converting a bike to use an IGH?

[martinn]

Hi all,

I have a aluminium frame sat in my shed, which has been on the cards to be converted to a load lugging bike of some description for a while.
its a ridgeback speed, and came with a derailleur 8 speed system.

I think to make this as close to a utility bike as possible, I was going to use a IGH. Rear spacing is 135
Is this
a) Possible
b) or am i better off purchasing a bike that is set up to take an IGH?

thanks

Martin

[cycle tramp]

Yes, its possible. I've done the same thing myself three times, I've also converted a hub only frame to deraileur gears.
Possibly to the second question, it all depends on your bike maintenance skills and what sort of rear drop outs your donor bike frame has and how you view your time...
....other transmission set ups you might wish to consider include a single speed. However if the bike already has an 8 speed deraileur I'm not sure if a hub gear is going to increase your gear range... if you are using it for loads and you live in place that's hilly you might want to think about keeping the 8 speed set up and adding a second chainring..

Have you a photo of the frame that you are prepared to show here, on this thread?

[slowster]

What bottom gear will you need? The answer to that question is likely to be decisive in determining which hub gears you could choose from.

My own experience is that for utility load lugging on non-flat terrain I need the same very low gears I would need for loaded touring, e.g. 20 inches or less.

[Tigerbiten]

It's possible but it depends on the back dropouts on how easy it is.
If the dropouts are vertical then you're into a fixed distance between the BB and the IHG.
If you're lucky then the chain will fit exactly with the correct chainring/sprocket combo.
If not then you can use a half link and/or chain tensioner to make up any difference.
If the dropout are horizontal/sloped then you'll have a bit it more leeway with chain length.
After that it's about how well the anti-turn washers fit.

Luck ........

[martinn]

hmm more questions to think of

I must admit I hadn't thought about the gearing ratios much, if at all.
The bikes I have are a fixed which has a gear inch of 74.5 (48x17), happy to do the more sedate hills round here on that
A steel long day ride, lowest gear 36/29

I would be happy with a small range of gears, would be a mainly a "go to the shops bike", which is flattish, but was thinking of IGH for the occasional snowy ride to work, which I can make relatively flat

The Frame has vertical dropouts, so would need tensioner

So its possible to do this but the dropouts might make it tricky to get the right tension.

Any thoughts on the IGH?
I did think of Sturmey Archer 5 speed, or the Alflin 8?

Thanks
Martin

[Brucey]

this is a 2018 model ridgeback speed



and if yours is like it, it has vertical dropouts.

Shimano make two chain tensioners for use with hub gears

CT-S510, which fits to vertical dropouts and replaces one of the NTWs (no turn washers), and is manually adjustable (fixed position once adjusted)


CT-S500, which bolts to conventional gear hanger and is spring loaded


In your case with VDOs you could use either. You should use CT-S500 if you are planning on using more than one chainring and a FD to extend the gear range. 135mm OLN is OK with a number of different hub gears; for a utility bike a three speed hub (with 3rd set to normal) or perhaps a Nexus 7 or Nexus 8 might be a good choice.

Remember that in Shimano IGHs you can also fit a low-maintenance roller brake at the rear (or not, on the same hub, oftentimes) or in sturmey archer gears their hubs are available with a reliable drum brake. This can add to the 'utility bike' feel of the whole thing.

cheers

[martinn]

Thanks Brucey

Yes thats what it looked like at one stage of its life.

The addition of a roller or drum brake is certainly worth considering.

Now just need to clear space in the garage...

many thanks

Martin

[gazza_d]

As most have already thought off and answered the usual questions.
If you haven't already got a hub either ready or in mind then Taylor Wheels in Germany do some excellent deals on ready built.wheels with IGHs built in. They have awheel with an Shimano nexus 8 with all the bits including a shifter etc for about £140 plus about a tenner for delivery. They do front/rear wheelsets too.
I would also suggest if you're considering a wheelset then spec a dynamo in the front hub and lights for even more utility appeal.

[mikeymo]

I've got 4 bikes with IGHs. Two with the roller brakes Brucey refers to. If you read reviews of roller brakes you might read negative comments. I think they're fine.

Yes, dropouts are sort of the issue. I never liked the idea of a chain tensioner, seems to mess up the concept of IGH to me. But that's me and my search for beauty in all things. All mine have semi-horizontal drop-outs.

You could try this:

http://www.eehouse.org/fixin/fixmeup.php

Which calculates a chainring/sprocket combination that will produce a taut chain, for a given axle to bottom bracket distance. Though I've never heard of anybody using it, and I expect it will rely on fairly accurate measurement of the chainstay.