Sherpa Mk3

[Relayer]

There has been some rejigging of sizes in the middle of the range with some sizes being kept and some sizes being dropped replaced by an increased choice of slightly different sizes

The sizes that have been kept are 485 L, 510 XL, 560 XL,585 L, and 610 S.

The 510 S is replaced by the 500 S and 500 L.
The 535 XL and 560 S have been replaced by 530 S and 530 L.
The 565 S and 565 L and 600 S have all been added.

All in all it will suit more people.
Unfortunately I think that the shortest and tallest may lose out from the changes (That is the way of the world I guess, shame but true).

Regards,

Iain.

Hi Iain

I think you have summed it up very well.

It would suit me if I was wanting a Sherpa, in the old range the 510XL with flat bars would fit me but not ideal, and with nothing between 510S and 560S there wasn't a drop bar option that would suit me.  The new 530L and 530S are spot on for me, and perhaps I could be tempted to migrate my MTB parts to a Sherpa Mk3 frame to try out as a balloon bike sometime in the future, although they could perhaps have gone for clearance up to 2.35" Big Apples - something to ponder anyway.

[macspud]

I'm really praying nothing (theft, damage) happens to my 2011 560S, as there really is no direct replacement for my needs. Sigh. Well, hopefully nothing will happen to mine for a very long time.

If the unthinkable did happen, fingers crossed it doesn't, you may be forced to move to a Rohloff frame in the guise of a Nomad II. I know that drop bars are your preference but after looking into the Sherpa MK3 I had a look at the 2012 Nomad II brochure And came across this:

http://www.thorncycles.co.uk/forums/index.php?topic=4272.msg19726;topicseen#msg19726

http://www.sjscycles.com/thornpdf/ThornRavenNomadBroHiRes.pdf

Looks like at very well engineered way round the problem of the Rohloff shifter and drop bars.

Sorry if I putting temptation your way but are there any Nomads that would a good fit for you?

Best,

Iain.

[macspud]

The new 530L and 530S are spot on for me, and perhaps I could be tempted to migrate my MTB parts to a Sherpa Mk3 frame to try out as a balloon bike sometime in the future, although they could perhaps have gone for clearance up to 2.35" Big Apples - something to ponder anyway.

Hello Relayer,

Glad that the changes are good for you, not so good for some better for others, those who don't gain by the changes with the MK3 better get in quick before the remaining MK2s are sold out.

As for the 2.35" Big Apples that sure would be nice, I think that the Sherpa will take up to 2.25" Marathon XRs so it may be able to handle the slightly larger Big Apples though you'd have to make quite sure. It would certainly make for a comfy ride. Something to tempt you anyway. I guess you will be getting better acquainted with that brochure as you ponder.

Cheers,

Iain. 

[macspud]

"Both the ST1 and C2 forks will take a 2.15” tyre if required.

Having reread Dan's post I realised that I may have been mistaken about the Sherpa taking up to 2.25" Marathon XRs.

[Danneaux]

If it is any help wrt to choosing larger tires, I just measured Sherpa, and there is 8.5mm of clearance each side between the sidewalls of my 2.0 Duremes and the inside lug-face of the fork crown.

Of that, some room must be left for tire wobble and an out-of-true wheel as well as road debris (mud, dirt). The real limiting factor would also be vertical clearance. A wider tire would preclude use of a fender, because there would be inadequate clearance between the center of the tread and the bolt that holds the fender into a threaded plate on the underside of the steerer (it isn't just the bolt head; the fender thickness itself eats up some additional clearance).

For what it's worth, on my road bikes I have set 5mm as the absolute minimum clearance between tire and fender, and much prefer 8mm minimum to avoid debris fouling the tire-fender. Sherpa's clearance is 12mm minimum at the front of the front fender and wider elsewhere. I replaced the original SKS cut stays set internally on their brackets and prefer external ones made by Planet Bike so I can increase tire-fender clearance when touring on desert playa, which can cake if damp.

All the best,

Dan.

[NZPeterG]

Thanks for the update's about the MK3, i'm I right on reading in full about the new Sherpa MK3 that the Ripio this a higher loading? for touring?
If this is right then i'll look at a Ripio or (go back to running with a Rohloff) Nomad MK2.
I'm thinking that a Ripio/Nomad would be a better tourer for me as I live in New Zealand and we have a load of offroad cycle touring/MTB track's being build around NZ at this time, plus old roads, dirt roads etc.
Plus i'm looking to go back to Africa and cycle all the way to Cape Town, on dirt roads!
If any one can help with which way to go it would be good.
Pete...

[Danneaux]

Hi Pete!

Yes, if one looks at the Thorn FAQ for "Which model suits my needs" ( http://www.thorncycles.co.uk/FAQ/compmod.pdf ), the Sherpa's listed luggage carrying capacity (according to type of terrain being ridden) is indeed lower in some categories than the Nomad Mk2 and the Ripio.

In every category, the Nomad Mk2 has the highest rating compared to the Sherpa and Ripio.

The Sherpa Mk3 is rated higher than the Ripio in Road/Commuting, LEJOG/B&B touring, and Camping (35kg vs 30kg).

The Sherpa Mk3 is rated lower than the Ripio in Mountain Touring, Desert Touring, and USA Spine/End to End (25kg vs 30kg).

The Sherpa Mk3 is rated equal to the Ripio in Tow Path/Forest (30kg).

The thing to keep in mind is the Ripio, *if equipped with a suspension fork* cannot carry front panniers unless it is equipped with a sus-compatable front rack like the Tubus Swing. *Or* if equipped with the Mt. Tura Fork ( http://www.sjscycles.com/thornpdf/ThornMtTuraForkHiRes.pdf ) and front pannier racks like the Thorn Low-Loader MkV. Putting the maximum rated weight only on the rear rack of the Ripio would not result in pleasant handling. Frame bags are always a possibility, as is a handlebar bag.

In every Thorn-rated category, the Nomad Mk2 is the load-carrying champ, at 35+ kg, the highest of the bikes Thorn offer.

In the same chart referenced above, Thorn do not recommend the Nomad Mk2, Sherpa Mk2, or Ripio for Audax/CTC rides.

I hope this helps. Please keep us posted as your Africa touring plans develop!

Best,

Dan.

[Danneaux]

Sorry if I putting temptation your way but are there any Nomads that would a good fit for you?

Hi Iain,

Good thought about considering the Nomad Mk2 as a possible replacement should disaster befall my Mk2 Sherpa.

I just had an in-depth look at the Nomad Mk2 sizing chart, and the problem seems to be the frame are a bit "oversquare" for me with my preferred drop handlebars -- the top tubes are really longer than I'd like. This isn't surprising, as the Nomad Mk2's frame seems really to be engineered for use primarily with straight handlebars, as many now prefer. I realize I am in the minority in preferring to tour on drops, but I like the additional hand positions and my wrists and after so many years on them, my wrists and shoulders are really more comfortable with my palms roughly facing each other on the 'bars.

My Sherpa Mk2 has a 550mm virtual top tube. Discounting the "X-series" Nomad Mk2s (I need the extra capacity of the standard, heavier model), the closest I can get is a 570mm top tube on the 510L, described as having a "small frame, long top tube". However, that comes with a seat tube (c-t) of only 370mm compared to my Sherpa Mk2's 500. As a result, I'd have 13cm/130mm more seatpost exposed (I have ~18cm exposed now on my 560S, so that would be 31cm; more than I'd like), and would have to run a stem with 2cm/20mm less reach (90mm vs 110mm) to make it all fit like Sherpa does now.

A 590M gets me much closer in many ways (445mm c-t seat tube mid-tube standover, nice long chainstays) but a 35mm longer top tube, doable with a 75mm stem instead of my present 110 on drop 'bars. Yes, the Nomad Mk2 in a 590M probably gets me closest to my present Sherpa Mk2 560S, and would be the best choice for me among the broad scope of Thorn's present (newest) lineup. Not as ideal as what I have, but workable with some effort. It would also include the additional expense and unknown of the Rohloff drivetrain for me, and derailleurs have always worked well for my needs.

No, it looks like there is no direct replacement for my Mark2 Sherpa in the Nomad Mk2 product line, but one model comes close(r). Good suggestion, Iain, and a worthwhile investigation. It never hurts to gain familiarity with options, and this helps to keep in mind.

Best,

Dan.

[il padrone]

H-bars..... for multi-positions and wrists in-line.

Yes, the Nomad Mk2 in a 590M probably gets me closest to my present Sherpa Mk2 560S, and would be the best choice for me among the broad scope of Thorn's present (newest) lineup. Not as ideal as what I have, but workable with some effort. It would also include [the additional expense and unknown of the Rohloff drivetrain for me, and derailleurs have always worked well for my needs.

You know you'll love it, Danneaux  

[Danneaux]

H-bars....You know you'll love it, Danneaux.

...says Pete, CBI (Certified Bad Influence). Welcome to the CBI Club, 'cos the H-'bars are beginning to grow on me!    Noooooooooo!    

And I can see the value of a Rohloff.  Noooooooooo!    

Where's the little emoticon for "angel on one shoulder, devil on the other"? They'll kick me out of the Drop'bar-Derailleur Roadie Club, Man! Maybe if I go with a dual-'ring-and-tensioner half-step Rohloff...? To which Pete says,    Noooooooooo!  

Best and chuckling,

Dan, CBI Emeritus.

(Lovely machine those 'bars are mounted to, Pete! Your rides are all exquisitely prepared...)

[Andre Jute]

...perhaps I could be tempted to migrate my MTB parts to a Sherpa Mk3 frame to try out as a balloon bike sometime in the future, although they could perhaps have gone for clearance up to 2.35" Big Apples - something to ponder anyway.

It's a feeling I've always had about Thorn bikes. I have a good deal of experience with a bike designed around the biggest available balloons (Big Apple 622x60) -- and all of it is favourable.

However, from a purely commercial viewpoint, I think you would find sales resistance among tourers to the really big balloons -- many, though they may have heard from creditable sources that balloons have less rolling resistance than narrow tyres, still haven't internalized this crucial message. It might even cost a few sales, as tourers will argue that the extra width means extra weight for zero benefit if they will fit narrower tyres anyway.

I'll tell you something else. I have a Kenda 47mm Kevlar banded tyre that I got free with my electric wheel and which I'm  trying, and at 50 or 55psi, except for the noise of the nobbles, you're hard put to distinguish the difference -- until the moment you ride over a square-edged ridge only about an inch high at speed, as I did this afternoon to escape a badly driven SUV by riding onto the pavement (sidewalk to you!) at a driveway, when the Kenda hit the rim hard enough for me to fear snakebites, and the 60mm Big Apple didn't even notice that I was doing something that could disturb its maker. Not necessarily suggesting the Kenda for touring (to much of an offroader for smooth roads, probably not enough of an offroader for really rough going), but it does okay surviving my rougher lanes through the potholes at speeds that would wreck a road tyre and rim. I'm impressed enough not to have swapped it out for several months now.

So I suspect that the 47mm (real width) tyres, that somebody said the the other day would fit, especially if inflated at the low end of the permissible band, and even more especially if not intended to be highly pressured in the first instance, could be a pretty good approximation to balloons, and closer still the smoother the tread. (It would depend on the sidewalls too, and the stiffness of the necessary anti-puncture  protection; a scaled-up Marathon Plus won't do this business! It's rubber protection is just too stiff to take advantage of even the slackest sidewalls.)

Andre Jute

[Danneaux]

Hi Andre,

I am always very intrigued by your balloon tire threads and want to jump right in with a reply, but don't want to unduly dilute the Sherpa Mks 2/3 thread.  Hmm. I think I've found a way to work it in...

...47mm (real width) tyres, that somebody said the the other day would fit, especially if inflated at the low end of the permissible band, and even more especially if not intended to be highly pressured in the first instance, could be a pretty good approximation to balloons, and closer still the smoother the tread.

Ah! The Schwalbe 26x2.0 Duremes I run on my Sherpa Mk2 (and will also nicely fit on a Sherpa Mk3), measure out to an actual 47mm in sectional width and profile (1:1). And...they have indeed been a revelation. When I rode them on the 200km ride up Mt. June and back, I had 65psi/4.5bar in them, and they pounded the snot out of my hands. They weren't bad on glass-smooth roads, but the 17mi/27km of singletrack followed by a goodly distance on benign and malignant gravel is where I felt the excess pressure. I came home, dropped the pressures to 45psi/3.1bar and it utterly transformed the ride without having much apparent effect on rolling resistance. I'm continuing my coast-down studies (cross-referenced with wind data, GPS readings, and bike computer, all as a function of time and distance), and will be interested to see what effect various pressures really have on resistance for these tires at the various weights I carry.

Now (swinging the prow of this post-ship once more toward the land of thread relevance), if one had a Sherpa Mk3 (or the fork from one fitted to a Mk2), then it would be possible to run a wider tire on the front, a la Sheldon Brown's expressed preference ( http://sheldonbrown.com/tires.html under "Mixing/Matching Tires"; subhead "Wider Front, Narrower Rear). Through sad experience, I am wary of too widely mix-matching tire section widths, but a marginally wider front tire, as allowed by the wider Sherpa Mk3 fork, might not be a bad thing, and would add to the "balloon-like" effect, especially if the sidewalls are as compliant as those on my Duremes (or their nearly slick cousins, the Surpemes). However, any comfort gains afforded by the wider-section, lower-pressure tires might be offset by the heavier gauge of the new Reynolds Super Tourist fork blades.

Whew.

From what I can gather, rear spacing of the chainstays and seatstays remains the same on the Mk3, so maximum tire width would be the same at the rear as on the Mk2. Really, we're talking about room for only marginally wider tires at the front (3.81mm, about 5/32" wider section width, 1.9mm/about 5/64in) per side, so given the available sizes, is it best to consider it just that much additional mud clearance?

Best,

Dan.

[janeh]

Hello,

The sizing of Sherpa MK3 seems quite different to MK2. My small MK2 has a 490mm top tube which is good for having drop handlebars. The shortest top tube now is 540mm, which is quite a difference as even the next size up was 510mm in the short length. This makes it no better than the Dawes Horizon I was replacing. Perhaps this means SJSC does not approve of drop handlebars. The thing is though; if the sizing is just for the mass market then one may as well shop elsewhere..

Traa

Jane

[Danneaux]

Hi Jane,

I readily agree, it appears life will be harder for those Thorn enthusiasts who also prefer drop handlebars. There's going to be a run on shorter-reach stems, methinks. Still, I'm reserving final judgement till the new brochures arrive showing photos of the new MK3s.

There is another issue that we haven't considered but might well influence Thorn's new geometry.

Going ahead, it is now very much more difficult to mix Shimano's road and MTB components thanks to a change in cable-pull ratios for their 10-sp MTB rear mechs compared to the road derailleurs and shifters. The cable pull in Shimano's 10-sp MTB RDs is different from everything else in their line, and will only work with matching 10-sp MTB shifters. The pulleys don't seem to be a problem, it is the geometry of the parallelogram and the resulting change in cable pull that is at issue.

It is still possible to use 10-sp road shifters (i.e. bar-end shifters) with a 10-sp cassette and a 9-sp rear derailleur.

Another alternative is to go with SRAM drivetrain components, as their 10-sp road and MTB components are compatible with each other.

Yet another alternative for future is the Jtek Engineering Shiftmate: http://jtekengineering.com/shiftmate.htm It is a bit like a v-brake Travel Agent adapted to rear derailleur use. Appears very nicely made. In muddy conditions? Dunno. Could be problematic, though it has a sealed bearing on the reduction pulley.

If Thorn wish to stay with Shimano or they see the handwriting on the wall wrt the future availability of 9-sp MTB derailleurs, perhaps they have decided to standardize on frame geometry that favors straight 'bars and compatible MTB shifters.

[EDIT: Immediately after I wrote this, Shimano announced 11-sp Dura-Ace drivetrains for introduction Fall, 2012. The mechanical Dura-Ace 9000 will be available in September and Dura-Ace Di2 9070 in November.].

Pondering...

Best,

Dan.

[JWestland]

I agree a 540mm top tube is pretty long for drop bars if you're a female...I had to fit a short stem to my second hand XTC (550 top tube) to make it work.

I read about this Shimano gear change in the CTC (UK cycling charity) letters section. Unless there is a clear performance reason, it could just be to sell more kit, as Shimano has done in the past with non exchangeable parts, or parts that need special tools to service.

#sigh.

Their kit IS very good though, that's the problem...SRAM/Campagnolo (especially) are more expensive for the same performance 

Well we're all going to Hub Gears with straight bars then?