Gravel road bike build, A few questions

Especially for light weight issues concerning cyclocross / touring bikes & parts.

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skiezo
Posts: 150
Joined: Fri Dec 26, 2008 2:32 am
Location: Mid. PA. USA

by skiezo

I am in the process of building a bike for gravel road rides. Here is what I have so far for the build.
1) Alan 7005 alum. frame. Cira 2005 or so.
2) alpha Q cx 20 fork
3) Wheels- HED C2 tubulars laced to WI H2 28 hole hubs
4) 7800 Shimano DA drive train
Plus what ever else I have laying around collecting dust in the basement.
So I do not have any brakes or tires. Like i stated this will be a gravel road/race bike with little mud or grass. Most rides will be semi flat with some hills in the mix.
What brakes would be well suited to go with the 7800 levers.
What chainrings would be well suited to this build? The cranks are DA 7800.
Also tire style and width is also foreign to me. I am thinking of 30mm front and 32/33 mm rear.
This cyclocross built is all new to me as I have been a road guy for close to 30 years.
Any help/recommendations on tires and brakes would be of great help.

Thanks Brian

by Weenie


gt5504b
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by gt5504b

I really like a big floating slick for dirt and gravel road rides as long as there aren't really long sections of big, deep, loose stones. I alternate between a set of 28mm Ruffy Tuffy and 32mm Pasela. I appreciate the reduced drag and lightweight puncture protection that you don't often find in CX tires. Rivbike.com has a good selection of these types of tires to get a feel for options.

That said I have just spent some time cross racing this season on tubular 32mm Grifo XSs and they are wonderful tires on asphalt, gravel, and dirt. And now that Challenge has melded this tread over into their 'gravel' category with the Almanzo you could do a 30/33mm setup that would be very nice.

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Juanmoretime
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by Juanmoretime

I just did a gravel road race yesterday. Took 1st in the open category.

My 46, 36 rings work and worked well. I also went tubeless with Michelin Mud 2 tires at 35 psi. They are claimed to be 30 but really are more like a 32 yet light and with great grip in the gravel.
RESIDENT GRUMPY OLD MAN.

mattr
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Location: The Grim North.

by mattr

Any cantilever or mini v type brake should work, trp eurox are favoured in cross circles, as are froglegs.
Mini vs can have mud clearance issues.

JBV
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Joined: Wed Jun 27, 2007 12:18 am

by JBV

mattr wrote:Mini vs can have mud clearance issues.


Myth. I've used them in enough muddy races now to be able to say otherwise with some certainty. Frames and forks pack up before these brakes do.

Only drawback of mini-V's is the pad sits closer to the rim, which can lead to rubbing if your wheel comes out of true any more than 1-2mm.

JBV
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by JBV

skiezo wrote:1) Alan 7005 alum. frame. Cira 2005 or so.
2) alpha Q cx 20 fork


I think the Alpha-Q is a 47mm raked fork. Nice, stiff fork, but make sure the head angle of the frame is slack enough that you have enough trail on this bike. A gravel bike still has to negotiate fast downhills, and having too little trail makes that less comfortable.

skiezo wrote:What chainrings would be well suited to this build? The cranks are DA 7800.
Also tire style and width is also foreign to me. I am thinking of 30mm front and 32/33 mm rear.


I'd ditch the 7800's and get a compact. 34/48 is good for gravel events, many of which (Tushar Crushar, etc) have some steep climbs. You'll want the 48 for road sections, although 46 would be OK with an 11.

Get the same size tires front and rear. Tire type is very event specific. You want to run slicks or file treads (like a Clement LAS) for faster gravel events where grip is not an issue, but if the event is looser with a lot of sand then an all around cyclocross tread (MXP, Grifo, etc) is more in order. Fatter tires (32mm) can be run at lower pressure, for a smoother ride on bumpy courses.

Generally, I favor tubulars for road racing, and for 'cross they're the best choice. But I think for gravel events you can consider tubeless clinchers. The reasons are that you may want to use different tires for different events, and that's easier with tubeless than tubular. Especially if you want to change the day before an event, after you see the course. Also, the ability to run lower pressures (18-24psi) is critical for cyclocross, but not for gravel events. Tubeless are still a bit iffy at those pressures, but are generally fine at the higher pressures you'll run for gravel. Finally, if you flat in a cyclocross race, you run/ride to the pit and change bikes. In a gravel race, you're self-supported. You can change a tubeless tire or put in a tube out on the road, but with a tubular, even if you carry a (bulky) spare, it won't be well-glued to the rim and you'll have to be careful the rest of the way.

Biggest downside of tubeless for gravel is the limited rim & tire selection.

mattr
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by mattr

JBV wrote:
mattr wrote:Mini vs can have mud clearance issues.
Myth.
Nah, i've seen enough clagged up mini-vs to know that it can be a problem. The straddle is lower than the crown and the arms are closer to the tyre than the fork legs, some claggy, wet, grass filled mud loves that sort of thing. Probably not an issue on a gravel racer as you won't be racing on freshly mowed fields.

skiezo
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Joined: Fri Dec 26, 2008 2:32 am
Location: Mid. PA. USA

by skiezo

Thanks for the replies. I will be building up the bike this weekend or soon thereafter.
The tires I chose are Challenge Grifo XS Tubulars. I chose these as I will not be doing mud or anything real wet or slick.
Mostly gravel and groomed fire roads in south central PA.
Brakes will be TRP euro-x with kool stops on them. The wheels are hed h2 laced to WI hubs.
So I will keep ya all up to date and let ya know how it turns out after a few rides.
Again thanks for your help and advice,
Brian

by Weenie


stefanot
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by stefanot

The MXPs seem like a great choice since they roll great on gravel and pavement and actually have traction in the looser/muddier stuff.

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