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Anyone making forks for dahon-style folding bicycles?

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Anyone making forks for dahon-style folding bicycles?

Old 05-08-21, 09:30 AM
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Nyah
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Anyone making forks for dahon-style folding bicycles?

Specifically ones compatible with Dahon designs? Dahon makes a pretty good chromoly frame but the fork that they include with it in their bicycles always leaves much to be desired. There are even companies that copy this frame yet perpetuate the problems inherent to these forks. I would love to be able to buy an aftermarket fork that solved the problems.
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Old 05-08-21, 09:49 AM
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With Dahon being such a bit player in the greater bike sales market and these bikes are mostly on line purchased we don't see many for service these days. So please explain the problems. Even better will be photos of the specific aspects for those of us who won't follow the text descriptions well.

Lots of us here could likely make a fork for a folder as long as any specific to that design elements can be fabricated or found already manufactured. Of course this would be rather expensive as making a fork needs all the skills of a frame build and perhaps more given the liability if done poorly. Andy
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Old 05-08-21, 09:57 AM
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I'm not sure why, but I have thought about making smaller forks. I think the best approach is a segmented design. The problem with a lugged fork is fork blade availability. Although maybe a track fork blade would work

I would also like to know what the specific problems are with this fork.
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Old 05-08-21, 12:47 PM
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There are three problems with the existing forks:
1. They use a 74mm hub. This is a standard with Brompton but proprietary in the larger scope that has accepted 100mm as the standard. Mini-velos, for instance (other than those produced by Dahon), use the same 100mm standard that all other bicycles use.

2. They use cheap materials that are sub-optimal for the purpose - aluminum or hi-tensile, instead of chromoly. The frame is chromoly so, why would the owner want a fork made of a rough-riding, non-dependable material such as aluminum or a heavier, weaker version of steel such as hi-tensile?

3. Lack of dedicated braze-ons/eyelets for racks. If you want to use a rack on the fork, you have to share the mounting bolts with the fender.


The widely-copied frame is the Dahon Speed (sometimes referred to as their K-series). This frame is copied by Fnhon as their Storm model (also known as the KC2018), by Crius as their Master-V (the 'V' for V-brake), by Banian as their Wind Speed model and by numerous other companies. This frame is light, strong and uses the 406 size of tire (BMX size, which is very common and comes in a multitude of offerings).

There are folding bicycles which don't suffer these problems. KHS's F20-JJ model is one, but which suffers a problem of handlebars that do not adjust for the rider's height.
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Old 05-08-21, 12:59 PM
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Some people make custom forks for less, but figure $500 and up for a custom fork with paint.
It would take some shopping around to find someone to do this. Maybe someone that specializes in BMX.
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Old 05-08-21, 06:28 PM
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1- the hub width is a non issue for someone with experience. At worst they might charge you for the one off dummy axle to fit their fork jig.

2- Cost and consumer awareness. It seems that many HAVE bought the CroMoly frame with the other material fork and not had enough complaint to bother finding replacements, or seeking help from forums that focus on frame building. I believe this group of buyers also contains you, until recently Do understand the weight savings are going to be pretty small.

3- Very typical for a non touring specific bike to have only one set of eyes. In fact that is likely that vast majority of forks that have any eyes, having only one set.

Eric's cost suggestion is pretty close to what I was thinking of. I've seen $400 for a more common 100mm wide drop outed fork for common 700c wheels using common crowns and existing tooling to make with a few years ago. About 6 years ago I aligned a Bike Friday's fork, after a mishap. IIRC the new replacement was going to be close to $350, and that's a production example likely built in batches and painted in batches to save costs. A far lower cost path might be to have eyes brazed onto the OEM fork. Andy
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Old 05-08-21, 09:34 PM
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I think the only thing I would do is have some rack mounts brazed on. Like Andy says, a chromoly fork isn't going to produce big weight savings. And I would figure out how to live with the hub width. There are enough hubs in that width, I think. The only thing I can see to worry about is wheel availability, but if you are spending $$$ for a fork, you can have a wheel built. There are even dynohubs that width, so it's not horribly uncommon.
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Old 05-25-21, 11:19 AM
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Last I heard the Bike Friday forks where made from seat stays. Is that right? We have had X employees here. Someone who could probably make one, if he was inclined to, and the price could be tolerated is English Cycles. He is very out of the box, and he is an X employee of BF. He uses the tiny rear triangle specs on his road bikes. Maybe a BF fork would fit, but there are a lot of dimensions that would need to be right for that to work. For one thing, most of their frames seem to use a tandem head tube.
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Old 05-25-21, 11:24 AM
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I assume Rob English would be on the "and up" side of "500 and up"
Also probably be a long wait from him. If someone didn't care about money, there are a number of people that would do this. There aren't many that would do it for cheap and you would probably have to wait a year.
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