BobbyG

My quest to rehab a $50 1989 Dahon Getaway V and upgrade it for higher speeds is probably at an end.

As others had mentioned, the severe chain angles caused by the short chain stay length limit the rear derailler to 5 gears. While it's possible to engage more gears, the further inboard or outboard the gears, the more likely the chain will fall off the front ring.

I fitted a 6-speed with a 13 tooth cog vs the original 14, but can only use the 5 highest gears, The lowest gear caused the chain to fall off the front, so I used the derailleur limit screw to block that gear. Yesterday I put the 7-speed 11-32 from my 20" Boardwalk on it, and was able to push the gears far enough inboard so that the chain stayed on the highest gear (the 11), but
then it rubbed against the next highest gear and prevented the chain from staying on the 11 cog. So I will stay with the 6-speed for now. (A front derailleur, or rear internal hub would be better).

The bike had only a slightly adequate rear band brake when I bought it (used) and I believe it came that way as Dahon did sell many like that.. I added a font caliper which makes the bike stop fairly assuredly. I planned on replacing the rear with a caliper brake, especially in light of my anticipated higher speeds, but for now, this will work.

And as far as increasing the speed, which was my initial quest. This almost 35-year old folding frame has a fair amount of flex, although the fold seems secure. But the buttressed mast does not instill confidence, especially since the original push-button latch was absent. My brass plumbing hack seems to work well, better than some of the OEM latches I have tried, but the whole two-part steering mast also allows for some flex.
(https://www.bikeforums.net/folding-b...h-success.html)

Given the frame and mast flex, the 30-lb weight, the complexity of a meaningful drive train overhaul and the need to upgrade the rear brakes, I think I am done with this project. Total cost and investment $125.

It's been a fun project, but it won't be a regular commuter choice for me. Now I'm thinking a tri-fold, or another newer 16-inch bi-fold with an internal hub and and more modern, more easily upgradable components.

Eyes Roll

Folding bikes are not intended for regular commuting of distances exceeding 5 miles at a time. They are well-suited for convenient transportation by easily fitting into the trunk or back seat of a car. They can be used in parks or tourist spots as a short-distance alternative to walking.

Anyway, if your goal is to improve the speed of the folding bike, you may consider replacing the stock folding pedals with wider pedals (eg., Crankbrothers pedals, or some other brand wider pedals). The upside of replacing with wider pedals is that they will increase the speed of your folding bike. The downside is that the wider pedals are not foldable, if you can compromise on that.

Bleu

B.S. my Brompton routinely does 20 mile rides and when I have the time I've ridden 85 mile days without trouble. It's my regular ride because I live in a very small space not because it's some project that I think looks cool (Bromptons look nerdy and I know it). So dont paint all folders with the same brush as it were. As for the original poster, it was interesting, thanks for sharing the project and even showing some of us a model we were completely unaware of.

base2 

It is also super common to use an internal gear hub of some variety. Shimano Nexus 7 can be made to be fairly narrow if you decide to forgo a roller brake. I think the Nexus 8 as well, but not as much so. Sturmy-Archer 3 speed is also a very common option. 135mm disk Alfine won't work for obvious reasons. But low grade carbon steel *could* be nade to fit most any hub if so inclined.

The advantage is getting rid of a problematic risk prone derailleur and failure proof any chain line or chain drop concerns. Set & forget.

tds101 

What? Where did you get this ridiculous idea that folding bikes are limited to short range travel? That's got to be the most uneducated "opinion" that I've seen here in quite some time. My usual shortest joyride time out & about is 10 miles minimum. And I have covid related breathing issues and a bum knee! As to your suggestion, apparently, you're not quite familiar with these types of bikes, let alone the Dahon Classic, so your one recommendation is irrelevant.

As to the OP's upgrades, excellent job. I'd also suggest looking into an internally geared hub, since it would be much less prone to shifting issues.

CrimsonEclipse

75 miles with 50lb in pannier bags and rack on a folder.

Someone should have told it had short range before I departed.
(I had no idea)

tds101 

You quoted the wrong person... Reread MY comment regarding folding bicycles

BobbyG

I took the bike out yesterday. and it shifted flawlessly. The gearing is slightly better than adequate. The biggest hills were doable in 2nd, which is now the lowest gear, and top end with the 13 was slightly better than the 14 I temporarily loosened the rear brake to prevent rub and the bike became more "alive and fun" Average speed was still only 10.2 mph (about 12 on my other bikes for similar runs) but it felt better. The DIY latch stayed secure with no constant tightening needed.

The biggest drawback is the frame. In a straight line on smooth pavement it feels normal. Any moderate turn or bumps induce noticeable "non-linear" handling.

I think I will go ahead and disconnect and replace the band brake with a caliper so I can free the wheel completely. It'll only be $5-$10 bucks for a used unit and I already have cabling and sheathing if necessary.

CrimsonEclipse

wrong quote, right idea....

tds101 

You are 100% correct. Folding bikes are "bicycles", more than capable of long range travel. 👍

BobbyG

Ok...last thing. After posting this morning I went back out to the bike and read up on the band brake and was able to adjust it to where it worked fairly well surprisingly so. Because of the kludge or bodge involved getting the gears to work the rear wheel is offset slightly to the left so calliper brakes would be very difficult to adjust.

Next, I read up about tightening up the frame. And while the latching mechanism has the classic loose pin syndrome, Simply tightening the latch itself a little more than I thought thought necessary seems to have stiffened up the frame considerably.

So now, I believe I am finished with the bike and if I really get an urge for a small 16 inch folder may buy something used but more modern... Although this original dahon fold and mast assembly really folds down small. Especially with the 2 stage seat post.

Schwinnsta

Rear wheel is misaligned with frame.

BobbyG

Yes,slightly.

Fentuz

Could you remove the spacer by the derailleur? looking a the picture, it seems there is a cylindrical spacer in contact with the derailleur by the frame and then hub locking nut. If it is a spacer, could you move it to the "non- drive" in order to bring the wheel back towards the center of the frame? it would shift both wheel and cassette and improve the chain line.

BobbyG

Actually, I put the spacer there to improve the chain line. With the original 5-speed gearing no spacer was needed. With the 6-speed I put on the angle to 5th and 6th was too severe and the chain would fall off the front chain ring. As it is, it now falls off in 1st, so I blocked it with the limit screw.

An internal hub would solve all the chain line problems,but the bike is not worth the investment to me at this time.

tds101 

Swap that out for an IGH. You'll have a single speed chainline w/the benefit of gearing. That offset is crazy.

BobbyG

...not the end!

I just ordered a bottom bracket adapter, American to euro...$14. If it fits I will buy a used three piece crank (~$20) then I can get a 58 to 62 tooth chainring. A 58 with the 13 tooth 6 speed will put me in the mid 90s gear inches-wise. A 60-62 will let be revert back to the original 14-28 5-speed. Even if I have to buy a used chainring and cranks, I think the whole crank upgrade will cost $50-$60 bucks. THat'll be worth it to me.

Then if I need to upgrade the rear brake to a caliper, I have everything except the caliper and that's an extra 5-bucks.

I'll keep everyone posted...

BobbyG

Got the crank adapter $14. Went to the bike co-op and picked up a 130 BCD square taper crank plus a square taper narrow-tube sealed cartridge bearing for $10 (!). The largest chainring they had was 53, only one tooth bigger than what I have now. So I found a 130BCD 60T chainring on Ali Express for $18 including shipping.

I'm at 64 gear inches now with the 13-28 gear cluster. So for about $45 bucks I will increase top gear to 79 gear inches. And then I will test it out and see if somehow it will work with the 11-32. And if it does, it would be 92 gear inches which is just under the 95 of the boardwalk. But that would mean another $50 for another cluster since I need the 11-32 for the Boardwalk. And maybe 79 gear inches will be good enough for this bike, since I'm not sure how fast I want to go on it anyway.

I probably won't get to this until after new years, so I hope to have an update by February 2024.

Duragrouch

I'll also add to the choir, I have a folder that is my townie, long exercise ride, and can tour long distances. Didn't start out that way. I had an early Dahon 3 speed with a rack and recyling crate on the back, someone cut the U-lock and stole, I think mostly for the rack, which was a nice one, adjustable height but sturdy. Replaced that with a Dahon Speed 7. Worked great. Found a rear rack that fit far enough aft for heel clearance with panniers, great. But it was always geared a bit too tall for the steep hills here, 52x11-30, and just a smaller single chainring would be too short a top gear. Finally, after 7 years, I got around to fitting a double crank, which I was told couldn't be done, but worked. First tried to fit a triple, 52/42/30, would not work because the low ring was too far inboard (due to the oversize seat tube), needed a wider-than standard BB spindle. Then found a better quality double, 50/34, almost as wide a range, it worked, via a derailleur mounting adaptor, and modification of the front derailleur. Bike was transformed, 21-85 gear inches. Cargo capacity is greater than a large-wheel bike. Center of gravity is low. Loading improves stability of small-wheel bikes. Frame fit for me is perfect (5'8", fixed (tall) Dahon stem, clip-on aero bars for stretched out). The bike is perfect, except for wanting disc brakes for the steeps; For that I would start with a Dahon Launch, which should be nearly identical in geometry (but aluminum instead of 4130 chrome moly steel like the Speed). It bugs me that Dahon discontinued the Formula 18, had disc brakes and double crank, but the latter was 130 BCD and I think 53/39.

I haven't touched my racing bike in many years, nor the hybrid bike I used as a townie after the first Dahon got stolen. I'm not a "frequent folder", but my wagon car got totaled from someone running into it parked, and I just wanted a folder to more easily transport on occasion, and be smaller in my tiny living space. It's vastly exceeded my expectations. For this point in my life, it's the only bike I use. For exercise when traveling, no touring loads, I'd love a Brompton, and would grab one if I see cheap. Don't laugh, Bike Fridays have sold so well, they are common on craigslist at less than half new price (though most have IGHs, which is unnecessary on a 20" so I won't touch). I've seen Brompton copies from China, but wouldn't touch one unless less than half actual Brompton price, and during the pandemic with shipping prices way up, was going to be like 2/3-3/4 Brompton list, no way.

But to sum up, the riding position, balance, speed range difference between an early 16" wheel Dahon and a 20" folder of any brand, is like night and day. Even a Brompton 16" will be better, because the tri-fold frame allows it to be longer in wheelbase and position, both of which cure a lot of ills versus the early Dahon 16".

BobbyG

The bottom bracket adapter isn't going to work... the seat tube intrudes just a hair too much for the narrowest sealed cartridge I found. I put the original crank back on and did some digging on the web And found a disk that replaces the single speed changing up front and has mounting holes for a 130 BCD ring which I already bought, a 60 tooth chain ring for upfront so this will take care of that period it's $27. I wish I would have known about this sooner but I Hadn't seen this solution on any folding bike discussion. However it's a common upgrade for bmx bikes apparently. Here's what I ordered stay tuned for more....

Duragrouch

Another possibility: So I take it, the bottom bracket adaptor (I am unfamiliar with it), would have been an adaptor sleeve inside the BB shell? An alternate solution may be any of the new style cranks that use "external" BB bearings, with a tube BB axle that goes through the shell, that may be small enough to not have interference with the seat tube. My favorite is "hollowtech II" style, now widely available as generic, with "ISO External" bearings on each side. I use a 110mm BCD 50/34 double on my 20" wheel folder, but the same style is available in 130mm BCD as doubles and singles (notably, Litepro), and really low cost. That style has other benefits as well, but your key issue is fit.

Let us know how things turn out.

sweeks

Darn it! I wish I had known that before I did a couple of century rides on my folder.

Duragrouch

I know, right? First, it's all about the fit; I'm fortunate that my folder fits me perfect. Then about gearing; I had to modify mine for wider range. Then about ride quality, my 20"/406-44 tires are not great, but not terrible. Then, if touring, about cargo capacity and stability with those loads; I gave careful thought to that and it's successful. Future concerns are durability of the folded hinge, but I've made modifications that should improve that.

"Folding bikes were originally intended for regular commuting of distances not exceeding 5 miles at a time, but have now improved to enable far longer rides, including equaling the longest rides on conventional bikes."

FTFY

BobbyG

While this particular folder may never be a long distance champ, my 20" Dahon Boardwalk with upgraded, higher gears does 30 mile rides with ease and comfort.

Duragrouch

Amen. Higher? Hmm, maybe Boardwalks have freewheels with 13 or 14 high cog. My Speed has a cassette with 11 high, and I needed a lower-low than 52x30. My 50/34 x 11-30 gets me 21-85 gear inches. I might go 34 low cog if I heavy tour on it. 85 is enough for the flats and to pedal down mild grades.