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Sammyboy 11-03-07 03:42 AM

Modded R20's are old news, let's talk Hotrod F Frame Moultons
The thread about the spaceframe Moulton (slaver, drool) reminded me of something I'd almost forgotten; the fact that I have two Moulton Mini's sitting in the back of my garage. I got the pair for £8, the gold one (a 3 speed, if memory serves, though I suppose it might be 4) is useable, but the rack is broken. The other is covered in stickers, and is in need of a complete strip down, but still has the rack. I'm thinking that when I'm done with my 20, (and perhaps I've completed a couple of other projects that are half done), I'll turn my attention to these. Having checked, it seems they run the same rim size as Brompton, so rims and tyres are readily available.

I though I might build the one with the rack still on it into a reasonably faithful but mildly warmed over restoration. I'm thinking a respray, alloy rims (I can't remember if they have alloy or steel at present), a Brooks, but perhaps replacing the AW with an FW four speed, or even one of those twin chain 5 speeds. This would be a period appropriate upgrade, but give it a bit more useability.

With the gold one, I'm thinking maybe I'd just clean it up, and build it into some sort of speed machine. It's already lost weight by losing the rack, and is never going to be "perfect" because of that. I'm tempted to imagine fixed gear, but I suppose a derailleur system could work. That, and Schwalbe Stelvios perhaps. I can't think of a reason I'd need either of these bikes, really, but they could be fun. Anyone got any experience?

stevegor 11-03-07 04:28 AM

Ouch, that title hurts......especially since I recently missed out on a F frame on eBay by only a few dollars.
Why stop at a 4 spd hub.....get a Rohloff

Sammyboy 11-03-07 05:00 AM

Hahahaha - well, the reasons are twofold. 1) They cost a bleedin' packet, and the bike only cost £4, really. 2) It doesn't fit with my idea of a period appropriate upgrade......

What about my speed model though. I have a nice Dura Ace rear mech with drilled jockey wheels, whaddya reckon? And drop bars maybe......

Simple Simon 11-03-07 06:18 AM

8 quid :eek: !!!

Nice 1 - the gold one still looks modern, ditch the mudguards and start pimping.
I got rid of my last F frame a few years ago (before bitten by the folding bug) .. dang !!

Edd 11-03-07 06:27 AM


This my Moulton F frame.
I was looking for a twenty but got this instead.
Suspension is good, lots of info on the web and parts available.
Well worth the effort.
Integrated racks, low centre of gravity of load, low step over height and I will say it again Suspension!!
They are a bargain for doing a 'Hotrod'.


Sammyboy 11-03-07 06:34 AM

How do you find it running a derailleur rig on that? And what sort of ratios do you have on the back? Also looks like you've put in a cotterless crank, I assume it's a standard BB (I've had these things for a couple of years, and haven't got round to finding anything like that out yet!). I've ridden the gold one a fair bit, and I'm quite impressed.

Edd 11-03-07 07:30 AM

I have a Sram dual drive with 52 tooth front chain ring and 355 wheels. Its been awhile since I rebuilt the bike and I can't remember the actual gearing. I replaced the bottom bracket which was a *** unit (68/110 but my chain line is not perfect) and replaced it with one I got from a local frame builder. The cranks are Tru Ativ Touro, has a two chainrings, I wasn't sure which I would need so I put both on. If you have a 4 speed SA I would stick with it, it was a fair bit of work to spread the rear forks and weld on the hanger etc. My wife as an F frame with a four speed SA and it goes very well.


Sammyboy 11-03-07 08:00 AM

One has a 3 or 4 speed (I can't remember, and they're right at the back of the garage, behind around 20 other bikes), but the other is single speed. That'd be the one to go to derailleurs with. I have a set of Shimano 7 speed cassette hubs around, and I'd probably use an old-fashioned claw hanger (of which I also have several) rather than try to braze or weld anything on. My main concern is getting high enough gearing! An SRAM dual drive is waaaay out of my price range, unless I could find one supercheap on the Bay, and I'm just wondering whether I could get sensible gearing with a 52 tooth chainring - I suspect what I have on there is considerably more.

A quick look at Sheldon's gear kwakulater indicates that 52 x 14 on a 16 inch wheel is a mere 59.7 gear inches, which is Italian for Not Enough. Even 60 x 13 only gets you to 74.2

If I could bodge a 5 speed freewheel onto an SA AW, which Sheldon has done, we're up to 79.6 for 52x14. Assuming that, as I suspect, the chainrings I have are 60 tooth, if I don't go to cotterless I can get 91.6 gear inches that way, with 30.1 on the bottom end, which is quite useable.

LittlePixel 11-03-07 11:46 AM

Edd - your Moulton is rocking! Any chance of sharing some more pictures?
Sammy: What about a Carpreo 9 speed gruppo? Little wheels aren't too happy with standard derailleurs..

Darnit this thread has got me wanting one (again) now! [fires up ebay]

Sammyboy 11-03-07 12:01 PM

The more I look at this, the more it's got to be internal hubs all the way. The only way either is gonna get a derailleur is if I can tackle Sheldon's "mount a freewheel to an AW" thing, which frankly looks quite tough.

LWaB 11-03-07 12:20 PM

I've reworked a few '60s Moultons - 2 drop-bar SA 8sp conversions and a drop-bar Duomatic Stowaway (now fitted with 56 x 13 fixed wheel). A few tips:
- SA 8sp hubs are a good match for small wheels, using normal chainrings gives about 100" top gear and don't require widening the rear fork.
- The wheel of a Moulton is closer to the nominal 16" than a thin 700C tyre is to 27", so the gearing difference isn't quite as much as it may sound.
- Stelvio tyres will lower your gearing (smaller overall tyre diameter) compared with Brompton or Primo tyres.
- Watch out for cracked Series 1 swingarms and cracked BB mountings on all F-frames.
- The BB is always English-threaded but often only 66 mm wide, shorter on the RH side.
- An 11t top cog will usually fit on a Shimano 7sp cassette hub.
- There is a (rare) 11-28t Shimano freewheel.
- Stiffening the front suspension can be helpful.

Sheldon Brown 11-03-07 01:36 PM

I'm a longtime Moultoholic.

Here's the 24-speed Deluxe I rode from Boston to Montréal in the early '70s

Here's my '62 Stowaway (take-apart) fixie

The 53/12 fixed gearing sounds impressive if you don't take the 349 mm wheels into account!

Sheldon "16 Inch" Brown

|  Nobody who has anything to do with bicycles  |
|  has _all_ of their marbles, and some of us  |
|              are certifiable!                |
|                          --Sheldon Brown      |

tcs 11-03-07 02:01 PM

Did you catch what A to B magazine said about the new BikeFriday tikit? "We’d go as far as to say that the ride and handling is the best we’ve seen with (ISO349 wheels), with the exception of the classic Moulton..."

BikeFriday tikit: 2007
"classic" Moulton: 1962

Would it be safe to say you're ahead of your time when it takes others 45 years to catch up? :)


"If Alex Moulton was never knighted, he should have been." John S. Allen, Bicycling magazine, upon being corrected for making the common 'Sir' Alex Moulton mistake.

LittlePixel 11-03-07 05:29 PM

Just adding this to the mix - A really nice bare-bones nice fixie F-frame that cropped up on the FGG earlier this year:

Sammyboy 11-04-07 11:20 AM


Originally Posted by Sheldon Brown (Post 5569598)
I'm a longtime Moultoholic.

Sheldon, just how difficult was it to do your multispeed freewheel on a Sturmey Archer job? The more I think about this, the more it looks like a really cheap project, if I could do it that way. I have several AW's hanging around, plenty of derailleurs, a bar end shifter with no home in view, plenty of drop bars. I'd need to buy a pair of rims, and some spokes. Things I'd like, such as a Brooks, cotterless cranks etc could wait, but I could have it built up and rolling for next to nothing. So do tell, is it within the scope of an amateur? It sounds like the only remotely hard bit is countersinking the hole in the derailleur claw (no problem), and chamfering the nut (harder, but I can do it).

LWaB 11-04-07 02:48 PM


Originally Posted by Sammyboy (Post 5572979)
just how difficult was it to do your multispeed freewheel on a Sturmey Archer job? <SNIP> So do tell, is it within the scope of an amateur? It sounds like the only remotely hard bit is countersinking the hole in the derailleur claw (no problem), and chamfering the nut (harder, but I can do it).

It is generally tougher than you might think. Fitting two cogs on a SA is trivial but more than that usually requires a hub with a threaded driver (old), a long axle (fairly rare) and often an old freewheel with large remover such as an old Normandy.

Sammyboy 11-04-07 02:53 PM


I have several 60's AW's, and I can order the axles straightforwardly. If the bike had a derailleur hanger, even the chamfering probably wouldn't be necessary. I don't suppose you know when the change from threaded drivers happened?

LWaB 11-04-07 03:24 PM

In the 50s AFAIR. Getting an old freewheel in rideable condition is getting more difficult.

Sammyboy 11-04-07 03:37 PM

That part I can definitely manage. Not only do I have connections, I almost certainly have a couple of old ones around.

MnHPVA Guy 11-04-07 10:18 PM

I've a lightly modified, very low mileage, 1970 Moulton Mk III. A morbidly obese woman I know bought it new, because she could get a leg over it. She quickly destroyed the rims and hung it in her attic for 30+ years.

Alloy rims, Brompton tyres, 1953 alloy 36h AW shell with S5 guts, alloy front hub (18 spokes, radially laced), Shimano V-brakes on the rear, BMX front brake, alloy seatpost, Brooks B-67, alloy bars and stem.

The reason it is still "Low Mileage" is that I like riding my R20 so much more.

Diode100 11-05-07 04:50 AM

I have a 3 speed midi moulton also. They're ok but they do have scaled down frames, to give a 'ladies size' & 14in wheels. I'd have thought that your updrade options were limited, can you fit gears and hanger etc to 14in wheels ? If you're going to refurbish a moulton, I'd have thought getting a full size F-frame & forks would be a better long term starting point. Only my opinion though, the 4 speed 14in bike was a sweet little thing, and I think they also did a two speed automatic model, but to be honest from riding mine around, you do need to be quite small of stature.

Sammyboy 11-05-07 04:58 AM

Ah - they're 14 inch on the Minis are they? Just goes to show I should've got it out. That said, I rode the gold one quite a bit last summer, and found it very pleasant, so I might just go with it anyway. What do I have to lose!

Sammyboy 11-05-07 05:13 AM

Hmmmm. Sheldon's site doesn't acknowledge the existence of any 14" wheels. Tricksy.

Diode100 11-05-07 07:12 AM

There was a post on the moulton message board about upgrading mini / midi wheels a while ago. The mini wheel is 298mm, and there was a view that 305mm rims could be made to work, with the added advantage of a better selection of tyres being available. St John's Street cycles seem to be the people to speak to, they list 305 rims. There was also talk of Japanese moulton fanatics who had fitted 16'' wheels to the mini / midi models, along with other tricking out. I don't know how you would access Japanese moulton boards or clubs, but it must be possible.

rhm 11-05-07 08:38 AM

I have a Stowaway, same color as Sheldon's, that I modded up with all lightweight parts, SA-8 hub, SA Dynamo/Drum and excellent (12v) lights, and it was a great ride. But having cables running from the handlebar to the back wheel (both shift and brake) ruined the look, and made it a hassle to take the frame apart, and the whole thing was just a little less than satisfactory. So one day not long ago I polished up all the old chrome parts and put the Stowaway back together the way it came from the factory, and I really like it this way. One of these days I'm going to rebuild the new alloy wheels, replace the SA-8 with a coaster brake so I can use the new alloy wheels and have lights on it again... but I think that will be as far as I go.

Sammyboy, if you can keep the fenders on your Mini, do it; they're really good. Oh, sorry, I meant mudguards.

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