So now that I'm back from Rome I've bit the bullet and revised the drivetrain on my Tikit. Here's the rundown of options:

• The baseline tikit has 349x37 tires, a 53T chainring, and an 8-speed 11-28. Sheldon says this comes to 31.2 -- 79.4 gear inches. Not fantastic.
  
• Upgrading to Scorcher TRs (about $80 for the pair), at 349x40, brought me to 32.0 -- 81.3.
  
• Upgrading to Capreo + Scorchers brings us to 34.4 -- 99.4, a significant loss on the low end but a great high end. However this is an expensive proposition. A Capreo installation involves upgrading to 9 speed shifters, a wheel rebuild, a new hub, a new chain, and a Capreo cassette. This is easily $350 in parts and labor. And Capreo cassettes, whose small cogs wear out fast, are a good twice the price of an ordinary 11-32. And Capreos are... scarce and likely to get scarcer. This nags at me.
  
• Upgrading to an IGH + Scorchers. I could get roughly the same gear inches as a Capreo with a hub, but they are even more expensive. And I have vertical rear dropouts, necessitating a tensioner which sort of negates the whole elegant point of an IGH. And as I've mentioned in an earlier post, though they notionally don't break down often, it seems to me that IGHs are even more problematic than Capreo when they do break down: not many shops can repair them, and I certainly can't.
  
• Upgrading to Dual Drive + Scorchers. Basically a 3-speed IGH plus a cassette. There are people who swear by Dual Drive, not the least of which because it's got an amazing range (19.2 -- 110.6!!!). But to me it seems like it combines the worst features of everything: it's got more things to break, it's got the difficulty in repair that comes with an IGH, it's got the grime and inelegance of a derailleur setup, it's got even more custom stuff, including its own special shifters and click box, and it's got about the same cost as bigger-geared IGH. It's fragile. It's not cheap. And it's less efficient than everything else. So I dunno.
  
• [EDIT]Upgrading to Schlumpf SpeedDrive, existing 53T chainring, and Scorchers. This bit of awesomeness would bump things to 29.1 -- 131.01, so high that it'd probably be worth having a smaller chainring. But now we're talking a lot of money: at least $500 plus labor, including chamfering out the bottom bracket.

So I've decided to go with the cheapest, most straightforward option:

• A 60T front chainring (the biggest the Tikit can take), plus an 11-32 9-speed in the back, plus the Scorchers. Requires a new cassette, new chainring, new chain, and new shifter. Because I'm doing 11-32 rather than 11-28 (so I maintain about the same bottom end), I'll need a new derailleur too. And it's nearly impossible to get a chainring guard at that size. And I'll look ridiculous. BUT the cassettes are standard and plentiful, the total cost is cheaper than anything else, it's easily and cheaply repaired and replaced. Gear inches: 31.7 -- 92.1. Not horrible. 11-34 would put me at 29.8 -- 92.1.

Where I've heard about 60T chainguards: (1) I'm told Sugino at one point sold them, (2) Bike Friday will make them but they're costly, (3) Toxy sells them for $50 apiece, and Greenspeed was selling some old ones for $2 apiece (!!!) in October, but someone bought their entire stock, and new ones are $60. That's the extent of my internet scouring and phone-calling. Other leads are welcome.

Last, I'd been hunting for front derailleur options. All I'd found were (1) Braze-on derailleurs, such as found on the Speeding Tikit, and (2) the odd front derailleur mount job in Taiwan that connected to the seatmast latch plate. Oh well.

Am also installing an old-style seatpost to enable my $1 Brooks, and looking at some North-road handlebars which won't make the folded size much wider. Maybe a few other gizmos too.

seems like you've done your research.

personally I'd go with an sram DD as it offers something closer to a triple.
going with a 60t and 11-34 cassette is something I wouldn't do because of the immense jumps between gears. it'll leave you wanting more inbetween gears.

I guess don't mind moderate jumps -- I tend to make big multi-gear jumps anyway. And in truth to get subtle changes that you can get out of a DD (like a front-rear derailleur combo) you have to change interleave changes in both shifter, and I just don't do that. Plus a DD is just too crazy expensive for me.

So given a choice between 11-32 and an 11-34, which would you pick? The 34 gives me 29.8 gear inches (the 32 gives me 31.7). But the jumps on the 11-34 are bigger, especially that 11 to 13 jump. Specifically:

11-32 jumps like this (11 to 32): 9.1%, 16.7%, 14.3%, 12.5%, 16.7%, 14.3%, 16.7%, 14.3%. It's basically exactly like the standard 8-speed 11-28 presently on the Tikit, plus an additional 32-tooth at the top.

11-34 jumps like this (11 to 34): 18.2%, 15.4%, 13.3%, 17.6%, 15.0%, 13.0%, 15.4%, 13.3%

That big 18.2 and 17.6 aren't great I guess. Which would you pick?

@feijai: Have you considered a Schlumpf Speed Drive?

We've had Dual Drive set-ups on two of our Bike Fridays for over two years with minimal problems. One time last year wife's click box wouldn't allow her to shift out of low range when we were 5-6 miles up the coast. I couldn't get the click box off, either, but she was able to ride home with the nine gears she did have.

Applied some WD-40 when we got home and I was able to get to come off and operate properly, to boot. Secret seems to be removing the click box and re-installing it once every few months.

In my opinion, it's biggest drawback is probably the weight it adds to the rear of the bike.

Lou

> @feijai: Have you considered a Schlumpf Speed Drive?

Cost.

I didn't include it by accident. Edited my message appropriately.

One of the biggest benefits to having a Dual Drive is that a very large gear range can be maintained, but a short cage derailleur can still be used, perfect for a bike like the Tikit where ground clearance is small and precious.

A short cage SRAM X9 would handle your proposed 60t crankset and 11-34t cassette, it would also be a good match for the dual drive system. Medium cages may still provide you acceptable ground clearance for city riding, which would include many more options.

Capreo cassettes can also be modified if you know what you're doing and people have modified them all the way to 9-34,

As an example, I see this business called Utahtrikes is doing Capreo wheel kits, and offering them with the cassette pre built into a 9-34.

https://www.utahtrikes.com/PRODINFO-S...Wheel_Kit.html

26.3"-99.4"

That's pretty good on both ends.

Combining that custom Capreo with the 60t chainring gives you 29.8"-112.5", heh.

It's been posted on other threads in the folding category since it's a common problem. 52T to 60T flat rings are available through Vuelta directly at $30 to $35:

https://www.vueltausa.com/products/ch...chainrings.htm

Why not just add a smaller chainring without a front derailleur, and change by hand? I use this method on two of my bikes and find it very satisfactory. The times you need to access the low gears are usually known in advance, so it's really no inconvenience. And if the lowest available gear in your big chainring is in the thirties, you can choose to thrash up the odd short hill.

A useful posting: but I see no chainguards on that page.

I suppose, but my aim is really more, not fewer, gear inches. I might at least slap on my existing 53, but in truth though: I think I'd find the grime of changing by hand unreasonable.

If you stick with an 11-32, you have a chance to make the present rear derailer work. Otherwise, just pick up a MTB GS rear derailer (medium cage) to maintain some clearance at the rear.

I thought the ticket required a braze-on due to its unique hinge and inability to mount a clamp-on FD. That's if his tikit model has that in the first place.

If I had to choose between those two, I'd go for a 11-32.
but you have to account for the fact that you're going to be using an even larger chainring up front.
I've tried this before with 11-34x42T on a 700c bike, and it wasn't very fun for me, the jumps are just too big in the mid to hi range of gears.

basic 3 speed IGHs like the one used in the Dual Drive are not at all difficult to repair

Just got the bike back. Here's how I've upgraded it:

• 60T front chainring. It's humongous. No 60T chainguard yet (they're like $50 and very rare). I expected the chainring to stick out a lot but it doesn't actually. It's quite close to the ground when folded now though: probably 1.5cm off the ground. So either I need to lengthen the Tikit's foot or take my chances. Note: I think you could theoretically go to 61T but that's it: otherwise when folded the chain will hit the underside of the frame.
• SRAM 11-32 in the back. With my 349-40 Scorchers, Sheldon says this comes to 31.7-92.1 gear inches. Gives me a good 12 or so more gear inches on top with no sacrifice on the bottom.
• New chain. Longer than a standard chain, so my store put together two chains with two master links. Don't know if I like that.
• SRAM X.7 short-throw rear derailleur.
• SRAM X.7 front grip shifter.
• Replacement cable housing.
• Koolstop salmons all around.
• I need to be able to rotate my wrists, but have decided against a North Road bar for now, and am sticking with my straight bar and some Serfas Stabilizer Bar ends.
• A pipe-type seatpost to accommodate my $1 Brooks-B72. Will see if I can stand it.

Of course, it's snowing big-time right now, so I don't expect to be able to *test* the configuration for a week at the earliest.

[EDIT] While I was in Rome, I also upgraded some parts, mostly for free. :-) Specifically:

• Shimano 105 cranks. Got rid of the junk machined-down triple-gear cranks BF puts on there, which snag the chain when it falls off to the inside and make it very hard to put back on. Makes a world of difference.
• Bianchi stem. Very slightly lighter. And free, what the heck.
• Aluminum mountain bike handlebar. Replaces the original BF one, which had gone clicky. But pretty straight; I may need something else.

What didn't get done:

• New pedals.
• New handlebar. Sure like the pseudo-North Road bar that Alex Wetmore put on one of his.

According to a few folks on the YAK list, finding parts for SRAM hubs is not easy. However, it turns out that Bike Friday is a very good source for them.

I have two master links on a recumbent bike. Don't worry about it.

I used the standard rear derailleur that came with the Tikit on another bike with an 11-32 rear cassette with no problems. I'd try that first before buying a new derailleur.

*ha! didn't scroll down. man.

Yeah, I had sort of lost faith in that derailleur after various incidents in Rome. Decided to get something a bit better. I dunno, maybe just superstition.

Greetings !

Glad to read you've upgraded your Tikit. What are you new impressive
with a 60t chainring ?
A friend owner of a Swift have placed a 61t chainring, he like it so much
and have a good development

I have a good new, i have finally purchased an used Tikit but in excellent
condition ! The bike i so beautiful and easy to find a good position
I am agree with you, the gear range is short, so the more cheaper solution
is a bigger chainring, i would like upgrade to a 58t one, but i don't know
which one choose.

58 tooth x ???
https://store.bikefriday.com/index.php?cPath=67&page=6

Thanks for help
Rav

I got Vuelta. They're nothing special, but they're under $50. Though BF is fine, there's no need to buy from them -- the bike's got all standard parts.

I've liked the new chainring so far. Though I've had several chain drops (likely mostly due to switching to a 9-speed chain from an 8-speed, plus not having any chainring guard -- may ultimately have to buy one).

the combination of short chainstay, chainring size and amount width in an 8/9/10sp cassette makes sharp chain angles, which makes it more likely to drop the chain.

best you can do is try and get the chainring centered to the middle of the cassette or with a slight bias on the side it drops most.

So my understanding is that many chain drops are essentially caused by a horizontal wave propagation along the upper chain starting from the cassette and moving towards the top of the chainring. Besides countering the causes of the wave propagation (thinner chains, shorter distance, having a cassette in the first place) the primary approach is to dampen the wave energy by installing something to one side or another. Such items include front derailleurs, one or two chainring guards, a chain keeper (either cheap or stupid expensive), and goofy looking rollers).

A front derailleur won't mount onto a tikit without a braze-on being installed, so it's out. Chain keepers are possible but all the current designs attach to the seat-tube, which the Tikit doesn't have. The rollerkit has similar attachment issues. So it seems to me that the main option would be to get a single chainring guard and snug it up next to the chain. Unfortunately the Tikit can really only have a guard on the outside. And 60T guards are extremely hard to come by (I think I know *all* of the sources, and there ain't many). And expensive ($50-60 at least).

I've got it on the inside which isn't really centered. I might pull it to the outside where it'd be centered better but was worried about the effect on my pant legs.

if you install a bash guard, it'll stop the chain from dropping off on the outside as well as keep your pant legs cleaner. sometimes the chain can fall off and float between the bash guard and chainring.

I know a cool guy in Kyoto who sell ring, maybe chain ring guard available ?
https://www.loro.co.jp/item/parts_etc/index.html

BF's part should be good, but i don't know the size of the chainring corresponding
of the standard crankset of the Tikit.

Is it 58t x 110, 130 or 135 ?

Have a nice day