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Non-Thorn Related / Re: +++Rides of 2024+++Add yours here+++
« Last post by John Saxby on Today at 02:01:40 am »
And the story cont'd to mid-May:

And Photo 5 shows the foliage of the greening woods on either side of an uphill in the lower reaches of the park.

On May 15, I set off for a ride to the summit of the road system in the park, the Champlain Lookout at the top of the escarpment on the east side of the Ottawa River.  This was a fairly significant marker:  I was last there in early June 2022 (BSE – the before Surgery Era).  Between early March and mid-May, I had made a few rides beyond Pink Lake (about 33 kms round trip from our house), extending the distance each time.  My route to Champlain would be 56 kms round trip.  The net gain of elevation is not huge, just less than 300 metres, but the ride features constant climbing, interrupted by regular descents.

The change in my surroundings, signalled by the trees in the photos above, was dramatic:  Photo 6 shows Pink Lake in its early summer foliage.  And it wasn’t just the trees that had changed.  The ferns in the woods beside the bikepath had unfurled, and the first trilliums (trillia?) of the year graced the verges of the roadway. (Photo 7.)

I was down a couple of cogs on the hills, partly by circumstance, and partly by choice, to maintain my cadence.  The day was warm and humid, and I reached the top in good order.  Photo 8 shows Freddie catchin’ some midday rays on a hazy summer day atop the escarpment.  The big river is just visible through the haze, in the upper left of the photo.  The Nameless Wee Brown Thing just above the river is not a bird:  it is a black fly on the lens of my Panasonic Lumix.  (Hence also the dark blotch in a similar spot above the left-side fir tree in Photo 6.)

Ahhh, the black fly.  “Normally”, a rider meets lots of other cyclists at Champlain Lookout.  We chat about this’n’that, admire the view, acknowledge what a treasure this place is, offer to take photos of each other & the bike, usw, usw.  Not today.  Even though it’s mid-May, and blackfly season doesn’t “normally” start until the beginning of June, today there are hordes of the brutes.  And, there is no defence against them.  A few nods and remarks about the bugs, a rapid inhalation of an energy bar or a banana, a ditto of water, and back on the bike, just a hundred metres or so to the first so-welcome downhill.

What would Keats have said, I’ve often wondered, had he known about such creatures?  “Hail to thee, vile spirit…”?   

Wade Hemsworth’s song-and-cartoon pretty much nails it:  https://www.youtube.com/watch?v=f389hIxZAOc

I made it home in surprisingly good time – about 3 ½ hrs’ cycling, an average of 16 km/h.  Once at home, my quads let me know that they were not entirely happy with the day, but some stretching eased the stiffness.  And remarkably, my time was around my “usual” for a there-and-back 😊 .
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Non-Thorn Related / Re: +++Rides of 2024+++Add yours here+++
« Last post by John Saxby on Today at 01:53:33 am »
Six weeks of rides from spring into early summer –

After an early end to a mild dry winter with barely 110 cms of snow – half of Ottawa’s longterm average of 220 – we waited for spring, and waited some more.  After the Easter weekend at the end of March, I rode across the river and into the Gatineau Hills.  Below, some notes and a few photos from several rides from early April to mid-May.

In early April the woods were desperately and dangerously dry.  (See Photo 1 below) The big river, the Ottawa, was a metre or more lower than its usual level during the spring run-off – no kayakers riding the big waves midway between the Ontario and Québec shores.  Up in the hills, the usual gurgling streams of spring were silent, reduced to a few semi-stagnant pools barely dripping into one another.

“Normally”, I would not ride up to Pink Lake lookout until late April, when the parkway would be free of snow and ice.  Photo 2 below shows Freddie at Pink Lake under a pale early-April sun.  The ride across the river on the Champlain Bridge, nearly a mile wile, is always a treat.  Photo 3 below shows the Québec side of the bridge from the bikepath downstream.  This photo, taken from a gap in the shrubbery at the water’s edge, gives a rider’s view of the structure.  (The bridge crosses three small islands on the Ontario side.)

In the following 4-5 weeks, we have had some rainfall, easing our collective anxiety about summertime fire hazards.  And, just to remind us of the source of our passports, we had some 24 hours of the worst road conditions I’ve ever encountered in Canada, a mix of wet snow and wind-driven rain.  Fortunately, I made it home safely from my midweek evening shift at our bike-recycling shop 6 kms to the west of our place, exhaled, and thanked the designers of 10-year-old wee 4wd Subaru.

This “extreme weather event” was, the weather guys said, the result of a “Colorado low” – warm moist air from Mexico meeting cold sub-Arctic air from northern Canada over Colorado, and whirling northeast.  My reckoning is that a Colorado Low is the evil and lesser-known twin of the “Rocky Mountain high” of pop-culture fame.  And why, Mr John Denver, did you not tell the whole story?

But one of the real benefits of a bit more precip, combined with warming temps, is that all-of-a-sudden in early May, we lurched into early summer. Photo 4 below shows a roadside apple tree in bloom, a reminder that this part of the Gatineau Park was farmed from the mid-19th-century onwards.  (Hardscrabble it was, too, but that’s another story.)

(cont'd in next post)




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The Andra 40s I bought for my tandem were way off from Ryde's listed specs of 534mm and also off substantially from the information SJS Cycles provided me in good faith (534, with 536 as closer based n personal measurements). In the end, I had to get my wheelbuilding supplies in two stages -- first the rims so I could measure actual wheel diameter at the spoke seat faces to determine ERD in my spoke calculator and then the spokes.

I found mine had an actual ERD of 540mm as measured by myself, verified when several spoke calculators agreed and my tensioned spokes ended even with the bottom of the nipple slots, as Phil correctly advised...

Quote
*Opinions vary, but the correct answer is flush with the bottom of the slot  ;)

Right. :) My standards are spokes ending at the bottom of the nipple slot as well. This ensures maximum thread engagement without the spoke protruding past the end of the nipple. Get the spokes too long and you can run a bit short on threads depending on nipple length used and you've got to deal with protrusion. Too short and the brass or alloy nipple supports the load on the hub side of the rim with the spoke end in the exposed end of the nipple column. The nipple is soft and includes lots of internal threads as stress risers. You might get away with it but a wheel with uniform high even tension will sometimes result in nipple fractures if the spokes are too short. What you want is full engagement with the nipple collar serving as the terminus for the spoke end.

Best, Dan.
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Thorn General / Re: Mullet nomad mk 2 (26" rear -- 27.5" front)
« Last post by E-wan on May 21, 2024, 06:30:39 pm »
Plenty to think about

For now, I've got 26-inch wheels front and back, but with a much wider rim on the front.

Velocity Dually 26”
https://www.velocityusa.com/product/rims/dually-559

This has a 39mm internal diameter compared to the Ryde Andra 30 which I think is 19 mm internal diameter on the rear.

It makes a noticeable difference to the tyre profile with more of the tread in contact at the front.
(it also lets me run tubeless at the front with pepi tire noodle, insert so that when I'm not carrying lots of luggage upfront, I can use a lower tyre pressure).

For interest, I'll probably end up trying the 27.5" Front wheel after seeing how this current set up handles for a few months.


While theoretically this might all make sense; on my E bike which I use for commuting with moderate load. I've got 27.5 inch wheels front and back but a much wider front tire.
2.35" at the back and 2.8 at the front"

Since making this change to a much wider front tire on the E bike the handling has felt much more stable and giving me a lot more confidence on my commute. (about 15 miles each way half of which is off-road on relatively rough tracks)

However, I did make other changes to the E bike at the same time, such as bamboo handlebars and a redshift suspension stem.

Will report back in a few months once I've made a comparison.

Ewan
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Online spoke calculators are telling me 266mm (for a 32h hub, 700c wheel, 2 cross lacing).
SJS suggested I buy the 270mm spokes.
Based on what ERD? If you're using a calculator where you can pick the rim rather than enter the ERD, they may be using manufacturers information and Rigida are notoriously bad, I think they measure to the face of the rim rather than where you want the spoke to end*.  I've already said what I'd do, measure a rim myself.  If you're not going to do that, I'd suggest buying rims and spokes from the same supplier, on their recommendation, at least if they get it wrong you have an argument for returning them (Something unlikely to happen if you specified them and had a go building with the wrong length!)

*Opinions vary, but the correct answer is flush with the bottom of the slot  ;)
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Did SJS say what length nipples they use with those spokes?

I am not sure why there would be a difference, but I remembered hearing in the past that SJS used a different length.

I built up my wheel with 36 spokes and I think SJS only does 32, so I never asked them what to use, I used the table from Rohloff.  This table is dated 2019, I built my wheel in 2014, so I do not know if there is a difference.
https://www.rohloff.de/fileadmin/user_upload/erd_32_36_Speichenlaenge_03_2019_de_en.pdf

Different topic, if your hub is an old one that did not come with the flange reinforcing rings, you might consider adding those at the time you build your new wheel.
https://www.rohloff.de/en/company/news/news/flange-support-rings

I added the rings to my hub, even though I was not rebuilding the wheel at that time. I have ridden into remote areas where I did not want a wheel failure.  The rings do not make the hub flange stronger, but if a spoke pulls out a piece of the flange, the ring will hold it in place so you can keep riding, then fix it later.
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Thanks everyone.
All super useful advice. I'm still getting some conflicting answers.
Online spoke calculators are telling me 266mm (for a 32h hub, 700c wheel, 2 cross lacing).
SJS suggested I buy the 270mm spokes.

Just wondering about this difference. Is that the kind of difference that doen't make much difference? or is there some reason why slightly longer spokes are going to work better, in spite of what SJS says?
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Thorn General / Re: Mullet nomad mk 2 (26" rear -- 27.5" front)
« Last post by Andre Jute on May 20, 2024, 07:08:40 pm »
What do you make of this description of the way the force vectors change with a larger font than rear wheel from mullet cycles
https://www.mulletcycles.com/mullet-bike-technology/

These mullet guys are describing a bike specialised for a gravel road without either crosswinds or other traffic and no close ditches or berms either. It has nothing to do with touring bikes because they are trying to shift even more of the bike's weight onto the rear axle, which on a touring bike like your Nomad, if Andy Blance had done it, we'd ask if he was all right on the day. (Yeah, I know, Mr Blance wouldn't, he is too experienced; I'm making a dramatic illustration.)

For those who're already put off by this sort of theoretical discussion, you can discover where the mullet guys went wrong by searching in the link E-wan gives for the word hysteresis. You won't find it, because the mullet guys say nothing about it, but it is what makes the tyres of all other bikes, except only bikes on a loose surface like gravel, work so well. Hysteresis is technically defined as an effect lagging its cause, and describes the compound of the contact patch on the tyre resisting change of direction or any other input, nibbling itself into the changed state. Okay, now you don't need to read the rest, because you don't want to turn your touring bike into an awkward duckling under perfectly normal circumstances for a tourer (weight distribution, crosswinds, heavy traffic close by your bike), even dangerous if you go too far.

The mullet guys even tell us it is a pure marketing exercise:
Quote
Bike Geometry is a standard of measure used to market how a bike is supposed to handle.

Remember when I pointed out that, regardless of what ERTRO permitted the clowns among the manufacturers to do for cost reasons, a "29-er" with rims less than 40% of tyre width across the rim beads was not, repeat not, a 29-er, but a fashion-victim's acceptance of his fate.

In the very next sentence, the mullet guys give away the game:
Quote
However, geometry plays a very small part in how the bike’s tires contact & react to the ground while in motion.

This is goldtropchen slurry-grade manure. The geometry of the bike, and all its dynamic vectors and all its weight, and all the inputs by the cyclist, react only through those two contact patches. But the misleading statement goes with "marketing" if you want to sell something else. That they contradict themselves in the very next sentence is par for this sort of marketing guff, five bob each way, but is too late. They've already given away the game.

I can do the same analysis sentence by sentence but there's no point. I'll just pick one more lowlight:
Quote
One major factor left out of traditional bike design is how the rear wheel turns & reacts with the terrain.
[my emphasis]

This is more prejudicial nonsense. How the rear wheel turns and reacts with the terrain is automatically arranged in the standard safety bicycle (whose distinctive feature in contrast with the penny-farthing is its two equal-size wheels) by hysteresis as described above, a valuable safety feature in that it automatically adds understeer. And also, I might add, on gravel or loose sand by the "terrain" shifting under the tyre, an analogue for hysteresis. The mullets substitute "scrub radius" but the effect is the same.

The mullets know exactly what I'm talking about, and tell us so when they mention "dirt bike geometry" and label the symmetrical bike (same size wheels and tyres) a "safety bike". It's apples and oranges -- and only the dirt bike will benefit from the mullet, and be a trailer queen if you live some distance on busy roads away from the dirt. Nothing to do with touring bikes.

If you're still with E-wan and me, try looking at the mullets' illustrations, which are pretty good conceptually, if you're planning a dirt bike. Again, nothing to do with touring bikes. But note that the steering vector of the rear wheel is faster on the mullet, which is less safe than on the safety bicycle.

WHY IS THE MULLET NOTHING TO DO WITH TOURING BIKES?
A touring bike, or a utility bike for that matter, needs first and foremost to protect the rider, which by definition means same size wheels and tyres (or very small differences in tyre diameters and/or widths) with understeering geometry. The touring and utility bike needs to be ridden on any road surface the cyclist might meet, which the safety bike does superbly well, especially if fitted with fat tyres. Finally, the touring and utility bike must be intrinsically safe in all its designed elements which, besides relaxed geometry, means a centre of aerodynamic pressure well back on the bike (and permanently behind the centre of gravity otherwise the bike will swap ends in a blink at the slightest crosswind--or suck you under a passing truck), and predictable in response which also means understeer which in turn requires a rising couple towards the rear for the centre of gravity.

I hope you won't think I'm a neanderthal luddite, E-wan. It's your bike; you do what you want. I put up these articles for information to everyone, but I'm not trying to persuade anyone of anything. In fact, I enjoy hearing about other people's experiments; the guys who're taking one for the team always get extra kudos from me. If you're doing it anyway, I for one would love to hear your impressions.
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Bikes For Sale / Re: Thorn Nomad Mk2 in Excellent Condition - Size 565L
« Last post by GBR66 on May 20, 2024, 06:10:38 pm »
Thank you - I hope so, it is just wasted on me.  I did a trial 2 day 110 mile trip to "fettle' my gear and would love to do a proper expedition....also good round the lanes on the terrible road surfaces we have for general riding.
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Bikes For Sale / Re: Thorn Nomad Mk2 in Excellent Condition - Size 565L
« Last post by in4 on May 20, 2024, 05:49:31 pm »
Someone is going to have a great summer riding this beauty.
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