Page 1 of 1

Shimano Di2 Alfine

Posted: Mon Dec 31, 2012 12:45 pm
by lechat
These look really nice. Too bad the hubs are so damn heavy.
mADEAodxQZBx6ICWbhBcELA.jpg
mADEAodxQZBx6ICWbhBcELA.jpg (5.01 KiB) Viewed 5480 times

Re: IGH

Posted: Mon Dec 31, 2012 1:06 pm
by Tinea Pedis
Sorry, I have no idea what you are referring to.

Can you make your post/thread title a little less ambiguous please.

Re: IGH

Posted: Mon Dec 31, 2012 1:06 pm
by Weenie

Re: IGH

Posted: Mon Dec 31, 2012 1:16 pm
by MattSoutherden

Re: Shimano Di2 Alfine

Posted: Tue Jan 01, 2013 6:21 am
by lechat
Sorry 'bout that.
Didn't see the BR piece, Just ran across them browsing eBay.

Re: Shimano Di2 Alfine

Posted: Tue Jan 01, 2013 2:52 pm
by ras11
I was very excited last year when they announced this group set for a travel/winter trainer I had in mind. With the 1600+g hub weight, and 135mm rear axel, it would be a hard sell for me now.

Like the nuvinchi hub before, the internal geared hub technology still has some distance to go IMHO.

Re: Shimano Di2 Alfine

Posted: Tue Jan 01, 2013 5:01 pm
by racermech
I wonder what the gear range is like? 11-23 or more like a 12-27? Could build up to be a pretty fun bike depending on the ratios.

Re: Shimano Di2 Alfine

Posted: Wed Jan 02, 2013 3:57 am
by freeloader
ras11 wrote:I was very excited last year when they announced this group set for a travel/winter trainer I had in mind. With the 1600+g hub weight, and 135mm rear axel, it would be a hard sell for me now.

Like the nuvinchi hub before, the internal geared hub technology still has some distance to go IMHO.


There's some improvement they can made. The motor unit looks bulky and heavy to me.

Re: Shimano Di2 Alfine

Posted: Wed Jan 02, 2013 4:28 am
by KLabs
racermech wrote:I wonder what the gear range is like? 11-23 or more like a 12-27? Could build up to be a pretty fun bike depending on the ratios.

I believe 11-38 or 10-36, and at least the hub weight is around the axle, and no dishing/offset issues ...

Re: Shimano Di2 Alfine

Posted: Wed Jan 02, 2013 6:29 am
by maxxevv
Alfine 11 supposedly has a 409% total gear range. From 0.53 - 2.153

The conventions are a little different from normal cassette stack. But if you configure it to be mated to a 22T fixed cog, it works out to be something like a 10-42 cassette.

Re: Shimano Di2 Alfine

Posted: Wed Jan 02, 2013 1:14 pm
by SWijland
Those levers look really nice. For a winter bike this would be pretty ideal.

Re: Shimano Di2 Alfine

Posted: Wed Jan 02, 2013 3:43 pm
by maxxevv
It must be noted that Shimano specifically recommends a chainring / sprocket ratio of ~1.9. And not to deviate too far from that. The exact reasons I'm not so sure but probably has a lot to do with the stresses internally.

Re: Shimano Di2 Alfine

Posted: Thu Jan 03, 2013 2:43 am
by KLabs
maxxevv wrote:Alfine 11 supposedly has a 409% total gear range. From 0.53 - 2.153

The conventions are a little different from normal cassette stack. But if you configure it to be mated to a 22T fixed cog, it works out to be something like a 10-42 cassette.

Interesting ... with that range only a single 46T or 48T crankring is necessary ...

Re: Shimano Di2 Alfine

Posted: Thu Jan 03, 2013 3:52 am
by maxxevv
But its really useful if and only if weight and overall efficiency are not priorities. Internal geared hubs can be a little draggy compared to their chain and sprocket cousins. Not sure the latest generation's figures, but the older generations can be as much as 10-12% difference in efficiency.

They are however excellent for commuting use as they generally require very little servicing. Even better if used on a quick and compact packing foldie like a Bike Friday Tikit or a Brompton as they eschew the convenience a compact clean fold with none of the (tangled up, dangling chain )issues of normal derailleur systems for these small wheel folding bikes.

Re: Shimano Di2 Alfine

Posted: Thu Jan 03, 2013 3:52 am
by Weenie