mrv 

Howdy!
Thinking of picking up a used Steamroller and adding 650b located canti posts. Kind of a Son of 650b(odge) project.

Bad idea? as the frame/fork is not designed for it?
Doesn’t matter, that frame is built for abuse anyway?
Will you quit murdering frames and just buy Crust Florida Man?

Your wisdom is appreciated.

ciao!

unterhausen

I don't see anything wrong with doing that other than you are going to ruin the paint and it might be possible to get long reach brakes to do the same thing just as well.

joesch

Steamroller is a great frame.
I have two setup with nice components.
Ya maybe buy a diff frame designed for your needs.

GrayJay

Before brazing post onto frame and fork, I would get the 650b wheels and tires together. Test fit and ride first to ensure that you have plenty of tire/frame clearance and that you like the results before picking up a torch. Tire to fork crown clearance is usually where contact happens first and you would want plenty of clearance for mud if doing a bit of offroad or CX. Seems to me it would be better option to use center mount long reach sidepull brake calipers so you don't have to permanently modify the frame and restrict its brakes to just the smaller diameter wheels. Other option would be to instead add mounts for disk brake calipers to frame & fork, then you could quickly swap between 650b and 700c wheel sizes depending on intended conditions for the ride without needing to make any brake adjustment. (I assume that a 120mm rear disk brake hubs are available or could be cobbled together from a flip-flop track hub threaded both sided?)

mrv 

I know 650b x 47mm clear

I’ve got mafac racer brakes, but I’m not keen to deal with remembering to infante the tire after it’s past the brakes.

Thanks for the pointers everyone!

unterhausen

I wouldn't think that Racers have enough clearance. You need some Raids or something with the same amount of reach. There are a lot of double pivot options.

tyrion

Crust Florida Man frame is only $850, takes bigger tires, and has the super hip paint job. Also 130mm rear drop outs.

mrv 

correct. Ready to build up frameset.

The Surly is used. Someone attempted a Varsity green paint job, but didn’t know what they were doing. Even less so than me!!

So $300. Frameset. Headset. Bottom bracket. Seatpost.




hoping another buyer decides before I do.
I think the Crust geometry would be more suited to my relaxed riding.

Andrew R Stewart 

Having serviced many examples of Mafac cantis I don't think I would plan of them if I were brazing on the bosses. They have less positioning range than most current choices. Andy.

bulgie 

I don't get it, why would you need any positioning range, if you put the bosses in the right place?
Fitting both 27" and 700c used to be a consideration, but nobody's going to do that anymore, right?
559 - 584 - 622 are all too far apart to change wheel sizes with one brake IMHO. Theoretically possible but the brakes will work like dung with one or both sizes, so with cantis you pretty much hafta pick a lane.

Sticking with, say, 650b, all rims are close enough to work with Mafacs if you place the bosses accurately. Yes, that's not always done right, I've seen them put on wrong, but we're all grownups here. Just mock them up with the actual wheel and brake before committing to brazing/welding. If brazed, you can even move them a little if you screw it up, as long as you find out before painting.

One caveat, ya gotta know that the short arm Criterium and the long arm Tandem have different heights, by 2 mm. So don't mock 'em up with Criterium and then install Tandem. It might still work, but starting out with a 2 mm error doesn't help.

Andrew R Stewart 

"I don't get it, why would you need any positioning range, if you put the bosses in the right place?"

Because it is easy to not get that right place if not careful. The axle to boss dimension is not the only aspect, although the usually mentioned one. The rim side to boss dimension (boss c-c is the often listed spec with no rim width info included) is also important as it speaks to the arc that the pads will rotate along and where along that arc the pads will contact the rim.

This is why I generally suggest a first timer (and many more timer too) do a mock up with the actual parts set in the center of their adjustment ranges. Too bad that the Mafac pad height adjustment also tilts the pad face WRT the rim as this reduces that practical range. Andy (who often replies with those who are not experienced in mind)

bulgie 

Yeah you're right Andy, I am maybe assuming too much ability from the people putting bosses on. We've all seen bosses put on wrong. I just don't see how you can shank it if you mock it up first, with the actual brake and wheel. But that might be a luxury you don't always have? Like putting bosses on under contract, for someone else to bolt their brakes to?

I'm just a Mafac fanboy I guess, sticking up for them when they don't really need me to stick up for them! But I still like 'em.

mrv 

Thanks again for the replies. The feedback gives me much to consider.
The Racer brakes I mentioned are the bridge amounted version. With a pivot bolt. My term might be off.
As far as a canti post, my plan ‘was’ a more typical cantilever brake.
Mulling over the Florida Man geometry, wheelbase, trail, angles- this seems better suited to the 75% dirt road riding I do. (And my wife said- why don’t you just get a new bike)
I believe Paul Motolites would accommodate 650b and 700c for us freewheelers
— granted, that’s a $376 experiment…. But hey, the prize is a set of Motolites!!

I’ll post again if-when I pull the trigger. I can also bring that Appaloosa touring post I started to a close…

cheers

unterhausen

I didn't think op was going to put Mafac cantis on there. I saw an insta post of a whole pile of the criterium variety without the pad post holders. Someone commented that many of them had the pad holders scavenged to use on some other brand of brake. The tandem variety is still somewhat in demand.
I think there have been a lot of companies and a few builders that messed up canti placement. I didn't think it was too hard to put Mafac cantis on my tandem and they work great.

ThermionicScott 

With Raids, you could always pop the straddle cable out of one arm to insert/remove the wheel. I wouldn't want to have to deflate the tire to remove a wheel either.

unterhausen

It seems like Raids might not be so much in demand since RH has their copy and everyone else is moving to discs. There are also brakes from Dia Compe and Grand Bois of about the same size. But I think I would just go with the long-reach Tektro double pivot. Shimano used to sell a brake like that but when I went looking for them last time I didn't find them.

bulgie 

Any brake that attaches above the tire and reaches around it, including Raids or dual-pivots, is going to limit your tire width. IMHO cantis are practically a must for any tire wider than 45 mm, especially if fenders and/or mud clearance are also in your wish list. Some might quibble with where I put the cut-off point, but you have to agree that for tires over say 50 or 55 mm, cantis become the only rim brake choice. While a "reach around" brake could still techncally work, the trade-offs are too annoying.

ThermionicScott 

Oh derp, you guys are right. If OP wants 650x47B tires, Raids are probably out.

unterhausen

I forgot about the limit. I think that's why everyone uses ~42mm tires

mrv 

For various and sundry reasons I picked up the used and mildly abused SteamRoller.

With the retirement of Matt Assenmacher in (outside of) Flint, I reached out to a new frame builder in Detroit to see what she would charge for a few braze - ons (canti-posts; bottle cage attachments, rack mounts, a small doodad for a coaster brake). No word yet.
https://jubileemfg.com/
https://theradavist.com/jubilee-manu...clocross-bike/

I will probably do the brazing my self. Of the few rack mounts I've done, I am not in possession of any of them that have popped off......
More updates to follow, or maybe I'll annoy the single speed group with a dedicated thread. (is there a kind of etiquette to this stuff?)

cheers.

Andrew R Stewart 

My experience in talking to a passionate user group about engineering type stuff is that their opinions can be too strong to allow some to better understand what is really happening. Andy

mrv 

—-as far as canti post placement? Or making bad decisions modifying frames to adapt them to an off label purpose?
…hope I’m thinking this through and not getting stuck on a bad idea…. but then again, I am using the Bad Idea Ride logo as my BF avatar 🤔

as far as the SteamRoller goes, it’s in the garage and I’m figuring out plan to
1 get it rolling soon (I got a coaster brake wheel on hand…)

2 strip / modify / paint

Based on suggestions I’d like to get the 650b wheels built up so as to locate the posts accurately.
Mostly I got a parts plan word out. A local FaceBook sales post came up. The guy showed the parts with no price. He said make an offer. I made an offer…and no reply or counter. A little frustrating….

cheers

plumberroy

Love that color, but I like green. My Steamroller is the root beer color . I love mine. It was my first good bike.

mrv 

yea… a well done sparkle Schwinn would be nice.
This is more John Deere. And while I appreciate the humor of it, the paint was poorly applied.

I’ve got a repaint idea in mind. But it requires experimenting with some Spray.Bike copper metallic. Then applying some acid (oxalic? Vinegar ? Not sure). And see if I can get some controlled verdigris as color bands.

I'm geeked to try it.

squirtdad

so no long reach dual pivot would work? or not what is wanted ? just curious (tektro 559 go to 73 mm)

have fun what ever you do