Latest version of the lightest folding steel bike

Discuss light weight issues concerning road bikes & parts.
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jahknob
Posts: 113
Joined: Tue Sep 07, 2004 1:27 pm
Location: London, UK

by jahknob

It was a close-run thing the day before the event, but we managed to finish the rebuild of my ULT "backpack" ultralight Steel Roberts bike (though not quite rideable yet - some tweaking still to do). It's now tipping the scales at a little under 4.7kg (though this is the "show" build - I wouldn't ride those track tubbies on the road - it'll be close to 5kg "ready to ride").

There's a show report about Bespoked Bristol (the 2012 UK handmade bicycle show) with some pics here:

http://road.cc/content/news/55537-bespoked-bristol-roberts-pegoretti-foffa-kurtz-quoc-pham-velobici-lots-pics

The reporter seems to like the front hub (have got other good stuff from B-T-P on there too) , but we threw on an Experimental Prototype carbon cassette that arrived just in time that didn't even get a mention. What an outrageous piece of work that is! (see other threads here for info) - and cheaper than some of the Ti/Al cassettes out there...

I'll get some other pics once I get the bike back and can sort it out. If anyone wants to see the spec sheet, I will post that here. May even get to ride the bike later this year (fitness permitting!), and will report further.

j.

ajz07
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Joined: Fri Jul 15, 2011 9:32 pm

by ajz07

looks absolutely amazing

by Weenie


bikewithnoname
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Location: UK

by bikewithnoname

nice! what's the frame weight?
"We live in an age when unnecessary things are our only necessities." Oscar Wilde

Pegoretti Responsorium, Parlee Z5i, Donhou Commuter, 1946 MacLeans Featherweight L'Eroica!, 2x MTB 'dales

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stephen@fibre-lyte
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by stephen@fibre-lyte

Blimey, I've never even heard of Bespoke Bristol. I guess that it's not overly publicised. Shame, I would have like to have gone.

Nice bike by the way. I'm surprised that you didn't just call up north for the carbon chainring and cassette :wink: Bear in mind that the cassette probably won't be very durable, we've done a few in our time. I haven't seen Mattias carbon parts up close, but I'm guessing that it's water jet cut prepreg carbon sheet. Mattias?

KLabs
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by KLabs

specs please :-)

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prendrefeu
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by prendrefeu

Looks great!

But, just for clarity - it isn't quite folding, it's more like "halving" no? I mean, the S&S couplers split the frame in two, the frame itself does not "fold"

Rob English has an ultra-light steel folding bike that he has made, and it's fully steel (stays, tubes) minus the carbon fork.
Exp001 || Other projects in the works.

bones
Posts: 414
Joined: Sun Aug 23, 2009 10:38 am

by bones

jahknob wrote:It was a close-run thing the day before the event, but we managed to finish the rebuild of my ULT "backpack" ultralight Steel Roberts bike (though not quite rideable yet - some tweaking still to do). It's now tipping the scales at a little under 4.7kg (though this is the "show" build - I wouldn't ride those track tubbies on the road - it'll be close to 5kg "ready to ride").

There's a show report about Bespoked Bristol (the 2012 UK handmade bicycle show) with some pics here:

http://road.cc/content/news/55537-bespoked-bristol-roberts-pegoretti-foffa-kurtz-quoc-pham-velobici-lots-pics

The reporter seems to like the front hub (have got other good stuff from B-T-P on there too) , but we threw on an Experimental Prototype carbon cassette that arrived just in time that didn't even get a mention. What an outrageous piece of work that is! (see other threads here for info) - and cheaper than some of the Ti/Al cassettes out there...

I'll get some other pics once I get the bike back and can sort it out. If anyone wants to see the spec sheet, I will post that here. May even get to ride the bike later this year (fitness permitting!), and will report further.

j.





S&S coupled bikes are not the same thing as a folding bike.

jahknob
Posts: 113
Joined: Tue Sep 07, 2004 1:27 pm
Location: London, UK

by jahknob

Well,

I'm not going to split hairs. Strictly speaking it isn't a folding bike, it splits in to two halves and can be packed into a suitcase. It's not a Brompton or a Dahon or similar folding bike - you can't go from riding to folded down in seconds flat. But you can travel with it and pack it into a suitcase which will incur no additional luggage/oversize fees (and fold up the bag and carry it away like a backpack - with all of your other accessories and packing materials inside).

The English concept is a beauty - but I don't think it has any advantages over the S&S couplings in terms of what you can do and how fast you can do it (and the couplings are probably a much cheaper option and more versatile).

Does anyone know of a lighter steel road bike (folding/splitting or not)? If it didn't have the S&S couplings, I believe we could have saved an extra 200g or so on the frame, making it under 1400g.

And, just to pre-empt any comments about the spec sheet that I'll post - the bike is in "show" mode. When I ride it, I use standard tubulars and steel/Ti/alloy drivetrain for longevity, so it comes in around 11lbs on the road.

j.

PS If anyone has any hints on how to format the specs a bit more clearly, please pm me!
Last edited by jahknob on Wed Mar 28, 2012 2:31 am, edited 1 time in total.

jahknob
Posts: 113
Joined: Tue Sep 07, 2004 1:27 pm
Location: London, UK

by jahknob

Part / Make + Model / Wt(g)
Frame (F&R) Roberts Columbus Foco, Dedacciai Blacktail, inc. S&S BTCs 1579
Fork THM Scapula SP Tuned 1.125" (182mm steerer) 231
Headset Cane Creek AER 1.125” 47
Top cap & bolt AX Lightness 6
Spacer 5mm carbon 1.125" 2
Seatpost collar BTP Carbon 7
Stem Carbonschmiede 97mm -7 degrees, 26,0mm 58
Handlebar Schmolke Carbon TLO Modolo-bend (42cm ctr-ctr) 142
Seatpost Schmolke in-line TLO 300mm 92
Saddle AX Lightness Phoenix 53
Crank/BB axle THM Scapula (LH 123g/RH & axle 157g) 280
Bearings/cups THM Scapula (27.5g per steel bearing) 55
Chainrings Dark Albert Carbon 50/36 (39/15g) 54
Chainring bolts AX Lightness aluminium 8
Brake/Shifters 2010 SRAM Red, BTP hoods & clamps (216+25+9) 250
Brakes AX Lightness 3000 49g + pads/bolts 21g + misc. fixings 10g 80
Brake cables Alligator iLinks/PowerCordz 32
Rear derailleur SRAM Red tuned w/Dark Albert carbon cage/pulley wheels 112
Front derailleur Campagnolo Record compact 10 Carbon (BTP tuned) 58
Derailleur cables Alligator mini i-Links/Powercordz 28
Pedals Aerolite Ti 70
Chain Yaban 10S Ti 106 links 218
Cogs/lockring Hellore Experimental Prototype Carbon 10s 11-23 68
Front hub BTP Carbon 50
Rear hub Tune Mag 140 145
Rims (2) Reynolds KOM (20/24h) 450
Spokes/nipples Sapim CX-Ray & DT Al 204
Tubulars (2) Tufo Elite 110g 224
QRs (2) Tune Skyline Road 18
Bar tape BBB Pro Light tape (black) 33g + plugs 2g 35
Tub tape Jantex 22
Bottle cages (2) BTP Kevlar & bolts 12
Total (g) 4690

bikewithnoname
Posts: 999
Joined: Tue Sep 22, 2009 1:29 pm
Location: UK

by bikewithnoname

To say that is a nice build is a gross understatement! :thumbup:

Top work :beerchug:

( I wouldn't ride those TUFO tubs on any road mind you...)
"We live in an age when unnecessary things are our only necessities." Oscar Wilde

Pegoretti Responsorium, Parlee Z5i, Donhou Commuter, 1946 MacLeans Featherweight L'Eroica!, 2x MTB 'dales

by Weenie


bones
Posts: 414
Joined: Sun Aug 23, 2009 10:38 am

by bones

Yeah, but it still isn't a folding bike. S&S coupled bikes are definitely not the same thing as a folding bike. It's not a splitting hairs thing. It's a big difference.

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