Nexus 7-speed hub gear combination. The main difference I had to get used to was the larger jump between gears compared to the 3x9-speed Oxygen. If the Cube was available with the Shimano Alfine 11-speed hub, it would be a great combination. OK, it wouldn't have the luxury of a super-low 1st gear, but it would have small jumps between the gears.

 

[Warwick]

One other thing that's dawned on me is the Cube/Bosch CX Performance set up stops power being delivered during gear changes to ensure the chain isn't over strained. When I'm scrolling through the gears, it sounds quite like a quiet motorbike with the motor whine.

 

[flecc]

no-one is actually using the combination I am, so no-one actually knows the extent of the 'problem'. Only I know that so I will take on board all your very helpful advice and - together with my experience - make a decision.

Not quite, I've plenty of experience with your problem. Running a Giant Lafree which had the low powered Panasonic motor, I swapped its three speed Nexus hub gear for an SRAM 5 speed one.

But the SRAM P5 is the slowest changing hub gear ever designed especially when changing down for climbing. It's far, far slower than your Nexus 8.

The answer to the problem is anticipation, changing down in advance of the climb, never leaving it until after the uphill starts.

But I'm still a hub gear fan and would stick with what you've got.
.

 

[Jimeno]

Again - thanks for the replies. Reading through, I think that sjpt had a point when they said...

"Maybe the sensor system on the Giant doesn't react quickly enough to the torque as you start pushing again? If so, could be a poor design or could be a slight mis-adjustment somewhere or error in the unit.

I see it has Giant PedalPlus 6-sensor technology; which sounds as if maybe it's being too clever for its own good. "

I think that might be right. Following the gear change, when I resume pedaling there is a long hesitation before the power comes in. So what with going up hill, stopping pedaling and that hesitation the bike slows dramatically .

Obviously anticipation helps.

I will persevere.

 

[Warwick]

That doesn't sound right to me. My changes and feed in of power are immediate with the Bosch. I'd ask to have it checked out.

 

[Jimeno]

That doesn't sound right to me. My changes and feed in of power are immediate with the Bosch. I'd ask to have it checked out.

+
I think I will. I'll let you know what happens...