Any How I Got Mine from Channell. several Years ago , then went with the Mountain Drive, Instead On my Brommy.

i wonder what you meant by this.

i've never thought of you as a nasty woman. that's terrible.

Oh, but I am baaad :innocent:

Good girls can go to heaven but bad girls can go wherever they want, did you not know??

Not going anywhere. Staying home and deciding what bikes get studded tyres this winter. First snow came today.. :mad:

The FD is a cheaper option, although the SpeedDrive is nicer:

• Double chainring: €60
• LitePro clamp + derailleur kit: €60
• Sunrace thumbie: €30

Total ≈ €150

SpeedDrive licensed to ATS : £230 + shipping ≈ £250/€280

Mountain drive (mine) is a Reduction gear (130-54) the Speed drive 110 is an overdrive 34-'54',

but the frame BB edges must be Chamfered That is where the torque transfer is..
and So you need the shop tool facing cutter.
.(in France shopt that used to set Up Mavic equipped bikes needed one for that company's BB installations)

The Mk4 BB edges are somewhat faced with a Bit of a Taper , just not enough for the needed grip of the SD installation.

because of the Torque transfer needing to be More solid, the B version MD has a Knob sitting on top of the Frame
behind the BB where the rear Fold Pivot is, .. on the end of a Lever .
so It turned out to be more User Installable . on my Mk 3 & moved to My Mk4.

[if you got the version for other bikes that torque arm has a bolt hole and you wrap a coaster Brake type strap around the right chainstay. ]

Of course the big difference between a derailleur and an Internal gear is shifting, you cannot push a chain off a sprocket while you are stopped .




'/,

I assume "Mr T" is Trump from badmother's signature.

As you know, I'm an economist. I am pretty familiar with research on race-ethnicity/sex/age wage and income discrimination literature. Long story short, I've revisited some of my conclusions from that literature as a consequence of the present election.

Anyway, this is the wrong forum for this.

There is the Actor that starred in the A Team . had quite a Career in "the Business", as my LA friends call it..

https://en.wikipedia.org/wiki/Mr._T https://upload.wikimedia.org/wikiped...istmas1983.jpg http://www.imdb.com/name/nm0001558/

It's no longer the case for the SpeedDrive sold under license by ATS from Taiwan:

Welcome to ATS

https://bikegang.ecwid.com/#!/Brompt...ATS/p/60194073

In terms of price, a SpeedDrive comes between a front derailleur and a Alfine/Rohloff built by Kinetics.

Quote your Link :

NB Overdrive gear, the torque in the Gear train from the planetary gear is just pushing against air resistance

since you kick it in to Go Faster..

The High speed Drive (non Standard splined vs 5 bolt chainrings) is a 2.5X overdrive

the 2.5 reduction gear needs a more rigid torque transfer because the resistance Is Gravity.

Clubber Lang!

"Brompton New Non-Chamfer BB Shell ATS Speed drive Gearing System"

Hamster wheel continues

Also works with LitePro's P clamp + derailleur kit.

Since it's supposed to be a sturdier alternative, I got a B-series LitePro clamp, and noticed that the part where the derailleur is attached sits further out than a K-series: At rest, ie. on the smaller chainring, a LitePro two-speed derailleur sits above the outer chairing.

Can someone confirm? And in that case, what two-speed derailleur would work with a B-series clamp on a Brompton?

https://cimg4.ibsrv.net/gimg/bikefor...6bde688aa2.png
https://cimg1.ibsrv.net/gimg/bikefor...119f0f77cd.png
https://cimg3.ibsrv.net/gimg/bikefor...9d89c55230.png

An important factor limiting the front derailleur operation is of the cage coming close to the seat tube and the derailleur mount itself. When the mounting point is above the band around the seat tube, the cage hits the band. When the point is near the band, the cage can go under the band, closer to the tube. For the K-Series Lightpro you have a proximity window to the seat tube, when you put the mounting point at the very top of the holding finger, as in your photo. However, then the torque bending the finger ends up being the highest then. Also the window narrows and maybe disappears if you get the angle right in the vertical plane for the derailleur - different for Brompton than Dahon. Litepro has a new edition of the mount for K Series, with a stronger finger, but that finger is pretty much free to rotate in the azimuth - no clue here why they mass manufacture flawed designs. In B Series, the mounting tab is presumably secured to the band with one screw. You need to add a second screw and secure both with threadlocker.

As to the specific derailleur, I got a used 105 off Ebay. Ultegra also worked in my memory. Given the challenging geometry and large difference in ring sizes I wanted, I was looking for a long steel cage that could be deformed. To get the angle right, you will need to get the Sram asymmetric washer. You will also need to push the bottom bracket axle out on the drive side, by whatever means, longer axle and/or spacers. For my 3 rings, I use a Suntour derailleur as I found their derailleurs to be slimmer allowing for a better fit against the seat tube.

would like to know this as well...

Thanks much. From a picture, is there a way to tell what K clamp it is (generation 1/2)?

So you used a B clamp + Shimano 105 for a double,and a B + Suntour for a triple?

Indeed, the K clamp I've been using for years with a Shimano Tiagra derailleur is slightly bent outwards, but it's working fine. At worst, you can slide a ziptie through the window:
https://cimg5.ibsrv.net/gimg/bikefor...5498617011.jpg

Below is a photo of 4 adapters. From left to right, they are the earlier Litepro, the more recent Litepro, Ridea and CM Wasson. Then there is Litepro B-Series with modified Suntour triple mounted. The earlier Litepro got bent and straightened several time as its holding finger is too feeble. The second has a more sturdy finger, like in the cheap, common, no-name adapter with a more coarse band, not shown here. The problem is that the finger is secured with just one bolts and is prevented from rotating with a small tab sticking out, that does not fit well and that will be sheared off in no time. The Ridea has a shorter sturdier finger, but the mounting point gets shifted farther away from the seat tube. CM Wasson is sturdy, but is basically overbuilt and heavy. The best for the purpose is the Litepro for Birdy.

I used the B-Series both with double and triple. With double there is though more flexibility and the cheap adapter, not shown, also worked.


https://cimg1.ibsrv.net/gimg/bikefor...94181fd847.jpg
4 adapters: 2 x Litepro, Ridea, CM Wasson

https://cimg0.ibsrv.net/gimg/bikefor...777a89fd71.jpg
Litepro f/Birdy w/triple Suntour. The chain is on the smallest ring in the photo.

Thanks a lot.

For others' benefit: On a 2021 Brompton, the Litepro B-series clamp didn't work with a "9 Speed Front Derailleur Folding Bike Double Gear" LitePro derailleur, because on a double crankset, the fork sat too far outward and wouldn't reach the inner chainring. It might be because I turned a triple into a 46/30T double with the outer ring removed.

I had better luck with the NC-100/Meijun/Mi.Xim clamp, but still had to install the derailleur a bit astray for the fork to reach the inner ring.

So, it's really a combination of a crankset, a clamp, and a derailleur. YMMV.

https://cimg1.ibsrv.net/gimg/bikefor...eeabd80296.jpg

Its because you kept the middle and inner chainring of a triple crankset instead of keeping the outer and middle chainring or used a real double or compact crankset.

Because the middle is a BCD110, which can only go down to 34T while I wanted a 30T.

I found no affordable 46/30T double, hence the hack.

Yes, that's a reason, but it causes the derailleur problem because the inner chainring is too close to the frame.

Maybe an old front derailleur for a triple chainring could do the job ?

I didn't have any, but I'll try a triple derailleur next time.

--
Edit: Because of its flexibility, would it be a good idea to always get a triple derailleur, regardless of the crankset — double/triple chainring —, and use the high/low screws to limit its run?

Thanks for the info. As to the chain going down to the inner ring. I modify the derailleur cages, in particular soldering a stainless strip to the outer plate of the cage, to push the chain in more convincingly when the cage moves inwards. The Mi.Xim clamp is the one I had problems with due to the vertical finger, on which the derailleur mounts, holding poorly with just one bolt. However, with two rings only on your bike, maybe the forces that the finger needs to withstand are still low enough for it to hold.

I'll ask the user for feedback in some weeks/months.

From what I could tell, and like on my own Brompton, shifting down is no issue, but shifting up requires dialing the shifter in one frank move; Otherwise, the derailleur sometimes doesn't have enough power to pull the chain up.

On modern bike gearing, upshifting with the front derailleur is helped a lot by pins and grooves on the bigger chainring (each brand has its own tricks and commercial name for that).

If your biggest chainring doesn't have these pins and grooves, it results in a slower sometime difficult upshifting.

For shifting up, I expand the lower lip of the inner cage, by soldering a stainless piece there. In the end, I tailor the cage to the rings and the derailleur mounting. The manufacturers may market a derailleur and rings as a set. I make a set out of whatever I want to put on for whatever reasons. I used to put in pins for upshifting on the rings that lacked them, but these days I achieve smooth upshifting by manipulating the cage only. My pins did not work that great anyway.