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Looking for a lighter Rohloff bike than my Mercury
Danneaux:
For a different perspective, my two derailleur randonneur bikes weigh right at 14.5kg dry and unladen. They're my "weapons of choice" for 200-400km/day rides in mixed/pretty hilly terrain due to comfort and how they are equipped for all weather and day/night use for long hours in the saddle.
I've often thought about lighter bikes for the task but these are comfortable over distance and of course I need 32-38mm tires, 3 bottles/cages, at least a rear rack, dyno lighting, my Brooks B.17 saddle, a pump, underseat bag for appropriate tools (usually a multitool, spare tube, patch kit, tire levers), preferably a sus-seatpost if there's a lot of gravel over that distance and mudguards for rain, so it is hard to get the weight much lower.
I have a 10.23kg go-fast bike that is stripped down...two bottle cages, mini-pump and lighter tools, no mudguards or dyno lighting, only battery front-rear blinkies made wholly from Tange Champion No. 1 tubing at 0.8/0.5/0.8 wall thickness. I can manage to get it up to 50kmh on the flat as I can my Fixie, but I tend toward an RA (running average) of 27-33kmh with an AOA (average overall including stops) of about 25kmh no matter what I ride on pavement, so weight hasn't really mattered so much except at the extremes. My Nomad weighs 20kg on the nose dry and unladen and my tandem (which I've also ridden solo on long day rides; it makes a remarkably good day tourer for one person...) weighs 20.86kg. Both of these bikes do end up being my slowest on pavement when ridden unladen, due to the extra weight. They are also the best at handling huge loads -- another whole person plus 4 panniers, a rack-top bag, HB and mid-frame bag plus trailer in the case of the tandem.
I have found the more I ride my bikes, the less I notice the weight. Where I really do notice the difference is when I take the loaded bags off a bike immediately after a tour. What a contrast! The unladen bike then feels like it can fly -- woosh!
Best of luck finding a bike that suits your needs ideally; there's nothing like the feeling of finally getting something wholly right for the intended task.
Dan.
martinf:
One way of taking a bit of weight off a Mercury would be to fit one of Thorn's 853 fork options. But AFAIK they only work for calliper or V-brakes. Which, in themselves, probably weigh a little less than a disc brake.
Springy 853 forks might also allow you to use narrower tyres for the same comfort level, saving a bit more weight on tyres and tubes, although I tend to do the opposite myself and fit the fattest lightweight tyres that still give me adequate mudguard clearance.
As an example of the weights of different tyre options, the difference (for two tyres) between the 622x32 Continental Grand Prix 5000 tyres on my old lightweight bike and the 559x42 Marathon Supremes on my Raven Sport Tour is 390g (would be more if comparing the same wheel size) and there is probably also a saving with the inner tubes. Saving weight in the wheel helps with acceleration and in my opinion makes more difference than elsewhere on the bike.
The 32 mm Continental Grand Prix 5000 tyres are comfortable enough for me on tarmac roads, the main difference I notice is that the 42 mm Marathon Supremes on the Raven Sport Tour are significantly better on tracks and paths.
According to this site: https://www.bicyclerollingresistance.com/ there is also a fairly significant difference in rolling resistance between Continental Grand Prix 5000 (11.4W at 75 psi) and Marathon Supreme (16.9W at 75 psi), which might be a help on group rides. I don't really notice this, as both these tyres are improvements on the ones I had previously on these two bikes.
Going tubeless (if you haven't already) or replacing butyl inner tubes with latex should also provide small gains in weight and/or rolling resistance IF the extra hassle of these options is worth it for you. I've not tried tubeless and don't intend to, but I do use latex tubes in the three bikes that I use for long-distance rides, although my reason for doing so is that I believe they add a bit more comfort as compared to butyl.
Moronic:
--- Quote from: Danneaux on October 22, 2021, 08:02:02 am ---
I have a 10.23kg go-fast bike that is stripped down...two bottle cages, mini-pump and lighter tools, no mudguards or dyno lighting, only battery front-rear blinkies made wholly from Tange Champion No. 1 tubing at 0.8/0.5/0.8 wall thickness.
--- End quote ---
Same wall thickness Thorn quotes for the Mercury, interestingly.
Thanks for the perspective from your distance bikes, Dan. That's very reassuring. 😄😄
My own outlook when choosing the Merc was that if it turned out to be comfortable, low-stress, low maintenance and still fun I would compensate for the extra couple of kilos pretty quickly with extra strength gained from riding extra miles.
So far that's proven well judged - except that I am having even more fun than I thought.
JohnR, I can barely believe you're dissatisfied with that lovely looking Mercury. It's like watching a man whine about the wife whom all of his friends envy him for. We all know it can't be just the weight - what's really going on? ;)
geocycle:
JohnR, the Spa elan you link is a great bike. I test rode one once. It was a fairly heavy build and felt very solid and smooth. For me it was too close to my RST so I bought an audax instead. Neither of these are rohloff designed frames of course.
PH:
--- Quote from: Moronic on October 22, 2021, 09:28:07 am ---
--- Quote from: Danneaux on October 22, 2021, 08:02:02 am ---
I have a 10.23kg go-fast bike that is stripped down...two bottle cages, mini-pump and lighter tools, no mudguards or dyno lighting, only battery front-rear blinkies made wholly from Tange Champion No. 1 tubing at 0.8/0.5/0.8 wall thickness.
--- End quote ---
Same wall thickness Thorn quotes for the Mercury, interestingly.
--- End quote ---
It's pretty much the standard for light touring/Audax bikes, it's no coincidence Thorn's own tubing for their Audax bike is called 858.
That's only part of the story of course, we don't know the butting or how gradual the transition, both will make a significant difference to the feel, as will the modern trend of shaping tubes.
To put it in perspective the common gauge for touring tubes is 0.9/0.6/0.9 with only some super strength tubes going over 1mm. What ought to be obvious is that it only requires a small difference in material quantity (Assuming the designer knows what they're doing) to make a big difference in strength and feel. The weight difference between two steel frames of the same size and geometry can be counted in g rather than kg. Neither I suspect is there anything magical about Reynolds 853, I'm guessing Thorn used it because it's the sort of label people spending that sort of money on a frame expect. There's usually more weight difference between forks, as they're subject to different forces.
I know, I know, I've posted such before and it's becoming a bit of a theme, still it is one of the most talked of subjects across several forums. I went to a frame building demonstration some years ago by well respected British frame builder Dave Yates, he said the two most common questions from potential customers were frame weight and wheelbase, and that they were the least relevant, both are a consequence of getting the important stuff right.
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