Thru axle vs QR (titanium disc frame)

[Simontm]

I won't be changing or bleeding anything myself. The difference in maintenance is largely irrelevant. Again I've had one shop sing the praises of TRPs and another hydraulic

Just the hydraulic hoods are so bloody ugly and uncomfortable to hold, at least the Ultegra ones

What did they say about Hy-Rds? Mech activated hydraulics, should sort out the hoods?

 

[vickster]

I forget, someone who spends more than £2k on a bike does not do any servicing. Hoods or not, whatever floats your boat regarding mech or hydro, I'll sleep better knowing you keep your LBS in business.

Excuse me? I'm largely mechanically inept so best I leave anything safety critical well alone! I'll spend my hard earned however I wish

 

[vickster]

What did they say about Hy-Rds? Mech activated hydraulics, should sort out the hoods?

Never heard of them

 

[vickster]

Anyhow, thanks all. Bedtime for me, work tomorrow to pay for all the bike servicing

 

[StuAff]

Yes, would need to be extremely convinced, significant £££. Enigma have decided not to go that route on the Etape, sounded like a considered decision

My Litespeed has through-axles, The Trek QRs. The main thing I notice is the Trek's discs rub from time to time, the Litespeed's never do. Whether that's down to the axles, the hydraulic brakes vs cable, or both, pass. Opinions among manufacturers clearly varies (a lot)- some have gone full on through-axle, some sticking with QRs, some mixing on the same bike. If you like the Enigma, stick with it. QRs on disc wheels aren't going to disappear any time soon.

 

[ColinJ]

[TRP Hy-Rd] Never heard of them

I put a TRP Hy-Rd on the front of my CAADX to replace the crappy mechanical disk brake that was there before. It is cable-operated, but the 'business end' is hydraulic. If you set the brake up properly then it self-compensates for pad wear.

It works very well with my bike's Tiagra brake/shifter lever but I find the amount of lever pull needed a bit disconcerting. The first 25% of lever movement doesn't do very much. After that there is a progressive increase in braking action, but I don't get full braking until about 75-80% pull. It often feels a bit worrying because the levers are close to the bars at that point. Having said that, I can lock the front wheel with a couple of fingers on the lever so stopping power is not an issue.

 

[vickster]

@ColinJ that does sound a little concerning, given I don't ride on the drops and do find it hard to get a lot of braking power from the hoods (which is why hood shape is crucial). My initial inclination was mechanical discs with crosslevers (as my Boardman) but I will try out a SRAM hydraulic. Due to hood size, shape and thus aesthetic, I don't think I could live with Ultegra (which given the cost esp makes it a no no)

I was thinking Spyre mechanical + SRAM force which would also reduce the cost and leave more for the frame finish

 

[Yellow Saddle]

If you set the brake up properly then it self-compensates for pad wear.

How does that work?

but I find the amount of lever pull needed a bit disconcerting. The first 25% of lever movement doesn't do very much. After that there is a progressive increase in braking action, but I don't get full braking until about 75-80% pull. It often feels a bit worrying because the levers are close to the bars at that point. Having said that, I can lock the front wheel with a couple of fingers on the lever so stopping power is not an issue.

To me, non-linear response is the sign of a poor brake.

 

[jiberjaber]

How does that work?



To me, non-linear response is the sign of a poor brake.

There's a particular position on the actuator of the brake caliper that opens the reservoir to allows it to move both pistons inwards to compensate for wear. Two problems with it are:
- if the brake cable is too tight the actuator may never return far enough to allow the system to do its job so the pads wear and the pull on the brake becomes less effective, there is a lock pin for cable set up built in to the caliper;
- the other issue is that if you stand the bike upside down, the fluid moves around and the brakes are spongy for the first 10 or so activations till the system has settled down again.


View: https://www.youtube.com/watch?v=_8T6cON6y_Y


I have tried Hy/Rd, Hylex and the Shimano R785, the 2 later being fully hydraulic and I find they are much better than the hy/rd, I found the hood on the R785 to be the same size as the normal Ultegra DI2 (they were both DI2), but hood size as always feels different for different people

I went for t/a on my new bike, I initially wasn't because I wanted to be able to transfer my dynamo hub between bikes as I do now between audax bike & fixie but most forks these days are arriving as t/a so I made the jump. For me the other upsides are less flex (so as Stu mentioned, no disc rub when honking out of the seat) and the wheel will always be straight when put back - the last bit is really handy if you are 'audax tired' and trying to refit a wheel in a lane somewhere in the dark!

There should be no reason to have to realign the caliper once it's been fitted unless you've changed/bent the disc or managed to not fit the wheel back on the bike in its original position. With QR this isn't that hard a task, simply fit the wheel, stand the bike up straight, and undo/redo the QR again to allow the axle to slip in to correct alignment.

There was some concern a while ago about QR coming loose due to the braking action of discs, I have had one time when my QR was loose on a disc based bike, this was after as a group we had stopped in a town square, when I went back to my bike the front QR was half open... who's to say how it actually happened, perhaps it was disc related perhaps it was something else (disturbed bike thief?). Obv, t/a will eliminate the chance of the axle loosening from the disc action if that is a thing...
I guess the other outside reason for t/a is it will remove the chance of using the disc to pull against when closing the q/r LOL

I think you'll be happy which ever way you go!

 

[Yellow Saddle]

There's a particular position on the actuator of the brake caliper that opens the reservoir to allows it to move both pistons inwards to compensate for wear. Two problems with it are:
- if the brake cable is too tight the actuator may never return far enough to allow the system to do its job so the pads wear and the pull on the brake becomes less effective, there is a lock pin for cable set up built in to the caliper;
- the other issue is that if you stand the bike upside down, the fluid moves around and the brakes are spongy for the first 10 or so activations till the system has settled down again.

Thanks for the reply.
OK, so it works exactly the same as other hydraulic brakes, it is just that the master cylinder is remotely activated by cable and if the cable doesn't move enough the piston cannot get to the open side of the reservoir past the feeder port. In a standard hydraulic brake the lever always returns fully.
I can't praise TA enough. It brought Quick Release back to quick release wheels. QR has become so degraded by safety features (lawyers lips and forward-facing opening) that it no longer is quick. It also isn't accurate enough for disc brakes, requiring fiddling after each wheel installation.

There was some concern a while ago about QR coming loose due to the braking action of discs, I have had one time when my QR was loose on a disc based bike, this was after as a group we had stopped in a town square, when I went back to my bike the front QR was half open... who's to say how it actually happened, perhaps it was disc related perhaps it was something else (disturbed bike thief?). Obv, t/a will eliminate the chance of the axle loosening from the disc action if that is a thing...
I guess the other outside reason for t/a is it will remove the chance of using the disc to pull against when closing the q/r.

The risk wasn't so much the QR opening itself as that of the wheel moving downwards in the opening against clamping friction. This problem only surfaced with too-loose QRs and when the wheel remained in situ for too long without having been re-installed and re-positioned often enough. The problem was exacerbated by cheap and rubbish QR mechanisms and a perfectly downward-facing opening in the drop-out. Lawyers lips sorted out the weak QR lever problem and forward-facing openings (semi-forward facing actually) sorted out the problem of a downwards migrating wheel.
Neither solution contributed to quick and fuss-free wheel fitment.

 

[SpokeyDokey]

TA's - dead simple to use, 100% accurate alignment every time the wheel is changed.

QR's will be consigned to the history bin in the not too distant future - same as rim braked bikes.

 

[jefmcg]

QR's will be consigned to the history bin in the not too distant future - same as rim braked bikes.

That's what concerns me. You buy a titanium frame with the intention of keeping it for decades. You really don't want it to come with moribund elements.

 

[Yellow Saddle]

That's what concerns me. You buy a titanium frame with the intention of keeping it for decades. You really don't want it to come with moribund elements.

Come now, you are trying to inject reason into this. Her mind is made up, the "Ti experts" have spoken.

"Enigma have no plans to change the frame to thru axles as they don't believe the ride of this specific frame will be improved, and the extra 'stiffness' might even be detrimental to comfort (they are Ti experts, know their frames and I have no reason to question this). "

 

[vickster]

@jefmcg was there with me at Enigma and heard the conversation

All I can do is ask Enigma how much to have a QR frame.

Did TA exist from the off when Disc brakes were first put on bikes?

 

[vickster]

That's what concerns me. You buy a titanium frame with the intention of keeping it for decades. You really don't want it to come with moribund elements.

Do you really think I'll keep this frame for decades? I'll probably need an e bike in 10 years to go with a new knee!

Maybe I just won't bother with a new bike