Author Topic: New member  (Read 380 times)

Smiffy

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New member
« on: August 15, 2018, 08:46:39 PM »
Hi guys,

I am new to this group but have just bought myself a used Raven with lots of goodies on it including a full set of Ortilieb pannier bags !

Attached is a picture of it in the front room because I have yet to insure it so canít leave it in the shed.

It was expensive, but in mint condition with no signs of use.

Plan to get myself fit ( for a 59 yr old ) and take it to France for a bit of gentle cycle camping.

It came with a 19 tooth rear sprocket , does that sound right ? Feels very low geared.






Danneaux

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Re: New member
« Reply #1 on: August 15, 2018, 08:56:36 PM »
Welcome to the Thorn Cycling Forum, Smiffy!

Looks like you scored yourself a winner in your fully equipped new Raven -- what a beauty!

The 19t cog will pay off in extended chain and sprocket life, but may result in gearing too low for your needs. The easy solution would be to fit a larger chainring. Keep in mind if you later wish to fit a Hebie Chainglider, they are only available in certain chainring sizes.

All best wishes for many happy miles.

Dan.

Smiffy

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Re: New member
« Reply #2 on: August 15, 2018, 09:09:06 PM »
Thank you Dan.
Is it usual that they are specced with such low gearing ?
I guess it was chosen to suit a fully loaded tour.
I will keep it as it is until I know what I am doing.

mickeg

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Re: New member
« Reply #3 on: August 15, 2018, 09:51:11 PM »
New Rohloff hubs are usually fitted with a 16T sprocket, Thorn/SJS usually use a 17T.

Since you bought this used, I assume that the rear sprocket is threaded onto the hub.  Recently Rohloff started shipping hubs with a splinned carrier and the sprocket is splinned and held on with a spring clip.  But yours is probably the older threaded on sprocket.

I agree with Dan that you can change the chainring.  If you buy a larger chainring, you will need a longer chain.

Then at a later date when you need a new sprocket, you can keep using a 19T but you would likely have to invest in the splined carrier at that time too.

I use a 44T chainring and 16T sprocket for around town riding on my Nomad, but on a bike tour where I might have to haul a heavy load up steep hills I instead use a 36T chainring with a 16T sprocket.

Regarding gearing, there is an extremely long thread with an extraordinary number of opinions expressed at:
http://thorncyclesforum.co.uk/index.php?topic=4412.0


martinf

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Re: New member
« Reply #4 on: August 15, 2018, 10:28:37 PM »
That chainring looks as if it is 40T. If so, you do have very low gearing with 40x19 giving about 15" to 79", if you use 50 mm width tyres.

Personally, I would be quite happy with that gearing for a loaded touring bike. My own Raven Tour is geared a bit higher with 38x16 (17" to 89") because when I bought it in 2012 Rohloff did not recommend such low gears (they changed their recommendation later). I very rarely use the 89" highest gear.

If the gear range doesn't suit you, instead of changing the chainring you also have the option of changing the sprocket. The screw-on type can be hard to remove.

I use a Chainglider in order to reduce chain maintenance. That is currently only available in the Rohloff compatible version for 15T to 17T rear sprockets and 38T, 42T or 44T chainrings, so not an option unless you change both chainring and sprocket.

Smiffy

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Re: New member
« Reply #5 on: August 15, 2018, 10:48:57 PM »
Yes , I have just checked , it is a 40t.

Iím not too bothered by low gearing , Iím not the strongest, and when itís loaded I will probably be thankful.

Better too low than too high I suppose.

mickeg

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Re: New member
« Reply #6 on: August 16, 2018, 12:56:46 AM »
One more thing, there is a special tool that is needed to remove a threaded sprocket.  If at a later date, you want do to that yourself instead of have a shop do it, a large wrench and chain whip would also be necessary.  Or maybe a big vice instead of the large wrench.  (I am in USA, we say wrench, you probably instead say spanner.)
https://www.sjscycles.co.uk/tools/rohloff-sprocket-removal-tool-inc-a12-adapter-for-135-142-170-177-mm-hubs-8508/?geoc=US

Once you get a splined carrier on the hub, you might never have to remove that since the sprockets would be held on with a spring circlip.

In the photo, the special tool I mentioned is on the hub and held on with the skewer.  Smaller tools might work to, but since I had some big tools, that is what I used.

I am not sure how handy you are with tools, I worked as a bike mechanic years ago so I do almost all of my own work on my bikes.

John Saxby

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Re: New member
« Reply #7 on: August 16, 2018, 02:34:23 AM »
Welcome, Smiffy, and enjoy your nice bike!

My Raven is now in its fifth season, and I've found it to be a comfortable, versatile, and robust bike.  I use it for loaded touring, lighter touring, and day rides.

There's a thread on Rohloff/chain ring ratios on the forum, here: http://thorncyclesforum.co.uk/index.php?topic=4412.0

Once you get some miles/hours/kms on your bike, you might find it useful to read about our experiences with these bikes and hubs.

My own experience, for what it's worth: I started with a 17t sprocket x 38T chainring.  After a season and a half, I switched to a 36T ring at the front.  I've found that the lower gearing works very well for me.  The difference is only about 5%, but I now spend much more time in the upper register, with gears 8 - 11 being the most commonly used. 

With my 1.6 Supremes, this gives me a gear-inch range of 15.2 to 80.  The low gear lets me climb just about any hill, loaded or unladen, and if I spin out in 14th going downhill, then I just coast. (The racket of the freewheel in 14th keeps the bears away.)

Like a number of people on the forum, I use a Hebie Chainglider.  My 'glider is intended for a 38T ring, but I've modded it slightly so that it fits my 36T item.  A note, though:  using a 'glider requires a chainring that's within the 3 mm maximum specified by Hebie. I use a Surly stainless-steel item, 2.5 mm thick.

Good luck with it all, in any case, and if you have any questions, I'm sure you'll find the Forumistas to be helpful and knowledgeable.

Cheers,  John

Smiffy

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Re: New member
« Reply #8 on: August 16, 2018, 07:52:47 AM »
Many thanks for helping me to begin to understand sprocket ratios.

I will leave it as it is until I get experienced.

Just one thing , I have attached a picture of the rear sprocket.

If you can make things out could you let me know if it is screw on type or the latest circlipped type.

I wonít bang on any more about sprockets here as I now now there is a thread for that.

Special thanks to John Saxby for his advice, to know that the clicking when freewheeling scares bears away is a great comfort to me should any bears in the South West of England take an interest in me whilst cycling ,, 😂😂😂

I never expected to learn that when I posted a photo ....

Danneaux

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Re: New member
« Reply #9 on: August 16, 2018, 09:15:28 AM »
You have the screw-up sprocket, Smiffy. It looks stunningly clean in your excellent photo.

Best,

Dan.

John Saxby

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Re: New member
« Reply #10 on: August 16, 2018, 02:24:10 PM »
Very clean indeed, smiffy -- you'll have to do something about that!

Given the hills in your neighbourhood (I was born in Dorset), I'd stick with your current gearing for the mo'. 

If things get too sedate, you could maybe contact Parks Canada to see if they have any rogue bears who need relocating. 'course, you could come visiting in these parts to check out the interplay of Rohloff freewheels & wildlife.

Enjoy,

John 

Smiffy

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Re: New member
« Reply #11 on: August 16, 2018, 02:58:02 PM »
Canadaís on my bucket list John , so maybe one day..
The hills around here where we live are severe.
We live in South Devon in a seaside location in a very deep river valley.
Options for cycling at this stage are to put the bike in the car and drive to somewhere sensible !
Hoping for good weather this weekend to start the training !!
Regards Smiffy