Cycling UK Forum

plancashire wrote: ↑8 Jan 2024, 6:06pm My tout terrain Rohloff 700c was delivered with 42x16T [20-104"] and I changed it later to 38x16T [18-94"] which gives 64" in direct drive. It got me up some short seriously steep hills recently - I had some of my wife's luggage too. I have an eccentric bottom bracket which works well. A 38x17T setup would give 17-89". This is all a lot more comfortable than my 12 gears on the Wester Ross of 27-108".

tout terrain fitted their own brand (Cinq) ratchet box and paddle shifters on my drop bars. Push one paddle for up, the other for down. There is no indicator of which gear I am in but who cares - in almost all circumstances there is another one when I want it. I think tt now fit brifters.

I hope you enjoy many miles on your new bike. Riding around town is so much easier than with derailleurs.

I have one tip and a comment: practise removing and replacing the rear wheel at home so you can do it on the road in the dark with cold fingers, which is when punctures usually happen. Oil change is easy. Make a note in the service book. Rohloff now recommend half the amount of oil and flushing fluid they did before. The bottles remain the same size I believe.

Still 25 ml of flushing oil, but now only 15 mm of lube oil.

pwa wrote: ↑8 Jan 2024, 6:18pm

slowster wrote: ↑8 Jan 2024, 3:23pm Edit - crossed posts with PH.

From https://www.stanforthbikes.co.uk/skyela ... hloff-home:

Screenshot 2024-01-08 at 14-58-18 Skyelander Rohloff.png

Thorn frames use eccentric bottom brackets, but Kevin Sayles, who was formerly their in-house custom frame builder, reportedly prefers sliding dropouts, and that is what he uses on the custom Rohloff frames he builds for Woodrup (https://www.woodrupcycles.com/bespoke/).

Thorn's eccentric bottom brackets do work, in a crude sort of way, but for purists they have the drawback of altering the effective seat tube angle every time you adjust the tension of the chain. The bottom bracket moves relative to the saddle and everything else on the bike. So your finely tuned seating position goes out the window.

Interesting.

pwa wrote: ↑8 Jan 2024, 6:18pm

slowster wrote: ↑8 Jan 2024, 3:23pm Edit - crossed posts with PH.

From https://www.stanforthbikes.co.uk/skyela ... hloff-home:

Screenshot 2024-01-08 at 14-58-18 Skyelander Rohloff.png

Thorn frames use eccentric bottom brackets, but Kevin Sayles, who was formerly their in-house custom frame builder, reportedly prefers sliding dropouts, and that is what he uses on the custom Rohloff frames he builds for Woodrup (https://www.woodrupcycles.com/bespoke/).

Thorn's eccentric bottom brackets do work, in a crude sort of way, but for purists they have the drawback of altering the effective seat tube angle every time you adjust the tension of the chain. The bottom bracket moves relative to the saddle and everything else on the bike. So your finely tuned seating position goes out the window.

As you say ‘purists’ might be aware of the position change, I’m certainly not. It is a very small change done incrementally. The EBB work fine and make things simpler and cleaner at the rear. I’d agree that mine is crude, basically a lump of aluminium secured by pointed bolts and will not please the weight conscious. The more recent versions used by Thorn are less agricultural.

I'd not worry too much about eccentric BB's. I've been using them on tandems since the mid 90's and really can't tell the difference when in use. Maybe I'm just not a sensitive soul or mebbies the effects are a bit exaggerated. Who knows?

Oxford Bike Works make the point that they fit the sliding rear rather than an EBB because:

Eccentric bottom brackets are heavy and are located in an area where lots of dirt and grime collects. To retension the chain using this method takes time, effort and cleaning, and means you're more likely to take it to a shop to have it done. By using sliding dropouts, its a 5 minute job that can be done by almost anyone with an allen key.

Rotating an eccentric bottom bracket changes the position of the pedals in relation to your saddle. For some people who are particularly sensitive to changes in saddle position, this can be a disadvantage.

We route our cables under the bottom bracket, along the non-driveside chainstay to the exchange box. The other alternative is over the V Brake bosses, creating a snagging hazard on clothes, panniers and the like. It’s just too exposed here, much better tucked away under the frame.

as a friend of mine might say, 'well those must have hit every branch on the way down, eh?' Then again beauty is as beauty does, so......

Bonefishblues wrote: ↑9 Jan 2024, 10:27am Oxford Bike Works make the point that they fit the sliding rear rather than an EBB because:

Eccentric bottom brackets are heavy and are located in an area where lots of dirt and grime collects. To retension the chain using this method takes time, effort and cleaning, and means you're more likely to take it to a shop to have it done. By using sliding dropouts, its a 5 minute job that can be done by almost anyone with an allen key.

Rotating an eccentric bottom bracket changes the position of the pedals in relation to your saddle. For some people who are particularly sensitive to changes in saddle position, this can be a disadvantage.

We route our cables under the bottom bracket, along the non-driveside chainstay to the exchange box. The other alternative is over the V Brake bosses, creating a snagging hazard on clothes, panniers and the like. It’s just too exposed here, much better tucked away under the frame.

I think OBW is exaggerating the disadvantages of an EBB:

1. The small change in saddle position relative to the pedals after adjusting the EBB has never bothered me, i.e. I have not had to adjust the saddle height. Even if I did, it is no big deal/major project/hours of faffing.

2. I cannot recall snagging anything on the cables as described. This sounds like imaginative waffle to me.

I agree that Thorn's original EBB could be described as ugly/agricultural/heavy and it needs a 15mm spanner and a pin spanner (combined in Thorn's special tool) to adjust it. As for it collecting grime; that's true but again no big deal, just clean it occasionally.

I guess that a disadvantage to a sliding drop-out is that you may have adjust the fitting of the rear mudguard or rim brakes (if fitted) after adjusting the former. Now that does sound like a few hours of faffing to me unless you allow a generous gap between tyre and mudguard (which is fine by me). May be users of a sliding drop-out on a bike with mudguards would like to comment.....

Maybe a Gates Belt is the way to go?

Stands back as the lid of the worm can creaks open

“Mis-aligning sliding dropouts is a job which can be done in 2 minutes by anybody with an Allen key”
Friend of mine has a Rohloff/ sliding dropout bike, his wheel is always cock- eyed.
On the other hand, eccentric BBs held by 2 pointy bolts are awful, there are several better ways

Bonefishblues wrote: ↑9 Jan 2024, 10:27am Oxford Bike Works make the point that they fit the sliding rear rather than an EBB because:

I have a real dislike of OBW's publicity. It's far more focused on being critical of what they don't use than extoling the virtues of what they do. I don't mind that a manufacturer tells me they're the best, I'm not in the least surprised that opinions vary and they come to different conclusions, I wouldn't expect them to be in business if they didn't think they had something better to offer. I'd just rather a positive attitude about what they offer than a negative one about what they don't. The World according to Thorn is of course in a different league, they go to the extremes of positive and negative, though at least in equal measure. Their redeeming feature is the way they back-up their product, I had a 100 days to try their EBB.

Before Thorn started doing Rohloff bikes I talked to a well known Derby framebuilders, they were also against the idea of an EBB in a solo bike. When I asked why that didn't apply to the tandems they'd been building for fifty years, the reasons were apparently too complected for them to explain in a way I might understand, I didn't buy from them.
I did buy a Thorn with an EBB a couple of years later. I carefully set it up with the BB in the middle position, for my perfect fit, so +/- 6mm for the full throw, then quickly found I didn't notice. There's probably that much difference in the other variables, shoes, clothing, where I sit on the saddle and since moving to flat pedals, even where I position my feet.

rotavator wrote: ↑9 Jan 2024, 11:44am May be users of a sliding drop-out on a bike with mudguards would like to comment.....

I've had sliding dropouts on a Kona Alfine and horizontal ends (I've been told off for calling them dropouts, because they don't) on a Surly with Rohloff. Mudguards are no big deal unless you're obsessive about the aesthetics, I set them on the Kona with the wheel in the rearmost position and on the Surly to come out with a deflated tyre.
The Kona had a disc brake fitting on the sliding drop out, the Surly needed the disc brake adjusting when the chain was tensioned.

531colin wrote: ↑9 Jan 2024, 11:58am On the other hand, eccentric BBs held by 2 pointy bolts are awful, there are several better ways

I thought mine was awful till I grasped how to best use it. I wrecked the first one in the usual way, micro adjustments and indents so close that the bolts slid between them. By the time I got a replacement, I'd realised how much variation in chain tension a hub gear can tolerate. Making just three indents and taking care to re-use them made it a lot easier to live with, though the clamp type is easier still.

rotavator wrote: ↑9 Jan 2024, 11:44am I guess that a disadvantage to a sliding drop-out is that you may have adjust the fitting of the rear mudguard or rim brakes (if fitted) after adjusting the former. Now that does sound like a few hours of faffing to me unless you allow a generous gap between tyre and mudguard (which is fine by me). May be users of a sliding drop-out on a bike with mudguards would like to comment.....

the exact same 'problem' has existed on every SS/IGH bike with mudguards I have ever had (which is lots). However the EBB fitted to the tandem (which is of the 'split clamp' type, and has been installed with lots of copper-ease) has been perfectly reliable, despite all the crud which gets thrown at it.. So with fat tyres I usually set the mudguard well clear of the tyre, so it didn't need to be adjusted, and with skinnier tyres and/or closer clearances I learned to live with the adjustments. IMV there isn't that much to choose between adjusting the mudguards or the saddle...However it occurs to me that if you want to do neither, then it is possible if the mudguard is partially or wholly attached to the moving part of the dropout, or is attached to a bracket which is held by the axle somehow..

Bonefishblues wrote: ↑9 Jan 2024, 11:51am Maybe a Gates Belt is the way to go?

While there won't be a need to make periodic adjustments due to wear, there is still the need to be able to adjust the bottom bracket - back axle distance to suit the chosen sprockets and belt.

Personally, I've made do with a chain tensioner for my Rohloff hub although it prevents me from fitting a full Hebie Chainglider.

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.