Idiots' Guide to Road Disc Brakes

[theclaud]

I could look up all this stuff, of course, but I am hoping it is easier to pick the brains of CC peeps.

I am building a new all-season commuter/workhorse. The frame is a Kaffenback. The idea is to have a tough disc-braked road bike, so as to stop wearing away so many rims with the salt-and-sand combo that is the hallmark of my otherwise enviable commute. However I know next to nothing about disc brakes, so this is a rambling question about compatibility. I've taken a fancy to TRP Spyres, as they are a bit less fugly than the BB7s and look easier to set up. My choice of wheels inclines towards cheapish Shimano factory stuff such as RX05s. I gather that there are two standards for rotor attachment, and that the Shimano ones are Centre Lock? Does this mean that the rotors supplied with the Spyres would be incompatible with the Shimano hubs (it looks as though you can select different sizes of rotor with the Spyres but says nothing about the attachment, although there is a picture which shows what I take to be a six-bolt rotor). Is there such a thing as an adapter, or would I have to buy Centre Lock rotors (and is there any reason these wouldn't work with the Spyres) or am I going to have to choose different wheels or brakes entirely?

 

[ianrauk]

BB7's are very easy to set up and are very little hassle or problems when done so. However, you are right. TRP's do look better. With TRP's both pads move to grip the rotor where as on the BB7's only one pad moves. Meaning the TRP's have better pad wear, modulation and less squeal.. apparently.

 

[jowwy]

And yes there is a centre lock to 6 hole adaptor so your discs will be fine

I have the trps on my synapse and will also be putting a set on the new Ti disc build next week

 

[Arrowfoot]

In case you haven't seen this.


View: https://youtu.be/wPTK0yEUI5s


<iframe width="560" height="315" src="https://www.youtube.com/embed/wPTK0yEUI5s" frameborder="0" allowfullscreen></iframe>

 

[MichaelW2]

Why can't you use a Shimano centrelock rotor with Spyre brakes.
The rear brake mount on a Kaffenback is in the std MTB seatstay location, you you need some thought to integrate with rack and mudguards.

 

[Crackle]

Disc brake racks for that kind of mount exist, I have one. One rack leg has a bulge to go round the disc brake.

 

[theclaud]

Thanks for the thoughts and advice, peeps. @Crackle, do you remember what your bulgy rack is called?

 

[Crackle]

Thanks for the thoughts and advice, peeps. @Crackle, do you remember what your bulgy rack is called?

Fleabay

http://www.ebay.co.uk/itm/ETC-Alloy...003?pt=LH_DefaultDomain_3&hash=item25a189af2b

I got a silver one. I think the likes of tubus and others do similar if you want better quality. That one has done a couple of tours though. No issues.

 

[theclaud]

Me again! I have installed the Spyres (160 front and 140 rear) and all is well except that I am slightly nervous about the minuscule clearance between the front brake and the spokes. Although the whole unit can be adjusted laterally, I don't have any leeway when it comes to moving it outboard, or the rotor will be rubbing the brake pad. I'm thinking that swapping in a 180 rotor on the front might be an option - the Spyres came with two different mount adapters, and the ones I'm not currently using appear to be meant for a 180 front or a 160 rear. However I don't think Spyre supply 180 rotors. Is there anything I need to know about rotor compatibility, or are all 180 rotors essentially the same barring the mount type?

 

[Panter]

Me again! I have installed the Spyres (160 front and 140 rear) and all is well except that I am slightly nervous about the minuscule clearance between the front brake and the spokes. Although the whole unit can be adjusted laterally, I don't have any leeway when it comes to moving it outboard, or the rotor will be rubbing the brake pad. I'm thinking that swapping in a 180 rotor on the front might be an option - the Spyres came with two different mount adapters, and the ones I'm not currently using appear to be meant for a 180 front or a 160 rear. However I don't think Spyre supply 180 rotors. Is there anything I need to know about rotor compatibility, or are all 180 rotors essentially the same barring the mount type?

Essentially the same, BUT...
You will need to check that your forks are compatible with 180mm rotors due to the increased leverage from the larger disks.

 

[theclaud]

Essentially the same, BUT...
You will need to check that your forks are compatible with 180mm rotors due to the increased leverage from the larger disks.

Thanks - that's helpful. I spose that's just a call to Planet X then, assuming there's no way to establish this from inspecting them?

 

[Panter]

Thanks - that's helpful. I spose that's just a call to Planet X then, assuming there's no way to establish this from inspecting them?

I really don't know. My experience is limited to MTB forks that list maximum rotor size in the specifications.
Actually, maybe rotor size is only of concern to suspension forks? Just thinking out loud though, I don't know the answer unfortunately.

 

[Smokin Joe]

Thanks - that's helpful. I spose that's just a call to Planet X then, assuming there's no way to establish this from inspecting them?

Good luck with that. The PX phone staff were on a par knowledge wise with those from Talk Talk when I had a query.

 

[theclaud]

Good luck with that. The PX phone staff were on a par knowledge wise with those from Talk Talk when I had a query.

Ah, right. I've sent them a query by email. The mount adapters came with the Spyres, so I'm assuming that it's not wildly unconventional to use a 180mm on a road bike? They are steel forks, and quite rufty-tufty in appearance, although I've no idea how one would go about a precise assessment of their tolerances. I have a friend called Dr Evil who might have an opinion on it...

 

[lpretro1]

You will not need bigger rotors on a road bike - 140s or 160s at most. You get less clearance too if you use the centre lock/6 bolt adapters