Internal Hubs
 

I've been looking at an internal hub for my Tern Link P9, I've done some reading up (Googling and on this forum) but I'd like some opinions if possible please. I like how clean it seems, both in how it looks and I think I could use something like the Freedrive which will keep it cleaner when the I lug it on the tube etc.

They are used on some other models of the Tern bikes. Any fans/haters of them on this forum? If you're a fan, any suggestions? The Shimano offerings look tempting.

Thanks!

If your bike has vertical drop outs then you will need a chain tensioner to use an internal hub gear, this will preclude the use of the rather nice Freedrive.

As to which hub gear it depends on how much you want to spend, and how wide your rear forks are, but either way the 8 and 11 speed shimano alfin hubs take a lot of beating, slickest gear change available.

half links can be used to tension the chain and there is a bottom bracket tensioner available.
How many gears do you need? The Sram has some nice hubs. I am using a 2 speed Sram on my Kingpin and have a Sturmey Archer 2 speed kickback for my Raleigh. I just ride around town so the 2 speed is enough for me. I have a Sturmey Archer 8 speed hub that I want to fit to my Minivelo. The Rohloff 14 speed hub is the premier hub of them all.

you could also consider the Nuvinci CRT (continuously variable transmission). i test rode an electra town bike with one installed. i found it to be very impressive.

Internal hubs are great, but they do tend to add weight to the bike. A big reason derailleur systems are used on folders is to shave some weight off. There are lots of hub options out there. You should determine your budget as that will quickly narrow the field (or keep it open to the high end too). Also determine what sort of gear range you want, as that might also greatly limit the field. Why did you purchase the P9 instead of the P7i (or other internal model)?

Use my Bike Friday-Rohloff a lot,

20" wheels 16:53t drive.

Thanks for the suggestion of the Alfin hubs, I'll look into them. It's a real shame about having to use a chain tensioner, that's a big reason I'd like to get the hub. I'm a noob with bikes so if you wouldn't mind filling me in with a quick as to why explanation I'd be really grateful please! Could I use half links like Dynocoaster suggests below with a Freedrive?

Great, thanks. I'm only around town at the moment and use three gears mostly but this is my only bike and I have very light touring plans for it. I'll take a look at the Sturmeys. Thank you for the suggestion.

Weight is something I'll need to consider. I already feel like the bike is a little weighty. I've been lugging it around trains and shops much more than I thought I would do. It would have made sense to get the P7i when I bought if I do the upgrade yes but the extra £125 was out of my budget at the time and the P9 had everthing I needed. As the bike has fast become more of a hobby than I thought it would, personal upgrades just appeal to me. I like to tinker :).

Thanks for the suggestion fietsbob, though I think Bike Friday stuff tends to be in the US. Another one to check out though :).

I'm in no rush at all, it's just something that seems like a worthy upgrade and would help me to learn more about bike workings.

I looked at the same kind of options when i had the Jetstream converted to hub gear, and I too was looking for a sleek, clean chainline.

You can get an eccentric bottom bracket, like they use on the strida, dont know how much they cost, or what external diameters are available, but you would have to be prepared to pay for some machining i would imagine.

A hub gear could probably be made to work with half links, but whether you would get optimum chain tension and how long it would be before the chain stretched and had to be replaced, I dont know.

I would suggest that if the clean line is important to you, and if there is a similar Tern that comes with a hub gear, then sell your bike and buy that now, because that may well be the only way you will actually get what you are looking for, anything else is a compromise.

Having been using Sturmey Archer 5 speed hubs for several years I'm still undecided as to whether they're keepers, they are bizarrely inconsistent in their performance. . . I may have tracked down most of the behavioural peculiarities to subtle specifics as to how they're serviced, but I've (even) more experimenting yet to do. I'd quite like to try a Nexus red band 8 speed / Alfine.

Nope. No machining required for some.

http://www.philwood.com/products/bbp...hilcentric.php
http://www.trickstuff.de/en/products/exzentriker_KL.php

http://farm4.staticflickr.com/3267/3...5841f436_b.jpg

I wouldn't buy an IGH for a vertical dropout bike and assume you'll be fine without a chain tensioner. There are some possible solutions: magic gear, Phil EBB, half links, but I have come across more than one unhappy rider who tried those solutions. If you can live with a chain tensioner go for it. You can always try and get rid of it and if you aren't happy you know you'll have a solution you are okay with.

I was able to setup my BF NWT with a Surly tensioner in push up mode [image above] - which kept the clean IGH chainline and worked with my vertical dropouts.

+1

-HANK RYAN-
Norman, Oklahoma USA

Thanks guys. Sounds like it may be more trouble than it's worth. Plus the added weight isn't ideal Though your set up looks great, Vik.

I like the bike too much to sell it to upgrade so I'll stick with the setup I have. Thanks everyone for your input!

Bike Friday has a Prototype 20" wheel design
where they relocated the rear fold pivot ahead of the BB.

so they can use the Gates Toothed belt drive..

that is already an option on the Tikit Folder.

As you see from Vic's picture the hinge is behind the BB, on the travel bikes.
so some sort of tensioner is needed..

I have a 2 pulley spring-loaded tensioner on mine..

This is just folder-itis getting a hold of you. You'll naturally just have to get a second folder with a hub gear.

Christ, I can easily see this happening :cry:.

Tern has bikes with internal hubs. You can sell yours and get one with an iHG.

Part of the reason I'm considering (considered?) the internal hub was because I saw the other models with one and thought I might be able to do something similar. I'm quite attached to the bike now so would rather do upgrades than swap.