nexus 7 versus nexus 8 versus derailleur

[ColBak]

Looking for advice on buying our second bike.

I have a Batribike Omega, (bought for my partner but used by both of us) and am pretty happy with that.

It has the Nexus 7 gears, but whilst I love the simplicity, I would like to be able to go a little faster than 7th gear comfortably allows under my own steam.

When I buy our second bike, will one with Nexus 8 give me the higher speed I am after, or would I be better off getting something with a good set of dérailleur gears?

 

[anotherkiwi]

Often bikes with IGHs are under geared to preserve the hub. The nexus 8 is a better IGH in the premium version, it uses roller bearings instead of bushings.

Just down from the top of this page you have the gear ratios - 307% nexus 8 vs 244% nexus 7.

 

[Trevormonty]

The Alfine 8 is little more up market and comes with trigger shifting. Avoid 11spd they don't have good reputation.

 

[Nealh]

Not forgetting although the gear ratios are set % wise, you can change the theoretical gearing by changing the rear sprocket size though this is dependant on which T size chain wheel is used. A front chain ring to rear sprocket ratio should be 2:1 for warranty purposes but you can get away with a greater ratio if your riding doesn't involve steep inclines.

16T sprocket will give an effective gearing of approx. 10/30T, whilst a 23T sprocket would give approx. 14/44T.
Typical gearing given a certain sprocket used.
16T = 10/30.
18T = 11/34.
19T = 12/36.
20T = 12/38.
21T = 13/40.
22T = 14/42.
23T= 14/44.
To see the effective gearing jumps, sprocket size T divided by each gear ratio/% gives an equivalent T count compared to a cassette.

Problem with Shimano geared hubs is the gearing T jumps, 1 or 2 in high gear but larger T jumps of 3 to 8 in the mid range to low gears.

 

[ColBak]

Thanks all.... I will go my homework on 'gear ratios' etc before buying

 

[Nealh]

I have used a double chainring 32/48 on a Alfine 9 with 20T sprocket with front hub drive and so far the IGH is still in working order.

 

[anotherkiwi]

I have used a double chainring 32/48 on a Alfine 9 with 20T sprocket with front hub drive and so far the IGH is still in working order.

That will always work well because you are reducing torque on the drivetrain with the assistance of your motor. I would love a 2 or 3 speed derailleur and the choice of same number of cogs on a nexus 8. That would extend it's gear range to that of a pinion or a Rohloff.

 

[dwvl]

When I buy our second bike, will one with Nexus 8 give me the higher speed I am after, or would I be better off getting something with a good set of dérailleur gears?

I have recently fitted a front hub ebike conversion kit to my Nexus 8 bike, because I love the internal gear hub.

It always seemed to me to be too low-geared before I converted it, but at a constant assisted 15mph in 8th gear, I found it really uncomfortable spinning the pedals so fast.

So I swapped the gear cog on the Nexus 8 hub to a smaller one, and also swapped the front chainring to a bigger one. Not expensive or too difficult to do, and I couldn't be more happy with the result

 

[ColBak]

Thanks dwvl... That sounds like the path I should take.

'spinning the pedals so fast' was not what I expected to be doing.... Either I am fitter than I thought (unlikely), or I need to change something.

 

[ColBak]

... And thanks to everyone else... I have a lot to learn, will do my research based on your tips.

 

[KirstinS]

I also use a alfine 8 paired to a bbsxx

16t sprocket and 42t front (lekkie bling ring)


Sent from my iPhone using Tapatalk

 

[Trevormonty]

At lower gearing of 2:1 should be able to maintain 35kmhr comfortably in 8th gear. With middrive like activeline or Steps will climb almost hill you are likely to find on sealed road.

My commute involves short hard granny gear grind on my MTB. Wife does it with bit effort on her activeline bike with 2:1 nexus gearing.

 

[Warwick]

I have a Ortler Wien with a 7-speed Nexus hub & I really like it. I have gone through two 8-speed Alfine hubs on other bikes, which were nothing but trouble. The shifting on the 7-speed Nexus is positive and quick.

I do spin out in top gear, but I also have a Badass box fitted, so that's not surprising. I am considering fitting a smaller rear sprocket to raise the gearing, but am holding back at the moment, so I may use the bike for touring and the lower gearing would then be a bonus.

 

[Rohloffboy]

IGH is the way forward for ebikes imho, that is until the manufacturers get there act together and start building the gears into the motor, like on the continental ebike.

Of course I am only referring to crank drive ebikes.

I have been riding a regular pedal bike for the last 14 years, and that is fitted with a Rohloff, great bit of kit the Rohloff, and mine rides just as good if not better than the day it was bought, the only maintenance has been the annual oil change.

 

[Trevormonty]

Shimano new 5spd 60nm IGH maybe way to go. Design specifically for ebikes. The 260% range shouldn't problem used with 60nm motor like bosch performance line or Shimano's new E7000. Smaller 50nm motors may struggle with it on steep hills.

 

[jarob10]

IGH is the way forward for ebikes imho, that is until the manufacturers get there act together and start building the gears into the motor, like on the continental ebike.

Of course I am only referring to crank drive ebikes.

I have been riding a regular pedal bike for the last 14 years, and that is fitted with a Rohloff, great bit of kit the Rohloff, and mine rides just as good if not better than the day it was bought, the only maintenance has been the annual oil change.

How do you find the shifting experience?