Thorn Cycles Forum

Community => Rohloff Internal Hub Gears => Topic started by: steve216c on April 16, 2021, 06:53:09 pm

Title: DIY Rohloff sprocket removal tool - 3 solutions
Post by: steve216c on April 16, 2021, 06:53:09 pm
When I bought my bike I'd already found this link http://ragun.com/Rohloff/RohloffSprocketTool.htm (http://ragun.com/Rohloff/RohloffSprocketTool.htm) on how to fashion your own sprocket removal tool. Always one up for a challenge I made one following those instructions. And it worked.  ;D

However I was pondering on how one might improve this DIY design. And I think I just made something that at least looks a bit prettier and that also works. In my opinion, it is also easier to securely grip than my first attempt given the nut head fitting is better formed than the previous adapter pipe I used to make first attempt.

There is a 3rd way with CNC custom tool. Not tried this and the costs would be similar to actually buying the original. But the CAD diagram is useful in marking up the correct measurements  as I will show in my photos that follow.
I have photographed each step. I hope this is self explanatory for any of you with a hacksaw and a sense of adventure.

First comparing my old and new DIY sprocket tools following the guide on link at start of post:
(https://live.staticflickr.com/65535/51119229329_c6793e5940_z.jpg)

first tool made using guide from ragun's site
(https://live.staticflickr.com/65535/51119391123_1a5278d42b_z.jpg)
(https://live.staticflickr.com/65535/51119224149_64c255513b_z.jpg)
(https://live.staticflickr.com/65535/51118886537_ed420b73da_z.jpg)






Title: Re: DIY Rohloff sprocket removal tool - 3 solutions
Post by: steve216c on April 16, 2021, 07:10:52 pm
Now for how I made tool number 2.

Firstly print out the CAD design on a4 paper so dimensions are correct using link: http://ragun.com/Rohloff/CNCabzieher.pdf (http://ragun.com/Rohloff/CNCabzieher.pdf)
find or buy a pipe connecting nut (not expensive) like the one I found in my shed from an old garden water pump filter set. Then follow the instructions as per photos:
You will also need a large washer bigger than the tool so your QR skewer can hold the tool in place when using it.

You'll need scissors, glue stick and marker pen to do ground work:

(https://live.staticflickr.com/65535/51119458341_e04a21b9af_z.jpg)
(https://live.staticflickr.com/65535/51119479926_dbd3328a1b_z.jpg)
(https://live.staticflickr.com/65535/51119475266_9d5db57040_z.jpg)
(https://live.staticflickr.com/65535/51119459106_bf8260cc2e_z.jpg)
(https://live.staticflickr.com/65535/51119229269_1bf3e44299_z.jpg)
(https://live.staticflickr.com/65535/51119224144_51d751fca6_z.jpg)
(https://live.staticflickr.com/65535/51119483826_c04256083a_z.jpg)

and then you will need a small saw and a file (or Dremel if you have one):

(https://live.staticflickr.com/65535/51119483366_9da3e6442f_z.jpg)
(https://live.staticflickr.com/65535/51118906782_dc8d3b6c91_z.jpg)
(https://live.staticflickr.com/65535/51119210804_71a4e13e9f_z.jpg)
(https://live.staticflickr.com/65535/51120273510_3ca29791f3_z.jpg)

"on yer bike Steve- that'll never work" .... but it does  ;D ;D ;D

(https://live.staticflickr.com/65535/51118901217_d72afbb9b3_z.jpg)
(https://live.staticflickr.com/65535/51118886462_8e8a52b11d_z.jpg)
(https://live.staticflickr.com/65535/51120265165_9979c23e87_z.jpg)
(https://live.staticflickr.com/65535/51120273365_9394b43149_z.jpg)

The whole job took less than an hour from start to finish. So you could order the genuine tool online and wait till it arrives. Of you could have some fun making your own, or having a spare for a tour that you won't cry if you lose it. And if you don't like it, you can still buy the original.










Title: Re: DIY Rohloff sprocket removal tool - 3 solutions
Post by: Danneaux on April 16, 2021, 08:46:50 pm
My! What a nicely done photo guide, Steve.  :)

All the best,

Dan.
Title: Re: DIY Rohloff sprocket removal tool - 3 solutions
Post by: PH on April 16, 2021, 09:55:16 pm
Nicely worn sprocket as well!
Title: Re: DIY Rohloff sprocket removal tool - 3 solutions
Post by: steve216c on April 16, 2021, 10:12:13 pm
Nicely worn sprocket as well!

I already have a splined carrier and socket to replace it with. But I want to reach at least 10,000 km first on the reversed sprocket, and then will either swap it on my next oil change or keep it going till the chain starts misbehaving. Either way, I have 2 tools now to remove it with plus all the parts ready for when the time comes, so im all set.
Title: Re: DIY Rohloff sprocket removal tool - 3 solutions
Post by: mickeg on April 20, 2021, 11:01:11 pm
If your sprocket was pretty tight, not sure if your tool would take the stress.  But there is nothing wrong with using it as long as it works, and maybe it will last forever.

But some have found that the sprockets are very hard to get off.  My point is that the Rohloff tool, while expensive is a solid piece.  I find that removing the sprocket is pretty easy with large tools so you have plenty of leverage.  I use a half meter long adjustable wrench and a good sized chain whip on my Rohloff tool. 


Title: Re: DIY Rohloff sprocket removal tool - 3 solutions
Post by: steve216c on April 21, 2021, 11:22:23 am
If your sprocket was pretty tight, not sure if your tool would take the stress.  But there is nothing wrong with using it as long as it works, and maybe it will last forever.

But some have found that the sprockets are very hard to get off.  My point is that the Rohloff tool, while expensive is a solid piece.  I find that removing the sprocket is pretty easy with large tools so you have plenty of leverage.  I use a half meter long adjustable wrench and a good sized chain whip on my Rohloff tool. 


You are not wrong on such concerns. My first attempted tool was able to remove my socket which was pretty tight. But I was able to do this twice without concern. However on assisting a friend with his sprocket reversal I found that I had to grip the tool's nut so tightly with a pipe wrench that the metal on the tool deformed slightly under that pressure. It was no longer perfectly round and needed to be teased back into shape  to grip all 4 points on the Rohloff nut. I was able to complete the job but realized that the metal (presumably copper alloy mix) of the tool was a weak point that could limit the usefulness of future attempts.

The 2nd tool made from a nut is intended as an improvement. Firstly it allows more stable grip with a wrench/spanner, and the inner screw threads probably increase the structural integrity to stop it bending. Additionally, it was much more of a pig to file down than the first attempt, suggesting the metal of tool number 2 is somewhat harder than the first tool- and hopefully less likely to fail in use.

I am in no doubts that a branded Rohloff tool is going to be the best solution for a tool for life. But once I switch out to a splined carrier later this year I cannot imagine I will have so much need to use the tool after that. I just like to cheat the system every now and again- and challenge the ol' grey cells to alternate solutions to problems most people aren't even looking to solve but which are rewarding in their own special way. Mr Kipling might make extraordinarily good cakes, but making my own are more enjoyable and rewarding than buying his  ;)
Title: Re: DIY Rohloff sprocket removal tool - 3 solutions
Post by: leftpoole on April 22, 2021, 08:58:40 am
Excellent! I bet that you are intending on a takeover bid for Rohloff?  ;D ;D ;D
Title: Re: DIY Rohloff sprocket removal tool - 3 solutions
Post by: steve216c on April 22, 2021, 12:17:24 pm
Excellent! I bet that you are intending on a takeover bid for Rohloff?  ;D ;D ;D

You found me out! First the shed built tool, and next week I will post photos of my belt driven hub alternative made from two cottage cheese tubs and some Royal Mail standard issue wide rubber bands with a bonus 15th gear thrown in for free. And all that for less than a fiver  ::)

You think the Rohloff's are nervous? The Pinion's down the road are already boarding up their factory windows.
Title: Re: DIY Rohloff sprocket removal tool - 3 solutions
Post by: leftpoole on April 23, 2021, 10:04:54 am
Excellent! I bet that you are intending on a takeover bid for Rohloff?  ;D ;D ;D

You found me out! First the shed built tool, and next week I will post photos of my belt driven hub alternative made from two cottage cheese tubs and some Royal Mail standard issue wide rubber bands with a bonus 15th gear thrown in for free. And all that for less than a fiver  ::)

You think the Rohloff's are nervous? The Pinion's down the road are already boarding up their factory windows.

Regarding the inside space of your shed. I have the solution! My bikes are indoors safe sound warm and clean. Loads of room now in the shed.
Love the idea of those Cottage cheese tubs, but, I think Yoghurt pots are stronger. Just a thought  ::) ::) ::)
Title: Re: DIY Rohloff sprocket removal tool - 3 solutions
Post by: AndrewJ on August 07, 2021, 01:48:10 am
It seems a rite of passage here to put one’s hand to a homemade cog tool. Here’s mine, I wanted to replace the 16T threaded cog, and splined cogs are what I can buy. I found an iron plumbing nut, and cleaned it up on my humble Chinese lathe & mill. The interior was bored to 28mm, I trimmed the exterior threads a bit, and then milled four 6m teeth. It worked a charm and I now have a 17T cog, a better mate for my 46T chainring.

That 2.706 ratio converts to 0.755 low and 3.970 high with the Rohloff, a better range than my half-step + granny road bike with its 0.800 low and 3.538 high. I might go even lower, to a 42:17, but will let that come after breaking in the new bike for several hundred miles of local flats and hills.
Title: Re: DIY Rohloff sprocket removal tool - 3 solutions
Post by: steve216c on August 07, 2021, 07:13:08 pm
Nice post Andrew. My power tools are a little more limited than yours, which you can see from how yours looks better finished than my initial attempt using similar piping.

What we really need is a Rohloff swiss army type took, with all foreseeable options for cogs, brakes, headset, chain and puncture repair that can be carried in your back pocket and doesn't weigh more than a box of TikTacs.  :o ;D