OT: Seeking wheel and brake recs for CX / adventure riding

[Daniel Chao]

Hey all!  I'm building up a CX frame for mostly mixed terrain / adventure rides but possibly a CX race or two.  Looking for recs on which wheels to get.  Must be clincher or tubeless, no tubies.

Also looking for brake recs, especially ones that minimize fork shudder.

Any and all recs much appreciated.  Thank you!

[Peter Chang]

2014-02-06 Daniel Chao <daniel...@gmail.com>:

>
> Also looking for brake recs, especially ones that minimize fork shudder.

mafac! :-)

actually, i think the trp mini-v might be one of the best bang/buck
rim (road-lever compatible) brake. (*way*) cheaper than the paul
mini-motos and come w/ shoes that are shimano/sram compatible (so you
can stock up on one variety when they go on sale).

the sram canits are good for cantis since they have a barel adjuster
(and a nice straddle cable thingee that has opposing hexes) but they
used to come w/ the dumbest shoes ever (the little bolt/pin mounts
from the top rather than the back meaning it takes an easily
cloggable, 1.5mm or 2mm hex). yes, the shoes are easily replaceable,
but that's another 20 bucks (or something w/ pads) of wtf annoyance.

\p

[steve armijo]

2nd that trp mini-v rec and 23mm rims (like hed belgium , h plus son archetype or velocity a23 ) laced to whatever hubs you like.

-s

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[Jason Thorpe]

Velocity A23 laced to Ultegra hubs, 32h 3x.  Full stop.

Fork shudder is eliminated with Paul mini-motos or mini-V brakes w/ a travel agent.

-- thorpej

Sent from my iPhone.

--

[Daniel Chao]

thanks for all the recs!  i think i'm going to go for the hed belgiums or h+ son archetype, depending on price/availability.  wider profile, all alloy and a million spokes seems like the way to go.

on brakes, anyone with experience with the trp revo x?  i'm impressed by the adjustability and semi-low profile design but it seems quite different from what was recommended on this thread.

pfc - i still have the mafacs and they are waiting to go on your cx bike :)

[Patrick Kitto]

The revo-x, like any canti brake, will be prone to fork shudder. Severity of the shudder will be based upon fork stiffness, headtube length, and brake setup.

 Is it a given? Not at all. Is it a pain to fight with? Hell yes. Once you have it dialed and not shuddering, will it randomly come back? Probably. 

All that said, TRP makes great brakes. 

And, you have mafacs?!? Those are worth building a vintage bike around. Find the moto levers and start building g a 1980ish stump jumper :)

[Jason Thorpe]

And the Paul mini-motos will not suffer from shudder at all. Winning!

-- thorpej

Sent from my iPhone.

[Maxence Nachury]

I have been following this thread with some interest since I will be "upgrading" my road Breakaway to a CX breakaway in the next few months. Why? Because there are always some fun trails at my destinations and because I'd like to give that CX racing thing a try. 

My plan is to move everything from the road Breakaway to the CX model and swap brakes and big ring (50->46). I was all set of the Avid Shorty Ultimate with a fork-attached bridge but all this talk of shudder has me scared. The mini moto sound neat but not as easy to deal with on a travel bike. With canti you just disconnect the cable at the brake. With Calipers or miniV you'll have to unscrew the front caliper and use a cable breaker for the rear. 

Is brake shudder that unavoidable with cantis? For a 160 lb rider?

_____________________________________________________________________________________

Maxence Nachury, Ph.D.

Assistant Professor

Stanford University School of Medicine

Dept. of Molecular and Cellular Physiology

Beckman Center Rm B-111A

279 Campus Drive

Stanford, CA 94305-5345

P: 650-721-1999 (office)

P: 650-721-1532 (lab)

F: 650-725-8021

nac...@stanford.edu

http://openwetware.org/wiki/Nachury

[Patrick Kitto]

The fork mounted hanger eliminates shudder. It has not been mentioned before, because not all forks can mount a hanger.

In addition to that, the mini-Vs are much stronger, making them still the superior brake, IMO.

[Peter Chang]

2014-02-10 Maxence Nachury <nac...@gmail.com>:

> My plan is to move everything from the road Breakaway to the CX model and
> swap brakes and big ring (50->46). I was all set of the Avid Shorty Ultimate
> with a fork-attached bridge but all this talk of shudder has me scared.

like patrick said upthread, it's
fork/brake/cable-length/phase-of-the-moon specific. i didn't have
issues on the old bike but the green machine had issues.

> The mini moto sound neat but not as easy to deal with on a travel bike. With
> canti you just disconnect the cable at the brake. With Calipers or miniV
> you'll have to unscrew the front caliper and use a cable breaker for the
> rear.

i'm not sure i understand, why do you have to remove the caliper? that
seems odd for any travel bike (canti or otherwise).

\p

[Jason Thorpe]

On Feb 10, 2014, at 11:31 AM, Peter Chang <d...@google.com> wrote:

> i'm not sure i understand, why do you have to remove the caliper? that
> seems odd for any travel bike (canti or otherwise).

On a BreakAway road bike, you remove the caliper from the fork and separate the cable couplers for the derailleurs and rear brake, thus a allowing the handlebar to be removed from the stem yielding a “cockpit module” that gives you some flexibility in packing the bike into the bag.

-- thorpej

[Scott Crosby]

yeah my (58cm) ti breakaway w/ stock cheapo shimano cantis braked well but shuddered violently. my cdale cx race bike w/Paul touring cantis shudders as violently as swissstops can grab carbon (not that well). but I might just suck at cantilevers.

meanwhile, the TRP mini-vs I just haphazardly and possibly drunkenly threw on Christine Ryan's "new" cx race bike stop so well I almost threw myself off. impressive.

I do like how the revo-x has toe adjustability that doesn't require 3 or 4 hands tho, that's nice.

[Maxence Nachury]

Very interesting feedback. No love for canti here. I had no ideas that they were so problematic. 

But why is it that CX bikes at races all run cantis (or discs)? Why no mini-V on those bikes? Is it just about mud clearance?

_____________________________________________________________________________________

Maxence Nachury, Ph.D.

Assistant Professor

Stanford University School of Medicine

Dept. of Molecular and Cellular Physiology

Beckman Center Rm B-111A

279 Campus Drive

Stanford, CA 94305-5345

P: 650-721-1999 (office)

P: 650-721-1532 (lab)

F: 650-725-8021

nac...@stanford.edu

http://openwetware.org/wiki/Nachury

[Christine Ryan]

(both excited and a little scared... ;) )

[ben....@gmail.com]

I kinda love cantis, and none of my (three canti equipped) bikes shudder. But I went through ~8 sets eliminating shudder on my tandem.

Properly aligned studs seem to help (I gave up and installed v's on a girlfriends sloppily built surly, but never had any issues on my best built lightweight custom). And sometimes v-brakes shudder, too.

[Patrick Kitto]

Both my cross bikes have mini-Vs. They are becoming more and more popular in the amateur ranks. Pros are going straight to discs at the insistence of sponsors. 

Truth is they are a pretty new thing. Until a couple years ago you could only have v-brakes (or linear pull, v-brake is a proprietary shimano term) was with a travel agent that modified the cable pull/brake actuation ratio. 

[Daniel Chao]

found a couple of great reads on fork shudder.  this one describes the mechanism behind the problem.  as others have mentioned, it's all about minimizing the length of cable between the cable stop and the brake.  v brake cables stop at the brake so it's as short as you can go.  lack of fork stiffness also contribute to the problem, hence the industry move to tapered forks.

personally, i wouldn't mind a bit of mud clearance so i'm attracted to canti's.  that said, i'd pick mud over shudder.  still coming back to the "45 degree angle to the fork" canti design that seems like a compromise between "right angle to the fork" canti's and v brakes.  three brakes seem fit this spec - trp revoX, avid shorty and paul touring brakes.  anyone have experience with these brakes?  hoping i can get mud clearance AND minimal fork shudder with these canti's.

[Carlin Eng]

Mechanical disc brakes will solve both fork shudder and mud clearance problems. Off the top of my head, some of the downsides to disc brakes are incompatibility with your other wheelsets, weight, and potential for brake fade on long road descents, which is enough for me to shy away from them, but I've never really had issues with either fork shudder or mud clearance (relatively dry Bay Area conditions, and smaller frame size I think have something ot do with it).

[Peter Chang]

2014-02-12 14:28 GMT-08:00 Daniel Chao <daniel...@gmail.com>:
>
> three brakes seem
> fit this spec - trp revoX, avid shorty and paul touring brakes. anyone have
> experience with these brakes? hoping i can get mud clearance AND minimal
> fork shudder with these canti's.

i think the avids are better than the pauls.

avids (and trp) have a barrel adjuster and they come w/ spherical
mounts on the shoes for toe-in. the shorties (maybe only the
ultimates) can be setup in either low-profile or clearance mode.

the pauls came w/ one-piece pads which i replaced w/ trp shoes when
the pads wore out. the lack of an adjuster means more futzing as the
pads wear (although i think the one-piece pads have less life than the
pad/shoe combo).

both have (side) independent spring tension adjustment. you can use
this to tweak rim dish variants and some pull tension.

\p

[Patrick Kitto]

woah, woah woah, brake fade on mech discs should not be all that different than any rim break as it will be caused by pad wear. One might argue that it would be less sever in nasty conditions as the braking surface is not in the muck.

Brake fade on hydraulic disc brakes on a road descent is a very real and very worrysome thing. it is THE thing that is keeping hydro discs off of road bikes, and it is all about heat dissipation. 

I cant seem to find the article now, but a while back i read a very good argument against them, which amounted to rotor size vs. weight vs. brake power alld compared to function and heat dissipation: basic argument being that roadies want super light, which means a small rotor, which will generate a ton of heat, which boils the brake fluid which fades the brake power to nothing. Point out that the difference of a MTB decent of 25-30mph down to 10  vs. a road descent of 30-60 mph down to 20 repeatedly which involves a ton more energy which is converted to heat. To get a sense of the difference in power needed, look at the front brake on an off road motorcycle vs a sport bike. the sport bike will have large twin discs, while the dirtbike brake will look more like a DH MTB brake.

Functionally, a rim brake already has the theoretical maximum size brake rotor i.e. the rim.

[Carlin Eng]

Ah, I see. I thought brake fade in general was caused by buildup of heat in the rotor, which reduced the friction between pad and braking surface, so both mechanical and hydraulic brakes would suffer. But if the real issue is the heat causing the fluid to boil, then that makes sense.

Here's an interesting discussion of using CX hydraulics on the road: http://www.bikerumor.com/2012/02/14/road-bike-disc-brakes-are-coming-but-will-they-work/

[Daniel Chao]

Reporting back on this.  Went with H+Son Archetypes with TRP RevoX cantis.  Used my morning commute as a mini-test ride.  Brake shudder was atrocious.  Noticed it immediately, even on flat sections with minimal brake pressure.  Then almost lost it descending Hyde from Russian Hill to North Point.  Mini v's ordered.  Anyone in the market for a brand new set of RevoX, lmk.

The fork on this bike is super flexy.  Wonder if that's part of the problem.  Anyone else have a problem with the flex on Ritchey CX forks?

[Peter Chang]

2014-04-24 12:50 GMT-07:00 Daniel Chao <daniel...@gmail.com>:
>
> The fork on this bike is super flexy. Wonder if that's part of the problem.
> Anyone else have a problem with the flex on Ritchey CX forks?

cx magazine had a fork shootout a while back. i think they found the
same thing wrt flex. the stiffer forks were definitely the pricier
forks.

\p

[Patrick Kitto]

so, the shudder can be addressed with your current set-up. not easily, but possible.

High straddle cable, excessive toe in. fiddle and repeat.

then get ready to do it every couple of months.

or ride the mini-v's and be happy :)

[Russ]

I've been wanting to upgrade my brakes to revox, though wonder if I too should go directly to mini-vs. Anyway, let's talk off-line.

Russ