Go Back  Bike Forums > Bike Forums > Cyclocross and Gravelbiking (Recreational)
Reload this Page >

CX versus mtb for gravel races

Notices
Cyclocross and Gravelbiking (Recreational) This has to be the most physically intense sport ever invented. It's high speed bicycle racing on a short off road course or riding the off pavement rides on gravel like : "Unbound Gravel". We also have a dedicated Racing forum for the Cyclocross Hard Core Racers.

CX versus mtb for gravel races

Old 04-04-16, 03:51 PM
  #1  
n00b
Thread Starter
 
Join Date: Jan 2008
Location: Austin, TX
Posts: 1,397

Bikes: Surly Karate Monkey, Twin Six Standard Rando

Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 428 Post(s)
Liked 466 Times in 273 Posts
CX versus mtb for gravel races

I just rode the 100K Castell Grind (central Texas). it was brutal. I am starting to question my wisdom riding a CX bike on terrain like this instead of a HT mountain bike. the route has many, many "washboard" sections that will either bring you to a halt or bounce you right off the bike if you're not careful, and a bunch of sand pits that make it impossible to ride in a straight line, if you make it though on your tires at all.

where do you draw the line between terrain for a CX-type bike and mountain bike terrain?

165 pound rider on my steel cx bike with tubeless 35mm tires at 35-40 psi.
mack_turtle is offline  
Old 04-04-16, 08:23 PM
  #2  
Full Member
 
sgtdirt's Avatar
 
Join Date: Sep 2013
Location: Mentor, Ohio
Posts: 262

Bikes: KHS Grit 400, Redline Conquest SS, Redline MonoCog SS,2014 Felt TK3,

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 9 Post(s)
Liked 22 Times in 9 Posts
i guess it would depend on the riders ability. the terrain would be a factor too. rock gardens are not fun on a cx bike, nor are roots and big jumps.
sgtdirt is offline  
Old 04-04-16, 09:38 PM
  #3  
George Krpan
 
Join Date: Jan 2007
Location: Westlake Village, California
Posts: 1,708
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 12 Post(s)
Likes: 0
Liked 1 Time in 1 Post
Where I live a mountain bike will run circles around a CX bike on 99% of the dirt roads and trails.

Try a no suspension 29er or 29+ with dirt drops.

GeoKrpan is offline  
Old 04-05-16, 06:38 AM
  #4  
n00b
Thread Starter
 
Join Date: Jan 2008
Location: Austin, TX
Posts: 1,397

Bikes: Surly Karate Monkey, Twin Six Standard Rando

Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 428 Post(s)
Liked 466 Times in 273 Posts
I think half of the people I saw on this past race were riding CX type bikes and everyone else was on a mtb. I think it was the washboard sections that killed me. 35mm tires at any pressure are just not enough to float over that crap. 2" tires at 25 psi would have taken care of that, maybe even suspension. I saw at least two Cannondale Slates, which would have been perfect.

this photo makes it look easy, but the first few miles had several sand pits and the rest of the route had tons of washboard surfaces that slowed me down a lot.



I might try the next one on my mtb with ~2" tires, bar ends, and a rigid fork. there is no way I could get dirt drops to fit on my mountain bike and I don't think tires wider than 42mm would fit on my cx bike.

what's a tubeless-compatible 40-42mm tire with a tight-fitting bead? it has to fit tight because I am using non-TLR rims with Gorilla tape.

Last edited by mack_turtle; 04-05-16 at 07:16 AM.
mack_turtle is offline  
Old 04-05-16, 10:20 AM
  #5  
George Krpan
 
Join Date: Jan 2007
Location: Westlake Village, California
Posts: 1,708
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 12 Post(s)
Likes: 0
Liked 1 Time in 1 Post
I use an upside down north road bar which, with the hands in the drops, is identical to a dirt drop. The advantages are that I can use MTB shifters and MTB hydraulic brakes, and, the drop is shallow so that I can use an ordinary mountain bike stem. No changes to the cable/hose lengths are needed when switching over from a riser bar. I have found, from years of riding rigid, that I can ride much more smoothly with my hands aligned along top tube rather than across like with a riser bar.

There are all kinds of alternatives these days. Surly Open Bar in zero and 40mm rise/drop and Jeff Jones bars.

I got a 29+ a few months ago. It's the ultimate no suspension bike.
GeoKrpan is offline  
Old 04-05-16, 11:26 AM
  #6  
George Krpan
 
Join Date: Jan 2007
Location: Westlake Village, California
Posts: 1,708
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 12 Post(s)
Likes: 0
Liked 1 Time in 1 Post
PS Pics of my setup.



Notice how low my handlebar is. More like a road bike than a MTB. I don't have to be concerned with the fork compressing and catapulting me over the bars.


Last edited by GeoKrpan; 04-05-16 at 11:30 AM.
GeoKrpan is offline  
Old 04-05-16, 03:08 PM
  #7  
Full Member
 
justin1138's Avatar
 
Join Date: Apr 2013
Location: Portland, OR
Posts: 459

Bikes: yes...

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 53 Post(s)
Liked 59 Times in 13 Posts
Originally Posted by GeoKrpan
PS Pics of my setup.



Notice how low my handlebar is. More like a road bike than a MTB. I don't have to be concerned with the fork compressing and catapulting me over the bars.


It looks like a REALLY fat tired path racer. Awesome!
justin1138 is offline  
Old 04-05-16, 03:42 PM
  #8  
George Krpan
 
Join Date: Jan 2007
Location: Westlake Village, California
Posts: 1,708
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 12 Post(s)
Likes: 0
Liked 1 Time in 1 Post
Originally Posted by justin1138
It looks like a REALLY fat tired path racer. Awesome!
Thank you Justin.
GeoKrpan is offline  
Old 04-05-16, 03:43 PM
  #9  
cs1
Senior Member
 
cs1's Avatar
 
Join Date: Feb 2004
Location: Clev Oh
Posts: 7,091

Bikes: Specialized, Schwinn

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 225 Post(s)
Liked 24 Times in 22 Posts
Originally Posted by justin1138
It looks like a REALLY fat tired path racer. Awesome!
It really is kind of cool. Something like a Salsa Fargo seems like the ideal bike.
cs1 is offline  
Old 04-05-16, 04:37 PM
  #10  
George Krpan
 
Join Date: Jan 2007
Location: Westlake Village, California
Posts: 1,708
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 12 Post(s)
Likes: 0
Liked 1 Time in 1 Post
Originally Posted by cs1
It really is kind of cool. Something like a Salsa Fargo seems like the ideal bike.
A Salsa can only take regular 29er tires. I can run regular 29er tires or 29x3 Plus tires. Also, because of the 135/170 hub spacing and 100mm BB shell I can run 26x4 Fatbike wheels/tires.
GeoKrpan is offline  
Old 04-05-16, 05:19 PM
  #11  
Senior Member
 
Join Date: Jul 2007
Posts: 1,039
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 75 Post(s)
Likes: 0
Liked 1 Time in 1 Post
Cyclocross Magazine article on the race:

Another Serving of Texas Gravel, The Castell Grind 100k - Race report, Photos and 100k Full Results - Cyclocross Magazine - Cyclocross News, Races, Bikes, Photos, Videos

Looks like it was won by a guy on a cyclocross bike who barely edged out a guy on a Slate(not that that really says anything about what's best for that course.)
Pendergast is offline  
Old 04-05-16, 08:06 PM
  #12  
Senior Member
 
grolby's Avatar
 
Join Date: Jan 2005
Location: BOSTON BABY
Posts: 9,787
Mentioned: 27 Post(s)
Tagged: 0 Thread(s)
Quoted: 287 Post(s)
Liked 85 Times in 59 Posts
Originally Posted by Pendergast
Cyclocross Magazine article on the race:

Another Serving of Texas Gravel, The Castell Grind 100k - Race report, Photos and 100k Full Results - Cyclocross Magazine - Cyclocross News, Races, Bikes, Photos, Videos

Looks like it was won by a guy on a cyclocross bike who barely edged out a guy on a Slate(not that that really says anything about what's best for that course.)
The long shot of the lead group in that article shows very nearly all of them on CX bikes, so I would say it tells you everything about what's best for that course. Well, best meaning "fastest," in this case. Other criteria may exist, but in the case of a race, that's what I think of.

Last edited by grolby; 04-05-16 at 08:21 PM.
grolby is offline  
Old 04-05-16, 08:56 PM
  #13  
George Krpan
 
Join Date: Jan 2007
Location: Westlake Village, California
Posts: 1,708
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 12 Post(s)
Likes: 0
Liked 1 Time in 1 Post
I think the average schlub could ride that course faster on a MTB than on a CX bike.
GeoKrpan is offline  
Old 04-05-16, 09:30 PM
  #14  
n00b
Thread Starter
 
Join Date: Jan 2008
Location: Austin, TX
Posts: 1,397

Bikes: Surly Karate Monkey, Twin Six Standard Rando

Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 428 Post(s)
Liked 466 Times in 273 Posts
average schlub is probably a closer description of my abilities than those beasts on CX bikes. that is why I am starting to think that a CX bike should not be my choice. I might be faster on my mtb.
mack_turtle is offline  
Old 04-06-16, 09:54 AM
  #15  
George Krpan
 
Join Date: Jan 2007
Location: Westlake Village, California
Posts: 1,708
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 12 Post(s)
Likes: 0
Liked 1 Time in 1 Post
Originally Posted by mack_turtle
average schlub is probably a closer description of my abilities than those beasts on CX bikes. that is why I am starting to think that a CX bike should not be my choice. I might be faster on my mtb.
Yes, they are beasts, most people aren't. You would have done better on your CX if you had a dirt drop and rode it drops only. Also, hydraulic discs make a huge difference.
GeoKrpan is offline  
Old 04-06-16, 11:05 AM
  #16  
n00b
Thread Starter
 
Join Date: Jan 2008
Location: Austin, TX
Posts: 1,397

Bikes: Surly Karate Monkey, Twin Six Standard Rando

Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 428 Post(s)
Liked 466 Times in 273 Posts
not sure if serious.

I barely used my brakes at all during the race and my mechanical discs work fine. dirt drops would require that I had a ridiculously tall stem on top of the already huge spacer stack that I have on my bike. I have Cowbells now, which have a decent amount of flair to them. I ride this bike on most of the singletrack that I usually reserve for mountain biking, so handling is not the problem. getting bucked off the bike by washboards and sand traps is, in addition to the sheer mileage of the course.
mack_turtle is offline  
Old 04-06-16, 02:05 PM
  #17  
George Krpan
 
Join Date: Jan 2007
Location: Westlake Village, California
Posts: 1,708
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 12 Post(s)
Likes: 0
Liked 1 Time in 1 Post
Originally Posted by mack_turtle
not sure if serious.

I barely used my brakes at all during the race and my mechanical discs work fine. dirt drops would require that I had a ridiculously tall stem on top of the already huge spacer stack that I have on my bike. I have Cowbells now, which have a decent amount of flair to them. I ride this bike on most of the singletrack that I usually reserve for mountain biking, so handling is not the problem. getting bucked off the bike by washboards and sand traps is, in addition to the sheer mileage of the course.
I've got years of riding CX/gravel and rigid MTB. The width of a dirt drop really helps. The grip in the drops is unimpeachable. Hydraulic brakes have much finer control. Brake lightly to control bucking and bouncing. The drop of a Woodchipper or Cowchipper is no deeper than a Cowbell. The hoods are suicide on washboard unless you slow way way down.

Last edited by GeoKrpan; 04-06-16 at 02:09 PM.
GeoKrpan is offline  
Old 04-06-16, 03:28 PM
  #18  
n00b
Thread Starter
 
Join Date: Jan 2008
Location: Austin, TX
Posts: 1,397

Bikes: Surly Karate Monkey, Twin Six Standard Rando

Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 428 Post(s)
Liked 466 Times in 273 Posts
Should have specified or used better words. Controlling the bike is not the problem. Maintaining momentum when things get bouncy and sandy is what kills me.
mack_turtle is offline  
Old 04-06-16, 04:15 PM
  #19  
George Krpan
 
Join Date: Jan 2007
Location: Westlake Village, California
Posts: 1,708
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 12 Post(s)
Likes: 0
Liked 1 Time in 1 Post
Originally Posted by mack_turtle
Should have specified or used better words. Controlling the bike is not the problem. Maintaining momentum when things get bouncy and sandy is what kills me.
What I do is pedal against the brakes, brake AND pedal at the same time, even though I'm not needing to use the brakes. This keeps the bouncing in check and keeps the rear wheel from spinning out.
GeoKrpan is offline  
Old 04-06-16, 06:27 PM
  #20  
Senior Member
 
Loose Chain's Avatar
 
Join Date: Sep 2009
Location: USA
Posts: 2,067

Bikes: 84 Pinarello Trevisio, 86 Guerciotti SLX, 96 Specialized Stumpjumper, 2010 Surly Cross Check, 88 Centurion Prestige, 73 Raleigh Sports, GT Force, Bridgestone MB4

Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 278 Post(s)
Liked 71 Times in 56 Posts
I would think that on nearly any terrain that a cx bike can roll it would be faster than a mtb/atb. But the rider might feel differently, you may be more comfortable and therefore faster on a mtb.
Loose Chain is offline  
Old 04-06-16, 10:24 PM
  #21  
George Krpan
 
Join Date: Jan 2007
Location: Westlake Village, California
Posts: 1,708
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 12 Post(s)
Likes: 0
Liked 1 Time in 1 Post
Originally Posted by Loose Chain
I would think that on nearly any terrain that a cx bike can roll it would be faster than a mtb/atb. But the rider might feel differently, you may be more comfortable and therefore faster on a mtb.
If that were true there would be no mountain bke races, only cross races.
GeoKrpan is offline  
Old 04-07-16, 09:10 AM
  #22  
n00b
Thread Starter
 
Join Date: Jan 2008
Location: Austin, TX
Posts: 1,397

Bikes: Surly Karate Monkey, Twin Six Standard Rando

Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 428 Post(s)
Liked 466 Times in 273 Posts
alternate issue-

rider is 165 pounds
35mm tubeless tires
course has lots of washboards and a few sand pits
tire pressure? I think I had mine too high.
mack_turtle is offline  
Old 04-07-16, 11:04 AM
  #23  
Senior Member
 
Spoonrobot's Avatar
 
Join Date: Jul 2006
Posts: 3,049
Mentioned: 63 Post(s)
Tagged: 0 Thread(s)
Quoted: 1210 Post(s)
Liked 167 Times in 107 Posts
I think the two classes of bikes hide the real differences. Which are tire size and suspension. A cross bike with 50mm tires and an rigid MTB with 50mm tires are pretty equal. Throw in wildly varying tire sizes and suspension and things change pretty quick.

At Southern Cross this year I rode my 26" hardtail and absolutely blasted by some riders on CX bikes during the descents. Once the washboarding gets bad enough and the road gets steep enough the CX bikes just can't keep up with a hardtail/full-suspension MTB.

I'm not a great descender but riding a MTB hides a lot of that and allowed me to ride downhill significantly faster than the previous year. I also found it a lot more fun to descend with a front suspension so even if my placing was slightly lower than it would have been on a CX bike I had significantly more enjoyable experience.

However, it was with much chagrin that I noted most of the narrower-tired CX riders who I passed on the descent caught and passed me quite easily on the flats.

I'm not sold on either one being faster, it really depends on the set-up and the rider. For me, the MTB was faster downhill but slower on the rollers and the flats. It was also kind of a pain to manually lock-out the fork dozens of times.

I have six gravel events left this year. I'll probably ride my MTB for 3 of them that have serious descents and ride my CX bike for the other 3 that are flatter and faster.
Spoonrobot is offline  
Old 04-07-16, 12:55 PM
  #24  
Senior Member
 
Tim_Iowa's Avatar
 
Join Date: Jun 2013
Location: Cedar Rapids, IA
Posts: 1,643

Bikes: 1997 Rivendell Road Standard 650b conversion (tourer), 1988 Schwinn Project KOM-10 (gravel/tour), 2013 Foundry Auger disc (CX/gravel), 2016 Cannondale Fat CAAD 2 (MTB/winter), 2011 Cannondale Flash 29er Lefty (trail MTB)

Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 167 Post(s)
Likes: 0
Liked 5 Times in 5 Posts
If you have a disc 'cross bike, you could try 650b wheels with ~50 mm tires. Maybe that would be the best of both worlds? Adventure/rando bikes like the Elephant NFE are using this setup.
Tim_Iowa is offline  
Old 04-07-16, 08:26 PM
  #25  
George Krpan
 
Join Date: Jan 2007
Location: Westlake Village, California
Posts: 1,708
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 12 Post(s)
Likes: 0
Liked 1 Time in 1 Post
Good comment. Around here there is dirt that is rideable on a CX, but not much, except if you are a spectacular rider, and such riders exist. I know that me, myself, I on a MTB could run circles around me, myself, I on a CXB.
My 29er and my 29+ have no suspension and have drop bars, dirt drops.

Originally Posted by Spoonrobot
I think the two classes of bikes hide the real differences. Which are tire size and suspension. A cross bike with 50mm tires and an rigid MTB with 50mm tires are pretty equal. Throw in wildly varying tire sizes and suspension and things change pretty quick.

At Southern Cross this year I rode my 26" hardtail and absolutely blasted by some riders on CX bikes during the descents. Once the washboarding gets bad enough and the road gets steep enough the CX bikes just can't keep up with a hardtail/full-suspension MTB.

I'm not a great descender but riding a MTB hides a lot of that and allowed me to ride downhill significantly faster than the previous year. I also found it a lot more fun to descend with a front suspension so even if my placing was slightly lower than it would have been on a CX bike I had significantly more enjoyable experience.

However, it was with much chagrin that I noted most of the narrower-tired CX riders who I passed on the descent caught and passed me quite easily on the flats.

I'm not sold on either one being faster, it really depends on the set-up and the rider. For me, the MTB was faster downhill but slower on the rollers and the flats. It was also kind of a pain to manually lock-out the fork dozens of times.

I have six gravel events left this year. I'll probably ride my MTB for 3 of them that have serious descents and ride my CX bike for the other 3 that are flatter and faster.
GeoKrpan is offline  

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service -

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.