700c disc wheel rebuild

woolwich

Folks,
I am currently riding a cyclocross bike as my only form of transport.
Usually the canti brakes are passable.However add some weight, speed or dampness and i find they become a liability on the road. I've lost confidence in them and a change is necessary.
I have ordered new forks that will accomodate a disc, a cable operated disc caliper and a disc hub.
I am new to wheel rebuilding but have recently done a basic course so have a rough idea of what i am going to do. However I want to check that it will ok to recycle the existing font rim? Or should i order a disc specific rim? Obviously with new spokes the correct lenght.
I am wondering if the design of the rims are different for rim activated brakes or hub activated brakes or am I worrying uneccessarily and should just do it.
Any thoughts gratefully received.

John.T

Just use the existing rim. If you get a new rim, hub and spokes it would have been cheaper to get a new wheel. I re-hubbed mine using centre lock disc hubs and was able to use the same spokes. Probably got the only bike out there with discs and ceramic rims.

woolwich

Thanks John. I'm sure it will be fine. If I re-build the wheel myself, with a cheapo £12 Deore hub and re-use the rim, i can do the whole conversion for more or less £200 depending how many spokes I need. So well worth doing.
Cheers

John.T

I used centre lock hubs where the disc is splined on to the hub and held with a lockring. The flanges are the same size as the non disc ones and the disc side flange is only a little further in so I was able to re-use all my old spokes. These wheels have been on my MTB for over 3 years now with no trouble at all. It saved quite a few bob.

Monty Dog

A rim brake rim is actually stronger than a disc brake rim as it has a sacrificial brake track and has to take the brake force at the rim. As said, just reuse the existing rim, but you're likely to need new spokes if the hub flange dimensions are different.

woolwich

Of course, a rim brake rim has all that material to wear away. I was sure there was a difference between the two rim designs but hadn't figured it out. Thanks.

Unfortunatley John I have already bought a six bolt hub. Top tip though, well worth remembering. Saves a few bob and some time working the critical dimensions out.

Cheers

ugo.santalucia

Remember to build the left hand side of the wheel opposite to the right hand side... if the right end side is built in a conventional fashion