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Folding Bikes Discuss the unique features and issues of folding bikes. Also a great place to learn what folding bike will work best for your needs.

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Old 03-31-05, 12:27 PM   #1
ETRTO 520
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Using a 100mm Front Hub on Dahon?

I have recently (last night!) acquired a late-model Boardwalk that I would like to modify somewhat for day-in, day-out, all-weather short-distance commuting. I think that this is a 2004 bike: it has the chromoly frame, straight fork and 6 spd. freewheel.

One proposed change is mounting on the frame an existing set of 20 in. (ISO 406) wheels that I built for another bike. These wheels use Shimano Nexus/Nexave roller brake hubs. These are standard hubs, the front hub having a OLN distance of 100mm. I note that being able to fully fold the bike is not a priority in my situation, and that I bought the bike for its other features (wheel size, frame dimensions, etc.).

I now realize (a little late ...) that the Dahon uses a proprietary fork / front hub combination with a rather narrow OLN distance. Any thoughts on how to proceed?

My first idea was to change fork. I would be happy to swap out the stock fork for a 20 in. chromoly fork, but I'm not sure if I will be able to find one with a 1 1/8 in. steerer. The 1 1/8 in. steerer is, of course, required for the stock headset and, more important, the Dahon handlepost. Is anyone aware of where to find such a fork? Gaerlan Custom Cycles has a couple of 20 in. forks, but both have 1 in. steerers.

The second idea involves cold setting the existing fork. But this would involve spreading the blades some 25mm, so it seems unrealistic and generally a bad idea.

Does anyone have any experience with this?

Of course, I could live with the front V-brake, but I have gotten quite used to the security and reliability of the roller brakes over the past couple of years, and I am prepared to pay a small weight and convenience price to have them on the Dahon.
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Old 04-05-05, 09:37 PM   #2
ETRTO 520
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I guess this topic leaves everyone speachless!

Of course, it's an obvious problem that I could have avoided if I had more fully researched my purchase ...

In the short run, I will live with the front V-brake. In the longer run, I will research both replacement fork and cold-setting options. If anyone has any experience with the latter on Dahon forks, I'd appreciate your thoughts. Is 20-25 mm of additional width realistic or advisable? I would assume not, unless I heard one or more success stories. Thanks.
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Old 04-06-05, 12:06 AM   #3
jasong
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It really is an example of a place where they choose to change the design just a hair and it results that things are completely frustrating when trying to use off the shelf parts. Are there BMX bike forks that are 1 1/8"? I don't know much about them - try asking Gaerlan for ideas or looking through the Better Bicycle catalog at places like aebike.com.

The same thing is frustrating with the rear dropout spacing. They choose sizes between 118mm and 126mm for a number of their bikes. Adding 14mm (7 on each side) is barely going to affect the folding size, but would easily allow putting a Nexus or Rohloff rear hub in one of those, or an off the shelf road or mountain hub. Why do they do that? There are some other frustrating examples of incompatibilities they bring in, like the SDG IBeam saddles on some of their new bikes. Dahon has such a commanding lead on their stuff they can do what they want. And the replacement parts aren't really overpriced relative to other cycling stuff.
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Old 04-06-05, 01:03 AM   #4
easy racer
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Hi Etrto 520,

You really only have three options:

1. Take the risk and get the front forks spread either by yourself, or a framebuilder.
I have done this on an old raleigh Twenty which also used a 75mm front hub, though I can't recommend this.
I accepted the risk that they may either snap when I forced them out, or worse while I am riding on them. As I am only about 130 lbs I thought I would be okay, and so far I have been.

2. You can buy 1.125" steerer BMX forks, but you may have problems getting the right steerer length, or a pair of forks that doesn't weight a ton, as they are designed to take the abuse of jumping and such like.

3. See if you can get a replacement set of forks made by a framebuilder. Though the cost of this may make this the most expensive option.

Hope some of this maybe useful?
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Old 04-08-05, 09:03 PM   #5
ETRTO 520
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Thanks to easy racer and jasong for your various observations and ideas.

I have spent a little time looking into replacement fork options. From what I can tell, the 1 1/8 in. size steerer is now commonly used on BMX bikes. But these seem to be threadless forks. While I think that it would be possible to convert to a threadless headset, I'm not sure how the interface between the steerer tube/headset and Dahon handlepost would work out. As a new Dahon owner, I just haven't spent the time working with these parts. Also, as noted by easy racer, for the most part BMX forks tend to be very beefy. For my use, I don't mind the extra weight, but I do mind excessive rigidity, as I'd like the fork to absorb some road shock and vibration. I did find a carbon BMX fork which looked a little more svelte, but at $200, it's about what I paid for the whole bike ...

As regards cold setting, I'm just going to hold off. I'd be more comfortable doing it with an old Raleigh Twenty, as there's lots of metal in those bikes. I just don't know how the Dahon Boardwalk fork is made. Also, in my case, I weigh in at 170 lbs., am often carrying luggage on the bike and ride bumpy New York City streets, so I don't want to push my luck.

I guess that, for the time being, I'll use the roller brake on the rear wheel and the stock V-brake on the front. I will report back if I come up with any ideas or solutions.

Thanks again.
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