Brake and gearing recommendations for "monster cross"/gravel bike

[Bruce K]

So I've got the build group pretty well figured out for my new "monster cross"/gravel bike project. I am using parts that I have but didn't end up selling plus a couple of small cost items that I have picked up but I could use suggestions in 2 areas:

1. Disc brakes - I am going with mechanical discs and thinking TRP Spyre because they are "dual action". Anyone have any other ideas/experience with mechanical disc brakes that close from both sides?

2. Gearing - I am going to run a 12-28 cassette and have 110bcd cranks. Options are 50-34, 50-36, 46-34, or 46-36. I am leaning towards the 34 for small but going back and forth on the big ring. Again thoughts/experience welcome.

The rest of the bike will look like this:

Surly Straggler frame/fork
Cane Creek head set (or something else mid-priced)
SRAM Red (it's what I've got) 10spd shifters, f/r derailleur
SRAM Force cassette, chain
SRAM Red crank set 110bcd (thanks eBaumann) w/ std. bottom bracket
Zipp SC alloy post
Specialized Romin saddle
3T Ergosum Pro alloy bars
Ritchey WCS or 3T stem (not sure yet - looking for deals)
Disc calipers -TBD
HED Ardennes + FR rims (25mm) w/ center lock disc hubs
Surly Knard 700X40 tires
Shimano XT pedals
Arundel Dave-O bottle cages

I know it's a bit over the top for the planned usage but all the SRAM stuff was lying around my basement waiting for whatever the "next project" was or to replace damaged stuff in cyclocross and it's time to use it.

BK

[PaMtbRider]

I really like the 46/34 option. I was using a 50/34 and on my gravel bike and changed the 50 for a 46. For my terrain I need the 34 and and thought the 50 was too big for most dirt road riding. I am using an 11-28 and never spin out the 46/11.

[Bruce K]

C'mon guys ......

I know we gave a bunch of folks with these types of bikes plus some MTB riders with disc experience

I need a little help here !!! ;)

Pamtbrider - Thanks for confirming my gearing thoughts

BK

[Likes2ridefar]

I ran out of gears all the time with a 46T on my cross bike when riding on the road, and I had an 11T for the smallest.

[Germany_chris]

34/44or46

BB7 road my campy levers pulled BB7 mountain but I don't know SRAM if they can then get the mountain version.

[Wilkinson4]

i run 50/34 with 28 out the back. works for me but if I could get a 30T or more back there I would. Gravel roads around here tend to be much steeper than the paved roads. I think you may be able to use SRAM XX rear der with their road shifters, exact ratio they call it. Mike at Black Mountain would be a great resource. That said you may feel under geared with less than 50 up front coming down some hills. 50/34 is a good combo.

mIKE

[holliscx]

Help me pimp my Surly, Obi-Wan Kenobi. You're my only hope.

[Likes2ridefar]

i run 50/34 with 28 out the back. works for me but if I could get a 30T or more back there I would. Gravel roads around here tend to be much steeper than the paved roads. I think you may be able to use SRAM XX rear der with their road shifters, exact ratio they call it. Mike at Black Mountain would be a great resource. That said you may feel under geared with less than 50 up front coming down some hills. 50/34 is a good combo.

mIKE

SRAM wifli derailleurs all do 32T. put a rival on my wife's bike and it works great.

[ptourkin]

SRAM wifli derailleurs all do 32T. put a rival on my wife's bike and it works great.

Yes. I run 46/36 on my PsychloX with wifli and a 32T - maybe overkill for cross but great on trails. I'm considering 34 when I replace the rings next.

[Pegoready]

I'd trade out the 12/28 + Red RD for a 11-3X and a long cage derailleur. A cheap Apex will do.

Your gearing sounds like a cross race bike. To me, monstercross/gravel should have semi-MTB gearing.

[sparky33]

I run 46/36 on my PsychloX with wifli and a 32T - maybe overkill for cross but great on trails.

^^^Hard to go wrong with this gear choice for a dirty dirt bike, unless you are an outlier in the leg strength dept. ^^^
Who cares what gears you would miss when you wander onto a paved road - it's a monster cross bike!

Mini-Vs are terrific off-road - I find them overly punchy for paved riding, but they really give confident stopping on the trail. Discs sound great too, so good on you.

[HillDancer]

I have road BB7s with SRAM road levers. Some advantages are, the pad engagement point and lever reach can be adjusted to suit. Be aware the Spyre requires a long throw to activate. For solid lever feel, use linear brake housing like Jagwire Ripcord, or Sram's SlickWire XL Disc Road Bicycle Brake Cable Kit, keep the routing as short as possible, and connectors as few as possible. Use the largest rotors that will fit within the fork & stays. Install SwissStop Green pads.

If the grades are steep on unpaved surfaces, low gears are more useful than high. One must remain seated to maintain traction while climbing on very loose gravel or dirt. The larger the circumference of wheel & tire, the lower the gear needed. My low gear is 1:1, and it always comes in handy. Keep the chain ring tooth spacing close, 12T or less.

https://lh5.googleusercontent.com/-5cypmanJzMs/UJ7_pQT5VLI/AAAAAAAAAeU/-PL7lA2epcs/s400/IMG_0200.JPG

[sparky33]

One must remain seated to maintain traction while climbing on very loose gravel or dirt. [/IMG]

Good point.

[aaronv]

Be aware the Spyre requires a long throw to activate.

I've just swapped my BB7 Roads for a set of Spyre brakes. I've found the opposite to be true, the throw on the Spyre is much shorter and the engagement is more precise. I have less than 100 miles on the new brakes, but they feel better and are quieter than the BB7s ever were. I would expect Avid to roll out some improvement in the near future for the BB7 line given the competition from TRP and similar price point.

[echelon_john]

I love my BB7s. Also, I agree with Pegoready about gearing. Admittedly, I'm not that fit. But when I grab my 700c big-tired road bike, it's to go explore, which often involves climbing and picking through things.

To me, 34/32 or 34/34 would make more sense for a low gear. 34/48 in the front with an 11/12-32/34 will give you great flexibility.

[aaronv]

So I've got the build group pretty well figured out for my new "monster cross"/gravel bike project. I am using parts that I have but didn't end up selling plus a couple of small cost items that I have picked up but I could use suggestions in 2 areas:

1. Disc brakes - I am going with mechanical discs and thinking TRP Spyre because they are "dual action". Anyone have any other ideas/experience with mechanical disc brakes that close from both sides?


Disc calipers -TBD
HED Ardennes + FR rims (25mm) w/ center lock disc hubs



BK

I would recommend the TRP if you are going to use center lock hubs. There is a tab on the pads for the BB7 that has to be removed in order to clear the rotor spider for the center lock.

The Spyre has a narrower profile and has a barrel adjuster in addition to an outboard pad adjustment.

https://lh5.googleusercontent.com/-eKrt6CIzOvE/UgzjQrJlznI/AAAAAAAAAgQ/qucwygW64Vs/w640-h480-no/trp1.jpg

https://lh6.googleusercontent.com/-GyavKO0fVVU/UgzjQlBSaaI/AAAAAAAAAgY/bxLm0PpnM2Q/w425-h566-no/trp2.jpg

https://lh5.googleusercontent.com/-_1YUI2l5Sf0/UgzjQuBRoyI/AAAAAAAAAgU/vV9lIc7rDgw/w425-h566-no/trp3.jpg

[VA-Scooter]

I have BB7's-Not bad but not real impressed either. Gearing--50-34 with 12-30. I live in the mountains & it gets me everywhere.

[aaronv]

2. Gearing - I am going to run a 12-28 cassette and have 110bcd cranks. Options are 50-34, 50-36, 46-34, or 46-36. I am leaning towards the 34 for small but going back and forth on the big ring. Again thoughts/experience welcome.


BK

Bruce,

I have 46/34 12-32 gearing currently. I also live on the North Shore, so that gearing is a bit low for the relatively flat terrain around here, but when I ride in VT or NH I'm glad to have the range so I can sit and spin without losing traction.

Aaron

[Bruce K]

While I agree the WiFli and an 11-32 would be ideal, I am working with parts I have to minimize additional expenditures, so yes, this is going to be a really "pimp" Surly and will end up geared more like a cross racer (where I use 46-36) than an ideal gravel bike. The 34 tooth inner ring should help that department a bit.

So gearing is set for 46-34!! :banana:

The build out is not my first choice, but if someone had bought all the Red shifters and derailleurs that I have (and tried to sell on the forum) then I would have gone with Force or something less "pimp", OK?:rolleyes:

So I am waffling between Spyre and BB7. May go with best "deal" but still reading opinions on brakes. I plan to run full-length housing, maybe even Gore, for whichever brakes I use.

BK

[Bruce K]

Just saw the note about center-locks and yes, the HEDs are center locks.

BK

[John Price]

I'm sure I'm in the minority here but I like triple cranks (living in Colorado may be why). With a Campagnolo Record triple and a 13-29 or 12-26 (9 sp) rear cassette you get a large range with minimal gaps in gears. And as been pointed out already a lot of gravel/country roads and paths can be pretty steep. Standing a lot of time doesn't work (slippage) so having good, low enough gears is nice.

I understand that a compact double is "simpler" but I don't see a triple as being all that complicated. And the weight difference is pretty minimal too.

As for brakes - no comment really, haven't ever used disks.

John

[krhea]

Bruce, I'm currently building a gravel grinder with the following:

50/34 or 46/34, 11-32, 9speed, M950 XTR rear derail, Shimano bar-ends.

BB7 rear disc, Tektro 926AL Mini Linear front w/Campy brakes levers

I'll be using Bruce Gordon Rock 'n Road tires but haven't made my wheel decision yet.

Aluminum frame, Wound-up fork

[Bruce K]

I understand the triple thing but the parts I have are for double and I am trying to use up sll my doare stuff.

I may have to re-think the rear derailleur/cassette thing

Look for the Red derailleur to get re-listed. If I can sell it then I'll go Force WiFli. I can always use the cassette as a spare for cross or if I go back to CO next year.

Thanks for the input gang

BK

[mossman]

not applicable to your components, but I love my 44-28 11-28.

[Mr Cabletwitch]

I run an compact 50-34 crank and 11-32 cassette on my surly crosscheck that sees everything from commuter duty, trailer towing, gravel grinding and even single track and it works well. Never really needed any more gear than that, although on some long single track grinds and some trailer towing I wished for lower gears but it always got the job done. When I do commute on the bike I'm glad I have the 50 on there instead of something lower.

[John Price]

Ah good point about the parts you have available.

For tires, I'm getting ready to test Challenge Strada Biancas (Strade Bianche) this weekend on the gravel roads in Black Forest. The short ride on pavement with them was quite nice though.

John

[dustyrider]

I know nothing about disc brakes with cables. I only use "wet" brakes on the MTB.
I'm running 50/34 and 11/36. I'd like a 48/32, a little easier to push the 11 and a little easier to sit back an spin the 36, but I get up and down and around everything now so.... Colorado type terrain.
Tires I started with 32c t serves, got some 43c rock n roads but those won't stand up to asphalt at all, so I'm thinking clement but they seem too be a low volume 40c...
I have a feeling the tire options should be more plentiful after eurobike and interbike....?