LittlePixel

@ everyone: Thanks for the kind words, though you probably shouldn't encourage me...

@ invisiblehand: Brake reach is reduced a little I think with the eccentric fit of the pantour hub, and I took maybe 2-3mm of material out of the fork ends to help matters slightly. Brake shoes are on the lowest possible setting in the caliper!

@ simplesimon: Thanks! James May (a fellow Bromptonaut) should take his on the show

@ ChiapasFixed: The chain gets a fair bit longer when it's folded - maybe about 6"? It's basically about double the offset between the bottom-bracket and the frame hinge. I think it might be possible on a Joey, though looking at a picture of one the hinge *seems* to be just about an inch below the bottom-bracket so the amount of slack will be a fair bit less. I don't think you'd need something as elaborate as the Brompton two-jockey tensioner - perhaps a rohloff or other singlespeed type tensioner might be enough?



@mconlonx: Bars are flipped north-road cruiser bars, with about 3 inches chopped off each end so the bike can get through London traffic. They work a bit like shallow drops and offer a few hand positions which is good for hills and speedy straights

@ bykerouac: Would a sweet 80's campag delta fit in there? Probably. I had to enlarge the bolt hole in the fork by about a mm for the campagnolo bolt to fit. Not sure if an 80s vintage caliper is the same size. Reach might be an issue though - I initially thought I'd need to build up some sort of drop bolt to fit these roadie calipers but a bit of adjustment (mmm dremel grinding) at the claw end of the fork and the eccentric fit of the pantour hub meant I lucked out and could fit it (just!).

I think about coming back to NYC often - lovely city! So yes - maybe sometime this year if the opportunity arises.

rekall

what a beaut!

ChiapasFixed

well, i tried a chain tensioner very much like the one pictured above on the joey, just with its current shimano nexus 8 speed gearing. sad to say it did not work
the chain was too short to allow the bike to fold, so i would need an articulated tensioner (right now it actually uses a shimano alivio derailleur!)
this makes me seriously doubt whether i can use a setup like yours to convert to fixed wheel...
i am thinking an eccentric bottom bracket, and just take the chain off the front chainring for folding....

LittlePixel

Little update I've been meaning to post for ages (thanks 14R for PMing and asking about my brake fixings - it reminded me to post about them)

Basically - someone on flickr pointed out to me that I had the front Pantour suspenision hub set up wrongly (D'oh! But easy to do with their TERRIBLE instruction sheet).
When I finally got it fitted right ("AH! THAT'S how the suspension should be - what an idiot!" ) the nice campag brakes no longer reached the rims. Oh noes!

I toyed with the idea of filing the calipers in some way to extend the slots but this would have looked cr4p, worked badly and is basically against my religion to defile Campag components in such a way. Then I thought about filing the drop outs to move the wheel 'up'. But have you ever tried to file Titanium? And it was gonna weaken things - possibly catastrophically. So I had to succumb and make some drop bolts.

I've seen these done, by way of Sheldon's site and others but I really wanted to as good and neat an install as possible. They can be a bit cludgy.
I actually made a couple of wooden blanks for a test fit before heading to B&Q (aka Home Depot) for some nice extruded aluminium.

So I spent the time and made some nice rounded blanks with just enough reach for the brakes. I also made a little alloy collar for the lower bolt to protect it from road crud. I hope you'll agree it's a reasonably nice install. Looks almost factory and the brakes themselves are excellent. I made the reach so that the brake shoes fit just nice and central to the slots. Great power when braking without need for too much pressure.

Oh and no rain goes up the cable like it does in the strangely inverted B designed caliper.

pix:


side view


Front ¾ view (sorry about crud)


Detail (you can see alloy bolt 'sleeve' in this one)


Underside. Don't know what the green stuff is. It looks like algae but I'm sure it's a trick of the light. I don't do much under-sea riding these days, not since the manta-ray incident of '96

SesameCrunch

Great job, LP! Elegant solution, indeed...

vincentnyc

Just curious, can u still get a merc or a mercton now a day, or it is pretty extinct due to the threaten lawsuit by brompton?

Simple Simon

Well done LP - neat job.
Question: have you done a back to back comparison with a steel Brommie frame for stiffness ( ideally with the same Ti rear triangle). The old 'lean bike at 45 deg bottom bracket torsion test' would do.
Lean bike over to 45 deg to the ground, with upper crank at 6 o'clock press pedal at 90 deg to frame ie towards ground. This old test can be used to crudely compare frame + forks (+ wheel) stiffness.

LittlePixel

@vincentnyc
The 'Merc' brand was pretty much exclusive to the UK but was really just a marketing name for Flamingobike, which I believe are still available. The most recent one's I've seen had hydroformed Alloy parts on the frame top tube that made the shape of the bike seem less 'brompton-like' despite the fact the fold and geometry are the same. Another clone I've seen is the Japanese Nishiki Oxford.
No idea about availability in North America though.

@Simple Simon.
I haven't done the test, nor could I as I don't have a 'real' brompton steel frame to do the comparison. My guess is the brommie's steel is a little more forgiving

I meant also to say the other good reason for fitting a sleeve over the bolt is to provide stiffness; if there is nothing in between the gap between the two drop plates, the natural thing to happen when you tighten the brake bolt is for the two plates to be bent inwards. I wanted to avoid this so the tubular spacer fills the gap and performs the same function that the bottom of the steerer tube does in terms of not letting the tube (or plates in this case) bend and deform when you attach and tighten the brakes.

ChainlessRev

Wow just saw this thread - nice bike!

Would love to see it if you're ever back in NYC again.

14R 

Very nice job, LP. Thank you for sharing.

I have some decision to make before I stir in one direction...your bike is very inspiring, that's for sure.

Edd

Great job LP.

How is the front brake cable run when folding the bike?

Edd

14R 

LP, do you have a rear triangle and a front fork that are V-Brakes compatible? I might be interested. Feel free to reach me privately at rcguerra at gmail.com

LittlePixel

This is very old news, the offer of bits...
Collectively EvilV and Sesamecrunch got the lion's share. The Rear and Fork I got did not have v-brake braze-ons anyway so I doubt you'd have wanted them...

SesameCrunch

Yup, the wheels are here:

griftereck

hey thats a nice looking bike.

you could remove the er braze ons from the fork and frame tube. would be a gram or 2 less.

Im thinking of welding cable stops to my city folders handle post. at the top and then just above the hinge at the headset. would be neater, give a more positive cable pull, save a few grams. But my handle posts steel. So realitivly easy to weld. My bikes 28 pound. About 4 KG heavier than yours. Gonna try to get it lighter. It was 30 pounds when I started.

have you thought of making drop bolts/ plates to fit on the brake pad slots? If you fitted them on the outside of the caliper there would be enough room to fit V brake washers. So it would be easier to toe in the pads.

kraftwerk 

LP nice hot rod,
us NY-ers should have had a fold-able gathering in your honor.
We could have checked your creation out in person. Ah well, our loss.
How did you like the big apple?

LittlePixel

loved it - was a bit cold in december though...
Maybe next time - I hope there's a next time....

phatatude

LP... Phat as usual...