Tweaking Dahon EEZZ/Curve to add/replace 3-speed IGH?
 

Hello

I'm not technical enough to know for sure, so was wondering if some experts here would know.

As an alternative to Brompton, whose price has been raised again recently, I was wondering if the Dahon EEZZ (which uses a derailleur) and the Dahon Curve (which uses the Shimano SG-3R40 IGH) could be doctored to use a Nexus/Alfine 8 IGH to increase its gear inches?

http://dahon.com/uploads/tx_dahonpro...MG_9825_01.png
DAHON Bikes:*Curve i3 16"

http://dahon.com/uploads/tx_dahonpro...EZZ_jaa634.png
DAHON Bikes:*EEZZ D3

It's too bad the EEZZ cannot carry a bag on the front, because the bike looks nicer and folds smaller too.

Thank you.

how wide is the rear frame spread? thats what you have to match with your hub choice..

shimanos 8 speeds are much wider. 32 , 36 spoke > (I dont own one)

for Brompton S-A makes a narrower Hub with 28 spoke holes .

maybe that Shimano hub on top picture is narrow too? measure and report.

Maybe you can find one of the old Dahon Curves with a Nexus 8.

I own neither, so can't measure nor report.

But some other BF users might.

2011 is the oldest archive on Dahon.com.

Here is a curve with a nexus 7.

DAHON Bikes:*Curve XL

before you think to mod those bikes, it would first be a good idea to check if they are indeed available,
anywhere ...

just saying
thor

Go to 20" wheels,, get one with an 8 speed cassette.
My Dahon Speed P8 8 speed tops at I think 94 gear Inches,,
52 tooth chain ring on 8th gear at (11 teeth) and 20 X 1.75" / ETRTO 47-406 wheels

Same gears with 16" wheels, 16 X 1.5" / ETRTO(47-305) would be 76 gear Inches,,yeah way too low for me....

AS for your IGH I bet you'd have far better luck fitting it on a frame made wider for the 8 speed cassette's

I ride mine on side walks, losts of cracks, dips, chunks missing,,20" wheels roll much much better in chudder and give a larger contact patch for better traction and
In general will ride better overall...

DAHON Bikes:*Speed D8

http://bikeforums.net/attachment.php...hmentid=460217

Thanks for the feedback.

It doesn't look like a good idea after all :innocent:

A place called Thorusa.com lists the Curve D3 as 'back in stock', but I've pointed out erroneous info on that web site before. :) Anyway, the Curve will certainly fit a Sturmey-Archer XRF8.

The EEZZ uses a custom super narrow rear hub. AFAIK, no IGHs will fit.

Interesting:

• 8-Speed internal gear hub with wide gear ratio of 325%
• Gear steps of 30%, 14%, 14%,14%, 14%, 14% and 30%
• Available with 28, 32 or 36 spoke holes
• Compatible with 20 to 23 or 25 teeth sprocket
• Weight - 1770g to 1790g


Sturmey Archer | X-RF8

By default, the Curve comes with a 46 tooth chainring and a 16 tooth cog.

http://www.nycewheels.com/dahon-fold...-curve-d3.html

ThorUSA is where I ordered my TernJoeP24 and rack for it from. Call Thor and he'll give you some assistance. I had an excellent experience myself,... :thumb:

About Thor USA

Gears looks pretty good to me using the stock 46T chainwheel and the XRF8W's available 23T cog (2.1 to 7.0 meters development, i.e. 27-87 gear inches).

Building up a robust, quality wheel with an ISO305 rim and a large hubshell IGH is doable but non-trivial. There's info on the sheldonbrown website about lacing large diameter hubs in small diameter rims and spoking 36 hole hubshells to 24 hole rims.

BTW, the Curve at one time was offered from the factory in a model fitted with Shimano's Nexus 8 speed IGH. If the current Curve model's rear OLD (over locknut dimension, the distance between the rear dropouts) still fits a Nexus 7 or 8, those are possibilities, too. I know the XRF8 will fit, though, because it's available in an OLD as narrow as any three-speed (and the Curve has used Sturmey, SRAM and Shimano three speed IGHs in various year models and regional markets).

Thanks for the infos.

The Curve is available from at least one shop in Germany, whom I asked about the feasibility of replacing the three-speed SA with an eight-speed Nexus/Alfine.

we do have a handful of red Curve D 3 in stock ... NOT the above pictured one as it is a so called global model ... might want to check with the german shop what color it is ..

yeah the curve sl was indeed available with a Shimano 8 speed at one time ... sold mine and regret it ( just a little bit )

lol

best thor

It's only 500€ in the Netherlands:
https://www.vanvlietbikes.nl/vouwfie...e-d3-rood.html

Someone in Japan put an Alfine 8:
https://www.youtube.com/watch?v=4eKnRupt1fA

Or find a curve sl with the lovely caspro cassette.

The SL is discontinued:
Dahon Curve SL|Super light folding bike

Besides, 38"-85" gear inches (3.04 - 6.8m) is too high to climb hills and not high enough on flat roads.

BTW, was it Nexus 8?

Yes, 28h Nexus 8 red band.

Thanks

In the archives, someone said "You don't want to build an ISO305 wheel 36 spoke."

I know nothing about building wheels: Am I correct in assuming that…

1. An IGH has a number of "holes" on its hub to connect it to the wheel through spokes
2. The bigger/heavier the IGH, the more holes it has
3. A wheel itself only has a number of holes, based on the weight it's meant to support
4. Therefore, a given wheel can only take a given IGH, and not heavier

Also, it seems like the OLD (Over-Locknut-Dimension) varies a lot: 113mm, 120mm, 130mm, 135mm.
Sheldon Brown's Bicycle Glossary N - O

I'll go by a store today that has a Curve, and check things out.

1 wheels and rims have a spoke number. The two need to match. Unless you use a denominater of the hub number. Ie a 36 s hub can be lace to a 24 hole rim or an 18 by leaving spokes out.
2 the spoke number is to increase the strength of the wheel. The more spokes you have the less stress on each one and therefore the chances of breaking spokes reduces.
3 the wheel has a number of spoke holes based on what it has. The idea is you pick a spoke number that suits for your use. Ie bmx bikes have a really high spoke number for stunts. Loaded touring bikes have higher numbers light weight rims may have 4 spokes only. Smaller wheels have less need for higher spoke counts due to the shorter spoke length and the increased rigidity of a relatively increased cross section to height aspect.
4 the weight of the ihg is unimportant. The type of usage and rider weight are the things that influence spoke count. More spokes is a heavier wheel you may not need the extra strength.

Get the hub you want then look for the rim. I bought a 36 hole dual drive and got a matching rim.
I could have opted for 24 spokes but I didn't. Maybe I should have done, but it's given faultless service and maybe the weight saving was 2 onces at 24 spokes.
Hope that helps.

I believe a curve has a 118mm OLD it will not fit a shimano nexus hub. The Sl version has a 135mm. So that version will take anything you want if the drop outs are right.

Thanks much for the infos.

I'll ask the shop owner if replacing the IGH with an Alfine 8/11 is a good idea, and which wheel I should get to match.

Doesn't that sound too narrow for a Nexus 8? I thought it has a little more than a 300% gear range. That must be a typo for 28".

I think you want relatively wide gearing then. You might think about a different bike or something that naturally fits a Schlumpf, SRAM DD, dual chainrings, Alfine 11, or Rohloff.

I was looking at the Curve because it's close to the Brompton in terms of size once folded.

Those options are way too expensive, especially when bought individually.

What bikes do you own now?

Then have you considered a used Brompton then?