Cycling UK Forum

Only spinning once around with a fair shove will be wasting quite a bit of effort and it's definitely not right.

Can you take a photo that shows the back of the chainset on the drive side? Just to make sure that the bottom bracket spindle is long enough and that the chainset isn't bottoming out either in the bottom bracket drive side cup or against the chainstay of the frame.

Having eliminated those possibilities there could be a couple of other causes. The bearings could be shot inside the bottom bracket, and/or the non drive side cup could be over torqued and pressing too hard against the cartridge bearing on that side causing it to bind up.

In any case you'll need a Shimano compatible internal cartridge bottom bracket removal tool. Ideally a fairly low profile one that will be stubby enough to be able to use the crank bolt to hold the tool in place and stop it camming out in use.

After removing the cranks but bb still in the frame first confirm that the spindle is stiff or can't be turned by hand. If ok it should turn easily and smoothly.

Before using the bb tool it's probably worth leaving a bit of spray lube on the threads to soak in for a bit first.

Second I'd try backing the non drive side cup off a full turn, (thread is normal direction and you may have to loosen the crank bolt a bit if you're using it to hold the tool in place) then make sure the fixed cup on the drive side is tight in the frame - reverse thread so anticlockwise (edited) looking at it from that side of the bike. Then again check if the spindle turns smoothly, stiffly or stuck. If it now turns smoothly it's a sign that the non drive cup was too tight, in which case nip it back up but not so tight that it starts to bind back up again.

If it feels rough or stiff to turn with the drive side cup tightened up but the non drive side backed off then it's likely that your square taper bottom bracket is knackered and you need another one. Remove and try to read the specs - you'll need to order one of the same bb shell width and spindle length assuming the current one is correct- either 68 or 73mm and 113-115, for example would be fairly typical for an MTB triple of that vintage, yours looks like it may be an Alivio or similar Shimano model.

peterh11 wrote: ↑28 Aug 2023, 9:00pm

hoogerbooger wrote: ↑27 Aug 2023, 10:28pm Peter: the symptoms you describe sound like the pad adjusters self adjusting ( and nothing to do with over camming). They come with a blue threadlock on the pad adjusters threads.......which wears off with time/adjustment. Then braking action causes the adjusters to self adjust inwards.

Over camming: when you pull the lever the brake arm the cable attaches to, moves in the direction of the cable. To produce the squeezing action that pushes the pads in, there are 3 ball bearing between two plates with ramped grooves ( same on both sides). As the arm moves (cams) the arm rotates the outside plates and the bearings are forced towards the less recessed part of the groove pushing the two plates apart...and pushing the brake pads inwards.

The overcamming problem is that if the brake arm moves too far the bearings are forced beyond the end of the groove ( usually you hear a metallic ping sound.. ......so you know it's gone too far)

When this has happen on my missus's Spyres it has continued to brake.....but as the bearings are off the ramps the brake pressure will not increase if you squeeze the brake lever harder. Fortunately the bearing have gone back into the grooves as the levers were released. So in our case they didn't seem too worryingly unsafe...but it will limit braking power. However, If you get to the point of overcamming ....usually because you have adjusted by using the cable and barrel adjusters rather than the pad adjusters....you should reset them properly screwing in the pad adjusters...so that the arm doesn't travel as far......but as I think you have found out the pad adjusters don't always stay where you set them.

There are videos on YouTube on servicing TRP spyres.

https://www.youtube.com/watch?v=N1Isb1vpENk

I suggest you look at to get your head round how this is done.......then remove the pad adjuster to apply more blue threadlock next time you need to put new pads in.

Thanks. I think I understand what over-camming is now. I was just curious. I know this is not what is happening with my rear brake.

It was all working much better 2 months ago after I serviced it according to the TRP manual (cable, pads, alignment), but now the cable is sticking and there just isn’t the power there (hard to lock the rear wheel when pushing which is not a good sign). The front brake seems fine.

I’ll be replacing the cable and figuring out what caused it to get sticky, making sure the brake arm is at the right angle, and also plan to replace the pads soon, at which point I will definitely put threadlock on. My benchmark is the low profile cantilevers on my other tourer which I just adjusted today to get rid of a tendency to squeal, and are definitely performing better than the Spyres today - smooth and powerful stopping. Some work to do, to get the Spyres back to that and better.

Peter H

Well, today I stripped out the inner cable. I verified that indeed the inner cable was not moving smoothly inside the outer, and when I pulled it out, the far (rear) end of it was quite rusty. No wonder it was sticking. I’ve done a temporary job with a new inner but I think that this means I need a new outer. I’m planning to re-tape the bars and replace the rubber hood on the levers soon anyway, I’ll combine the jobs. For now performance is restored - on my test in the street I was able to stop the bike very quickly.
Clearly I need to change my lubrication method on these cables.

I do remember someone (CJ?) posting in this forum about problems with water ingress on the rear cable of Spyres or another similar brake, and proposing a solution. But I can’t find it. Anyone remember this and able to find the original post?

PeterH

hoogerbooger wrote: ↑27 Aug 2023, 10:28pm Peter: the symptoms you describe sound like the pad adjusters self adjusting ( and nothing to do with over camming). They come with a blue threadlock on the pad adjusters threads.......which wears off with time/adjustment. Then braking action causes the adjusters to self adjust inwards.

Over camming: when you pull the lever the brake arm the cable attaches to, moves in the direction of the cable. To produce the squeezing action that pushes the pads in, there are 3 ball bearing between two plates with ramped grooves ( same on both sides). As the arm moves (cams) the arm rotates the outside plates and the bearings are forced towards the less recessed part of the groove pushing the two plates apart...and pushing the brake pads inwards.

The overcamming problem is that if the brake arm moves too far the bearings are forced beyond the end of the groove ( usually you hear a metallic ping sound.. ......so you know it's gone too far)

When this has happen on my missus's Spyres it has continued to brake.....but as the bearings are off the ramps the brake pressure will not increase if you squeeze the brake lever harder. Fortunately the bearing have gone back into the grooves as the levers were released. So in our case they didn't seem too worryingly unsafe...but it will limit braking power. However, If you get to the point of overcamming ....usually because you have adjusted by using the cable and barrel adjusters rather than the pad adjusters....you should reset them properly screwing in the pad adjusters...so that the arm doesn't travel as far......but as I think you have found out the pad adjusters don't always stay where you set them.

There are videos on YouTube on servicing TRP spyres.

https://www.youtube.com/watch?v=N1Isb1vpENk

I suggest you look at to get your head round how this is done.......then remove the pad adjuster to apply more blue threadlock next time you need to put new pads in.

Thanks. I think I understand what over-camming is now. I was just curious. I know this is not what is happening with my rear brake.

It was all working much better 2 months ago after I serviced it according to the TRP manual (cable, pads, alignment), but now the cable is sticking and there just isn’t the power there (hard to lock the rear wheel when pushing which is not a good sign). The front brake seems fine.

I’ll be replacing the cable and figuring out what caused it to get sticky, making sure the brake arm is at the right angle, and also plan to replace the pads soon, at which point I will definitely put threadlock on. My benchmark is the low profile cantilevers on my other tourer which I just adjusted today to get rid of a tendency to squeal, and are definitely performing better than the Spyres today - smooth and powerful stopping. Some work to do, to get the Spyres back to that and better.

Peter H

Peter: the symptoms you describe sound like the pad adjusters self adjusting ( and nothing to do with over camming). They come with a blue threadlock on the pad adjusters threads.......which wears off with time/adjustment. Then braking action causes the adjusters to self adjust inwards.

Over camming: when you pull the lever the brake arm the cable attaches to, moves in the direction of the cable. To produce the squeezing action that pushes the pads in, there are 3 ball bearing between two plates with ramped grooves ( same on both sides). As the arm moves (cams) the arm rotates the outside plates and the bearings are forced towards the less recessed part of the groove pushing the two plates apart...and pushing the brake pads inwards.

The overcamming problem is that if the brake arm moves too far the bearings are forced beyond the end of the groove ( usually you hear a metallic ping sound.. ......so you know it's gone too far)

When this has happen on my missus's Spyres it has continued to brake.....but as the bearings are off the ramps the brake pressure will not increase if you squeeze the brake lever harder. Fortunately the bearing have gone back into the grooves as the levers were released. So in our case they didn't seem too worryingly unsafe...but it will limit braking power. However, If you get to the point of overcamming ....usually because you have adjusted by using the cable and barrel adjusters rather than the pad adjusters....you should reset them properly screwing in the pad adjusters...so that the arm doesn't travel as far......but as I think you have found out the pad adjusters don't always stay where you set them.

There are videos on YouTube on servicing TRP spyres.

https://www.youtube.com/watch?v=N1Isb1vpENk

I suggest you look at to get your head round how this is done.......then remove the pad adjuster to apply more blue threadlock next time you need to put new pads in.

Cyckelgalen wrote: ↑19 Aug 2023, 3:51pm Sorry to say I didn't send the video to Tektro because a very timely thread in this forum discussed the Spyres' many issues, and Brucey said clearly it was over camming. He said that adjusting for wear should always be done with the piston/pistons adjuster, not tightening the cable. After becoming aware of what the cause was, and acting accordingly, it never happened again, but I ended up discarding of them. Apart from the faff of adjusting all the time, because they easily loose adjustment, there are many other issues that Brucey pointed out several times. They don't perform better than other cable discs despite all the hype about the dual piston movement, and they more difficult to keep adjusted for long and free of internal corrosion and clogging.
I went back to my good old single-piston Hayes Expert and have never looked back.

I’d be really grateful for an explanation of over-camming please. I had a quick search on the internet but everything I found related to cars. Also if you are able to link to a copy of your video, that would be helpful. I’m reading this and other threads about TRP Spyres with interest as I have a pair which are now starting to be hard to keep in adjustment, after 4.5 years and about 16K km on my touring/Sunday-ride bike. They work well when adjusted right, but don’t seem to stay that way long. I will be working through some obvious adjustments and replacements, including the hints here in this thread.

Peter H

Thanks for the extra info. These are sold in the US, you'd have thought with US litigation habits the instructions would be cleared/better to avoid over camming.

Been there with over camming with spyres as a result of using the barrel and cable to adjust rather than the pad adjusters. You get a nice 'ping' as ball bearings escape off their ramps. Even had one pad adjuster go all squiffy

The instructions say the barrel adjusters can be used, but unhelpfully give no clue about over camming.

I've reapplied loctite blue several times to the pad adjusters ( after pad replacement and calliper service) and so farchaven't had them self adjust

Sorry to say I didn't send the video to Tektro because a very timely thread in this forum discussed the Spyres' many issues, and Brucey said clearly it was over camming. He said that adjusting for wear should always be done with the piston/pistons adjuster, not tightening the cable. After becoming aware of what the cause was, and acting accordingly, it never happened again, but I ended up discarding of them. Apart from the faff of adjusting all the time, because they easily loose adjustment, there are many other issues that Brucey pointed out several times. They don't perform better than other cable discs despite all the hype about the dual piston movement, and they more difficult to keep adjusted for long and free of internal corrosion and clogging.
I went back to my good old single-piston Hayes Expert and have never looked back.

"I disagree with Eyebrox.
You should not use the barrel adjuster or tighten the cable as the pads wear.
That will cause "over camming", and the brake will nor work effectively."

I hear what you say, and agree with that for my BB7 brakes (instructions are to dial pads in to adjust for wear and specifically not to use a barrel adjuster after the brake has been set up). Also many other brakes I have seen at work where they over cam due to previous mal adjustment and/or excessive pad wear/the caliper being mounted too far to the left.

However, looking at the Spyre instructions, https://www.trpbrakes.com/userfiles/fil ... 281%29.pdf
it says
"E) Fine-tuning
There are two ways to fine-tune the caliper to improve lever feel: the barrel adjuster and the pad adjuster.
· Thread the barrel adjuster out to take up cable slack or compensate for pad wear.
· Using a 3mm allen wrench, turn the pad adjustement screw clockwise (located in the outboard piston) to
compensate for pad wear or imrpove lever feel. You may need to re-align the caliper. [Fig. E-1]"

So it seems barrel adjusting for wear is permitted for Spyres. I don't know if you get over camming with (say) worn pads with these brakes, or they build in a lot more cam to prevent over camming..

Disc brakes seem a lot more variable between models in terms of correct adjustment method than rim brakes, rim brakes tend to be (mostly) much the same across the board for a given type.

I disagree with Eyebrox.
You should not use the barrel adjuster or tighten the cable as the pads wear.
That will cause "over camming", and the brake will nor work effectively.
Tightening the cable will vary the travel of the arm in relation to the body of the brake, and you don't want that.
You should use the 3 mm Allen key to adjust the pistons and allow for pad wear. And pray to all gods that they will hold that adjustment for a while.
search.php?keywords=over+camming

The Spyres may be easy to adjust, but they are awful at holding the adjustment. There is nothing to lock the pistons in place other than a smearing of blue threadlock, that stops locking the threaded pistons after you adjust them a number of times. The Hayes CX I use on my tourer have a much larger diameter thread to move the piston and a grub screw to lock adjustment.
Very pleased with them, actually, despite having only one moving piston.
The Spyres have other shortcomings that Brucey pointed out in several occasions. The thrust bearings are minuscule and likely to jam when they dry out or get gritty. The three larger loose bearings that move along the ramps are also prone to corrosion. I have taken a few apart to clean and lube and it is a real PITA. I have also seen a couple of cases of malfunction, the arm moving back with a loud noise and loosing grip. It was discussed here and someone attributed it to "over camming".
Brucey was never fond of the Spyres and when I asked him once why they were becoming ubiquitous on tourers and gravel bikes, he said that it was probably because their cable pull married better with modern STI shifters rather than any inherent virtues of the design.

rareposter wrote: ↑25 Jan 2023, 4:57pm

doffcocker wrote: ↑25 Jan 2023, 4:50pm ... but obviously to see the potential for the wheel to suddenly click out of the grasp of the pad is the last thing I need when I'm already having anxiety going downhill.

Cable disc brakes work by having one moving pad and one fixed pad. The moving pad contacts the rotor and pushes the whole lot against the non-moving pad.

What you've got there is the moving pad worn to bits and the non-moving worn partially (which is what usually happens) but I suspect you've tried to adjust them using the cable rather than the pad adjuster screw/knob.

Hence on braking, the system is over-camming and then releasing itself. It needs new pads bit it also needs a careful set up from scratch and then the new pads will need a few hard pulls to bed them in.

Hydros are different, both pistons move together and will self-centre.

Not all cable disc brakes, e.g. TRP Spyre.
This is from https://trpcycling.com/product/spyre-2/
"This is a dual piston actuated mechanical disc brake caliper which provides precise clamping force. This translates into even pad and rotor wear"

531colin wrote: ↑25 Jan 2023, 4:12pm friction material is bonded onto the backing (not riveted) and you are recommended to fit new pads while enough friction material remains to stop the heat from braking melting the bond.

i imagine the brake is coming to the end of its travel (over-camming, as before) and releasing the disc

The 'rivets' I mention are actually just the bonding points for the backing and are a 'telltale' and shows the wear well before the pad gets to the metal (in theory) but as you say his cable tightening instead of just using the proper adjuster has killed that pad, and very early at that judging by the good one. The telltale idea is similar to the telltale in a rim pad (or the rim itself).

rareposter wrote: ↑25 Jan 2023, 4:57pm

doffcocker wrote: ↑25 Jan 2023, 4:50pm ... but obviously to see the potential for the wheel to suddenly click out of the grasp of the pad is the last thing I need when I'm already having anxiety going downhill.

Cable disc brakes work by having one moving pad and one fixed pad. The moving pad contacts the rotor and pushes the whole lot against the non-moving pad.

What you've got there is the moving pad worn to bits and the non-moving worn partially (which is what usually happens) but I suspect you've tried to adjust them using the cable rather than the pad adjuster screw/knob.

Hence on braking, the system is over-camming and then releasing itself. It needs new pads bit it also needs a careful set up from scratch and then the new pads will need a few hard pulls to bed them in.

Hydros are different, both pistons move together and will self-centre.

Thank you.

I had booked this afternoon off to go on a long ride and as that hasn't worked out I'm instead trying to educate myself on how these things actually work as I've only previously dealt with rim brakes.

Unfortunately I can't find anything really on this type of mech.
It's the first time I have so much as removed the pads and I'm not confident about reassembling as with every video on YouTube, the mech looks very different. For example I have a silver clip that separates the two pads and I can't find anything that clearly shows how this needs to be positioned.

doffcocker wrote: ↑25 Jan 2023, 4:50pm ... but obviously to see the potential for the wheel to suddenly click out of the grasp of the pad is the last thing I need when I'm already having anxiety going downhill.

Cable disc brakes work by having one moving pad and one fixed pad. The moving pad contacts the rotor and pushes the whole lot against the non-moving pad.

What you've got there is the moving pad worn to bits and the non-moving worn partially (which is what usually happens) but I suspect you've tried to adjust them using the cable rather than the pad adjuster screw/knob.

Hence on braking, the system is over-camming and then releasing itself. It needs new pads bit it also needs a careful set up from scratch and then the new pads will need a few hard pulls to bed them in.

Hydros are different, both pistons move together and will self-centre.