All references to GAHB are to our mutual friend, The Golden Age of Handmade Bicycles.
DIMENSIONS/GEOMETRY.
The frame I built in Doug Fattic's class is nearly perfect. My one aesthetic issue with it is that I'd like about 2cm less seatpost showing. But the main consideration when designing this frame will be getting my handlebar position perfect, which it needs to be with that clamp-on stem. I want the top of the handlebars to be 7cm below the top of my saddle (80.5cm).
So the frame should probably look something like this. All measurements c-c, in mm.
BB drop: 82.5
Seat tube length: 640
Seat tube angle: 73
Top tube length: 590
Head tube angle: 73
Fork rake: 61
FRAME MATERIALS.
| All tubing: | Reynolds 531. |
| Fork blades: | Reynolds 531 Imperial Oval. |
| Crown: | I have a nice semi-sloping Imperial Oval crown... |
| Dropouts: | Single eyelet F&R, Verical rear. |
COMPONENTS.
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DESIGN.
I would like this to be very much like a randonneur version of your Capriolo city bike. By this I mean:
— fillet brazed
— using that cool handmade lug at the ST/TT junction — although I'd prefer it without the "seat tube extension"; ie., with the top of the clamp more or less level with the top of the TT.
— using the Alex Singer-style two-bolt seatpost clamp (which will "rhyme" with the 2-bolt clamp on the stem)
— using a "continental" seatstay attachment (though I'd prefer a longer "cap" — around 5cm long.)
— having those nice, low bends on the fork blades.
... though of course the randonneurish twin principles of "performance" and "reliability" should be kept in mind, which aren't necessarily the city bike's ambitions.
The bikes I think mine will be friends with are the following (all from GAHB):
1946-47 Alex Singer (pp. 42-43). Black like mine will be, fillet-brazed, similar seat cluster, similar stem, FD...
1947 Concours des Machines René Herse (pp. 44-47). I'll have a very similar colour scheme, I love the fork bend.
1947 Alex Singer Porteur (pp. 58-61). Beside the fact that it has no clamp bolts, this seat cluster is perfect. Beautiful fork bend. Perfect proportions of seatpost and stem: I would ideally like exactly that much seatpost showing, and have my stem about there (though I want it level with the TT).
BRAZE-ONS.
— Mafac brake bosses F&R
— Brazed-on loops for generator hub wire on inside drive side fork blade.
— Front rack mounting points (water bottle bosses)
— One downtube shift lever boss (drive side) — Mounts for 2 water bottle cages: 1 DT and 1 ST.
— Stops for brake cable on drive side of top tube. "Loop and stop" style.
— Pump pegs brazed on underneath top tube for 48.5 compressed pump. See GAHB 64.
— Cable hanger of some sort.
— Light mount on seat tube.
— Fender mounting points on chainstay bridge and seatstay bridge.
— Slap protector braze-ons on drive side chainstay (for Champion slapguard).
— Derailleur cable stop w/ loop.
THINGS THAT ARE GENERALLY IMPORTANT TO ME.
— Nice fender lines.
— Sufficient clearance between fender and tire, tire and chainstay, crankarms and chainstays, and big rings and chainstays.
FORK.
I like nice, low bends on fork blades. The ones on your Capriolo city bike look pretty much perfect. There is something magical about the bend on the Rene Herse pictured on GAHB 44.
Some way of attaching the fender to the fork crown will need to be worked out. I don't want to use a "fork crown daruma" since I want to keep the brake bolt holes clear for wire routing. So probably a water bottle mounted under the crown. Mike Barry makes little tabs and brazes them to the crown:
http://www.mariposabicycles.
On the inside of the drive side fork blade, I'll need loops brazed in to guide the generator wires. Like here:
http://bp2.blogger.com/_
CABLE STOPS.
My favourite detail on the bike I made are the cable stops for the rear brake cable. They're of the "loop and stop" (the stops being derailleur stop braze-ons) variety. See them here:
http://3.bp.blogspot.com/_
http://4.bp.blogspot.com/_
Note that on this bike, since I'm using non-aero levers, these need to be on the drive side side of the bike. Or, if you want to get really fancy, you could do the cross-over style like the Alex Singer on pp. 54-55 of GAHB.
I'd like these to be used for the derailleur and for the rear brake cable. Herse and Singer didn't use loops on the rear brake cable stop, but I think they make sense. My loops are placed 5cm in from the edge of the seat and head tubes, and the stops 9cm.
FENDER-RELATED.
I want to use eye bolts to attach the fender stays to the dropout, so there might be clearance problems on the drive side of the rear dropout. I am using a 6-speed freewheel on a hub designed for a 7-speed freewheel, so there is some room for manoeuvre. But maybe "offsetting" the eyelet on the drive side rear dropout would be a good idea.
Another option is to do what Mike Barry does and construct custom stays out of steel tubing. Only if you're interested, of course. See:
http://www.mariposabicycles.
STEM.
I like the Alex Singer stem on Jan Heine's Grand Bois quite a bit.
http://www.
— I like the placement of the steerer and bar clamp bolts. I like two bolts for each (to match the seatpost binders!)
— I would like a bell mount (a wattle bottle boss) in the same spot as on this stem.
— I like the stem cap/switch
— I like the cable hanger also. Though if you think a hanger right in the stem extension makes more sense, I'd be fine with that.
The clamp area on my handlebars is exactly 3.1cm wide, and would enjoy being clamped by a stem clamp of the same width. The clamp diameter is 25.0.
We'll need to figure out the inner diameter of the stem-clamp tube needed for the switch to fit into.
FRONT DERAILLEUR.
Tony Pereira's design is pretty and apparently works well. Something like that would be great.
http://www.pereiracycles.com/
TAILLIGHT.
I could probably make an ugly one myself. But if you're at all interested in making one (perhaps Peter Weigle or Curt Goodrich would have tips?), that would be great. Theirs are pretty. (But they're battery-powered; this would need to be generator-powered, of course.)
DECALEUR.
I have a Velo Orange headset-mount decaleur. The part that attaches to the bag is fine. But if you were interested in making the other part, and finding a way of attaching it to the stem, that would be way better.
FRONT RACK.
Here is a photo of my Mariposa front rack:
http://2.bp.blogspot.com/_
Here is a photo of a similar one in action:
http://www.mariposabicycles.
4 comments:
I'd hate to be your frame builder...
Hehehe.
Listen to what you want in a bike. I have just learned that lesson in getting a custom Randonneuse from a well known young builder. It's a 90% perfect bike - but not 100%. After the large amount of money paid (and the hard work required to make that money) and the many months of waiting in the build queue, it is a slightly disappointing experience. Don't get me wrong, it is a fine bicycle. However, I should have been more precise about my wishes and you appear to be avoiding that pitfall. Bravo. I look forward to seeing your new bike.
M
If there's any discreet way of sharing your experience, I think a lot of us would like to hear it.
Even with my maniacal attention to detail, a lot is still in Dan's hands. These things are always a leap of faith to some extent. But I trust Dan's taste and skill, and have been extremely satisfied with the various ways he's "surprised" me thus far...
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