Andy_K 

That looks great! I can't wait to hear the details on the paint and see the build progress.

bwilli88 

This is what comes next!

But with a different Brooks Flyer. I need to find my leather bar tape and get it ready to install.

Chr0m0ly 

Hi gugie,

Are there any qualities that make a bike a good candidate for the The Treatment? Minimum tire clearances, certain eras, marques or models? Maybe a good frame with marginal paint?

What makes a bike a good conversion candidate?

52telecaster

Personally I think if you're going to do it you need to start with an excellent frame. The time and cost seem like it would pay off better with better steel. If you want to use a standard set of brakes that fit in the existing brake bolts it helps to have a frame made with 700c wheels in mind, or sewups of course. This makes the reach more manageable. Finally look for good clearance at the chainstays. These can be massaged but some bikes already have plenty of relief there.

Andy_K 

I've found that frames which can you short reach brakes (<47mm) use 700c wheels will work with Tektro R559 brakes and 650B wheels. (The specs say that would leave 7mm to spare.) The trouble is, most frames that were designed for short reach brakes like that don't have the tire clearance you'd want. Sometimes dimpling is sufficient to fix that. Of course, the "full gugie" modification involves brazed on mounts for center pull brakes, so reach isn't an issue. I opted for cantilever brakes on mine, which also solves the problem.

I agree about starting with a good frame. I would imagine that starting geometry is also a consideration. Re-raking the fork is de rigueur but I would imagine that you need a good starting geometry for that bit of magic to work correctly. Or maybe not. Here I'd have to defer to @gugie himself because the low trail part of this still feels like dark magic to me.

ThermionicScott 

My conversion didn't start off with a re-raked fork, and it worked fine as a bike. But I ultimately (inevitably?) decided I wanted low trail to go with the handlebar bag, so the decision needed to be whether to re-rake the fork, or get a different/custom fork. Re-raking the fork shortens the distance between the axle and crown of the fork, reducing tire clearance. Since my tire clearance was already marginal for 38mm 650B tires and fenders, a custom fork was the next logical step!

52telecaster

I agree on tire clearance but for some reason on some higher end framesets, the AD and my latest moto, the insides of the chainstays are already dimpeled for big clearance. The AD was definitely 700cx28 max. The mazerati I have is the same way. Not sure why they have the clearance only at the chainstays but it does make it easier to convert.

TimmyT 

I missed this the first time around ... very cool

bulgie 

Since width between the chainstays is so often the limiting factor in tire size, look for a frame with indents, rather than just ovalized. R-O-R stays (round-oval-round, oval at the clearance point) with less clearance became more fashionable roughly '75, and newer frames also tend to have shorter chainstays, which compounds the problem. Bikes with indents from say the '50s through early '70s are more likely to have the clearance for 42 mm tires without extra modification needed.

Especially French 531 bikes it seems; they practically all used the same Reynolds "factory" indents (as opposed to making their own indents). Peugeot PX-10 is the quintessential example, and they're plentiful. My own fave is a late-'50s Follis that has super-skinny (rapid-taper) fork blades with a ton of small-radius bend, internal routing for the rear brake, and hand fillet-brazed lugs, i.e. lugs with a fillet added over the juncture to make the transition swoopier. Just a fancy-looks thing. Fits 42 mm tires with no other mods, and RAID brakes reach the rim with no brazed-on posts needed. Though I may do the braze-ons eventually, for now I like having the option to turn it back into a skinny-tire race machine.

French frames do bring some extra PITA in the headset and BB threads and handlebar stem being metric. Freewheel threads too if the hubs are original. All those metric parts are still available with some searching, but sticking to almost any other nationality will make some parts easier to find.

If you're willing to add indents to a chainstay that's currently round or oval, then that opens up a lot more possibilities. Personally I'd stick to something with light&lively tubing though, and one reason is the stays are easier to indent! My own indenter is weak, and recently failed to add any clearance to an extra-large custom touring frame I was working on, with thick heavy chainstays. I think they might have been Reynolds tandem stays which are about 1.2 mm wall IIRC. My indenter didn't budge them even one mm. I really need to make a stronger one! But light tubing has lots of other advantages beyond being easy to dent. Just stay away from hardened tubing like 753, 853 and other modern "super steels".

Much has been made of the advantage of vertical dropouts for fender bikes, but I find Campy 1010 and similar to be fine as long as you tend to put the wheel at the forward end of the slot. Especially if you're replacing the bridges (a Full Gugie feature). I still get a nice even fender line, and I can take the wheel out no problem. If you would need to run the wheel toward the back of the slot (for example for better tire clearance), then fender line will be suboptimal. Converting to verticals is doable but kind of a Big Hairy Deal, and doesn't usually add length to the chainstay (rather the opposite) so it's not helpful for tire clearance.

My last point is just personal preference and YMMV, but I shoot for the high end of frame size that I can ride. On level-toptube frames, a bigger size lets you get the handlebars up to a comfortable position without goofy-looking spacers or Technomic stems raised all the way up. Nothing wrong with a Technomic, just doesn't look right to me eye, that was trained on '70s and earlier bikes. I guess standover clearance becomes more important if you use the bike off-road much, but I think clearance is over-rated for road bikes. Oh yeah and on bikes I've ridden with Technomic style aluminum quills sticking out by a mile, the amount of flex was alarming, especially hitting bumps on a steep downhill. Maybe they never ever (ever!) break, but thinking about what would happen if it broke was damping my enjoyment of the ride. But I'm a clydesdale so that last bit may not be such an issue if you're normal-sized.

Larger frames tend to have longer toptubes, so you'll use a shorter stem, which can help with the bag/decaleur situation. Easier (usually) to keep the bag close to the head tube, which helps with handling.

lonesomesteve

I agree with everything Bulgie said, but I'll add one thing that I look for that's maybe a little controversial. If you plan to use centerpull brakes mounted on brazed-on posts, then I think you're better off starting with a bike that was built for 27" wheels. With braze-on mounted centerpulls you don't have to worry about brake reach, and the seatstay bridge and fork crown height tend to be closer to where you want them. On bikes I've owned built for 700c wheels, the seatstay bridge and fork crown height didn't provide enough room for fenders with 42mm. I'll admit that most of my experience has been with old Treks of the 80s, so other brands (and your mileage) may vary.

gugie 

@bulgie and @lonesomesteve bring out good points. I remove/relocate the bridges, so they're not limiting, they get replaced with ones at just the right spot to make a good fenderline without having to add more than a leather washer as spacing. Most of the time the chain stay length/indentation/shape limits tire size. Sometimes the fork crown to dropout distance does, but that's more rare.

Ratty looking frames with good bones can be gotten inexpensively. Since this is major surgery you'll be repainting or powder coating anyways.

Generally speaking, early 70's production frames are often great candidates for 650b, low trail conversion, and are still plentiful and reasonably easy to find. My Flickr albums have many examples, lots of Raleighs, a few Trek's, some Motobecanses of certain models each. Typically they have "long legs", lots of clearance from fork crown to tire, and long chain stays. I've cherry picked some inexpensive frames ready for Gugificazione.

52telecaster

That's a great shop man!

jdawginsc 

Agreed. It is a cool odyssey.

Went with the red instead of the green? Can’t go wrong with that!

ironwood

Is the frame a British Witcomb, or an American made one?

bwilli88 

I believe that it is a British made. It has a date of 72 and I think that Witcomb USA started after that.

bwilli88 

So original paint was going to be English green and found some nice candy red (red is faster and I wanted to be faster) and started with that but ran out. So I sanded it down and found a nice candy green that would work but somehow it ended up black, ugh. So I am sanding it all down to primer and found this mark, can anyone ID this bottom bracket mark?

Andy_K 

That's a lot of painting and sanding!

I don't know anything about the bottom bracket mark, but a Google search turned up a mention in @smontanaro's CR archive and a picture in this set: Bobet bike from 1950s

bwilli88 

got these in the mail in the US

Soon to be here.

Paint and repaint

rhm

@juvela probably knows!

juvela

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Etablissements Dardanne Aunay-sur-Odon

https://www.pressreader.com/france/l...82505774743609


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Mike V3

Do smaller frames have problems with clearance?

bwilli88 

This was a tight fit for the 42mm tires I have on this. I dimpled the chain stays a bit and have the wheel all the way to the rear in the dropouts.
I have some 38mm Donnely tires but love these.


Now to decide what bar tape, some Cenelli rubber/cork or some brown leather.