megavovan

Went and bought this bike in Performance Bike locally for $212 out of the door. They matched online 15% off.

Pictures:
Dahon folded and road bike
Dahon and road bike - already mounted the lights

I don't like that it goes slow, so I want to replace the cog or chainwheel. Took apart the bike and found strange shaped cog: pic of thee cogs. Top cog with 3 "inside teeth" is one on Dahon, bottom right is a single speed cog for shimano hubs, and bottom left is smallest cog from 7 spd casette.

Figuring I don't even know what kind of cog I should buy (never saw one like that), I decided to change front chainwheel, but not sure what to do, so I started a thread in bike mechanics on that.

Any questions or suggestions, I'll be glad to answer.
(No, I do not have the weight of Dahon, but it's pretty heavy)

Update 7/11/2009
So I installed some upgrades:
-pedals with straps 9alloy body)
-12T cog in the back (kept front 44T for now)
-basket
-lights, front Romisen RC-N3 CREE Q5 LED and rear PlanetBike SuperFlash - Stealth (clear)
-Wald basket and some bungee cords
-cheap, wired bike computer

Feels a little slow with 69 gear inches [my road bike is 78GI], so I may change front chain ring to a bigger one in future (probably replace whole crankset... or at least spider + chainring?). Loving the coaster brake. Cruising speed around 16 mph according to the computer, top speed downhill 31 mph. But i suspect these numbers are higher because I suspect the default value for 20" wheel does not include tire. Include tire, and you got bigger wheel = more distance in number of same revolutions. But I am too lazy to measure distance myself and correct the computer.. In two days I had the bike computer, it shows 45 miles already.

Enough talk, here are the pics:

datako

That sort of cog is fitted to hub gears or coaster hubs. It is used on a variety of different makes, eg SRAM, Sturmey-Archer, Shimano, and an endless list of coaster hub manufacturers.

The good news is that they are dirt cheap, very durable and available from almost any bike store.

The bad news is that yours is a 14 tooth which is a small size, and finding a smaller one in stock may not be so easy. However, S-A have them in their current catalogue so it can be ordered.

Dr. Hellyes

Ebay has Kore BMX "freecoaster cogs" for about $8 SHIPPED. They've got 13 and 12T and I know this because I just put the 12T on my Boardwalk yesterday taking it from about 63 gear inches to about 73
gear inches ... a bit more top end but quite a bit harder to pedal. I think the 13t on the rear may be ideal with the stock 44t front chainwheel. All ya gotta do is take the back wheel off, pry the little cog-retaining ring off with a screwdriver and slide the old cog off. Slide the new one on, replace the retaining ring (I just used the factory one again because I didn't have the tool to spread the new lock ring that comes with the cog) and put your wheel back on again ... takes about twenty minutes and $8 for the whole job. Here's the link:
https://cgi.ebay.com/KORE-BMX-COG-FRE...3A1%7C294%3A50.

megavovan

Perfect! This is what I need! I ordered 12T and 13T for $15 shipped for both!
Thank you Dr. Hellyes!

edit: datako - I found 13T in their catalog, and one in shop in UK. Here is sprockets page from catalog.

Dr. Hellyes

You're welcome. I'm on my second Boardwalk after I gave my son my first one as an excuse to buy another bike; then when I missed it and wanted it back he said "no deal." I put a 13t on his and could spin up to 25mph on it but that was really maxing my spinning ability. I don't have a speedo on my new Boardwalk with the 12t but I'm guessing I can spin to about 27mph max. I also put a Wald rear basket on
the back rack and it's working out very nicely carrying my commute/gym/book bag ... lots of fun and practicality in this "cheap" bike! Enjoy yours

Foldable Two

My 2005 S1 is a great bike. I wish I had it here in So CA instead of my "slug-like" cruiser. (Shown behind my NWT, below.)

Dr. Hellyes

Yeah my older Boardwalk is red too. My new one is black. Both great bikes ...

vmaniqui

see it worked out ok for you. performancebike has good reputation as far as online matching price is concern. that's a nice bike. i have 2 dahon boardwalks (D6 and D7). although they are older and the cheapest of the dahons, i am loving it. the only problem is my boardwalks are both green in color. how i wish the other one is a red.........Congrats on your new bike....any other upgrades you're planning....

megavovan

Yup, although I did have to tell the cashier. Originally he rung me up for like $240 after tax, I say, "there's online 15% off!" he quickly types it in and I get $212.

re: green bike: well you can have frame sandblasted and re-painted professionally in red Won't be cheap (over $100), but will be good quality paint.

Other upgrades: DUH forgot to mention them!
Here's what I plan to have:
1. pedals with straps (they are 3/16)
2. (maybe) a bike computer, preferably cheap and wireless (and one for my road bike too)
3. (maybe) folding baskets or at least a cargo net
4. If 12t rear cog will be too slow (STILL) I'll upgrade whole crankset (though would like to keep stock cranks, I like them a lot - so I guess new "spider" and a chainring)
gear ratios with 170 mm cranks, 44T upfront, and 20 X 1.75 / 44-406 / BMX tire are:
14T - 59 GI
13T - 63 GI
12T - 69 GI

megavovan

Installed 12T rear cog, kept stock 44T front ring. Had to remove a link from chain to achieve proper tension (no half-links used). Went for a 10 min test ride.

Bike is much faster. Seems like a great compromise of:
Acceleration from dead stop (not too difficult)
Mid-ride speed boost (when I temporarily double my RPMs to pass someone or speed up)
Top speed (not TOO high but okay)
Cruising speed is decent.


Eh I am not inclined to change front assembly too much. I'll wait for strap pedals to arrive and ride for a while. If relatively low gear bugs me I'll break down and install bigger ring upfront.

Also on the way is a rack-top, non-folding, chrome wire basket

James H Haury

The small cog has angled teeth as if it is meant be on a derailluer cassette or freewheel. Check looose screws bicycle small parts for single speed cogs.

megavovan

Correct, it is a cog off my cassette from my road bike (I took cassette off because road bike is now single speed).

I updated original post with upgrades and pictures!

LACyclist

I just ordered a Boardwalk from Performance. I like the basket. How did u mount it to the rack so that it won't fall off?

megavovan

I used one mounting clip that came with basket, a wire, and many zip ties. Hint: with zip ties, don't cut off loose ends too close to the base of loop - leave some hanging.

Way I mounted it is the only way to mount it so it is stable and I don't hit it with my heels.

Just to clarify: basket does not come with bicycle.

LACyclist

Ah! The old zip tie trick. Thanks--Great idea!

Dynocoaster 

Here is my Boardwalk that I have been modifying on and off for the last year.

megavovan

Update 9-11-2009
Odometer now has 270 miles on it.

This is how I roll to school (college) every morning. Sorry about the unclear pic - that morning it was raining, and the camera fogged up.

Basket holds backpack full of heavy books (keeping the load low to the ground). On top of it I strap (using bungee cords... with hooks) the gym bag with full change of clothes (all but the shoes) and tool bag for bike. Again, the basket is held with zip ties and one metal connector that came with this Wald basket.

Tools are too many to list, but some are: patch kit, manual pump/co2 adapter, co2 cartridges, multi tool, chain tool, spare chain links...


All that on a bike with one speed, no suspension, and 20 inch wheels.

Tires are rated for 65 PSI, but I run them 80-85.

MarMek

Do you fold it up and bring it into class, or lock it outside?

megavovan

I take off the seat post (quick release lever) and bike computer, the rest lock up outside (without folding). This bike is bulky and heavy to carry around inside buildings.

megavovan

Some updates...

Been riding Boardwalk to and from work/gym now and then, about 12 miles roundtrip. She holds up good.

Replaced rear tire with one from LBS that's rated for 100 psi - original rear tire got few flats in a course of 2 weeks, which means tire's erased too thin. Only 1 flat with new tire.

It's been great carrying books and random stuff in my (custom) backet from niagaracycle.com

Some problems:
1. Rear hub developed grinding noise when I pedal, apparently the coaster arm rubs against something inside? I don't know. I just ride as is, and when it breaks completely I'll just buy another rear wheel for like $40.
2. Kickstand broke (opens at too big angle, b/c one spring slipped)

Here is me carrying backpack + a chair.
https://i40.tinypic.com/ris13t.jpg

Might motorize my bike one day, like Kevin here (page2):
https://www.bikeforums.net/showthread.php?613851-New-Dahon-Boardwalk-owner!

Dahon.Steve

It's good to see the OP is getting alot of use from that Dahon folder. I would suggest you
you upgrade the rear tire to a Schwalbe Marathon and use a Tuffy tire liner. You'll get one tire a
year if that! You'll have to run the tire at a lower pressure but the benefit of not getting flats
is worth it.

If the rear hub is going bad, why not upgrade to a Sturmey Archer 3 speed hub? There are loads
of used ones on Ebay going for nothing. Have a bike shop lace it to your rim and you're set. Now
you have a high and low gear for starts.

Also, I would get a New York 3000 lock and leave that at school on the rack. A bike like yours is
going to get hit soon and a cable lock is not enough.

megavovan

Hi Steve,
Thanks for reply!

How can I buy another wheel/rim to re-lace for this Sturmey Archer 3 speed hub?
I would like to keep original wheel a) while new hub is in the LBS and b) as a backup in case I don't like Archer hub.

Also, how do I know how many holes need to be on that hub? Go to LBS and ask the guy there? It depends on my rim/spokes?

Yep, I need a better lock. I take out seat stem to deter thieves but it will work better with beefier lock (maybe in addition to my cable lock).


As for tire, the flat on new rear tire was due to internal pinch since tube was wrong size (like 2 inches slack when wrapped around the rim; I just folded it inside, lulz, and it worked for a month). Now I put proper size tube and don't want to change tire until I start getting flats again.

Kevinator

The SA hubs are usually 36H, which is probably the most common drilling for 20" wheels. I used BMX rims with my Nexus 8.

For $50, you can get the older SA 3-speed already laced to a wheel from Utah Trikes. It comes with the shifter and cables. The only issue is that this one doesn't come with a brake, so you'll need to add a handbrake for the rear. A cheap sidepull brake for the rear is about $10.

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

You will need to widen the rear dropouts by about 6-10mm, which isn't a big deal on a steel frame. Your bike shop would be able to do it easily. I widened mine by 25mm to fit my nexus hub.

If you're interested in just replacing the wheels with Dahon stuff, I'd be willing to sell you the wheels and kickstand off of my Boardwalk for $60 + shipping. Everything is in new/like new condition. The rear wheel has less than 2 miles on it, the front wheel has maybe 20 miles, tires both look brand new of course, and no punctures in the tubes.

v1nce

Just a heads up about putting those 12 and 13 T cogs on the coaster hubs! :

Due to the design of those cogs those sizes have rather little material left so they are fairly weak. It is somewhat common for them to shatter into pieces when
people pedal hard or brake hard with them over time. I know because i am a bike mech in NL and about 75% of the bikes here use coaster brakes hubs or other hubs that take those cogs. I would just try it and see what happens but make sure you have a front break as well! Also the 13 T is a safer/stronger bet than the 12.

megavovan

Hi Vince, thank you for input!
I had 12t on my Boardwalk for a few months and the cog is still in one piece. My "Kore" BMX cog is thick and feels solid.
Boardwalk comes with a front brake and I am definitely keeping it.

Anyway, in this thread I was looking for a 3 speed internal wheel in 20" size to replace my boardwalk's wheel. Long story short, I had to spread the frame my muscle to slid the wheel in (and frame locked the wheel). Here is a picture:

Boardwalk S1 now S3, with Shimano Nexus in-3speed hub. Rocking white chain in there too
The cog is Boardwalk's original 14T cog. The 12t cog was a little small so chain skipped. Maybe with a spacer 12T cog would have worked.

Now, does anybody know what gear inch ratios I am getting with this hub? Front is 44t, rear 14t, wheel is 20 inches.