Custom lots-of-titanium Brompton

Why not invest in the full size O Bag. This is hardly a budget build and deserves the best!

This is my favourite project. It will still be a Brompton, but ah well... at least it's a Brompton with ambition.

Any updates? Wheels?

The front wheel's laced but not trued. The rear wheels is still in component form. In order to true the wheels I need to make some new tools, and modify my existing truing stand. I'll try and post something when I get back from Tenereeeffffeeee.

Why not invest in the full size O Bag. This is hardly a budget build and deserves the best!

Well I've already got a C bag, and I really don't like the O bag. It's expensive, but IMHO it's also very, very fugly.

Looking good, just finished converting my Brompton to bullhorn bars. Enjoying the ride at the moment. Look forward to more pics.

Any progress on the Brompton?

Yeah, should be an update shortly. I've been busy making/modifying tools so that I can finish off building the wheels.

Great, look forward to seeing it.

Now that the Hetchins is finished, it's time to push on with the TiBrompton, if only because the drivetrain on my poor unloved but overused rat Brompton is now making such a racket that the bell has become rather redundant and it's started making small children cry when I ride past.

The next big thing to do is the wheels. I've got all the parts, and I've already laced up the front wheel, but when I went to true the front wheel I hit a number of problems. The first, which I had anticipated, is that my truing stand isn't designed for 16" wheels. I built it so that it would take anything from 26" MTB wheels up the 27" rims on the Hetchins and a margin of error either side - but not a 10" margin of error. As you can see, the rim is quite a long way away from the DTIs, and that's with the lateral truing DTI as far up as it will go.

So some mods to the truing stand were necessary. I cut out a second set of dropouts from 3mm steel sheet and made up a dead axle to hold them in place. After removing some of the paint from the fork legs, I could clamp them in place and weld them onto the fork legs.

Splash of black spray paint, and job done - a truing stand capable of doing Brompton wheels.

Next up, more tools - two spoke tools. Then the wheels themselves. Honest.

nice - am very jealous of your tools - i have a semi pimped ti brompton myself but am yet to tackle the wheels but i did have a stab at a rack instead of the bag - for the record i wouldn't reccomend it - it's not a light option!

hollow wheel axles, tt brakes, ti swift, new clamps throughout, carbon cranks, carbon bars, custom shifter, wooden mudguards but was trying to make some ti ones (if you decide to make some for yours make me a pair too please!

brompton rack by monomaniac(tom), on Flickr

hollow wheel axles, tt brakes, ti swift, new clamps throughout, carbon cranks, carbon bars, custom shifter, wooden mudguards but was trying to make some ti ones (if you decide to make some for yours make me a pair too please!

Nice looking bike there. I'm definitely not going to be making titanium mudguards! I've tried bending titanium sheet before, and it really doesn't like it - it splits rather than bending. If I could get some very thing CP titanium it might be possible but I have another plan - I'll use standard mudguards at first, but the long term plan is some home-made Kevlar ones. That's going to take a lot of work though. Although I do have a couple of square metres of rather nice ex-Russia military Kevlar fabric.

If I could get some very thing CP titanium

CP Ti 0.5mm, £340 for a 1m² sheet. Loads of other forms and grades available, and they are nice people to do business with.

Yep, I've used them before. Eye-wateringly expensive (that's titanium for you) but a nice bunch. However, sourcing the material is the (relatively) easy bit - the real problem is that my metal-bashing skills aren't up to the job. I've got plenty of experience making composite parts - but not much with forming sheet metal. I may try making some titanium ones in the fullness of time - but Kevlar first.

anyone know what the rear axle spacing is on a brompton? wondering whether I could swap out the rear assembly for an alfine 11 sp hub.

anyone know what the rear axle spacing is on a brompton? wondering whether I could swap out the rear assembly for an alfine 11 sp hub.

ah, not wide enough for this without cold setting:

http://www.tillercycles.co.uk/page6.html

Loving your work, danstuff!

FWIW, switching out the awful Brompton brake levers to some Shimano BL-R550's has been one of the best things I've done to my barely pimped Brommie. That said, I chatted to them at Bristol Bespoked, where they had far nicer own-brand levers on their Ti model, and on the way once they've ensured they can get a regular supply.

anyone know what the rear axle spacing is on a brompton? wondering whether I could swap out the rear assembly for an alfine 11 sp hub.

110mm I believe.

You can try getting the Tannus tyres. It is puncture proof. You stop updating.

Don't worry Kllow14, that was just a brief pause in this project while I concentrated on getting rained on doing sportives. Before finishing the wheels, and in order to true them, I needed some more tools.

My normal spoke key and spoke holder (on the left) don't work with the weeny Brompton wheels as there's not enough space. So I made up my own (on the right). The only downside is that you can only turn the spoke nipples by a quarter turn at a time, but given the very limited spacing between the spokes on such a small wheel that's pretty inevitable anyway.

So, without further ado, here they are.

Velocity Aerohead rims, a Phil Wood Brompton front hub, a Sturmey Archer SRW-5 rear, and Sapim CX-Ray spokes.

They're both laced 2-cross, but the front wheel's interlaced while the rear isn't - interlacing the spokes on the rear wheel would end up with them bending through improbably tight angles.

I've fitted Marathon Plus tyres rather than the faster and lighter Schwalbe Kojaks on the basis that while the Kojaks may be fast and light they're also horrifically prone to flats. Since I fitted Marathon Pluses to the Rat Brompton, I haven't had a single p*nct*re, despite my usual commute taking me over the luxurious carpet of glass shards which adorns the roads around Kings Cross.

And with that, the Brompton project will go back on the back burner for a while - I've got another project I need to finish at some point in the next three weeks. More of that on a separate thread.

lovely wheels

Nice setup. I called Yoeleo carbon today and was told they do not make 16" BMX rims, on the 20" ones are available.

You should look at the derailer from bikefun.tw. Nice.

Thanks for the pointer on the bikefun.com.tw stuff, Kllow14. The chain tensioner is indeed rather fine:

http://blog.yimg.com/2/9Met_Fp7s5._MPkWTZM8yTQwNm_WQs5FK5dV9aLDl7NiJb.7cJqIPw--/27/l/C6eN14NNodWkBSj0QPlKHQ.jpg

I thought it might be rather heavy compared to the standard Brompton version, given it's in ali rather than plastic, but I've weighed the Brompton plastic one and it's 127g, so only 20g lighter. I think that's a reasonable trade-off for bike jewelry like that.

I'll send bikefun an e-mail and see how much getting one shipped to the UK will cost. I hope they understand English, because my Mandarin's not all that good - hello, one large beer, thank you and 'five-eight-one-eight' is about it. I quite definitely don't know the Mandarin for 'chain tensioner'...

Danstuff,

Let me know if you need help. I can point you to the right direction.
In the meantime, you may like to check the rear spring suspension from wworks.

Cheers,

I just got my rear derailleur from bikefun. All thanks to a friend who was holidaying in Taiwan. The derailleur comes in 2 colours ( bronze and titanium/silver) & take note they also come in 2 model ( single speed, 3speed, 5speed & dual speed, 6speed). Take note when you make purchase.

Nice! Unfortuately Bikefun haven't replied to my e-mails, and none of my friends are going on holiday to Taiwan as far as I know. I want a bronze/single/3/5 speed tensioner, but at the moment it looks like I won't be able to get one.

On other news, work on the Brompton has been put on the back burner again, as I've found a chap who makes carbon fibre mudguards for Bromptons, but there's a three week lead time...