Some pointers please

[NickTB]

I’ve just bought a new to me CAADX Tiagra . I posted in another thread that the left shifter isn’t working but as I haven’t ridden it yet I thought I’d take it out for a quick spin. Positives are the geometry is so comfortable. Fits me perfectly. I’ll change out the tyres for something a bit skinnier and it’ll be a lovely road bike for me. Negatives... the “brakes” are non existent! So much so that I ended up up face first in ditch!
Onto my point. Does any one know a mechanic in Essex who’d be willing to take a look with a view to upgrading the brakes to possibly hydrolic or at the least something that will possibly save my life in the unusual event I may want to stop... I have a feeling that once this is done, it’ll be a thing of beauty to me. I’m happy to travel to them within reason, as I think the bike will be worth it once done. And I have no idea when it comes to these things.
I’ve tried Yellow Jersey in Billericay but they’re full for the foreseeable future.
Any advice will be gratefully received.
Thanks
Nick

 

[Deleted member 1258]

Tiagra rim brakes ? I have these on my Eastway and they are good brakes. Have you tried to change the brake shoes? I'm using kool stop salmons on mine and they are very good.

 

[NickTB]

Tiagra rim brakes ? I have these on my Eastway and they are good brakes. Have you tried to change the brake shoes? I'm using kool stop salmons on mine and they are very good.

Sorry should have said Promax Render R mechanical disks

 

[Racing roadkill]

Sorry should have said Promax Render R mechanical disks

Aha. You’ll have to constantly manually adjust the position of the pads as they wear down. It’s possible that’s what’s happening. The pads have worn, and the compensating position hasn’t been achieved.

 

[Deleted member 1258]

Sorry should have said Promax Render R mechanical disks

OK, sorry I can't help you with those.

 

[NickTB]

Aha. You’ll have to constantly manually adjust the position of the pads as they wear down. It’s possible that’s what’s happening. The pads have worn, and the compensating position hasn’t been achieved.

Would it be normal for the lever to pull straight back to the bars? Very very spongy

 

[Cycleops]

Promax Disc brakes may not be the best but with new cables and pads correctly adjusted should work fine. Simple diy job.

 

[Racing roadkill]

Would it be normal for the lever to pull straight back to the bars? Very very spongy

Yes, if the pads aren’t wound in. The only other reason for that on a mech disc set up, is a problem with the cables ( frayed or not routed properly ).

 

[Ajax Bay]

https://www.ribblecycles.co.uk/trp-disc-brake-cableset-compression-less/
https://www.chainreactioncycles.com/trp-cableset/rp-prod169681

 

[figbat]

Cable disc brakes really benefit from compressionless cable outers - normal, spiral-bound outers can lead to ‘sponginess’.

 

[vickster]

Sorry should have said Promax Render R mechanical disks

Promax branded brakes have a poor rep, get some TRP Spyres 👍

 

[DRM]

Promax branded brakes have a poor rep, get some TRP Spyres 👍

This, in spades, also fit compressionless cable set(inners & outers) too, so at least you know all is good and new in the braking department, set them up properly and bed them in, and the jobs a good 'un

 

[C R]

Promax branded brakes have a poor rep, get some TRP Spyres 👍

My Triban RC500 has promax mechanical discs and they are fine, I have seen reviews of bikes with promax brakes and they're generally positive. Check that the pads are not worn, that the gap is set properly, and get compresionless cables if you don't already have them.

 

[Drago]

New pads (of a different make if you prefer), bed them in properly. Clean the discs properly first. Ensure the cables are adjusted correctly fit new cables if in any doubt. All easy DIY stuff, well documented on the webernet.

It's very difficult to diagnose from afar, but provided you felt reasonable pressure at the lever your experience describes the effects of badly bedded in, glazed, or contaminated (or all 3) pads perfectly. Even the finest disc systems will be rendered near useless by this.

The Promax system doesnt have a good rep, but its bull - they're perfectly capable of hauling up my 260+lbs of lard rippling muscle in short order when set up correctly.