Cycling UK Forum

geocycle wrote: ↑9 Jan 2024, 7:37pm A number of folk mentioned the Hebie chain glider. I used one for a year or so on a Thorn raven tour frame. It did a reasonable job of keeping the chain clean and the friction of the chain rubbing was tolerable. But, it made removing the rear wheel more hassle and when I changed to a narrower raven sport tour frame it wouldn’t fit. Given how little cleaning the chain on a rohloff needs and how long they last I don’t really miss it. I’ve no experience of a belt drive but would be interested in trying.

I don't see the point of belt drive. You have to have a more complicated rear triangle, and for what? To solve a maintenance problem that was never much of a problem anyway. Single speed chains can be stronger and more reliable than derailleur chains. And there is just one sprocket and one chain ring to deal with when cleaning. No dodgy chain lines, just nice low maintenance, low wear chain on teeth stuff. Where is the problem with that? I think some folk just imagine problems to justify new "solutions" that were never needed in the first place. The fact is, cleaning and lubing with a single speed (inc IHG) set-up is already very quick and easy, with a chain.

pwa wrote: ↑12 Jan 2024, 8:56pm

geocycle wrote: ↑9 Jan 2024, 7:37pm A number of folk mentioned the Hebie chain glider. I used one for a year or so on a Thorn raven tour frame. It did a reasonable job of keeping the chain clean and the friction of the chain rubbing was tolerable. But, it made removing the rear wheel more hassle and when I changed to a narrower raven sport tour frame it wouldn’t fit. Given how little cleaning the chain on a rohloff needs and how long they last I don’t really miss it. I’ve no experience of a belt drive but would be interested in trying.

I don't see the point of belt drive. You have to have a more complicated rear triangle, and for what? To solve a maintenance problem that was never much of a problem anyway. Single speed chains can be stronger and more reliable than derailleur chains. And there is just one sprocket and one chain ring to deal with when cleaning. No dodgy chain lines, just nice low maintenance, low wear chain on teeth stuff. Where is the problem with that? I think some folk just imagine problems to justify new "solutions" that were never needed in the first place. The fact is, cleaning and lubing with a single speed (inc IHG) set-up is already very quick and easy, with a chain.

IME whilst it is certainly easier to maintain a chain in an IGH or singlespeed setup, I don't think it is a coincidence that most chaincases are fitted to bikes with IGH's. IME a well lubricated chain of reasonable quality inside a chaincase can be expected to last 20K miles or so, far longer than if it is exposed. I blame chaincase designers for not making rear wheel removal easier/unnecessary and the cycle industry in general for not making a derailleur/chaincase combo that works and/or anyone wants to buy. IMHO either problem is readily soluble and the fact that you can't just buy something suitable shows just how much effort people have really made and it is a crying shame to boot.

One thing that should be bleedingly obvious about a belt drive but maybe isn't, is that there needs to be some way of opening the rear triangle so that you can put the belt on or take it off. No idea what's the best way of doing this, but I've seen 'splitter' type things. Yet another complication and added expense...

Brucey wrote: ↑13 Jan 2024, 1:53pm

pwa wrote: ↑12 Jan 2024, 8:56pm

geocycle wrote: ↑9 Jan 2024, 7:37pm A number of folk mentioned the Hebie chain glider. I used one for a year or so on a Thorn raven tour frame. It did a reasonable job of keeping the chain clean and the friction of the chain rubbing was tolerable. But, it made removing the rear wheel more hassle and when I changed to a narrower raven sport tour frame it wouldn’t fit. Given how little cleaning the chain on a rohloff needs and how long they last I don’t really miss it. I’ve no experience of a belt drive but would be interested in trying.

I don't see the point of belt drive. You have to have a more complicated rear triangle, and for what? To solve a maintenance problem that was never much of a problem anyway. Single speed chains can be stronger and more reliable than derailleur chains. And there is just one sprocket and one chain ring to deal with when cleaning. No dodgy chain lines, just nice low maintenance, low wear chain on teeth stuff. Where is the problem with that? I think some folk just imagine problems to justify new "solutions" that were never needed in the first place. The fact is, cleaning and lubing with a single speed (inc IHG) set-up is already very quick and easy, with a chain.

IME whilst it is certainly easier to maintain a chain in an IGH or singlespeed setup, I don't think it is a coincidence that most chaincases are fitted to bikes with IGH's. IME a well lubricated chain of reasonable quality inside a chaincase can be expected to last 20K miles or so, far longer than if it is exposed. I blame chaincase designers for not making rear wheel removal easier/unnecessary and the cycle industry in general for not making a derailleur/chaincase combo that works and/or anyone wants to buy. IMHO either problem is readily soluble and the fact that you can't just buy something suitable shows just how much effort people have really made and it is a crying shame to boot.

I used to have a MZ 250 which had a fully enclosed chain. The top and bottom runs were made of flexible plastic with bellows at either end to facilitate chain adjustment. The rear sprocket was carried in its own bearings with a cush drive which engaged with the wheel. To remove the wheel, the spindle nut was unscrewed, a spacer removed (which allowed the wheel to pull out from the cush drive), the torque arm and brake rod unfastened and that was it! The sprocket and chaincase assembly remained bolted to the RH swing arm, From memory, I think other Eastern Bloc motorcycles had the same kind of arrangement. I was so impressed with the zero maintenance and cleanliness of the design that my next bike was a Moto Guzzi - shaft drive being the next best solution to exposed chain drive barbarity.

There is no reason that this type of design could not be adapted for bicycle use for IGH and single speeds. I am even getting a slight urge to look into it myself.

"Why though have Rohloff so doggedly stuck with that twist-grip shifter?" I often thought this, until I got one.

I agree with Brumsters response to this.
Generally I don't like twist grips (on derialleurs), but I find the Rohloff one ok. It is simple (just a smooth seamless action within the lever (the indexing is in the hub), and changing multiple shifts is easier than with a trigger type set up. So far it has been a very light action. If I so choose, I can grip the lever between the end of my thumb and end of my index finger and shift with no effort.

The only annoyance with the Rohloff shifter is where the gear numbers are. On a flat bar, no problem. I have mine on the end of drop bars with the cables coming out sideways. Thus the reference point and associated gear number is on the right side of the lever, not visible while riding. The lever design is such that you can't move the rubber (and numbers) round by 90 deg or so (which you can on a grip shift rubber). I make do for now with using the lever clamp bolt head as the reference point, and subtract 3 from the lined up number. In reality, I only really want to know the gear number to check if I am in my cruising gear (11).

The elephant on the room is that you can't use dropped bars, which many or most UK touring bike buyers will want. Well, you can use dropped bars, but the solutions are not elegant. The least obtrusive is the VN split bar and stem, but you have to trust a bar that splits at its most highly-stressed point, and it's not the ideal location for a shifter.

No elephant in my room!
I used a Hubub adaptor or what ever it is called. Cut a small length off the end of the bars, fit the adaptor (internal wedge) and then the lever on the adaptor. Once the bar tape is on, you don't see anything different. The twist grip on the end is no more intrusive (kneewise) than the bar end shifters on my other bike (which isn't a problem, for me at least).
For those who have not used bar end levers, it isn't really a case (for me at least) of reaching down for the lever, more a case of swinging my arm down to the lever.

I too would be sceptical about split bars for a tourer.

rogerzilla wrote: ↑14 Jan 2024, 7:37amThe elephant on the room is that you can't use dropped bars, which many or most UK touring bike buyers will want. Well, you can use dropped bars, but the solutions are not elegant.

Sure you can. Here's what I made up for my touring bike about 25 years ago. That setup has worked well ever since - the shifter is in the same position as a barend shifter:

1. I turned down part of a section cut off an old MTB flat bar so that it was a slip fit inside the end of my drop handlebars, and used Loctite 641 to bond it into the RH end of the handlebar. These days, the Hubbub adapter is a commercial equivalent: https://www.sjscycles.co.uk/gear-spares ... rip-73-mm/. 2. Mounted the shifter to this section, and ran the shift cables around the front of the headtube and along the top tube to the Rohloff mount on the LH cantilever post. I used Sachs twin cable zip ties to run the cables along the top tube. The cable holder on these has a snap fastening and can be popped open if the cables need to be removed. Nowadays several companies market drop bar shifter setups for Rohloff hubs. The Gebla Rohbox (http://www.rohbox.com/) uses modified SRAM doubletap shifters to change gears on a Rohloff, and Co-Motion and Gilles Berthoud have twist shifters that mount next to the stem.
https://co-motion.com/collections/store ... hub-500-14
https://berthoudcycles.fr/en/1196-twist ... ilver.html

sorry, but I agree with the 'not elegant' comment. I had planned to make my own shifter; bits bought, design finished and everything.

Jezrant wrote: ↑12 Jan 2024, 5:24pm ...

Why though have Rohloff so doggedly stuck with that twist-grip shifter? It's not as if they haven't had the time to come up with something better.
...

Pinion also uses the same system with two cables and a twist grip. They have bent the cable exits from the shifter. See DS2 ROTARY SHIFTER and scroll down a bit.

Is it a coincidence that both gear systems that use internal indexing and two cables are German? The one cable plus spring system originates with French derailleurs and like much on bikes was just copied with no thought for decades.

a spring-loaded single cable system is usually cheaper, simpler and lighter than a twin cable setup. The rohloff is a bit of a throwback in this respect. Nonetheless I think it should be possible to use a single cable setup with an unmodified hub (ie. with the indexing where it usually is) if you go about it in the right way.

Deleted

Good choice

Image

That is a really nice bike! What size is it, and what size wheels?
Thanks!

cycle tramp wrote: ↑14 Jan 2024, 6:58pm

Brucey wrote: ↑14 Jan 2024, 6:18pm a spring-loaded single cable system is usually cheaper, simpler and lighter than a twin cable setup. The rohloff is a bit of a throwback in this respect. Nonetheless I think it should be possible to use a single cable setup with an unmodified hub (ie. with the indexing where it usually is) if you go about it in the right way.

Having used a rolhoff hub over several thousand miles, I doubt that a spring loaded cable system will be lighter, after all, the lever of the spring mounted system who have to have enough friction to over come the tension of the spring - should that tension fail, then the hub will then move to either the highest or lowest gear depending on how the spring is set. Whilst the twin cable design may not look 'nice' it works, and needs very very little maintenance. I can't see a single cable being any cheaper either...

The twin cable idea does work, and the indexing is at the hub end so doesn't go out of adjustment like other IGHs can. Bomb-proof gear changing.

cycle tramp wrote: ↑14 Jan 2024, 6:58pm Having used a rolhoff hub over several thousand miles, I doubt that a spring loaded cable system will be lighter, after all, the lever of the spring mounted system who have to have enough friction to over come the tension of the spring -.

no it doesn't. The indexing in the hub will greatly lower this force. In fact if everything works out, you won't be able to select a 'between gears' position because it will always shift by itself until it gets to another index point. For example, suppose it takes 8lbs force to overcome the indexing detents and the spring delivers 10lbs force; the lever only has to contribute about 2lbs in friction, and it will stay put in one gear once that gear is selected. Let's say the lever is set to provide 2-5lbs frictional force.

If the hub is in is in good shape it'll need very little force to move between detents. This is the usual state of affairs with a rolhoff hub, so let's say you only need ~2lbs cable tension to get it to move once you are between detents. Now the spring has about 8lbs force in hand; if this 'overforce' is always in excess of the lever's frictional force (which we have already set to be between 2 and 5lbs) then the spring will automatically pull the lever until you hit the next detent position., which I call autoshift.

Should the cable (singular, note) ever go bad the autoshift ought to be the first thing that stops working properly. No problem, you will just have to give it a helping hand pending a cable service.

Similarly if the spring ever gets a bit feeble, it should be noted that the cable force required to go through a detent position without stopping is usually considerably lower. This means that by fiddling with the gear lever you may be able to live with a failing spring for a short time, pending a proper repair.. My plan was to install a so-called 'constant force' spring inside a CF reaction arm. Accordingly I have obtained a suitable CF tube (originally part of a golf umbrella, and cheaply made via 'pultrusion' I think) and if I ever get better, it'll be high up on my 'things to do' list..I also plan to integrate a brake caliper with the reaction arm, making it very difficult to lose centre on the brakes when the wheel is out as well as greatly extending the range of frames which will accept the hub.

In theory the use of a spring like this should not impose a very great increase in the fatigue loadings in the shift cable, because the load during shifting is the same as ever, and the rest of the time the load is constant. This will need to be proven though.

I think that the goals of improved simplicity, weight and cost are well within reach. I even know which bits to buy for this conversion, despite the fact that making a thumbshifter pull about 100mm of cable ain't exactly easy..