[Skippy]

Hey Guys,

I have a question for ya. Do you see a big advantage of putting 130mm disk hubs on cross bikes or keep them 135mm?

135 is a stronger wheel and there are many more hubs avaible. Does anyone see a benifit of going to 130mm disk hubs?

Let me know, thanks!

 

[Serial Midget]

I don't get it... isn't the 130 just going to need a 5 mm spacer???

 

[Skippy]

Well right now road bikes have 130mm spacing and mountain bikes use 135. Most disk hubs are made for mountain bikes. I was talking to a prodcut manager that that thinks that cross bikes should use a 130mm spaced rear end. I think I 135 builds a stronger rear end and gives people more choices for hubs.

 

[oldfart]

I don't see any anvantage at 130mm. The only reason you'd keep it compatible with road width is for interchangeability and for races where you might get a flat and need a wheel from neutral support, but if you have a disc brake that's moot.

 

[indieboy]

well lets start off w/ this first and let me say that disc brakes do not belong on a cross bike. just way to much stopping power and you'll begin to slide and skid out way before the disc will ever meet their max braking power.

and cross bikes use road wheels so 130 would be the way you'd go anyways. there aren't to many road disc hubs out on the market, however there are a lot of mtn bike disc hubs that if you do a custom build you could have the frame builder put 135 spacing instead of 130. the only downside to going that way is if you ever want to race and have to have a wheel change then you better have some backups and not try to relay off of neutral support b/c i can almost gurantee you they won't have a 135 mtn bike hub laying around built up w/ disc on open pros

 

[Serial Midget]

Gotcha. I don't think the extra strength is going to be needed for cyclocross. I'd stick with the one that won't force you space and re-align your frame.

 

[JamesD]

I think cyclocross is the only other place discs are an advantage. The mud is usually equal or worse than mtb races so for those situations, discs on cyclocross would be a real benefit.
Several cx frames come with disc tabs for this reason.

 

[indieboy]

Originally posted by JamesD

I think cyclocross is the only other place discs are an advantage. The mud is usually equal or worse than mtb races so for those situations, discs on cyclocross would be a real benefit.
Several cx frames come with disc tabs for this reason.

you will NEVER get the full braking potential out of disc brakes on a cyclocross bike. your wheels begin to lock up and skid way before you ever reach that full potential.

manufacters are making the tabs on their frames b/c ppl who don't own a cx and are coming into the market from the mtn bike industry think disc brakes are the end all solution to everything . all the builders can do is feed the ppl what they want right......

 

[oldfart]

Having raced road, cross and mountain, I disagree Indie. Its true that its easy to over power then skinny tires on just about any surface, I think your missing the fact that rim brakes don't work at all when wet but discs are not nearly as affected. Most of the dozen or so cross races I did here were in rain or it had just rained and mud was every where. Short downhills were sketchy because the brakes didn't work and you would accellerate until the rims dried enough that they did work. Plus the mud clearance you get with discs is way better.

 

[Squeak]

Use a smaller disk brake system designed for road/CX. That would be a great solution.

 

[indieboy]

Originally posted by oldfart
Having raced road, cross and mountain, I disagree Indie. Its true that its easy to over power then skinny tires on just about any surface, I think your missing the fact that rim brakes don't work at all when wet but discs are not nearly as affected. Most of the dozen or so cross races I did here were in rain or it had just rained and mud was every where. Short downhills were sketchy because the brakes didn't work and you would accellerate until the rims dried enough that they did work. Plus the mud clearance you get with discs is way better.

the poitn of cross isn't to stop

 

[-dustin]

i agree with Indee on the 130.

 

[oldfart]

Originally posted by indieboy
the poitn of cross isn't to stop

Exactly. If you ride into the rhubarb because you couldn't control the bike, you stop.

 

[indieboy]

Originally posted by oldfart
Exactly. If you ride into the rhubarb because you couldn't control the bike, you stop.

hehe did you see the footage of steve larsen busting his face on barrier a couple years back? tripped on a set of triples, foot clipped the first one and hit his face on the last one.

 

[JamesD]

The issue isn't stopping, it is braking modulation- to be able to dive into a turn and drop the chute late, getting thru turns fast, hitting descents and setting up for barriers quicker. The problem now is weight but maybe things will get better if they come up with cx hydros (not enough market to justify probably). In certain conditions, you would have a huge advantage with discs compared to zero braking with rim brakes.
I would try it but the choice is limited to Avid road disc mechanical brakes.

 

[indieboy]

Originally posted by JamesD
The issue isn't stopping, it is braking modulation- to be able to dive into a turn and drop the chute late, getting thru turns fast, hitting descents and setting up for barriers quicker. The problem now is weight but maybe things will get better if they come up with cx hydros (not enough market to justify probably). In certain conditions, you would have a huge advantage with discs compared to zero braking with rim brakes.
I would try it but the choice is limited to Avid road disc mechanical brakes.

well the day shimano and/or campy makes a hydro verison of their road sti shifters for cx is the day my farts start smelling like cinnamon :devil:

 

[oldfart]

I think that day will come but not for a while. It would allow some really light rims though. As it is now, the full carbon rims are a hazzard especially when wet. I think Ulrich blamed poor braking performance for his ride into the shrubs in the 01 tour. Another thing that's happening is that frames are getting superlight as are many other parts. Simoni for example actually used some heavier parts on his Cannondale to get it up to the 15 pond UCI weight limit. It could very well be that by using lighter stuff elsewhere, that a slightly heavier disc brake set up will be feasable. Sniff sniff, is that....cinnamon?

 

[SuspectDevice]

Moderator dear god kill this thread!

For top-level cx racing discs are so so stupid. just becuase chris peck thinks they belong on acx boesn't mean that they should be there. look at the companies that have disc compatible cx bikes. they are all heavy, poorly designed taiwan clone bikes.

There is no need for discs when an good brake like the spooky's or empellas are so light, have so much clearance and are ridculously powerful. So if you gave Page or Nijs the choice of a pair of carbon spooky's with wehstar ceramic pads or an xtr level hydraluic disc they would take the canti's any day. Why?

you barley need brakes in cx racing, it would be prohibitvely expensive to build up 7-8 pairs of wheels that would be useless on a road bike (3 bikes x 2 sets of wheels + road wheels and a spare set). Any decent rider could get a few seasons out of even the lightest road wheels on the market today, with the correct pad compounds carbon braking surfaces work fine.