2_i 

Fenders?

Winfried

On the rear, I removed the (nice looking but 300g) wooden board on the rack and attached a plastic fender.

As for the front, the collapsible fender seems to hold better. At worst, I could replace it with an ass saver cut to fit — while less aesthetic, a small fender could have been installed below the top tube permanently.

Duragrouch

OHHHHH! I didn't grok that you had an Ahooga! I hadn't noticed that was YOU who posted the video. Oh that'll be sweet when you convert it to 2X. A 50/34 won't add that many more gears, you'll have a bunch in the middle that are duplicates, but those 2 or 3 additional lows make all the difference on a steep and/or long hill that you can't climb all standing, so need to spin up. Pushing hard while seated can hurt my knees.

For travel, I should be able to get just as small with my 20" bi-fold, by taking off both wheels. But the Ahooga is a lot less effort to get that compact. Taking off the rear wheel on my bike is a mess, not to be done frequently.

Duragrouch

Uh, I just noticed a possible hiccup to swapping in a 2X crank. Now that I know the bike you are talking about, and looking at the pic in your first post (above), you may not be able to use a Hollowtech II (HT2) style crank, at least in the standard "road" chainline of 43.5mm. On my folder, the inner chainring with chain overlaps most of the external BB cup on that side. That means the chain on the inner ring may be very close or will actually rub on the righthand down tube, your bike's 2 tubes there are wider than a single downtube. It'll be close. That's why the current 1X crank has what you measured as 52mm chainline, much larger than mine (43.5mm). So, let's say, you find a Hollowtech II crank with that bigger chainline (possible, if designed for a much wider BB shell) and in BSA threading (what I guess your BB uses), or, use a square taper crank with a long BB cartridge, you still may have a problem: When I mounted my 50/34, I couldn't get the front derailleur in far enough inboard for the inner ring, due to the very big seat tube diameter, plus the thickness of the FD adaptor. So I spaced the bearing and crank outward 4mm. Two problems arose: 1) When on big chainring and big cog, would drop the chain when shifting to small chainring, because the chainline was off, and only 4mm. I always had to do that from the second largest cog or further out. 2) Left crankarm clamp connection came loose from the spindle, because extended 4mm off end of spindle, even though still had 70% engagement. Solution: My FD had an unusually large lip on top, overly strong in that area, I ground that off flush, only in the interference area, removed the 4mm spacers, put the crank back on, worked perfectly in every respect; No dropped chain, no crank arm coming loose, installed as intended, and at perfect chainline of 43.5mm. Note: My bike is 7-speed rear on 130mm spacing, so if yours is the same, it may not work well at 52mm chainline. Mine didn't at 47.5mm (with spacers), it needed to be 43.5mm (standard 2X road chainline spec).

I'd say, first off, try installing a square taper 2X crank on the same bottom bracket spindle, see how it looks, how close chain is to down tube.

I hope you can get it to work, because the frame folding design is excellent.

EDIT: I'm a huge fan of 2X cranks on 20" folders. But in this special case, if one won't fit due to the downtube configuration, this may be a candidate for 1X crank and megarange cassette. It looks like you already have a medium or long cage rear derailleur, it's a question of the maximum big cog size it can handle (my guess is 34, that's pretty standard), but there are other new derailleurs that can go much bigger, though it still needs to be finessed to not have the derailleur hang too low to the ground, such as chain length such that the derailleur cage is swung forward when on the big cog. Ron Damon, a frequent presence on the folder threads, seems to have specific knowledge in that department, he runs 20"/406 and 16"/349/305 bikes with big cassettes.

Ron Damon

Indeed. On 20" (406) wheels, the RD of choice is the affordable, medium-cage, 10-speed Shimano Deore RD-M6000-GS part which can span a 46T cog without problem.



For 11-speed, there's the pricier Shimano SLX RD-M7000-GS and XT RD-M8000-GS parts.

Duragrouch

Wow, it's like calling out for Superman, and he's there!

Ron, he's running a 7 speed freehub (hopefully), are there megarange 1X cassettes in 7? On a standard 7, he can't even fit 8, 8 needs a longer freehub.

Ron Damon

The issue is the RD and ground clearance. Say there is a mega-range 7-, 8- or 9-speed cogset, what medium-cage RD are you gonna use to span it? There simply ain't any in the Shimano lineup. 10-speed is where Shimano starts offering medium-cage RD that you can use with wide range cogsets. Again...and again...and again, the entry point is the Deore RD-M6000-GS, 10-speed part.

Duragrouch

Yes, I get that. I suppose this will clarify my question: For that Deore RD, are the linkage ratios workable with a 7 speed indexed shifter? Because there's no indexing on the RD itself. If yes, and someone makes a megarange 7 cassette, it should work. If not, then he has to, at minimum, swap out the freehub body (if that will fit), and if that doesn't fit on his hub, swap out the whole wheel for one with a 10 speed compatible freehub.

So on a new bike, that would be
- new rear wheel
- new cassette
- new rear derailleur
- new shifter
- (probably) new 10-speed compatible crank

A bit of an expense on a brand new bike. Unless 7 will work.

Thanks in advance.

Ron Damon

I don't know the answer to your question. Sorry. It's been at least a decade since I owned/used anything below 10-speed.


9-speed, 11-46T. Which GS RD, though?

Winfried

No issue with the chalnline with a compact 50/34 and a 52/34, for riding or folding. Considering how rare I need to shift to the smaller ring, I'd much rather use a double crankset and a smaller cassette such as the 7s that came with the bike.

To reduce the chance of the rear deraileur hitting something, I might replace the long cage Acera RD-M360 for either a medium cage or even a short cage eg. Claris RD-R20x . I wonder why the mfg chose a long cage for a 7s cassette, especially for a 20" wheel.

Once the Litepro clamp comes in, I'll report back at how the Sora front derailleur works with that setup.

Duragrouch

Fair enough. I'm sure no one has used that Deore RD on a 7 speed, but even if it did work with the shifter, it would assume they made a really wide 7 cassette, probably not, I don't see an option in sheldonbrown gear calc, and the jumps would be big.

9 speed would require a new freehub body, so in for a pence, in for a pound, I'd then recommend 10 road (I think road is on 130mm OLD?).

So yeah, a lot of new parts for a new bike. But at least it does offer an option if he really likes the bike in terms of fold.

Again, thanks.

Duragrouch

Oh, all good to know! Glad a 2X crank can fit, if so, it's definitely the better route to go on 20" wheels. Yeah, that derailleur cage did look long for just the existing cassette. For compact 2X with existing cassette, you may need a medium (GS) cage length, though some recent "short" cages seem as long as GS. Check "capacity". My 2X setup needs a total RD capacity of 35, and the GS provides up to 43 capacity I think, and max cog size of 34.

Looking forward to more pics and comments, very interesting, different bike from other 20" folders.

Reddleman

Microshift Advent, medium length derailleur

Ron Damon

Well, there you have it.

Though in my parish, Microshift is virtually non-existent. Barring availability problems, the issue would then turn to whether the Microshift part is substantially less expensive, lighter or studier than the Shimano part. Otherwise, why bother.

Duragrouch

I generally agree. However, a Microshift front derailleur (braze-on) fits on my FD adaptor, whereas Shimano doesn't, the linkage interferes with the mounting point. The Shimano linkage is double-shear, generally more durable, but the Microshift linkage is cantilever, so is more compact and thus fits. (This would not be an issue if the frame had an FD braze-on.) I want to swap out the Microshift (9-triple) because the spring is ridiculously strong, so much so, I could not use a gripshift, and even with a Shimano lever, it's still a hard push.

Ron Damon

Front what? Front derailleur?? What's that??? 🤔

Duragrouch

Took me a minute... reading back through my post... didn't I mention it was the front derailleur?... OH, very funny.

My dad, retired: "What's a weekend?"

Winfried

To install the Litepro B clamp, filing down the upper bracket for the bottle cage was super easy because of the aluminum frame. For that reason, the other clamps with the flange at the bottom (Litepro K/P/SP8, etc.) might work too. The Sora derailleur works very well with a compact 52/34 crankset.

Duragrouch

Nice job. If you ever need that bottle cage boss again, or someone needs to repair one, look up rivet nut, aka rivnut. The wiki page shows one but not as installed. It has a flange on one end, you insert it into the hole with the flange out, and use a pull-tool or nut to pull on the threads, and the shaft between the threads and flange, expands like a hollow wall anchor on the inside of your tube, until a tight squeeze on your tubing wall. I've repaired things that had very shallow threads into something thin, easily stripped, a rivnut makes it better than new, much longer thread engagement. Plus I use a stainless rivnut, better durability than aluminum.

Winfried

Thx. There's ample room on the top tube for a bottle cage; If need be, I tie the bottle with a velcro strap.

Fentuz

Looking how the thread is evolving, I thought I'd add food for thoughts.

I get the 2x appeal to add range to the current 7s 11-28 cassette. During the 1st lockdown, I run my helios with 2x 7s tourney (53-39 x 14-30 from memory) on big apple 50-406 tyres and while it was OK for touring, I found the gaps between gear quite big (annoying) and redundant (3 gear over laps). Because on this, I moved to 2x9 with a cheap close ratio cassette and that was much better... but it was more complicated.
Since then, I built several bikes and for simplicity, the 5 bikes are now 1X. For touring on 20", I found that a 50T chainring with a 11-34 or 36 cassette works well however, with 20% climbs, 11-40 is required. For flatter stuff a 56T chainring is better.
Talking to Ron and racing gravel, CX and XC, I swapped the helios transmission (again) . Now it is simpler and more importantly, the risk of chain drop and chain slap is reduced. As such, I fitted a narrow wide chainring with a 10s clutched derailleurs and a wider range cassette. The result is excellent and simple.


Going towards 2x with a 7s system is going to give ~310 to 350% range with redundancies and complexity. Moving to a simpler 1x 10 would give ~310 to 360% with a 11-34 or 11-40 cassette and a Zee/Saint clutch derailleur and ~418% with a 11-46 and deore derailleur. These solutions involve simple part swap and are easy to service. To me, they seem very suited to touring.
Note also that many ultra distance racers run 1x aero system with wide range cassette for simplicity and weight and some "adventure" racers have gone back to 1X9 because simple, cheap and durable.

Ron Damon

Yeap. 10-speed 11-42T, 1x since 2018...


Six-year old Deore CS-M4100 & RD-M6000-GS

Winfried

But it requires a long cage, which isn't a good idea with 20" wheels. While riding in the woods, I got a twig stuck in the derailleur cage, which is why I'll be swapping it for a short cage — and is fine for a 7s cassette anyway, and makes me wonder why the mfg chose a long cage.

52/34 + 11-28 = 1,83m - 7,14m = 390%

I've been using a double crankset + derailleur for years on a Brompton successfully. I don't mind the close/overlapping gears as long as I have the right gears for hills and flat. Besides, I rarely switch to the small ring — but am glad it's there when needed. I do touring, not performance cycling :-)

Duragrouch

(above #71) Only 3 gear overlaps? My 50/34 11-30 (7-speed) has 5 redundant gears. So with regard to that, there's no question that 1X is superior. But to get 400% range with 21 gear inch low on 20"/406, I need 2X, or, a cassette with such a large low cog (44), that rear derailleur clearance to the ground, and to the tire on wide tires, is worse, marginal with cheaper derailleurs. And I can't shrink a 1X chainring smaller than 50T and still get the 85 gear inch high that I need, on 20"/406. 1X works fantastic on 24"/26"/700c/29er, you name it. But more iffy on 20"/406, unless you go to one of the freehubs that offers a 9T high cog, so the low is only 36T, which is more expensive in parts and a bit less durable. I wish it were not so, because 1X would give me finer gear steps and no redundant gears. I know folks here have done it, but I still want more RD clearance than that, if I can.

There are sailboats with only one sail, they're called "cat-rigged", simpler to sail. I don't find sailboats interesting unless they have a jib as well, two sails. I also prefer manual transmissions, and can synchronize my shifts to save wear on the synchro rings.

Ron Damon

No, it doesn't.