Duragrouch

[QUOTE=shadowbrush;23306854]It's easy to space a square taper crank out further, you just need a wider bottom bracket cartridge. But if symmetrical, 4mm wider = 2mm per side. So adding 5mm on the drive side means 10mm wider BB spindle. It's more difficult if you can't get a standard BB length that spaces out enough for you. Also, not all tapers are the same! There is Japanese Industrial Standard (JIS, most or all of japanese brand cranks and most others), and International Standards Organization (ISO), which some or all Campagnolo cranks use. There is an excellent article on Sheldon Brown that covers this:

https://sheldonbrown.com/bbtaper.html

If you go with a hollow spindle crank with external bearings, there is much less adjustability; As I may have mentioned, I tried to space my crank out 4mm and with that much less clamp space on the left arm, it came loose. So I modded the FD to eliminate the spacers. If the hollow crank is designed for BOTH 68mm and 73mm, that might allow up to 5mm of spacers because the spindle will be longer. And I really love the external bearing system.

But before doing ANY of the above, first, determine your chainline requirements; The distance from the center of the frame, to the center of the cassette. Because if that is too far off, you may be dropping chains when shifting on a 2X. Chainline equals (rear O.L.D./2) - (distance from right-inside dropout to center of cassette). My crank chainline is 43.5mm, this seems to be fairly standard for 2X on 130mm O.L.D. on 7/8 speed. Then, once you know your desired chainline, you can measure the crank you have and figure out if spacing it out to clear the frame, will give a good chainline. By the way, you can just remove the inner ring for more clearance, or remove the outer ring and put the inner ring on the outside for more clearance. Whatever gearing you want. If the BB is cartridge and a *little* loose, it'll work for tests. If the BB is cup and cone (loose parts), you can rebuild it all, if you have BB wrenches.

FD adaptor: Dahons use one about 40mm. The Bike Fridays, I am guessing will be below 35mm, there are several sizes between 35-25mm, derailleurs with built-in tube clamp are very common in that range, no need for special adaptor. But, clamp derailleurs come in different clamp height; Low, medium, and high; You'll want low if you can get it, to clear the main frame tube. Here's a good article, jumping to that section, but you should read the whole page:

https://bike.bikegremlin.com/260/front-derailleur/#5

And, I don't know if the BFs will use bottom or top cable pull; My dahon, I ran the cable below the BB, so it's a bottom pull. The frame did not have a housing-cable-stop, so that just the inner cable comes up to the derailleur; My housing wraps under the BB shell and then is stopped in a stepped hole in the base of the FD adaptor, and then the inner cable goes to the FD.

john m flores 

Some photos of the front derailleur hanger of my ~20 year old Bike Friday Pocket Rocket with a 53 tooth big chainring. Note how the derailleur hanger sits almost directly behind the main tube.

Duragrouch

That's helpful to see, thanks. Even though the bracket sits high (probably to allow an oversize chainring for fast riders on small wheels), the derailleur mounting to it low is encouraging, in terms of mounting a band-clamp FD, if the clamp is low-mount. A couple notes:
- Having the derailleur that far back, reduces possibility of interference between inner cage and seat tube. But...
- The BF seat tube intersects with the BB shell (like most bikes), which it can do because of the way the seatpost folds. On the Dahon, the seat tube passes completely behind the BB shell, in order for the seatpost to collapse to ground level. This places the seat tube at a steeper/higher angle than typical bikes, however at typical seat height, the fore/aft distance to the crank is about the same. But that means the seat tube is significantly further aft at the FD mounting point. Now, my FD adaptor puts the mount well forward, and has a fore/aft sliding adjustment, that helps in adjusting the FD optimally to the chainrings, but I'm still left with the issue of interference between the inner cage lip and the FD adaptor over the oversize (40mm) seat tube diameter, which required removing a small part of the FD inner cage lip. So everything should be easier on a BF, though it does result in a skinnier and more flexible long seatpost, which some might prefer if it provides some suspension effect. (The tall handlepost, I think I would prefer the much larger diameter tapered ones pioneered by Dahon and typical on bifolds, for its better lateral rigidity. I think one could be adapted to a BF by using a fork with internal threading.)

EDIT: Oh wait, I am assuming on a BF that the "seat tube" at the BB is same diameter as the "seat tube" that holds the seatpost, and they may not be. I'd be interested to know the diameter of the lower seat tube at the BB shell.

shadowbrush

Sorry for the delay. We went camping, then had to catch up with work.

OK, thanks for explaining that. I think I understand that now.

I can do that when I installed a new cassette. Focus is now on my wife's bike, and she's getting a wide cassette with a medium cage DR. I did a bit more reading and YT watching, and it really seems the simplest setup, especially for her. With 3 weeks left, I'll get the parts minus BB and cranks here and do the work in Europe. Install rear hub/relace wheel, install cassette and RD and then measure the chainline. Then worry about the crank and chainrings. The local bike shop in Germany is now run by the grandson of the guy that grabbed our chins when we were little, while hollering something I don't remember. I don't think we ever heard what he was shouting because having our chin in his vise grip was alarming, every time. You can see him here standing in front of his shop. We were afraid of him, but the grandson is nice.

I'll report when I have the parts.

Duragrouch

Yes, 1X system with wider range cassette is a more straightforward conversion, provided the rear derailleur cage has ok ground clearance (increasingly possible with newer RD designs).

Couple hints:
- By wider bottom braket, I meant longer spindle; The threaded part stays the same width to fit your BB shell.
- New rear hub? Upgrading in quality, or did you need in order to use newer (wider) freehub body for more cogs?

Ron Damon

The only thing simpler than 1x is single-speed, fixed gear.

Duragrouch

Our posts crossed paths; I added a note saying the same. No question, now that ground clearance is not a problem, 1X is simpler to implement. About the only thing I can claim with my 2X is really good chainline when climbing hard on the low ring and low cogs. I may also be limited in 1X by 130mm OLD, I'll see when the time comes.

Ron Damon

1x and 130mm rear OLD work together just fine. Here are two examples:

Duragrouch

Good to know, thanks.

Say I just noticed the magnets on the drive side on the black and white bike. That means it folds with the drivetrain to the inside, like a brompton (differently), that's nice.

shadowbrush

Got it, thanks!

My wife's BF has a 1x7 drive. So yeah, I thought I had to replace the hub to install a 10s cassette.

shadowbrush

Your explaining the 1X really helped me out, so thanks, Ron! And by digging around in this forum I see it's not the first time this has come up. Takes some patience to go through it again. That B&W bike is absolutely gorgeous. What is written on the white part?

Ron Damon

The writing is a stylized rendering of "FSIR Spin", the bike's brand and model names.



Indeed, I am one of the principal champions of 1x setups around these parts, having trialed them with wide range cogsets on folding bikes since 2018.
​

Duragrouch

You may only need to change the freehub body on the hub, but I'm not certain; I don't know if they narrowed the hub when they widened the freehub body.

If it has the typical 7 speed hyperglide cassette body, you can't even go to 8 speed without a wider freehub body, 8 is just a skosh wider. Then it gets easier.

Sheldon Brown has an article; Note below, when it says hub, it means freehub body. Cassette means the cogs alone.
https://sheldonbrown.com/k7.html

Excerpt:
Also note, not all Shimano style freehub bodies have the same "interface" with the hub body (that the spokes attach to), so you need to make sure you get the correct freehub body to fit it, and that the total width is what you expect.

Dahon's typically came with 28 spoke hole rear hubs which is not the most common. If you can't find the correct freehub body or complete hub, buy a new rear wheel already set up for the cassette you wish to use.

Ron Damon

One newer, promising part is the 10-speed, medium-cage Shimano Deore RD-M5130-GS Linkglide part which, though rated for 43T max cog, can in practice span up to 48T max cog for 436% range.

Duragrouch

That's a plus. I was thinking after I wrote my last post, whether 1X can solve all; For typical use, yes, but for heavy touring I think 500% is needed (from the advice of tourers more experienced than me, some say 526%). With 11T high cog, I'm not sure if you can get there, even on a large-wheel bike. Pretty sure no on smaller wheels. But with 10T high, definitely on large wheels, maybe on 406.

I was in the LBS yesterday, saw a surprisingly cheap bike in a good brand, Kona Dew, $549, on 650s, and surprised to see it had 2X (compact, 36/22), but lower end parts, not walmart low but... discs, but the cable calipers push from only one side, chain looked WIDE, wider than on my 7, but was 8 speed altus 11-34. Decent entry level bike, suitable for a college town, and supported by a really good bike shop with (I think) good mechanics in the campus district. Kona corp is semi-local, couple hours north. LBS seems to like them and has a fleet of rentals.

Ron Damon

No, 1x cannot solve all, but it can solve a lot. There are now 10-52T cogsets for 520% range. Obviously those require a different, non-standard HG hub carrier and can't be used on small wheels due to the need for a long-cage SGS RD. But today you can get 464% range with a standard HG hub carrier and medium-cage GS RD on small wheels That's a match, as I showed you a few months back, for a double crank with a 11-34T cogset.


Shimano Deore CS-M6100-11, 11-51T on 622 wheel

I've posted YouTube vids elsewhere of the 11-51T cogset in the image above working with this medium-cage XT GS RD.


Shimano XT CS-M8000-GS


11-50T, 10-speed, $25

Shimano Cues offers this medium-cage GS RD rated by the manufacturer up to 50T max cog. You know me and these wide-range GS medium-cage RD. I just had to check it out so I went ahead and ordered one for $42. It's now on my way to me.



Shimano Cues RD-M6000-GS

My view is that in cases where 1x matches the range of 2x, the burden of the argument is on 2x given its greater weight, price and complexity. In those cases, the ball is squarely on your side of the court.

Duragrouch

(above) I agree with all. It's nice to know there are multiple options going forward. For the 1X, especially so, for ebikes and others with weird frames just above the bottom bracket, with no option for mounting a FD. Conversely, for 349 trifolds wanting to avoid an IGH, a FD may offer the solution; I met a guy at the LBS who was touring on a Brompton with a Schlumpf drive, but I can't recall if it was for reduction or overdrive at the crank. I know fat tires can help with ground clearance on 349 (as you have demonstrated), but that can also get tricky with lateral chain clearance on the low cog, though perhaps worse with 2X or 3X as the tire is closer to the chainrings; a touring blog I saw with a Bike Friday and 3X had that very problem after he fit larger Schwalbes (and was wondering why it felt like so much *drag*) and he redished the wheel while on tour.

Considering the above, it's nice to know there are more component brands out there now than just the few of the past. Otherwise, they could all make a change in one direction and the rest us would be searching for "vintage/NOS" parts to do what would have previously been a mundane task. "Brother, can you spare a front derailleur?"

shadowbrush

Time for an update. After not having heard from the LBS and their assessment of my wife's bike I went and got the parts to upgrade it myself. Some of the 10-speed parts weren't in stock, so I went 11-speed and spent more $$ than planned, but was glad to have all needed parts. And it turned out the LBS left a voice message on Saturday that I missed. They went ahead and ordered a Microshift Advent super shot cage drive set. I was a little surprised that they'd do that without getting the customer's OK, but oh well. That left me with the Shimano parts, so I installed them on my bike. Together with the handlebar of my first mountainbike (35 years old) and a chainring I found in a box that a guy in Switzerland gave me.

With the 47T chainring and a 46T max cog in the back it's going plenty low. Ground clearance is marginal (I would have gone the Microshift path had I known). Still need to replace the worn brakes, but we're getting there! Thans again for all your help!

shadowbrush

I had adjusted the "B" screw, but will check it again, thanks!

I forgot to mention that I got lucky with the wheel. After punching the parts and numbers into the online spoke length calculator, the old ones were the right size. Lacing and truing really wasn't a big deal. Maybe I'm overlooking something obvious. I found using a dial indicator pretty helpful.

Duragrouch

You nailed the gearing right on the nose! I think the photo shows tires at 406-47, so your gearing gives you nearly exactly 20-85 gear inches, that is the sweet spot, you will not regret having that low, and 85 is enough to pedal down mild grades, steeper and you just coast. Well done. And with a minimum of modifications.

Rear derailleur ground clearance is marginal in the middle gears where the cage is vertical, but you can make do on pavement fine. Some fine tuning as noted above, or replacement may help, but you're good for now.

Ron Damon

Thank you very much!

Duragrouch

"I love it when a plan comes together."

Duragrouch

"I remember searching for the perfect gears
I was hoping it would change itself
I remember swimming through apologies
Riding on the Metro"

Duragrouch

According to description on microshift, the advent super short rear derailleur is compatible only with 9-speed 11-34 to 11-38 cassettes and largest cog 38, 27 tooth capacity, so it would be mighty iffy on that 11-46. It looks to function different than most; Very little incline to the pantograph, instead, the cage pivot is between the pulleys, so that as the idler/bottom pulley gets pulled forward as you downshift to the large cogs, the jockey/upper pulley swings back and down to provide clearance to them.

shadowbrush

Did you compose it, or AI?

Hey, I do listen to you guys, so I understand that this isn't likely to work. I'm going to run with the Shimano drive I installed on my bike, and the LBS is installing a Microshift drive on my wife's bike. It's going to be interesting comparing the two. Hers is going to be lighter, but won't have the gear range. I may have to install a smaller chainring for her. I should also try to find a flashy piece of gear for her bike so she can one up me. That's always helpful.