Mercury Mk 2 frame replacement

[ianatstanage]

Hi,
Recently I had a burglary of the garage.
An attempt was made to steal my Mercury Mk 2, purchased new in 2015.
Fortunately it was well secured with good locks and the thieves could not take it.
Unfortunately, due to the use of a crowbar while attempting to break a D lock, the frame was significantly bent and is beyond repair.
I am now wanting to source a replacement frame.
Having noticed that there was very little stock of Thorn frames, I have just seen Robin’s post from December 2023, indicating a decrease in model availability.
For the last few years I had been running my Mercury with 40mm tyres and no mudguards (they don’t fit with 40mm).
This suited my riding and provided a noticeable increase in comfort, although being splashed with mud and road grime was unpleasant.
I am therefore thinking of getting a Mk3 Nomad, possibly with 650B wheels.
If I go for a 650B Nomad, should I go for a similar size frame to my Mercury (55L) or a bit smaller (52L)?
I would need to get the Rohloff re-built with a 650B rim.
I’ve not found any reviews for the Mk3 Nomad, so possibly not a popular bike?
Alternatively, are there other frames suitable for a Rohloff?
Many thanks,
Ian

[PH]

How dreadful.  I had a bike trashed in an attempted sale, it upset me more than when I had a bike stolen.
I have a Mercury (Mk3 but originally the previous model) and a Nomad, the Mercury is 700c and the Nomad started out 700c and was swapped to 650B. Despite the obvious similarities in looks, they ride considerably differently.  The Nomad is a good bit stiffer, it doesn't have the same zing (I know it's subjective!), I feel much more like I'm sat on it rather than in it, the steering is slower.  It's a bit heavier, I've got it written down somewhere, I think in the same spec it's about 800g. Though my builds are different, so the actual bikes weight difference is considerably more than that.  Those things are not necessarily downsides of course, depends on what you want and what you like.  The Mercury is by far my favorite bike, yet last year it did less than half the mileage of the Nomad.
When I wrecked my original Mercury, I did fleetingly consider two others, a Stanforth Skylander and a SOMA Wolvarine.  The Stanforth suffers the same tyre restriction of earlier Mercury models (The Mk3 takes 40mm tyres), the SOMA has sliding dropouts but isn't otherwise Rohloff specific (though I've seen Rohloffs fitted) There's also some Shand models, but I'm not keen on the geometry (Or the price!) The Cyclingabout website has a list of Rohloff frames, though not many are readily available in the UK.  The Rohloff in my Nomad started life in a Surly Ogre, which didn't really suit me  - Someone else on this forum went Nomad Mk2 > Ogre and preferred it, someone else did PBP (1,400km Audax) on their Nomad, which demonstrates how subjective it can be - For that swap I was considering frames from Tumbleweed and Brother.  In the end I wanted something less MTB geometry and more touring.

The Nomad Mk3 was reviewed in the CTC magazine a while back, the review is full of factual errors, so worth a read but don't take it on trust.   

EDIT - Link to Cycle UK review:
 https://www.cyclinguk.org/cycle-magazine/bike-test-expedition-tourers#

EDIT EDIT - my previous musings on the Nomad
https://thorncyclesforum.co.uk/index.php?topic=14854.msg111738#msg111738

[iGom]

I bought a Mercury MK3 last year and don't think there were any restrictions in availability - except the colour.  I would have liked green, but the gunmetal grey is very nice IMO.
Ordered on 4 July & collected 7 August.
700C wheels, with rear disk brake & front rim.
The tyres are "Schwalbe Marathon Supreme HD HS469 Folding Tyre - 700 x 40 42-622" (to quote the receipt) and it came with mudguards.  Not problem with fit.
I am very happy with it & like the way it rides, but oviously can't compare with the MK2.  My first Rohloff bike (wish I bought one years ago).

So, in theory at least, I don't think you should have a problem in getting a new Mercury frame.

[JohnR]

I can see several 52 L and 55 L Mk 3 Mercury frames and a 550L Mk 2 frame (red) https://www.sjscycles.co.uk/thorn-mercury-frames/. A possible alternative frame is the Spa Elan which will take 40mm tyres with mudguards (and 50mm with mudguards using 650B wheels). It's not designed to be Rohloff ready but I figured out a torque anchor solution, most satisfactorily with the Ti frame but adequate with the steel frame. See https://thorncyclesforum.co.uk/index.php?topic=14396.msg110737#msg110737 and https://thorncyclesforum.co.uk/index.php?topic=14396.msg108175#msg108175 which have some photos. (BTW, the steel Elan frame needs a new home.)

[ianatstanage]

Many thanks for the responses, very much appreciated.
I've rejected the Nomad as I like the ride of the Mercury too much - it has served me well for the past 9 years.
There are indeed some Mercury frames available, which is a relief, as I obviously didn't look harder enough.
Nonetheless, it's a shame that the Thorn bike range is being slimmed down.
Hopefully the Mercury will survive in some form.
I'm going to go with a Mk3 Mercury as this gives me the option of converting to 650B.
I may also lower the gearing a bit.
I will be speaking with Thorn on Tuesday to confirm frame size and then get it ordered.
Hopefully I will be out on a Mercury soon.
Cheers,
Ian

[ianatstanage]

I now have a new Mk3 Mercury frame & fork as a replacement for my damaged Mk2 frame.
There was a very limited choice as Thorn is running down supplies, prior to releasing a new Mercury.
I had to settle for either a gunmetal or gunmetal frame with either a black or black fork!
I was told that there is no timeframe for the new Mercury, but it is likely to offer a combination of 700C/650B wheels with Rohloff/derailleur rear dropouts.
The Mk3 fork appears to have identical tyre clearance to the Mk2.
There is a few more mm of clearance at the rear.
Nonetheless, I think that I will be very happy riding a Mercury Mk3.
Ian

[PH]

I now have a new Mk3 Mercury frame & fork as a replacement for my damaged Mk2 frame.

Sounds like a good decision if you were already happy with the damaged one.  Are you sticking with 700c?  The extra frame clearance comes from dropping the ability to take a caliper brake, which also allowed for the full sized EBB.  I have a 40mm Schwalbe Efficiency on the back, their replacement for the Supreme, a bit chunkier though Schwalbe claim - "Our fasted ever touring tyre" There's adequate clearance under the 55mm guards, though they can collect enough mud to rub on mucky lanes.
I have the 700c only 853 fork, same as I had on my previous Mercury, there's a 40mm Supreme in that with adequate clearance, though those measure closer to 38mm on my rims. 
Black fork on the gray frame look neat together IMO, I had a black touring fork in mine at one time.

[ianatstanage]

I'm sticking with 700C for now.
I like mudguards, but I also like riding on muddy trails.
As you say, the two don't always mix well.
I may try some 'gravel' guards and see if that works as a compromise.

[Moronic]

Thanks for giving us a sense of what's left, and some news on the replacement. Glad to hear you got what you needed.

I love my 650B Merc Mk 3. On 48mm Rene Herse tyres it's swift, extraordiarily comfy, and secure.

But I ride mainly gravel and paved cycle paths, a bit rough and with low average speeds.

[PH]

I love my 650B Merc Mk 3. On 48mm Rene Herse tyres it's swift, extraordiarily comfy, and secure.

I'm still curious to try my Mercury in 650B, I have everything I need, It just requires swapping the fork and wheel from the Nomad (They even have the same headsets).  I think what's stopping me is the thought I might prefer it...   

[Moronic]

You may indeed, PH. I've never wondered about the benefits of 700C on the Merc, having had that wheel size on my prior steed.

From memory, 650B x 48mm has a diameter within a couple of mm of 700C x 30 or so. The wider tire and tube will weigh a bit more. On the odd occasion when I've followed a narrower 700C shod bike downhill I've not noticed it rolling away.

Might be different on a long, smooth alpine descent. Also might not.

What continues to surprise me is the comfort of high-end 650B x 48s on a Mercury on rough surfaces. Anecdotally, there's a huge reduction in fatigue over the 700C x 30s I was running before. On high-pressure rubber, you take for granted the bouncing around that your body undergoes as the tyres transmit the surface to you through the frame. Little by little though, it's wearing you out.

Bigger tyres at low pressures - I've settled on 30-odd psi, give or take a few pounds - seem to leave me much fresher over a couple of hours.

[JohnR]

My bikes have disc brakes and I've decided to standardise on 650B wheels and need to rehome my 700C wheels. Apart from the benefit of being able to fit a bigger tyre within the frame and forks, I also like having the side-effect of the bottom bracket being slightly nearer the ground so I can get more of my foot on the ground when stopped.

I think that the difference between 650B and 700C rolling resistance is much less than the difference between tyre types.

[John Saxby]

What continues to surprise me is the comfort of high-end 650B x 48s on a Mercury on rough surfaces. Anecdotally, there's a huge reduction in fatigue over the 700C x 30s I was running before

Ian, I run 650B x 1.6 Marathon Supremes on my Mercury.  (Their actual inflated width is 37.5 mm.)  I've found them to be a decent compromise among comfort, durability, and rolling resistance.  But, although I have one unused spare, Supremes are now Unobtainum.

How durable are your RH 48s? Do you ride mainly on tarmac or gravel, in cities, etc.?  I'm thinking of getting a 650B Babyshoe Pass RH tire (650B x 42 mm) with the "Endurance" casing, with a view to mounting it on the front wheel on day rides, & keeping the Supremes for tours.

In 2017, I put two 26 x 1.6 Compass tires (before they became RH) on my Raven.  They gave a lovely ride & were also a cog faster than my Supremes.  BUT:  I had three punctures in 400 kms, all slow-ish leaks from glass shards. (And this was in Ottawa, not on 'Straya's Gold Coast!)  Those tires had the "standard" casing, IIRC -- they predated the current "endurance" option. I took them off, donated them to the bike-recycling group with whom I work, and reverted to my 26 x 1.6 Supremes for the following four seasons, before I sold the Raven.

Welcome your thoughts on these issues, Ian.

Cheers,  John

[Moronic]

Hi John, we're getting a bit off topic here and I'm the chief culprit. But I'll offer brief thoughts.

I don't run a cyclometer so can't give accurate mileage, but I'm pleasantly surprised by the way my RH Switchback Hill tyres are lasting, especially as I got the Extralights.

I won't jinx myself by speaking of punctures. Let's just say they're doing better than my Schwalbe G1s, which I did repair once.

I've been riding them mainly on dedicated gravel and tarmac cycle/walking paths. Biggest risk is from bottles dropped on the paths as they pass though parkland that gets picnic/party use. I've spent very little time recently on roads with significant motor traffic.

They're pretty slick where it's muddy. I'm considering fitting a set of RH Juniper Ridge knobbies for winter use here.