Danneaux's Nomad

[triaesthete]

I spy the heritage of the Raleigh Chopper in that Sting Ray. http://en.wikipedia.org/wiki/Raleigh_Chopper

Dan! What was your father thinking!

 In England in the early 70s there were two types of parents: Those that bought their children Raleigh choppers,and those that didn't because they were "gimmicks". 

My parents even took much persuasion on drop bars as so many kids (so the papers said)  rode into the back of parked cars and skips. Mind you they were right about mudguards!

Thanks for your c of g overlay too. The novel and clear presentation demonstrated clearly to me the need for greater front/rear tyre pressure differential than I had been using based on my assumption of 55/45 rear/front weight distribution. This was clearly incorrect as I probably ride more upright than you.  Very very useful indeed, thanks.

Ian aged 10.

[mickeg]

My bathroom scale is about the same thickness as a common piece of lumber used in construction in USA.  I put one wheel of my bike on the scale, the other wheel on the lumber.  I then put some bricks on the ground that I could stand on to get on the bike, since my top tube was now roughly 40mm higher I needed the bricks.  I did this reasonably close to a building wall, it was an iterative process, I shifted the setup closer or farther from the wall until I had it right.  By leaning against the wall, just barely with almost no pressure on the wall but enough pressure so that I did not fall over, with my hands on the handlebar where I would normally have them when I ride, I could measure the weight on one wheel with me on the bike. Then repeat the process with the scale under the other wheel.  I did this several years ago with my Long Haul Trucker.  When I did that measurement, I got 90 pounds on the front wheel, 150 on the rear. 

At that time I weighed roughly 35 pounds (~15 kg) more than today, but I do not see it as an important reason to repeat this experiment for my new weight.  I also have not repeated it with different bikes since my three touring bikes all have similar length chain stays and similar wheelbase lengths and all three use about the same geometry with drop bars.

Using this article chart for weight with 37mm width tires:
http://www.bikequarterly.com/images/TireDrop.pdf

That correlates to about 68 psi rear and 38 psi front UNLOADED.

If I add a load of 40 pounds rear and 20 pounds front with 37mm tires which is roughly what my camping and touring gear weighs, that correlates to about an additional 16 psig rear and additional 8 psig front, for total of 84 psig rear and 46 psig front.

But, for touring on this bike I usually have run about 65 to 70 psig front, 85 psig rear.  The 37mm tires I use are rated for a max of 87 psig.  In other words doing the math was interesting, but I am not really using the results of the calculations.

I have not redone the calculations for my Thorn bikes, when I did the calculations on the LHT, that was the only touring bike I owned.  And, I usually use 50mm wide or wider tires on the Thorns, I think that the author's selection of 15 percent for tire drop was specific to narrower road tires on pavement, not the wider off road tires that I am more likely to use off of pavement with one of my Thorns.  I did one tour on the Sherpa with 40mm wide tires on pavement, I used about the same pressure on that tour as I have used on tours with my LHT 37mm width tires.

[Relayer]

I'm not sure I would use weight on each wheel to calculate tyre pressures, especially when you end up with far lower pressure on the front; remember your centre of gravity will move forward when you are going downhill.

[Danneaux]

Good methodology and thoughts, mickeg and Relayer!

I'm not sure I would use weight on each wheel to calculate tyre pressures, especially when you end up with far lower pressure on the front; remember your centre of gravity will move forward when you are going downhill.

I agree; I have found tire pressure did not necessarily correlate directly with weight distribution. After many careful trials, I have settled on F/R tire pressures of 29/34psi or 1.99/2.34bar for riding unladen with the setup shown in the photos above.

I have not yet measured my F/R weight distribution on the Nomad when carrying various touring loads, but have found 45/55psi or 3.1/3.8bar works well for me carrying very heavy loads on very rough ground.

It isn't all about comfort and rolling resistance. Please note Andy Blance's recommended maximum F/R pressures of 53/60psi or 3.65/4.1 bar for 2.0 tires: http://www.sjscycles.com/thornpdf/ThornRavenNomadBroHiRes.pdf pg.6. Fat tires can exert considerable lateral forces on sidewall beads when pumped to high pressures, and this has been known to fracture/split rims, sometimes at the sidewall or right down the center: http://forums.mtbr.com/wheels-tires/cracked-rim-opininon-needed-718410.html

EDIT/Addendum: Below ~29psi in front, I felt like I was "pushing" a too-low tire on pavement when riding unladen (wheelbarrow effect). It would be interesting to see what might happen if I pumped the rear tire from 34psi to perhaps 38psi or 40psi now I have the Thudbuster LT to absorb road shock form the rear. I'll probably stay with what I have, but it will still be fun to experiment when I find time.

Best,

Dan.

[Danneaux]

Hi All!

An addendum to the seatpost trials...

Earlier in my Thudbuster seatpost reviews, I mentioned I wasn't using anywhere near the full published travel and the results were still excellent. Curious to learn how CaneCreek (who build and sell Thudbusters under license) got their published travel measurements, I emailed them and received their reply, as noted. I put the same query to the folks at Thudbuster.com and today brought a very informative reply from Ryan McFarland, inventor and founder of Thudbuster...

The suspension does move on an arc… if you were to measure the distance from top-out to bottom-out, it would measure (along the arc) to nearly 3.5”.  If you measure the straight line (rather than the arc) from topout to bottomout, you’ll get just slightly over 3”.  That is a pretty big bump though and you’ll not want the suspension set so soft that it is using that on small bumps or you will likely hard bottom the mechanism when you hit something bigger.  Like most suspension, you operate in the upper ˝ of the travel most of the time and the lower ˝ is there when the occasional big hits come.

This is consistent with what I have found in my own trials of the LT version. It continues to work very well for my needs even on extremely rough roads at slow and touring speeds and it is nice to know there is still some "give" remaining under compression in case I get caught out and hit a large unseen bump while seated. I will continue to stand ("post") and ease over larger bumps, of course.

Best,

Dan.

[Danneaux]

Hi All!

Since deciding to keep the Thudbuster LT seatpost, I sent for a neoprene cover for it to keep the pivots clean and free of moisture and wind-blown dirt. These are variously sold as "Crudbusters" or "ThudGloves" but are the same product, with models specific to either the ST or LT seatposts. Pics online show the ST's cover logo reading vertically and the LT cover's logo reading horizontally.

The first one -- via Amazon from a shop I've used successfully in the past -- was an ST cover in an LT-labled zip-top package, and carried the ST-style logo. I returned it for a refund, as it would.not.fit no matter how much I pulled and stretched.

The second one arrived in today's mail, also from a trusted supplier. It also sports the ST-style logo, but the velcro is on the opposite side and the cover "reads" verticaly from the rear, like the engraving on the 'post. With some effort, it slid on with no slack -- it is drum-tight. The velcro goes in the rear, and it does just fit, where the first one didn't come close to fitting the LT's longer links.

I think the first cover was mislabeled and the second sports a revised logo (see attached pics). Once on, all seems well.

I have a support ticket in to Cane Creek to confirm all is well given my cover has the "wrong" logo, but the results are encouraging. Since there seems to be considerable confusion among online reviewers about how to fit these (no instructions or photos are included with the covers), some photos seemed in order.

I  will probably use a black acrylic paint pen to cover the white logo so it will blend in better with my black Nomad.

Best,

Dan.

[jags]

 ;)looks nice and neat dan happy cycling buddy.

[mickeg]

If I did not know better I would think you have a spare tube wrapped around your seatpost.

[Relayer]

Looks good with the cover   

[Danneaux]

  Thanks for the thoughts on aesthetics, fellows.

I wish there was a way to get the Thudbuster LT's function with the appearance of a conventional seatpost, but the positive difference in ride and usability make the sus-post a winner in function-over-form much like the rest of the bike, which is a tool suited for my specific needs.

I have traditional "randonneur-style" bicycles and touring bicycles in my stable, but the Nomad has evolved to be everything they are not, and excels at its given purpose far better.

I can always grab another bike if I want "faster" or "lighter" or more conventionally "pretty", but the one I'm riding most is still this odd-looking do-anything, go-anywhere-in-all-weather super-duty drop-'bar expedition-tourer-and-road bike-MTB mashup. It is my "hyphen-bike", a Swiss Army knife of go-anywhere versatility. It doesn't really do anything my other bikes cannot; instead, it does those things better for me 'cos it is geared for extremes. That has sometimes come at a cost for lighter, less extreme duty, but things like the sus-'post make it better suited even for unladen use on-road or off.

Regarding the cover, it seems a good idea to keep the pivots protected to ensure longer service life, but I'm not so crazy about adding the flashy logos without the sponsorship money that comes with it. I think I'll go tone-on-tone and black them out for a more subtle appearance to better match the rest of the bike.

I've a few more ideas for the bike and am pondering how best to implement them. Meanwhile, I'll get started on the new spoke-retaining plug, assuming it isn't too cold out in the garage to work. It's been pretty cool at night (24°F/-4°C this morning), so I may wait till afternoon to turn and shape a new plug, cut it down, and fit it with reduced compression washers. I'll take some pics to show the finished product.

All the best,

Dan. (...who notices the thermometer still isn't cooperating, but sunny skies promise a warmer afternoon)

[George Hetrick]

Thanks for the pictures, Dan. I was putting my cover on backwards, and trying to figure out how to close the velcro tab (which was basically on the top) -- when I saw your picture all became clear.

[Danneaux]

George...

Does your cover have the same logo design and orientation as mine?

All the best,

Dan.

[George Hetrick]

Does your cover have the same logo design and orientation as mine?

A picture is worth 10^3 words ...
(sorry about the orientation problem -- it displays properly locally)

[Rotated photo. -- Dan]

[Danneaux]

Looks wonderful, George, and sets my mind at ease wrt to the unified logo change.

A very thoughtful posting; thanks! I hope yours works as well for you while riding as mine does. Love the thing!

All the best,

Dan. (...who thinks yours looks especially nice with that lovely hole-punched Brooks saddle)

[Andre Jute]

I agree. If Cane Creek want you to advertise their product, they should pay you.