cs1

What about a brake drop bolt in conjunction with long reach brake bolts. https://www.sheldonbrown.com/dpdropbolt.html

nlerner

Tires are Panaracer Nifty Swifty. They're the widest I can use with fenders and that front rack. The rack is a custom job from the Rack Lady:

https://www.flickr.com/photos/26811168@N07/

She'll build you whatever you want, front or rear, I believe.

Those rims are Rigida Sphynx, no longer made. That's a sweet wheelset w/ Campy NR hubs, and is now on my Ebisu rather than on my gritty commuter!

Neal

Speed2XS

I may have to go this route, but have been trying to avoid it as I don't have the skill to fabricate as nice a piece as the production drop-bolt. What my goal ultimately is, is a 27" frame with 650x2.0 knobbies. I have the frame for it, but no brake solution yet.

fenderbender

DiaCompe has dusted of the old molds and started producing the DC750 with 60mm-78mm reach again. I believe Tektro have several side pull models but they keep changing the names and finishes so I can only find the R556 or R559 w 53-73 mm reach. I'm sure there are other brands out there. But I wouldn't buy any of these as there are such abundance of perfectly decent Weinmann Vainqueur 999, Altenburger Concorde and Shimano Tourney's out there.

hhabca

A 27" bike with long reach brakes from the factory is a really nice frame to convert to 700C as it most likely allows for a wider tire and fenders with the smaller 700C rims. How wide a tire can fit with fenders depends on the frame, but typically it's the next size up (or 2 sizes up) from the widest that originally fit. A 27" bike with 'racer' dimensions might work going to 650B if the frame was originally sized to fit really skinny tires, no fenders, and used short reach brakes with the pads at the top - but that's not a common frame design for a vintage 27" bike.

nlerner

I have a set of Dia Compe 800 centerpulls; max reach is 85mm. A popular and pricey option is the Mafac Raid, which have at least 75mm of reach. I really regret selling the NOS set I had for $32! Excellent comparison chart here:

https://ruedatropical.wordpress.com/2...l-brake-specs/

Neal

Speed2XS

Thank you everyone for your input. I look forward to making this conversion happen.

redxj

Why do the French always have to be a PITA. After reading this thread and seeing pics and mentions of a 650b Px10 I thought why not let's give it a try. I have a 72 px10 that has been repainted and upgraded with a mostly NR Campagnolo drivetrain. It also has a French Cinelli stem. I have been looking for a long French Cinelli with no luck. I bought it earlier this year and with the too short stem and needing new tubular tires I have ridden it. So I figured a 650b conversion might be in order.

I test fit the 650b wheels I pulled from an 80's schwinn mtn bike and put on a set of col de la vie tires I bought awhile ago. Everything fit perfectly and I found some weinmann 750 brakes that reach with room to spare. Then I found why the French can be a pain. The bolt hole on the fork isnt drilled even close to straight. I have thought of a few options and think I am going to replace the fork with a dimension 700c I can get from work. This way I can fix my brake issue and stem issue all at once. The wheels are steel hubs laced to single wall aluminum rims. I rebuilt both hubs at work today and converted the rear to a q/r instead of the stock bolt on.

I am thinking Tiagra hubs to Velocity Dyad rims running a 7 or 8 speed cassette friction shifted of course. The bar and stem will be Nitto Noodles and a Technomic I just traded for the other day. The CdlV tires will stay in the meantime and I plan to order some Tektro R556 brakes along with the wheel parts and fork. I just hope the fork can fit the 650b rims and the tektro brake has enough reach. It has the same axle to crown as the stock PX10 fork so I hope it will work.

LeicaLad 

I have an old 27" frame that I'd like to go to 650B on, but it may be just too far of a reach.

The photo below is that of Zeus calipers against a 700c wheel. As you can see, I'll need long reach brakes to go to 700c.



Is it silly to think of trying for 650B? Or should I just get fat 700c wheels & tires, plus, of course, long reach brakes?

NormanF

You can get long reach brakes... or if that's not an option, drum brakes will definitely solve your clearance issues and give your bike a cleaner look.

Speed2XS

Your sidepulls don't look all that long, which may be why they're adjusted to the bottom of their reach. You can figure out your current reach needed for 27" wheels, and what you will need for 650b's.

If you remove your front caliper, and measure the distance from the center of the brake hole in the fork crown to the center of the braking area of the rim, then add 23mm, as this is the rough difference of radius between the two sizes, 27" and 650B, this should give you the brake reach needed for a 650b conversion. Using a caliper to take this measurement really makes things infinitely easier.

At least this is how I determine brake reach.. I think it's correct...

redxj

All finished:

Chris W.

Very classy Nice mix of old and new! How does it ride?

Cheers,
Chris

LeicaLad 

Very nice. A Stronglight 93 w/ 105bis rings? What RD is that, please? While you're also commenting on the ride.

It sure looks great!

southpawboston

very nice! if i may ask, how tall are you? i'm guessing around 6'6".

redxj

Correct 6'6" with monkey long arms. It rides nice, but I am not sure how long of rides will go on it. The stem is a 100 mm and I would like at least a 120mm. Anyone have a 120-130mm French sized (22.0 quill)Cinelli stem? I did a quick trip to get some food for lunch today and the fat 650B tires really soak up the crappy local roads. It didn't feel slow or sluggish either.

The parts are a mix of old and new. The original owner I purchased it from had it repainted and after the repainted bought almost full Campagnolo Nuovo Record group for it. I didn't like how the r/d and rear shifter were working with the now 8speed cassette it sports on the rear wheel.

Here is the full parts spec:
63cm 1972 Peugeot PX10 frame and fork repainted by Matt Assenmacher
Stronglight roller bearing headset
Stronglight bottom bracket
Stronglight 93 crankset 170mm arms with 52/42 Stronglight rings
Crank Brothers Eggbeaters
Nuovo Record clamp on shifter mounts with Rivendell Silver shifters
Nuovo Record brake levers
Cinelli 1A stem (still too short)
Cinelli 66-42 bars
Tektro R556 dual pivot monster reach brakes
basic seatpost with a Brooks Swallow copy
Campagnolo BB cable guides and top tube housing clips
NR Front derailleur
Shimano 105 rear derailleur
KMC X9 chain
SRAM 12-26 8 speed cassette
Planet Bike Cascadia fenders (700c)
and the wheelset hand built by yours truly with Shimano Tiagra Hubs laced three cross to Velocity Dyad rims with DT Swiss 2.0/1.8 double butted spokes with Panaracer Col de la Vie 650b X 38 tires

NormanF

I like your build. It does look like a Rene Herse or Alex Singer bike.

This is the poor man's way to build a homage to the great constructeur/porteur bikes in France of the 1940s and 1950s.

I have a Peugeot PX 10 built up as a 650B porteur ride.

Sigurdd50

Latest Conversion finally finished:

John Howard 'Turbo Dog'

I believe this is a 1985 KHS John Howard Turbo frame (with some of the cheesy decals removed)
Tange Infinity
I am running a 1 x 8 drive train with a single bar end shifter

Wheels: Rigida Sphinx rims
105 hubs w/8 speed cassette
Soma B-Line Tires
Grip King pedals
V-O City Levers
Tektro R556 brakes
V-O Porteur Bars
Nitto Technomics Stem
Cinelli tape
Brooks b-17
some ebay big setback seat post
PB Eco Rack
Tourney Crank (scrounged)
Modified 'chain guard' (52 tooth chain ring with teeth ground off)
Shimano Deore RX (scounged)
Planet Bike Cascadia Fenders (hybrid size)

Way fun to ride!



Home Made Chain Guard






(phantom left side shifter!)




(reverential pose)

woodrupjoe

Wow, these are some beautiful conversions. Some help please, if you will. My daily commuter was stolen a couple of weeks ago and I've been thinking about how to replace it. I have a speedy bike, and a touring bike, and an oldie bike (all really nice fun bikes), but my daily commuter was fitted out with baskets and racks etc. I work as a carpenter and I've occasionally loaded my full kit onto my old bike to trek it across town to some job that requires my immediate appearance. I could make it on my old bike but it always seemed too wobbly for my taste. I've got a miyata 310 frame (for 27" wheels) and having read these great 650B conversion stories, I'm wondering if I should do the same. I would really like a sturdy bike to move my (heavy) tools around. I don't want a mountain bike type frame or anything really beefy, just a little bit sturdier ride than I had. Would this miyata 310 frame work for what I want to do? I'm ready to take the plunge.

thanks for any advice. I didn't want to start a whole new thread. Sorry if this is a hijack.
cheers Joe

southpawboston

I've done two 650B conversions. One was a new Soma mixte frame built up for my wife with a 650B wheelset and extra long-reach Tektro R559 brakes. It wasn't so much a conversion, per se, but more of a build conceived from the start, around a frame that was desigend for either 700C or 650B wheels:





The other was a true conversion of a 1980s Japanese touring bike built around 27" wheels. This was more of a challenge because the frame had cantilever brakes, and the mounting bosses had to be removed and rebrazed to fit 650B wheels. You wouldn't want to do this on a frame that you want to keep original, but I made the decision to do this knowing that the frame didn't come from any particular provenance and that I would be powder coating it anyway:





siggurd-- you can mount a bell to the unused shifter boss!

woodrupjoe-- a frame made for 27" wheels presents an extra challenge because it may not be possible to source brakes with enough reach. Bikes built around 27" wheels require, on average, an additional 23mm of brake reach compared to 19mm when converting a bike designed around 700C wheels.

robatsu

What is the story on that taillight? It looks interesting.

-holiday76

does anyone have trouble with 175mm cranks hitting pedals on the ground in turns on 650b conversions?

Sigurdd50

Yeah, what southpawboston said... resolving the brake drop from 27" wheels to 650B wheels requires some real MacGyvering (see Sheldon Brown's Drop Bolt). The 310 Frame is a good, sturdy frame (my daughter's boyfriend used it to bike from St. Louis to Portland, fully loaded, no sweat). I've always targeted late 80's steel frames as they were after the advent of 700C wheel use as standard. Tektro R556's cover that drop no problem. As noted above, some old centre pull brakes do have longer drops, but they can be hard to find. For heavy tool movement as you need, it's almost more efficient to explore purpose built 650B bikes (custom, can be costly) or keep an eye out for a Kogswell frame and fork. They are no longer made but they are out there. Some of their forks are perfect for front loads. Touring-specific bikes (Fuji Touring, Trek 520, etc) are much more stout frames... BUT they are usually built with cantilever brakes, meaning that you can't convert to 650B unless you braze on canti bosses in a different location (see Southpaw boston's Japanese touring bike above...turned out sweet, but did need a repaint after the welding work)

I've always found that I have to be reeeeeeally patient when I do conversions... waiting to find parts that will work locally for a good price.

Holiday 76: I may get a pedal strike if I'm really swooping around a corner. I think I run 170MM cranks. For me, the bike is a town / commuting bike so I just back off on speed and watch my pedals. It's not a suicidal issue. I have to be leaning way over to hear the *bink* of pedal metal. Quoting BikeMan "The bottom bracket will come down a bit with 650B tires, you can expect a lowering of about 8mm-10mm converting from 700x23mm tires to 650x38B tires. So a good 650B conversion candidate will have a bottom bracket height of about 275mm with 23mm 700C tires. More is better, but anything lower than 270 is risky. "

kiwigem

Would it be terribly tacky of me to mention in this thread that I have a pair of brand-new VO 650b fluted fenders that I can't use? (too wide) Sorry if it's not the appropriate place to do so. It's pretty tough to find a 650b audience locally. I'm loving everyone's conversions. Can't wait to do mine!

southpawboston

The housing is a NOS Soubitez Catalux 6 that I scored from an eBay seller in France. I retrofitted it with the internals of a new B&M Seculite plus LED taillight with standlight:





The Seculite is a screaming bright taillight, and the standlight function works very nicely... maintains full brightness for about 4 minutes.


I find this to be pretty accurate. My Shogun dropped 13mm after conversion from 27" to 650B, so that's consistent with Bikeman's estimate of 8-10mm for 700c to 650B conversion. I was patient in waiting for the right frame to come around for converting. The early 80s Shogun touring frame that I ended up with had a very high bottom bracket to begin with, at 182mm. After conversion, it's about 169mm... very safe. Also, if you end up getting more BB drop than is safe, this can be somewhat mitigated by using a narrow crankset and/or narrow pedals. The TA double crankset I chose has a Q factor of only 136mm, so it's very narrow.

For 175mm cranks, I would say you need a BB height of at LEAST 265mm after conversion, or 275mm before.