Dahon modifications?
 

Now that I have put a few miles on my first folding bike, I have a clear idea what is going to need modification.

The current set up; single big ring, 8 speed cassette, and Neos 8 are not going to work for the hilly area I live. In addition, flat bars make hill climbing a challenge. (These need to be solved together) I have a deep parts bin box; cranks, front/rear derailleurs, etc. And I am competent with wrenches.

My initial thought was run a double up front, use a front derailleur adapter for the FD, add a 8 speed long cage Ultegra in the back. But, the connected issue is the setup up front; handle bars & shifters. I am not interested in STIs.
So, assuming I could make the double drive train set up mentioned above work, what options are there for handle bar/shifter set up that would work well for a hills. My thought was bullhorn with bar-end shifters? If I go with drop bars, won't in need one of those stem-extender things? If so, than the current stem I have wont work b/c you need a T shape stem?

Lastly, what bottom brackets are going to work on a (2003) Dahon P8


I appreciate any advice. Thanks.

I'm not a fan of flat bars because the lack of different hand positions (even with bar-ends) discourages longer rides. Also don't like the Neos because it's expensive, not necessarily long-lasting and has no other replacements in the chainstay-mounted configuration. I much prefer a traditional dropout RD hanger setup, can't remember if your bike has another mounting point for traditional RDs or if you have to get a RD hanger adapter. So I understand your wanting to upgrade both.

That having been said, I'll steer you to two excellent articles on upgrading your drivetrain:

Hands On Bike: Guide to Upgrading your Dahon / Tern Folding Bike

Hands On Bike: Road or MTB Components for Dahon / Tern Folding Bikes? - Part 1

For the BB , Asia adopted the British threading pattern , so abundant choices.


I manage to gain more hand positions with Ergon's grip/bar-end ,, and figure 8 bend Trekking bars ..

But none of mine are Dahons..


there are 2 speed gearbox cranks, and now a 3 speed too .. chainring turns at a different rate than the crankarms..

no derailleur needed..





....

I wonder about axle length.....too.

wonder on.. its related to the crank you choose.. see your other thread..

Dahon's that I have modified all have a 68mm English threaded BB as noted above. Axle lengths vary by bike and depending upon what you are doing, you may consider changing your axle length when you are putting in a new BB. Best to look at your chainline to see if you want to adjust things. Cranks are an issue, folded ramifications, and where your toes and heels may end up also issues to consider.

Did you look into changing to a Dual drive hub and solve the gearing problems without getting into the fiddely bits in the front? Made by Sram and still made by SA.

https://www.google.no/search?q=dual+...w=1366&bih=635

Think you will struggle to find an adapter to take a conventional rear derailleur unless you find a frame builder..Perhaps a dual drive hub may be cheaper or even a 8 or 11 hub gear may be the way to go..Sell your old P8 and buy a new one..The ones currently on sale in Thailand have a braze on for a front derailleur and a conventional gear hangar at the rear..presumably they will have in the USA..

Yes, looks like a great product. I tried to get a general understanding of price; looks expensive. Click box, hub, labor on rebuilding wheel. Also, I probably need a new rim as well b/c of hole count. I went to my LBS to ask what they knew about Dual Drive....silence. They had never heard of it. I would be on my own for setting it up, or have to travel to another shop; extra hassles. Also, it looks like its paired with a grip shifter and/or trigger shifter. Neither will work with bullhorns, the setup I really want to have. It does look like a great system though.

Actually the Speed P8 has a hanger. Please see photo.

I bought a used wheel from E-bay, sram. If I buy more I`ll buy the hub only and build my own and I would buy Sturmey Archer becous they built it so that you can use a regular left hand three speed shifter (not a three speed IGH shifter) for just the reasons you mention, different bars and shifters on different bikes.

I found I messed with the front shifting on my NWT a lot, it is a much bigger challenge to keep it tuned perfectly on a folder than on a regular bike. Stuff get bent out of tuning all the time IMHO.

Sturmey-Archer | CS-RK3 Silver

You can get it for rim brake too, not sure if there is other brake options, black and silver. 28, 32 and 36 hole options. I think it is quite common to use it on "serious" folders and recumbent bikes.

http://endless-sphere.com/forums/vie...p?f=31&t=24449

This page say flat bar shifters: http://practicalcycles.com/products/...rim-brake.aspx

I found a black 32h one on Amazon for $80 and free shipping. Only one.

There are different diameters of Bullhorn bars--smaller ones for mtn bike gear I think, you won't get gripshift on them but you will fit mtn bike shifters just fine. I like bars with bar ends much better than bull horns because of the long rounded corner on bullhorns when riding the flat position makes my little fingers go to sleep.

I have been riding bulls and flat bars with barends since 87 and I have a new favorite bar end.-- https://www.ebay.com/itm/331951072972

With Adjustable height stem on both my swift and Dahon it is not an issue changing hand height on a ride especially when fighting a nasty headwind.

I would stick with Mountain bike gear. Most Road bike brake levers don't work with V-brakes.

Gearing is an issue if you cannot get by with a single up front and an 11/34 in back. I love the simplicity of the single up front on my folders. The new 11 speed GX 11/42 works well but the derailler is going to be close to the ground with 20" wheels.

The complexity of adding dual drive to an old bike does not sound like fun to me.

The MU frame from Dahon is about 1.6 pounds lighter than the Speed frame. I think the Speed frame folds a little better for putting into a suitcase.

Enjoy your new project.. Simple is my go to.

There are many kinds of bar ends, including ones that effectively make a flat bar into a dropped bar, or, if long enough, into a bullhorn set up. I switched out the SRAM gearing on my Swift for 11/32 and found it wouldn't index and converted an old Mtn bike shifter by filing away a little of the internal detente which allowed it to mover further than stock. I agree that simple is best if possible. What if you just replace the chain ring with a smaller one, combined with a larger rear sprocket (11/32)?

Never used a thumb shifter. Can it be indexed with the Sturmey Archer. Theres a big learning curve here for me; but either way I go, Sturmey/Archer or double rings in the front) it gets complicated. But, you have me thinking. It would be a sleaker, simpler set up with the IGH. I need to do some homework. So, the Sturmey takes a cassette? And you use a traditional derailleur?

Yes and Yes.

Most likely you can use the old casette, chain, front chain ring, right shifter and rear derillium with the iGH hub.

Sun race owns sturmey archer and microshift, and yes they make a 3 spreed indexed thumb shifter for their own hubs.

I just looked at the product line: +/-10 models of thumb shifters. I reckon' I could make one of them work.

Look at the S-A site they make one for the hub.

I have an indexed 3 speed shift lever on my Brompton. They get their own made..

the traditional steel trigger shifter is still made as well.

I've owned a Dahon Speed for years and it has had a few mods, when I get to 10 you'll see!

Does your Speed P8 have a steel frame? Then many bits will fit it.
My Speed TR is from 2004/5 and I have replaced the original cartridge BB/crank with a modern SRAM crank with external bearings ... lost at least 0.5kg

Cheers
Andy

Yes, its a 2013 Speed P8. Did you have to use a spacer to push the BB out? What size was spacer?

My favorite uograde right now is Gates CTX to the Dahon NuVinci N360. I'm about to bump one from 360% gear range to 576%.

Almost a Rohloff at 1/3 the original price.

Pics posted of 360% (N360) with Gates elsewhere here.

No spacers needed...
 

I moved the big ring to the inside position , retained the chain protector and everything seems to line up OK
Photos will follow soon.

Cheers
Andrew

What does "move the big ring to the inside position" mean? Thanks

The chainring can fit in either side of the crank mountings. Generally it goes on the outside but can be on either. Putting it on the inside sometimes makes a better chainline on a single chainring bike. Roger

rhenning : you got it !

...couldn't have put much better myself

Ok, but I am doing a double setup. I believe someone had mentioned that he/she had needed to put a spacer to push the BB out 2mm. I may have got that idea from another thread; cannot recall.

Generally speaking if you are doing a double the derailleurs will take care of chainline problems because they route the chain towards the sprockets. With a single front cog and a wide rear set of like 8 gears plus it is best to get the chainring in the middle or sometimes the chain will come off the front chainring. I suspect from h88711's post he has a single chainring bike. Roger

So, my plan has "evolved". It has gotten more complicated than I anticipated. (I haven't starting the build, so if there is an issue, I can still turn back.) I plan to use the following: double Ultegra crankset, adapter with a front derailleur, a Shimano 105 long cage rear derailleur and STIs (10 speed). I have a 10 speed cassette also. I am trying to do this with bullhorn handlebars, ControlTech clamps and a new T style handlepost. My question is: should I also be installing a second set of brake levers (inline Cane Creek cross top for example) so I can brake when I my hands are not positioned on the ends of the bullhorns?

Caveat emptor
 

I would not install a long-cage RD on wheels smaller than ISO451.