Author Topic: New Thorn Mercury owner  (Read 4608 times)

JohnR

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Re: New Thorn Mercury owner
« Reply #30 on: February 27, 2022, 08:55:14 am »
I'm impressed by the miles you have clocked up during the winter months. I've noted elsewhere that I've created my own bike that's more suited than the Mercury for the very light (supported) touring which is the upper limit of my ambitions. I've never felt the Rohloff hub to be draggy and am happy to live with any extra drag there might be because I like the advantages that the Rohloff offers. Perhaps the seals on your hub aren't properly bedded in? You might also want to change your gearing to reflect your different uses with higher gearing when not carrying any load. Changing the chainring and/or sprocket is easy.

PH

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Re: New Thorn Mercury owner
« Reply #31 on: February 27, 2022, 10:22:05 am »
Glad you're enjoying the new bike, though I share some of your opinions, other's have me scratching my head:
Quote
I now know what an EBB is.  I changed the tires, the chain went back on loose.
This one has me completely puzzled. you changed the tyres and the chain went slack? I can't see how that happened!
As for the bad run of punctures, just how much heavier is the new bike! It's hard to see how an extra couple of kg's are responsible, maybe if you were already on the limit of race tyres, but those Armadillos look pretty tough (I haven't used them) Of course if you load it up with twice the maximum recommended, it's also a good idea to increase the pressure to match, but you probably knew that.
I notice from your first post that you stopped recording on Strava, maybe it's time to do so again.  The impressions of speed, drag, momentum, don't always match the reality.  I've had a few excellent Audax/Sportive bikes that felt so much quicker, but the numbers showed the difference was nothing like as great as the impression.  The hub does sometimes feel draggy, but these things are measurable and the difference is minimal.  Likewise uphill, yes I've had bikes that seem to fly up the hills in comparison, but again, for me, the reality  is there's little difference.  It's possible that as the speed increases the gap widens, I wouldn't know, but it's the numbers that will show that rather than the impressions.  The claimed independent Rohloff testing showed the efficiency increased at higher input, indeed they were criticised for using these figures, rather than the more average riders input.
You're out of luck looking for a lightweight steel disc fork, there's no 853 option, seeing how easily 853 crumples in an accident I'm not surprised.  The weight difference between your fork and an 853, is less than the difference between your change of front tyre.
I've described the Mercury elsewhere as a midpoint between an Audax and touring bike, I Audax on mine, but then I tour my way around Audax. It's a shame IMO the attitude it's a race has become so prevalent, there's always been a wide range of riders, but that has become narrower as the popularity increases.  Fine for those riders of course, they can ride however they like within the reg's, but it has changed the sport with more organisers catering for that group to the detriment of the 'tourers'. A decade ago, steel touring bikes made up a huge proportion of the average field, now they're very much the minority, I blame the relaxing of the mudguard rule! It's made me a lot more selective in ride choice, though there's still more on the calendar than I'll ever get to do.  maybe I'll see you on one, though it'll probably only be at the start!

EDIT - And where's the photos?  Are you riding so far and fast that you don't have time for a pic or two?
« Last Edit: February 27, 2022, 10:38:44 am by PH »

Marcc72

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Re: New Thorn Mercury owner
« Reply #32 on: February 27, 2022, 04:08:45 pm »
I now know what an EBB is.  I changed the tires, the chain went back on loose.  The reason for this was that I had no clue how to tighten the chain back up.  I followed the instructions, but nowhere did I read or take in what a EBB was.  I have never owned a bike with an Eccentric Bottom Bracket before.  I did not understand what it was, that it was even there.  So that's something I learned about the bike, what that tool was that came with the bike, how to use it!  I have pushed to what I can do over a 100 KM on the Mercury.  I am at the 5-hour mark which took a lot of effort. So about 20km an hour on average. I like to go a little faster to allow a longer break. Plus controls and whatnot.  A 200km Audax yeah for sure, but a 600km, no chance.  I decided to respect an 853 frame I have here which will give me the times I want. Yeah, i will post some photos soon.

Marcc72

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Re: New Thorn Mercury owner
« Reply #33 on: February 27, 2022, 04:29:33 pm »
Here is the Ox as it's been nicknamed!

JohnR

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Re: New Thorn Mercury owner
« Reply #34 on: February 27, 2022, 07:33:01 pm »
My other observation is that you will most likely find that the bike feels faster once winter is out of the way.

Mike Ayling

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Re: New Thorn Mercury owner
« Reply #35 on: February 28, 2022, 12:25:03 am »
I was running Armadillo Elite 30mm.  They do run very smoothly.  But due to the weight of the bike "and me," I had a flat every month.  They're my go-to choice Audax tire. They are not suited to the Mercury in its present state.  Rohloff doesn't tend to roll as nice in a free wheel situation.  I feel that there is more drag due to the weight, build and design.  This bike could be used in an Audax, but I would need to rebuild the front end, forks, wheel, remove the rack, then remove the rear rack.  There are carbon forks that will slot right in, disk wheels that are far lighter.  I would even want to replace the Thorn Crank.  It is a heavy well built touring crankset, which is great for touring.   A Middleburn crank would run a lot lighter.   Even then it would be a little heavy to run at an average of about 23km over 400km.  Could I be arsed to do this every time I wanna use it for a different purpose, "NOPE"! Yep, it seems to like carrying the weight.  The design and build of the bike then make complete sense to me.  It starts to feel correct.  The only thing i will now change is the front fork.  I feel the bike will improve with front and rear disk brakes.  I find the front rim brake a little lacking I think Thorn offers the 853 forks which can run a disk set up.  The TRP Spyke cable brake is very decent.
Hi Marc
If you want a disc brake on the front you will need a heavier, stronger fork and the disc caliper etc weighs a lot more than your current V brake. IMNSHO you are under rating the V brake. Our Thorn Twin Raven tandem has V brakes fore and aft and I have never had a problem stopping with a crew weight of 125kg plus about 20kg in the panniers.
YMMV
Mike
Another happy Mercury owner.

PH

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Re: New Thorn Mercury owner
« Reply #36 on: February 28, 2022, 01:00:42 am »
I now know what an EBB is.  I changed the tires, the chain went back on loose. 
I'm still a little puzzled by this, there's no need to touch any adjustments to take the wheel in and out, so the chain should be the same tension after as before.  Oh well, hopefully you've got the hang of it now.
Looks good in the photos  ;)
If you decide to go for a third party fork,, be aware that Thorn design the short top tube sizes (For drop bars) to have a fork with a 50mm offset rather than the more common 43-45mm.  The extra 5mm will slow the steering down, by how much and if it bothers you are subjective, but it might be a good idea to try one before buying anything fancy.
I've done a few Audax on my Mercury, the only time I sometimes feel it'd be nice to have a faster bike is on summer 100's, but I don't do enough of those to warrant having one.