Cycling UK Forum

I'm right with you on the hexbolts issue. The only thing I'd add there is that if you use a suspension fork (and some others I guess) the bolt heads need to be about half as thick as normal on the front disc, else they may chew into the fork.

Ask me how I know....

The rear always has more clearance.

cheers

I've been thinking a lot about Spyres recently but the cost has put me off and the price of BB7 of very competitive right now.

Is there THAT much difference, for the extra dosh ?

SpannerGeek wrote: ....Is there THAT much difference, for the extra dosh ?....

no. The underlying premise (i.e. that bending the disc 0.2mm sideways when the brake is applied is a terrible thing) is basically cobblers. (There is no inherent MA difference in the brake action, either).

FWIW quite a lot of hydraulic brake systems move the disc more than that, even though they are 'balanced'....

cheers

reohn2 wrote:

Brucey wrote:isn't the torx key the same size as that which is used on most disc bolts? Or have I remembered wrongly?

cheers

It is,but why do the rotor bolts have to be torx?

PS,I have no qualms about using SS hexbolts with threadlock for rotor bolts.There may be technical reasons for not doing but I haven't found them lacking,six 4mm SS bolts are quite a bit of 'meat' to shear.

anti tamper I do believe.

reohn2 wrote:I didn't find that to be the case as I found the 3mm allen key to be a bit fiddly whilst out for a ride and had to carry a special 3mm allen key as I couldn't get the one on the multitool to fit the inside adjuster due to the spokes being in the way.

Yeah, the inboards can be fiddly, mostly with multitools which tend to require more hub clearance to turn. I thought I'd mentioned it but I see I hadn't.

But with the Spyres you can adjust for wear with the barrel adjuster.

Although Spyres tend to be close to spokes this can be an advantage as it means the caliper is further inboard than many cable operated disc brakes. I have a bike with the rear caliper mounted on the seat stay and the BB7 I originally fitted made attaching a pannier rack and mudguards a nightmare ( special disc rack and custom extra long mudguard stays and stays fitted to the rack light bracket), but a spyre caliper fitted within conventionally fitted rack and mudguard stays.

yostumpy wrote:anti tamper I do believe.

But not if you have a Torx key,which are just as freely available as allen keys

Bez wrote: ........But with the Spyres you can adjust for wear with the barrel adjuster.

Which alters the MA/brake arm angle,BB7's can be adjusted tool free on the road just as easily without altering the MA/brake arm angle.

Jeff31 wrote:Although Spyres tend to be close to spokes this can be an advantage as it means the caliper is further inboard than many cable operated disc brakes. I have a bike with the rear caliper mounted on the seat stay and the BB7 I originally fitted made attaching a pannier rack and mudguards a nightmare ( special disc rack and custom extra long mudguard stays and stays fitted to the rack light bracket), but a spyre caliper fitted within conventionally fitted rack and mudguard stays.

This is my answer to seatstay mounted calipers and mudguard stays(which are shorter than standard stays:-

The rack leg is spaced off the rear dropout by a chainring bolt(both halves)and a couple of washers,there's 3mm clearance between rack leg and caliper adjuster.Though I admit the rack isn't suitable for heavy loads.IMHO the best place for rear disc calipers is on the chainstay.

Brucey wrote:I'm right with you on the hexbolts issue. The only thing I'd add there is that if you use a suspension fork (and some others I guess) the bolt heads need to be about half as thick as normal on the front disc, else they may chew into the fork.

Ask me how I know....

The rear always has more clearance.

cheers

Domed head bolts?

reohn2 wrote:Which alters the MA/brake arm angle,BB7's can be adjusted tool free on the road just as easily without altering the MA/brake arm angle.

Well, it's what TRP suggest in the instruction manual, and I've never noticed any detrimental effect from doing it. Personally I find a quick turn of one barrel rather easier than having to check and adjust both wheels on the Avids. But to be honest, if we're talking about use on the road, it's not really an issue either way: pad wear just isn't rapid enough. Certainly I can't imagine how far you'd have to ride before adjustment via the cable barrel was any sort of an issue.

Bez wrote:Well, it's what TRP suggest in the instruction manual, and I've never noticed any detrimental effect from doing it. Personally I find a quick turn of one barrel rather easier than having to check and adjust both wheels on the Avids. But to be honest,

But if that method of adjustment is overused the angle of the brake arm is altered quite severely in the later stages of pad wear,and some people will use only that method of adjustment rather than winding the pads in with a 3mm allen key.
That's what I like about BB7's,adjustment on the road or trail is easy via the big red knobs that even my arthritic fingers don't find a problem adjusting if they're kept lubed as I mentioned up thread.

On Promax Render such as the OP's and Avid BB5's,cable adjustment is the only method of adjusting the outside pad,with the inside static pad adjustment the same as BB7's,so at least there's tool free adjustment.
But a problem can occur if the user doesn't adjust the static inner pad in conjunction with cable adjustment of the outer and the inner pad can wear so much that the rotor can contact the caliper body as it's pushed over by the inner pad,severely compromising braking.
A situation which,in the right circumstances could prove disastrous.
It's another reason why caliper adjustment and not cable adjustment is better practice on disc brakes.
Of course TPR Spyres/Spykes shouldn't suffer from the same problem because both pads move when the cable is adjusted.

if we're talking about use on the road, it's not really an issue either way: pad wear just isn't rapid enough.
Certainly I can't imagine how far you'd have to ride before adjustment via the cable barrel was any sort of an issue.

I agree rapid pad wear in clean dry conditions isn't a problem.
However if organic* pads(standard in the TRP calipers,why is anyone's guess ) are used in mucky road conditions or MTB trails,pad wear is rapid and adjustment constant,it's the reason I use sintered pads.

*I have worn a pair of organic pads out in two rides on really mucky lanes with wash off from arable fields.

I presume that adjusting the Spyre's pads with the allen key, you should use the adjusters on both sides, and probably try to use them reasonably equally? Access to the inside pad's adjuster could be tricky having to go through the spokes. Well, you could just take the wheel out, but it'd be more convenient if you didn't have to. I don't know but presume that the BB7s, having only one moving pad, don't have this.

Bmblbzzz wrote:I presume that adjusting the Spyre's pads with the allen key, you should use the adjusters on both sides, and probably try to use them reasonably equally?..

When I adjust mine, I adjust the outer one until it's as close at it can be without rubbing, then I adjust the inner one so that the disc doesn't visibly bend when I squeeze the lever.

re the adjuster thing; IIRC the barrel adjuster on the Spyre/Spyke caliper has about 5mm of travel. It isn't clear to me that (on Spyres, depending on where the arm is set to start with), you definitely won't 'run out of ramp' in the mechanism if you use the full barrel adjuster travel.

'Running out of ramp' (or 'running out of arm travel') is/are common problems with 'road bike' mechanical disc calipers.

This arises because the ramp mechanism is usually designed originally to use a MTB cable pull, then redesigned for a road bike cable pull. The former type generally uses the full arm movement (i.e. until the caliper arm hits something) and you are still on the ramp. The road bike versions have steeper ramps, whilst the total ramp height is the same. This usually (but not always) means that the road calipers either have

a) an arm that doesn't move as far as you expect (e.g. road BB5s, where the arm just stops at what looks like 'half-way' when compared with the MTB version ) or
b) an arm that moves full stroke, but does nothing useful past half-way. Some models just go 'click' and then do nothing, because the balls have run out of the ends of the ramp.

Needless to say either thing can be flippin' dangerous (no brakes...) but neither thing happens if you use the pad adjusters like you should do.

I don't remember offhand what Spyres do exactly .... anyone?

cheers