Chain tensioner with Alfine 8 IGH ?

[yach]

Hi,

I noticed a new ebike built by/for the online dealer Alltricks in France. Brand is unknown and custom (Bicyklet).

Vélo de Ville Électrique Bicyklet Jacques Shimano Alfine 8V 500 Wh 700 mm Noir à partir de 2 698,99 € au lieu de 2 999,00 €

Retrouvez un large choix de produits sur www.alltricks.fr

www.alltricks.fr

Why would they put a chain tensioner on this Alfine 8 ? All other ebikes I've seen so far with internal gear hubs don't use chain tensioners. Are there any advantages or drawbacks using this ?

Thanks

 

[Nova Haibike]

Because the frame has vertical dropouts, there is no way to move the wheel to adjust the chain tension without the tensioner.

 

[yach]

Because the frame has vertical dropouts, there is no way to move the wheel to adjust the chain tension without the tensioner.

Ok I see, thank you.

So this is mandatory with such a frame. Isn't it weird designing an ebike frame with IGH that way ? Doesn't it look like a design error, or reusing a frame not meant for IGH in the first place maybe for cost reducing (which seems odd given the need to adapt the frame to the battery and motor) ? I mean, shouldn't a € 3k ebike avoid using such a frame design when it's meant to be equipped with an IGH ?

And what about the consequences on maintenance and "performance" (even if it's not a bike designed with performance in mind) ?

 

[Nova Haibike]

Like many manufacturers, they use the same frame for different models, with the other models using a traditional derailleur. While they could have designed the frame with horizontal dropouts and a hanger so it could work with either a derailleur or with an IGH without a tensioner, they just chose not to. There is a slight advantage to vertical dropouts in that there is no question as to where the wheel hub sits in the dropout. With a horizontal dropout, if the quick release is loose or you are just not careful, you might end up with brake rub or worse, the tire rubbing the frame.