Author Topic: Thorn Nomad MKII comments after 6000 km on dirt roads of American west  (Read 15344 times)

revelo

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1. Only design problem was the nylon rim strip. This got wrinkled up somehow when I was replacing the tire, and the sharp edge then later abraded my inner tube. I replaced with Velox cloth rim strips. I think Thorn should offer cloth rim strips as an upgrade. Based on this experience, I strongly advice against thorn (as in goathead thorns,  not Robin Thorn) protection liners, since these are even more likely to get installed crooked than a rim strip. Use sealants instead if goatheads are a problem. My full writeup on the subject of goathead thorns is here: http://frankrevelo.com/hiking/biking_flatprevention.htm

2. I cycled in wet conditions and never found a front fender or crud catcher necessary, partly because my typical speed is under 15 mph and that is not enough to fling much dirt up, partly because the down tube is so thick on the Nomad that it provides a good deal of protection by itself, but mainly because I get so filthy from perspiration and not bathing while touring that a little dirt from the road is hardly going to matter. Rear fender is definitely unnecessary when touring, because the rack bag protects me. Fenders might be needed for people who are freshly showered and wearing clean office clothes and who are traveling at higher speeds than what I can manage while touring.

3. I went with the 42/17 front/rear sprocket combo and that is working fine, but I'll probably switch to 40/17 since my existing gear 13 is almost as good as 14 for my purposes, while there might be some situations where I can use a lower gear than my existing gear 1. Low gears are more valuable than high gears for dirt road touring as far as I'm concerned. Also, I spend a lot of time in gear 7 now and moving to 40/17 might allow me to spend more time in the quieter gear 8.

4. Chain wheel takes a beating when dragging the bike over boulders. I haven't noticed any damage to my chain wheel, and these Thorn chain wheel are from the high-quality 7075 alloy rather than cheapo aluminum, but they are still aluminum. Anyone broken their chainwheel teeth from banging on rocks? Anyone gone with the steel Surly chainwheel as a sturdier alternative?

5. Though an IGH like the Rohloff greatly reduces the need for a clean and flexible chain, some maintenance is still needed if traveling in very dusty areas. If sticking to paved roads, I could probably just ignore the chain for months at a time with a Rohloff IGH. My scheme for cleaning the chain in the field or motel parking lots is as follows. Bring along a toothbrush, 250ml bottle of citrus chain cleaner, some paper towels and a bottle of silicone lube (White Lightning Epic Ride). Dip the toothbrush in the bottle of chain clean and then wipe it against the chain. Then wipe the chain with a paper towel. Finally, apply new lubricant. Be sure the top to the lube bottle is secure. Avoid the prolink Gold bottle, since it will leak due to changes in atmospheric pressure as you go up and down mountains.

6. The 640mm wide Thorn flat-track handlebars work nicely, but are just barely wide enough for me (I'm 182cm tall). I think Thorn should make the bars slightly wider to accommodate taller riders. Wide handlebars are essential on descents on rugged roads.

7. I've changed the Rohloff oil twice so far and the procedure is much easier than I expected.

8. Pedro's Vice whip is expensive, but makes removal of the Rohloff sprocket much easier than using a chain whip. "Quality is remembered long after price is forgotten" applies to this vice whip just as it does to the Rohloff hub and the other high-quality components of the Nomad. Another adage to keep in mind: "Only a rich man can afford cheap tools". Also, writing off the Vice whip over 20 years makes the price much more bearable.

9. If going with the Shimano PD-MX30 pedals, make your decision about long or short screws BEFORE the screws get filled with mud, because then they will be impossible to remove (the tiny allen wrench goes inside the screws). The long screws give better traction but I nevertheless went with the short screws, because the long screws cut my leg while I was pushing the bike. Better to have my feet slip now and then than tear up my legs and pants.

10. I rest the bike on its right side each night while touring, since my Mirrcycle mirror is on the left side. (We Americans drive on the right side of the road.) This causes some oil leaks out that side (sprocket side). British cyclists who have a Mirrcycle mirror on the right side might rest the bike on left side, in which case oil would leak onto the EX box. Anyone had a problem with this?

11. I noticed some abrasion to the inside of the chain stays, right where the tires pass. Not sure what this is from, since there is plenty of clearance between the chain stays and tires. anyone else had this problem?


12. In general, I am very happy with my Nomad. I was a bit apprehensive at first about the Rohloff, but now I have complete confidence in it. The sturdy Rigida Andra CSS rims and well-built wheels mounted with Schwalbe Mondial 55-559 tires also give me tremendous confidence. And there is little wear on either the rims or the brake pads, despite riding the brakes constantly while descending mountains.

13. The only thing I would possibly change is to go with the lighter Nomax-X frame. I use the 590M frame size, my max load is 40KG (10kg gear and bike spares, 7kg food, 23kg water) and I weigh 80kg including clothing and boots. I'm not counting racks or panniers as part of my gear. Rather, I consider them part of the bike itself, which thus weighs about 20kg. Anyway, this is right at the limit of the Nomad-X capacity. If my frame size were smaller, I would definitely go with the Nomad-X and if my frame size were larger, I would definitely stick with the Nomad. Anyone used both the Nomad and Nomad-X who could comment about a situation like mine? I have no plans to order a new frame, but I would like to be more informed about this issue so I can advise other people better.

My full writeup on the Nomad is at http://frankrevelo.com/hiking/biking_nomad2012.htm
« Last Edit: October 23, 2012, 01:21:05 am by revelo »

JimK

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Re: Thorn Nomad MKII comments after 6000 km on dirt roads of American west
« Reply #1 on: October 23, 2012, 02:43:18 am »
Thanks, Frank, it's really great to get such reports - detailed, and based on pushing the bike hard.

Matt2matt2002

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Re: Thorn Nomad MKII comments after 6000 km on dirt roads of American west
« Reply #2 on: October 23, 2012, 12:51:49 pm »
Great post
So much to take in

Interesting point about inside chain stay wear.
Wonder if anyone will come up with the answer?
Never drink and drive. You may hit a bump  and spill your drink

Andybg

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Re: Thorn Nomad MKII comments after 6000 km on dirt roads of American west
« Reply #3 on: October 23, 2012, 01:38:49 pm »
I think PeterNZ on here has a Nomad and his friend has a Nomad x so he has ridden both. He seems more than happy with his choice. May be worth you having a look at his thread in the Gallery.

Andy

revelo

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Re: Thorn Nomad MKII comments after 6000 km on dirt roads of American west
« Reply #4 on: October 23, 2012, 03:39:40 pm »
I think PeterNZ on here has a Nomad and his friend has a Nomad x so he has ridden both. He seems more than happy with his choice. May be worth you having a look at his thread in the Gallery.

Andy

I looked in the list of members and didn't find any PeterNZ. Maybe that's his real name and his user name is different?

[Edit: never mind. NZPeterG. But he didn't have that much too say on the subject from the posts I could find, other than the weights were similar and he could hardly tell the difference. Maybe that's the right answer. To wit, once you load a bike up with gear and heavy tires and rims, 500g frame difference hardly matters, assuming both frames can actually carry the load.]
« Last Edit: October 23, 2012, 04:21:45 pm by revelo »

Danneaux

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Re: Thorn Nomad MKII comments after 6000 km on dirt roads of American west
« Reply #5 on: October 23, 2012, 04:18:40 pm »
Here you go, Frank, a link to NZPeterG's gallery page here:
http://www.thorncycles.co.uk/forums/index.php?topic=4418.0

Best,

Dan.

revelo

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Re: Thorn Nomad MKII comments after 6000 km on dirt roads of American west
« Reply #6 on: October 23, 2012, 04:25:52 pm »
Yes, thanks Dan, I found that just before you posted.

Danneaux

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Re: Thorn Nomad MKII comments after 6000 km on dirt roads of American west
« Reply #7 on: October 23, 2012, 04:52:22 pm »
Hi Frank!

I've delayed responding about your scuffed chainstays because I've been putting a lot of thought into the matter. Like you, I have a 590M Nomad, but the difference is I am running 26x2.0 Schwalbe Duremes. Mine shows no similar damage, and I keep looking to see what could possibly cause the problem.

Please, can you tell us a little more about the scuffing? What I'd like to know a bit more about is...
1) Is the scuffing on both inside chainstays, or only the right side (I think that's the left side in the photo?). It sure looks to be only on the tire side, and right where the chainstay swells closest to the tire. Can you correlate the scuffing with a particular part of the sidewall? In other words, is it where the tread-cap meets the sidewall, or further down, where the sidewall swells out?

2) As far as you can tell, was it a one-shot occurrence, or has it recurred (wondering if you might have touched-up the area with paint, only to have it scuffed again).

3) Any sign of similar scuffing on the insides of the rear v-brake arms? (wondering if whatever caused it whipped around to the top as well).

Whatever has caused it, it must have resulted from a repeated scuffing to have removed the paint so thoroughly. Thinking about how the goathead thorns penetrate and stick in the tires...could something else have gotten picked up and rotated a few times by the tire before it fell out? [EDIT: I wonder...could some sun-warmed tar have come loose from the road and stuck to the tire long enough to grind on the 'stay as the wheel rotated? I've sometimes had this happen on the tread itself, and it makes an awful racket inside my fenders (mudguards) till it fall off. I suppose it might be the culprit if it stuck to the side of the tread cap...].

This looks so much like when a hub quick-release becomes loose in ramped dropouts and the wheel is pulled askew by pedaling torque, but of course that is impossible in this case, thanks to Thorn's use of vertical dropouts.

I'm currently reading an anthology of "locked room" mysteries that includes stories written as far back as the late-1800s. I don't think any of them are as baffling as this problem!

Best,

Dan. (....not "Elementary"...so far!)
« Last Edit: October 23, 2012, 04:58:52 pm by Danneaux »

NZPeterG

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Re: Thorn Nomad MKII comments after 6000 km on dirt roads of American west
« Reply #8 on: October 24, 2012, 10:10:35 am »
Here you go, Frank, a link to NZPeterG's gallery page here:
http://www.thorncycles.co.uk/forums/index.php?topic=4418.0

Best,

Dan.

Very good Dan,
But here it the right link.. http://www.thorncycles.co.uk/forums/index.php?topic=1208.msg24727#msg24727
Because the "X" is almost the same weigh as the STD Nomad, I think that the L are better sized for offroad  cycling then M size frame's.
As for the wear to the paint inside of the chain stays, this has always been around as long as MTB's have been around (late 1970's)

Pete.....
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il padrone

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Re: Thorn Nomad MKII comments after 6000 km on dirt roads of American west
« Reply #9 on: October 24, 2012, 10:33:33 am »
The paint rub on your chainstays - I'd agree with Danneaux, this is one of the more obscure frame damage problems. Vertical dropouts make tyre rub impossible. Maybe on you 6000 dirt rd kms you have picked up a lot of mud on your tyres at some stage and been riding through with it? The mud might cause such abrasion - depends on the dirt composition.

However I have had such mud build-up on my old Giant Sedona (vertical dropouts) to the point that the wheels would not turn, and I've just checked the chainstays..... no paint rubs there. Same with my Thorn Nomad Mk 2, after 1600kms in the outback.... no paint rubbed off.  So I don't have an answer for you  :-\

Incidentally, re mudguards and water/mud I have to make a couple of comments - I would fairly rarely get much above 15mph (25kmh) on a loaded tour unless there was some gravity or wind assistance, but I certainly find water gets flung from the tyres at this speed. True, the Thorn frame and your touring load will stop much of the water, but your feet will cop a pasting and I hate drenched shoes. Also one of the main advantages of mudguards is that they keep your bike significantly cleaner, always something to value on a long trip.

revelo

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Re: Thorn Nomad MKII comments after 6000 km on dirt roads of American west
« Reply #10 on: October 25, 2012, 01:45:12 am »
Very good Dan,
But here it the right link.. http://www.thorncycles.co.uk/forums/index.php?topic=1208.msg24727#msg24727
Because the "X" is almost the same weigh as the STD Nomad, I think that the L are better sized for offroad  cycling then M size frame's.
As for the wear to the paint inside of the chain stays, this has always been around as long as MTB's have been around (late 1970's)

Hi Pete. Could you elaborate on that last statement?

There's less than 1cm of space between the 55-559 Mondials and the chain stays, so I suspect what is happening is that mud is being scraped off there and it eventually abrades the paint. I haven't cleaned the bike since I got back and there is a coating of mud on the inner chain stays where the abrason occurred previously, with vertical lines in this coating of mud, as if something had been scraping that mud. Mostly I ride in dry weather, but even dry dirt and dust clings to the tires and some of inevitably circles all the way around and comes off on the chain stays. 6000km is a lot of revolutions of that rear tire. So I'd tend to agrees that this has always been a problem with MTB's.

As for L and M frames, my previous bike before the Nomad had geometry like a 565L and it was definitely less comfortable for me than the 590M before it forced me into a more bent over ("aggressive") posture than I prefer. I like being in a more upright position for long distance touring, whether on paved or rugged dirt roads.

Anyway, regarding the Nomad and Nomad-X issue, I think the differences would be minor for a 590M. But still, no need to add weight unnecessarily. So the question becomes, assuming a typical load of 30kg and a max load of 40kg and rider weight of 80kg including clothes and boots, would going with the Nomad-X rather than Nomad for the 590M result in frame damage? I'm not worried about a little wobbling when loaded with 40kg, because the bike is already cumbersome to use on rugged roads at that weight simply because it is so heavy. A little extra wobbling is hardly going to make a difference to me. I'm mainly concerned with permanent damage to the frame, like cracking of the welds. Anyone feel free to throw in opinions on this subject, whether informed or not, and I'll weigh the results (wisdom of crowds approach).

revelo

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Re: Thorn Nomad MKII comments after 6000 km on dirt roads of American west
« Reply #11 on: October 25, 2012, 01:58:00 am »
Incidentally, re mudguards and water/mud I have to make a couple of comments - I would fairly rarely get much above 15mph (25kmh) on a loaded tour unless there was some gravity or wind assistance, but I certainly find water gets flung from the tyres at this speed. True, the Thorn frame and your touring load will stop much of the water, but your feet will cop a pasting and I hate drenched shoes. Also one of the main advantages of mudguards is that they keep your bike significantly cleaner, always something to value on a long trip.

I found the contrary to be the case. The mudguard and crud catcher both collect mud and then make it that much more difficult to clean the bike. The mudguard, in particular, can be a menance in heavy mud, since so much mud collects that the wheels won't turn. I had this happen to me the very first time I used the mudguards. The Mr Crud crud catcher didn't have this problem, but on balance it didn't seem to do much good, which is why I discarded it. Many people say rim brakes don't work in the mud and that has always been one of the major arguments for disk brakes. My experience, in the same sort of mud that would have jammed the wheels if I was using mudguards, is that the rim brakes quickly cleaned themselves off without my having to stop and clean the mud off with a stick or similar. Typically, I only encounter patches of mud, such where a dirt road dips down and water collects in a puddle after rain and mud forms. The tires and brakes get muddy when I pass through these patches of mud, but then the brakes clean themselves off with a few squeezes. I have no experience of non-stop mud (and don't want any such experiences either!  :) )

As for drenched shoes, that is of no concern for me while touring.

revelo

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Re: Thorn Nomad MKII comments after 6000 km on dirt roads of American west
« Reply #12 on: October 25, 2012, 02:08:57 am »
Can you tell us a little more about the scuffing? What I'd like to know a bit more about is...
1) Is the scuffing on both inside chainstays, or only the right side (I think that's the left side in the photo?). It sure looks to be only on the tire side, and right where the chainstay swells closest to the tire. Can you correlate the scuffing with a particular part of the sidewall? In other words, is it where the tread-cap meets the sidewall, or further down, where the sidewall swells out?

2) As far as you can tell, was it a one-shot occurrence, or has it recurred (wondering if you might have touched-up the area with paint, only to have it scuffed again).

3) Any sign of similar scuffing on the insides of the rear v-brake arms? (wondering if whatever caused it whipped around to the top as well).

Whatever has caused it, it must have resulted from a repeated scuffing to have removed the paint so thoroughly. Thinking about how the goathead thorns penetrate and stick in the tires...could something else have gotten picked up and rotated a few times by the tire before it fell out? [EDIT: I wonder...could some sun-warmed tar have come loose from the road and stuck to the tire long enough to grind on the 'stay as the wheel rotated? I've sometimes had this happen on the tread itself, and it makes an awful racket inside my fenders (mudguards) till it fall off. I suppose it might be the culprit if it stuck to the side of the tread cap...].

This looks so much like when a hub quick-release becomes loose in ramped dropouts and the wheel is pulled askew by pedaling torque, but of course that is impossible in this case, thanks to Thorn's use of vertical dropouts.

I'm currently reading an anthology of "locked room" mysteries that includes stories written as far back as the late-1800s. I don't think any of them are as baffling as this problem!

No scuffing on the seat-stays or V-brake arms, because there is much more clearance there. The scuffing is right where the tread meets the sidewalls. On the mondials, this is the widest point of the tires and does collect dirt and mud. And the scuffing is on both chainstays. I touched up the area, but it is now covered with mud. It is definitely not from the wheel mounted wrong or getting untrue, because I am very alert to any rubbing of the rear brakes. Indeed, that is one of the things I check daily, by lifting the biking and spinning to check for brake rubbing. The brakes would rub the rims long before the tire was pushed far enough to the side to actually rub the chain stays.

As noted above, I agree with NZPeterG that this is always going to be a problem with MTBs using tires wide enough that there is little clearance between tire and chain stay. The tire simply picks up mud and dirt and pebbles and then flings some of this crud at the chain stay. Do this long enough and you eventually abrade the paint. A mudguard would make things worse, since that would cause additional crud to hit the chain stay from ricocheting off the mudguad.
« Last Edit: October 25, 2012, 02:12:25 am by revelo »

Danneaux

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Re: Thorn Nomad MKII comments after 6000 km on dirt roads of American west
« Reply #13 on: October 25, 2012, 04:10:26 am »
Hi, Frank!

Thanks for the fuller explanation of the rubbing and areas where it occurs. Yes, it surely sounds like dirt and mud, carried by the tires and then rubbing with successive revolutions of the wheel.

As a suggestion to ponder, perhaps a small bit of black tape applied to the area after painting would provide a bit more abrasion resistance and prevent a recurrence while protecting the area.

Regarding the suitability of the Nomad X for your proposed use, it might be worth sending an email inquiry to Andy Blance to get his take on things. As designer, he would be most likely to provide an informed opinion, and might be intrigued by your proposed use. If you do check with him, can you let us know his reply? I'm sure others have similar questions related to similar use. As an aside, I see Andy himself rides a 590M with straight 'bars. It is pictured on page 14 of the Autumn Update 2012 edition of Andy B's Living With A Rohloff downloadable brochure, available here: http://www.thorncycles.co.uk/thornpdf/ThornLivingWithARohloff.pdf

Best,

Dan.

NZPeterG

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Re: Thorn Nomad MKII comments after 6000 km on dirt roads of American west
« Reply #14 on: October 25, 2012, 09:39:45 am »
No scuffing on the seat-stays or V-brake arms, because there is much more clearance there. The scuffing is right where the tread meets the sidewalls. On the mondials, this is the widest point of the tires and does collect dirt and mud. And the scuffing is on both chainstays. I touched up the area, but it is now covered with mud. It is definitely not from the wheel mounted wrong or getting untrue, because I am very alert to any rubbing of the rear brakes. Indeed, that is one of the things I check daily, by lifting the biking and spinning to check for brake rubbing. The brakes would rub the rims long before the tire was pushed far enough to the side to actually rub the chain stays.

As noted above, I agree with NZPeterG that this is always going to be a problem with MTBs using tires wide enough that there is little clearance between tire and chain stay. The tire simply picks up mud and dirt and pebbles and then flings some of this crud at the chain stay. Do this long enough and you eventually abrade the paint. A mudguard would make things worse, since that would cause additional crud to hit the chain stay from ricocheting off the mudguad.

Thanks that is the point I was trying to say, But after working 11+ hour days! it's just to hard to think and write after working.
Trying to save for my next tour  ;)

Pete..
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