Thursday, September 9, 2010

Brake Configuration

As anticipated, yesterday’s discussion on wheel size was dead even between 650b and 700c. During this discussion, there were references to brake configuration and geometry not out of temptation but understandable necessity. It is for these reasons I have decided to let today’s topic on brake configuration determine the wheel size of the rSogn.

While we are at this, I wanted to suggest that the rSogn project is also a perfect opportunity for us to come up with a completely original concept. That could be like the cantilever Sogn or something that is currently unavailable. At any rate, the concept should be consistent with the “Any Bike, Anywhere” ethos of Chris Kostman.

To begin today’s discussion, please do review the comments from yesterday and then make a comment(s) on your preferred brake configuration. Let’s roll!

Sean

39 comments:

Cody Larson said...

Canti. They look better. They are lighter. They work well in wet conditions if the right pads are used. The pads are easy to find at any shop. The pads don't wearout without warning. Also, I have heard of new disk pads wearing down to nothing in a matter of miles on wet, silty gravel.

Alex Wetmore said...

Cantis positioned for 650B, or disks.

I think disks ultimately will make the bike more marketable, because they allow the frame to be used with 700C or 650B wheels (designing it with BB drop for 650B will make it an attractive "Monster Cross" bike for the 700C set). Of course you would have an idea of how the original dSogn and cSogn sold.

Another good option would be to put canti posts and a disk brake mount on the frame, and sell two different forks. One very nice thing about canti forks is that they can be made with lighter tubing. Sell the high offset (65mm) canti fork to those who want more of a dirt road randoneeuring bike, and a slightly low offset (55-60mm) disk fork for the rough stuff and megacross riders.

If disks are used it would be nice if the calipers were placed on the chainstay, but without using big plate dropouts. This is an example of a very nice mounting:
http://www.flickr.com/photos/7447957@N08/3580335888/

The finish work is probably higher than what can be achieved in a mass produced bike, but the location and implementation is spot on.

Guitar Ted said...

Okay, this goes back to a couple things from yesterday. The frame tubing will necessarily have to be heavier with disc brake mounts, and if you add in canti mounts in an effort to satisfy everybody you penalize everybody with unnecessary frame braze ons.

Again, versatility means "not really great at any one thing". I would suggest that here is an opportunity to focus on lightweight, ride quality, and ultimate simplicity and function. Cantilever brakes do this marvelously well.

You avoid the compromises that must be made in wheel strength, frame weight/complexity, and for single speeders, having to deal with compromises to allow for disc brakes in terms of the drop out are now gone with a canti set up.

Sean brings up wheel size: I say- choose one or the other. How hard is that? 700c or 650B really is a matter of practical choices for cyclists who are going "anywhere at anytime". Base the wheel choice off this, then design the frame around those wheels, and keep the disc brakes on mountain bikes.

Quadmod said...

Cantilevers, sticking with the light as possible, but mix terrain capable guiding principles.

Anonymous said...

I vote for cantilevers positioned for 650B wheels, in the spirit of what this project seems to be about.

Mark

Doug said...

Again- in the interest of keepin' it simple, light, and affordable, I vote cantis/700C. I like that I can mount 2.1" 29er tires, or 23C road tires, or anything in between- on the same bike.

franklyn said...

Cantilever brakes--screw-on posts with these adaptors:
http://aebike.com/product/sinz-brake-post-extension-sku-br9529-qc30.htm

so one can potentially use different wheels.

I don't quite understand how brake configuration can determine wheel size. If you decide to go with discs, then you don't have to decide wheel size--that's one of the arguments for discs. If you go with cantilever (and not using the adaptors I mentioned above), then both 650b and 700c proponents can vote "canti" and you still wouldn't know which way to go

Guitar Ted said...

@franklin: Disc brakes force too many compromises in weight, wheel strength, and single speed-ability for such a vision of a light-weight, all-road steel bicycle. As I said, keep the disc on the mountain bike. To my mind, the Draakar fills that bill quite nicely.

Secondly, for a road-ish bike, one must answer the question: "Why fit 650B wheels?" Traditionally, on the "Rough-Rider" type bicycles, this was done to attain to a better tirefor the purposes. No room for a 700c fat-ish tire, if even any were available "back in the day". Now we have before us an opportunity to design a light-weight, road-ish geometry, all-road going steel bicycle. Why not dial in the clearance from the get go, use the widely popular, easily gotten 700c wheel size, and use cantilever brakes? (I'll save further wheel size arguments for later)

franklyn said...

@GT when you mentioned "lightweight, roadish, all-road-going" bikes, I immediately thought of two of my bikes--an ebisu all-purpose, and Kogswell P/R. Lightweight tubes, big tire clearance--both of them are 650b bikes!

700c for some operational compromises, especially for smaller size frames; such as toeclip overlap.

I emailed Sean several times in the past pleading with him to keep canti-sogn, that disc is simply not appealing to me. If I need to get a 700c bike, I have plenty of choices today.

John Speare said...

I vote 650B + canti's and less stout forks than what are on the current Sogn. The world does not need yet another 29'er/700c Monstercross/fatty 700c-- whatever you call it-- you can't swing a dead cat without hitting a 700c big bike.

I've beat the heck out of my dSogn and I've really enjoyed it, but the tubing is just too stout for me.
I'd love to set up my wife with a new lightweight small Sogn -- OS 747 would be great, but a standard 858 would be even better.

Rory said...

I want a bike that fits 60mm tires, but can also ride well with 35 mm tires for the road. a 650b sogn would do that, and i dont really care if it's disc or canti, but prefer canti simply because they're lighter and seem to work better with drop bar levers.

Stuart said...

I vote for cantilevers (preferably positioned to stop a 650b wheel).

To my mind, discs complicate things -- the frame gets more complex, the strength of the wheels is potentially compromised, plus it's a more complex mechanism than a cantilever brake (to my mind anyway).

I've happily ridden cantilever-braked bikes for years and years with no problems. Of 6 bikes in the house right now, 4 have cantilevers and I couldn't be more pleased. The benefits of discs don't wildly recommend them above the alternative (cantilevers), so I have to vote cantis.

Tom said...

Casting my vote for canti's positioned for 650B

Travis said...

I vote for canti's positioned for 650B. I think 650B is a good wheel size for wide tires. I like that 650B keeps with the theme of the original Sogn.

And regarding the brakes, as someone else pointed out in the other post, you can fit 700c (if you need micro-knobbies) using Paul's MotoBMX brakes:
http://www.flickr.com/photos/gzahnd/2927365700/in/set-72157607364174687/

Anonymous said...

A vote for 650B + disc brakes

jimmythefly said...

Discs with removable canti posts for me.

Phil said...

Easiest question of all of them: canti.

superfreak said...

please no 650b. seriously, as soon as someone comes out with a plush 559 fat tire, 650b will immediately be obsolete. think about that for a moment and you'll agree. 584 is only 4% greater in diameter than 559. 650b offers nothing new except hype.
thx superfreak

alex said...

A vote for cantis positioned for 650b. I favor a light fork over provisions for a disc set up too.

Alex Wetmore said...

I've changed my mind on the brakes a bit. If the bike is focussed as a light Rough Stuff bike then I think canti's do make more sense.

This is my recommendation for the whole bike, based on what I've seen so far:
* light steel (7/4/7 oversized or 9/6/9 standard)
* lighter fork blades and seatstays than the sogn
* clearance for the quasi-moto, but not much more (so a little shorter forks than the original sogn, and the narrower crown)
* cantis (disks as an option, but I don't think the benefit is as clear)
* ~45mm trail with 38mm tires
* 43-44cm chainstays
* vertical dropouts
* 650B wheels
* similar geometry to the original Sogn
* sloping top tube for standover clearance


I think that will build a very nice All Road/Rough Stuff bicycle without being too heavy. It refines the Sogn a bit and makes it more specific as an All Road bicycle instead of something that can also be seen as a mountain bike. It is not a "one bike does all" quite as much. The tire clearance and sloping top tube would differentiate it from a Polyvalent or P/R.

Jim G said...

Canti studs located for 650B wheels.

Sounds like what the world wants is the best of the Sogn mixed with the best of the XO-1. 'nuff said.

And with that, I give you http://www.flickr.com/photos/26117248@N03/4923419093/

Anonymous said...

another cantis-for-650s vote.

DS

rory said...

ir ead alex's suggestions, and most i agree with ,except, I would buy one if it fit 650b neo motos. I would not buy one if it only fit 650b quasi motos.

jono said...

My vote would be similar in spirit to G-Ted's. 700c wheels and Canti brakes. The availability of parts, rims, tires in this set is unmatched. Skinny tires or fat, you could do it all. Budget cantis or nice cantis too--it wouldn't matter but you'd have a more level playing field than a disc-equipped frame.

650b wheels don't allow you to run a narrower tire for road endeavors, but 700c wheels would. I don't always want to be running a 48mm tire.

Jim G said...

Wait -- I KNOW! This bike should be designed around 650C wheels! Yeah, that's it!!!

rmb said...

Canti

giant hogweed said...

cantis

Stuart said...

jono said: "650b wheels don't allow you to run a narrower tire for road endeavors, but 700c wheels would. I don't always want to be running a 48mm tire."

I sez:

You don't have to run 48mm tires on the road in 650b. You can run 38mm or 32mm. There are light, fast, supple tires available for 650b in those sizes. You don't give up speed on the road with a supple 38mm tire vs a 700c tire in 28mm or 32mm or 23mm or whatever. You just don't.

You might gain some comfort though.

For me this is either 650b or I'm not interested. I have 700c bikes that are too similar already.

Jim G said...

+1 to what Stuart wrote.

I just built this up over the weekend, and it's been tons of fun so far...

http://www.flickr.com/photos/jimg/4967090260/

C said...

Cantilevers. They're lighter and simpler which is in the spirit of this bike. Also there currently are no truly great options for discs and drop bars. For all out performance discs are better but only if you're talking about higher end hydraulic set ups and those only work with flat bars. I suspect most people who will build these up will want to run some sort of drop bar so cantilevers make more sense.

Aaron Marburg said...

Cantis. There's never been anything wrong with them and there are plenty of choices.

As I'm a day late, I'm afraid I'll vote 650b. I'll admit, it makes anti-business sense, but there are already plenty of 700c fat-tire bikes, so lets promote some diversity. This, of course, coming from New Zealand where you can't buy 650b anything for love or money.

Dan said...

I vote for cantis and either 650B or 650B in the small and medium sizes and 700 in the large sizes.

I think the smaller wheel size makes a lot of sense for the smaller sizes especially with fat tires.

Anonymous said...

No brake bosses at all! Instead, Rawland needs to come out with a new version of the old Moots Mounts! Cantis, centerpulls, whatever wheel size you're in the mood for, just slide the mounts up and down as needed.

Ryan

Michael_S said...

650B and Canti's. see above. can we just move on to the other stuff already?

James Black said...

650b and cantilevers. I think Alex Wetmore has it right again. Why not just ask him to design the thing and the rest of us can just go off and start collecting components for our new framesets?

Scott Gamble said...

I'm with Jimmythefly in that I want removable canti posts AND disc brake mounts. I'll happily deal with a smidgen of weight as tradeoff.

Again, I'm thinking expedition bike stuff. I prefer mechanical disc brakes, but want to go canti if need be.

The Moots Mounts are brilliant. I'd never seen those before but that's exactly what I had in my head when I thought about what a system like that would look like.

http://www.mombat.org/383MootsMount.jpg

If I HAVE to have one over the other - I want Canti's at the 650b mark. I'll figure out some kind of long reach V-brake for any desired 700c compatibility.

I hope full housing brakes aren't even being considered. Routing is ugly and hydraulic is overkill for this kind of bike.

I'll state the obvious since I haven't seen it here. By going disc brake you maintain support for multiple wheel sizes. Unless someones making long reach canti's or long reach V-brakes, or unless you're using a Moots system (please please please!), by going Canti you're are implicitly deciding on a wheel size.

Protorio said...

650B + Cantis. If you want to run 700c, no problem! Just use Franklyn's adapters or spring for the Paul brakes;

http://www.flickr.com/photos/25671211@N02/3374567128/

http://www.flickr.com/photos/25671211@N02/4142672486/

And its gotta fit the 58mm tires, for sure. I use my Sogn for trail riding, and they get up and over anything.

Jim G said...

Canti studs set for 650B. Just please use UNSCREWABLE studs so those that want 700C wheels can use the Sinz adaptors.

rperks said...

if the posts come off, a well placed brake hole will also solve a ton of future wheel size options for those inclined. The dsogn is not too bad in the front for some things, but there is nothing in the rear