How important is thru-axle?

stueys

Veronese68 wrote:

I thought, possibly wrongly, that one supposed advantages of the thru axle on a rigid fork was to do with the disc brake trying to twist the axle out of he drop out with a normal QR. Saying that I've ever experienced this, but I think it is wise to use a good quality QR with disc brakes.

Advantages are supposed to be two fold, (1) stiffness as you've identified in terms of resistance to the increased forces that discs can impose, and (b) more precision in placement of the wheel so less fiddling with the discs.

Having said that I'm reassured by the number of disc users not seeing a need for them.

marcusjb

I'd certainly go with the concept that a good quality QR is important on discs (Shimano closed cam are really all anyone needs) - certainly none of the spindly little external cam things anyway.

Our last two tandems have had discs - no through axles on them and I am sure you can imagine the forces going on in tandem braking!

I am just toying around with the idea of a new (solo) frameset and might go discs, but the whole through axle thing needs to settle down a little. My biggest reservation is all the non-disc wheels I would end up having to move on (powertaps, dynohubs etc.).

I don't get the improvement in locating the wheel with through axles - it's not hard to put a wheel in straight on regular drop-outs. I suspect through axles are being mooted on road bikes primarily as they are a lot more idiot proof and may serve to protect the bike manufacturers from lawsuits a bit better than regular Q/R (even with lawyer lips). I think as long as you are not stupid, then regular Q/Rs are more than adequate for disc braking even with 2 people and big **** off rotors.

veronese68

As above Shimano QRs are fine. I've never had a problem locating a wheel with QRs to line up the disc on my crosser or my MTB. In that respect it's a solution looking for a problem, unless you are really cack handed possibly.

Anonymous

FransJacques wrote:

this will be the new disc brake debate. you don't need discs on cross nor commuting bikes but people LOVE to convince themselves they do

What has necessity got to do with it? Just get things because they are better

Anonymous

Whats the main reason for thru-axles? I thought it was strength.

If so I would have thought they would be quite useful (but ok, not necessary perhaps) on a rigid fork CX bike that does not have suspension to soften the blow.

Quite nice knowing your wheel is not going to come off too.

Whats the downside to them? weight?

kajjal

Stueys wrote:

Veronese68 wrote:

I thought, possibly wrongly, that one supposed advantages of the thru axle on a rigid fork was to do with the disc brake trying to twist the axle out of he drop out with a normal QR. Saying that I've ever experienced this, but I think it is wise to use a good quality QR with disc brakes.

Advantages are supposed to be two fold, (1) stiffness as you've identified in terms of resistance to the increased forces that discs can impose, and (b) more precision in placement of the wheel so less fiddling with the discs.

Having said that I'm reassured by the number of disc users not seeing a need for them.

On my mountain bike as long as the QR is done up tight enough I get no problems at all weighing 15st7 and riding on rough trails. For a full on downhill bike they would make sense.

on-yer-bike

what do you mean by thru-axles?

cntcasey

This bike does not have thru axles http://www.specialized.com/us/en/bikes/ ... -comp-disc

But this bike does. http://www.trekbikes.com/us/en/bikes/ro ... _compact/#

Why would two bikes from two different companies in the same category and in the same price range differ on this important issue?

I don't understand why Trek has them and Specialized does not?

thomasmorris

On a GCN video riding the trek he said one of the main reason was to stop annoying rubbing of the disc when misaligned in QR. He makes the point that you don't notice this on a mtb as much because of the trail buzz, but it's annoying on the road and the thru axle solves this.

However, the extent to which you get this problem I would imagine depends on the amount of pad-disc gap your brakes have. I have Formula on my MTB, which have a very low tolerance, and any, even tiny missalingment in the QR and they start to rub or ping. Shimano have a larger gap, so I think it depends also on the brake your using as to whether it's a problem.

Edit GCN video: https://www.youtube.com/watch?v=xdWsSB9QGkY

veronese68

cntcasey wrote:

Why would two bikes from two different companies in the same category and in the same price range differ on this important issue?

I don't understand why Trek has them and Specialized does not?

Because it's not an important issue. Have you read the rest of this thread?

nferrar

Veronese is correct, one of the main benefits of a thru-axle is it eliminates the possibility of the twisting force of the disc brake being applied ejecting the wheel from open drop-outs. That said if you use decent QR's and remember to do them up properly you probably have as much chance of winning the lottery as this happening. It has happened in MTBing though although the loads are greater there.
For now I've gone with a standard QR axle on my disc road bike but in future, once a thru-axle standard for road is established (if that ever happens...) I'd def go thru-axle - not worth waiting on that though if you're ready to buy now.

Dippydog3

My new winter bike has through axles. Not my choice, that was the only option.

I prefer QR's without a doubt. When taking a wheel off I now need a tool, and when the wheel is off I have to keep track of a tool and two components. A pain if you are changing a flat in the middle of nowhere.

With QR's there is no tool, no loose components, and I can seat a QR wheel into the dropouts, properly aligned, a lot faster than I can align the two components of the through axle so that they do not cross thread.

Progress is a wonderful thing.

marshall_a

my look at it if QR where so bad at alignment then you'd need to index your gears every time you popped the rear wheel out

blinddrew

Actually the wheel alignment thing does make a small difference. I've got QRs on my mountain bike and when popping the wheel back in it can take a second 'seating' to get the alignment right sometimes (it's only a tiny amount but enough for a brake pad to rub). My wife's new bike has a through axle and it's much more precise (and takes no longer to change the wheel).
Not sure what type of through-axle dippydog has that needs a tool though? None of the ones I've seen do.

andrew_s

nferrar wrote:

Veronese is correct, one of the main benefits of a thru-axle is it eliminates the possibility of the twisting force of the disc brake being applied ejecting the wheel from open drop-outs. That said if you use decent QR's and remember to do them up properly you probably have as much chance of winning the lottery as this happening. It has happened in MTBing though although the loads are greater there.

I've seen it happen on a road bike too.
The forces are higher on a road bike due to better traction and bigger wheels - they are proportional to the disc/wheel size ratio, and to the rate of deceleration.

Monty Dog

Been running discs on road bikes for nigh-on 10 years and never had any problems - I have a disc fork without lawyer tabs and I haven't died! I can see the point on suspension bikes, but for rigid the benefits are far more marginal IMO. I have specc'd a 12mm through axle on my latest custom design - a fatbike frame with 5" tyre clearances and with 197mm hubs where the forces trying to twist the wheel are a little greater.