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Gearing help for our Raven Tours

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gregmacc:
Hi all ... my wife and I have recently had a pair of Raven Tours shipped out to us here in Australia. We are extremely happy with the bikes and the excellent customer service provided by SJS. The only thing we are thinking of changing is the gearing. We went for the 17/40 sprocket/chain-wheel combo but after some initial rides around our hilly neighbourhood we believe we will be running out of low gears when fully packed and touring. So we are considering getting a couple of 39T chain wheels sent out. I'm just wondering if there are any issues I need to consider. I'm assuming I will need to adjust the EBB or maybe even remove a chain link. Is there anything else I should be aware of?
Cheers
Greg

rualexander:
I believe that using 17t sprocket and 40t chainring gives you the lowest gearing that remains within Rohloff's recommended limits, therefore if you use a 39t chainring with the 17t sprocket you may invalidate your warranty, although you are unlikely to suffer any ill effects with such a small change in the syatem.

JimK:
If you're going to the fuss of buying new chainrings, and invalidating your warranty on top of that, I would push further, to the 38 tooth chainring. Each step of the Rohloff is about 13%. Moving from 40 to 39 is 2.5%. I suspect it'd be hard to notice. Moving to the 38 would be 5%.

I have the 38 in the front... I do get tempted to put the 17 tooth sprocket in the back. I notion that I could over-torque the hub is a bit ridiculous!

Danneaux:
Hi Greg,

Congratulations to you and your wife on the new Raven Tours!

I notice Andy Blance has issued an Autumn, 2011 update for his online publication, "Living With A Rohloff Hub".  It is available for download as a PDF here:

http://www.thorncycles.co.uk/thornpdf/ThornLivingWithARohloff.pdf

Page 24 has a nice chart showing various chainring/cog combinations for the Rohloff, and makes clear what constitute "unadvised" ratios, shows at which point (in gear-inches) the 7-8 shift occurs, and where the various ratios place direct-drive 11th gear.

I found it a nicely done piece of work and it answers in one place several questions that have occurred to me.

Hope this helps,

Dan.

gregmacc:
Thanks people ... Yes rualexander, I'm aware or the warranty issues but we are both lightweight/average in the leg strength/weight  department. From what I can gather from the Thorn  documents we would need to be built like gorillas to overly stress the hubs.
On second thoughts, Jim's suggestion of the 38T chainring sounds like a more sensible choice.
Dan ... thanks for the link ... I've been looking at the previous PDF for a while now. The new charts are a worthwhile update. It's all pretty clear ...
Cheers
Greg

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