Wressen

So I did not no where to post this, but here goes. Im about to build up a front wheel with a dynamo hub (shutter precision), the wheel is for a cross check bike, so no disc brakes. But I was thinking that i might as well choose a hub with a disc option (PD-8 hub), incase I want to buy a disc fork.


So is it stupid? Is it harder to build with the disc compatible hub(different flange sizes)?


Just need some help to decide.

hueyhoolihan

i've just gone through a process of retro fitting a front disc brake to my road bike. i had a to find and buy a disc specific front hub and spokes of the proper length, among other things, to do so... didn't work out, but if it had, i would have been better off buying a disc specific hub (and spokes) in the first place. i my case, anyway, it didn't make any difference because i ended up putting it back the way it was.

and yes, two different spoke lengths were required.

anybody want to buy an XT hydraulic brake, full carbon road fork (short steerer), DIY hydraulic bleeding kit, and a couple of brake rotors (i fouled that up too)?

jsigone

You will need the disc fork, disc brakes and a rotor. The disc brakes must be roadie style as the brake lever is designed to work with brifters.

I'd estimate the conversion is $250-350.

I'd go all in or nothing at all. Building the wheel is the same, but harder to find lower spoke counts than 28H on the MTB (disc) hubs.

fietsbob

May make sense if the frame and fork is made with both rim brake posts and with disc caliper mounts ..

I bought a 6 bolt Schmidt hub for my Koga WTR, though the Magura HS33 rim brakes work so well,

I havent considered the disc conversion necessary. .


My Bike Friday also had both fittings, But it shipped with BB7 discs..





you may keep the wheel and get another bike , as well..

Wressen

I have disc brakes, rotors and all, only need a new fork if I would like to go that way.

But the main thing is, why would one not choose the hub with disc option? The Shutter precision PD-8 instead of PV-8. The price difference is 5$.

Tim_Iowa

Not stupid. A dynamo setup is an investment that may outlast your current fork.

So, "future-proofing" your dynamo hub by making it disc-compatible makes sense.

The PD-8 is a little bit heavier than the PV-8, and it requires two different spoke lengths. Not big drawbacks. The flange width is the same.

However, one advantage of a disc-brake wheel is you can use lighter rims (without the rim brake surface).

If you're just re-using the stock rim, then I say go for it, and switch to disc maybe when you wear out the brake track on the rim.
If you're buying a new rim for this wheel, I say buy a Straggler fork (~$100) and do the switch to disc.

As others have pointed out, if you are using drop-bar (road) brake levers then you need to use disc calipers for road bikes (for example, BB7r).

unterhausen

it's not stupid. I just bought a through axle version for a non-through axle bike because I thought I might convert. That adds considerably to the price of the hub.

I think their disc hubs might actually build into a marginally stronger wheel

Oh, and my commuter bike has a disc hub on it

fietsbob

I like the centerlock design , its great for touring , with the bike boxed on either end of the trip.

because the disc can be removed easily to be packed separately and so stay flat.

cobba

That mightn't always be the case, here's some specs from a Mavic catalog.

Wressen

No, the thing is that 99% of the disc rims are for MTB, so you can't compare it to rad rims.

simplybao

Not disputing the rest of your post, but this could be wrong based on the combination of parts. I'm runnng RS-685 hydro road brifters, XTR calipers, and 160 mm XT ice-tech rotors on my lynskey.

Tim_Iowa

The OP doesn't have hydro brake levers; he currently has rim brakes on a Cross Check.

With mechanical road brake levers, you need road calipers. (different cable pull than MTB levers and calipers)

But you are correct, hydro brake levers work with any hydro caliper, and hydro levers are available in both flat bar and drop bar designs.
Sounds like you have a killer setup. The ice-tech rotors made a huge difference (better stopping power, less noise) from single compound rotors on my fat bike.
And, in my experience, rim brakes < mechanical discs < hydraulic discs.

JohnDThompson 

The hub mounting for the rotor moves the hub flange inboard, deceasing the bracing angle of the spokes and correspondingly weakening the wheel a little. But, as another person pointed out, disk hubs are usually available with spoke counts of 28 or higher, so perhaps it's not a big deal.

simplybao

I wasn't even thinking about mechanical brakes. I was going to go with TRP hybrid calipers where they are cable actuated but hydro calipers but in the end, I already had XTR brakes so I decided to keep hydro.