Replacement Thru Axle

What is the lightest and highest quality thru axle for a road bike?

I’ve looked at DT Swiss, Robert Axle Project and Enve. The DT Swiss is the lightest at 31 grams for a 12mm axle while the Robert Axle Project is 38 grams. I couldn’t find a weight for Enve’s thru axle.

Is there any difference between brands or are all thru axles from a reputable brand nearly the same minus the minimal weight difference? Thanks.

There are thread pitch differences, so be SURE and check that.

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@ggeiger Thanks for the heads up - that makes sense. I suppose that Robert Axle Project is probably the better choice between those three since they have an axle finder program that verifies that their axle will fit your specific bike.

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For 7 grams, use the Robert Axle Project and leave your handkerchief at home…

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Our shop uses the Robert axle ones quite a bit. They’re a good choice.

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They’re all different sizes. It’s not just the diameter, but also the thread and length. I have two Trek road bikes and they have different rear axles for example. There’s not even a coding system. It’s a big mess.

The best deal out there are J&L on ebay. They’re either the lightest or very near it as well as the cheapest. If you need something they don’t have listed, they’ll make it. I’ve got 4 of these

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Thanks for the heads up @jfranci3. I appreciate it.

Does anyone else remember the weight weeny era when folks looked for the lightest quick releases?

You know, the era when people’s QRs would snap during a descent or during a wheel change? OK, obviously not the same mechanism or stresses but chasing “lightest” has been proven to be a dangerous thing.

My fear would be how the threads on the TA are cut/rolled. I’ve already seen several TAs lose their threading because of bad MFG processes (or QA/QC).

I don’t mean to tell you not to do this . . . just proceed with caution, yo.

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@elysianbike - Yeah man I’m with you 100%. I would much rather carry around a few extra grams to ensure that I have a well built, sturdy and dependable thru axle.

I mentioned the weight as a factor but I am looking for a replacement thru axle that is of quality construction, being light would be a side benefit but definitely not the priority of the two factors. I assume that given the market, that the reputable brands make TAs that are both reliable and light.

So far it looks like the Robert Axle Project is probably the route I’m going to take.

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This is not that. A lot of the effort here is just machining out the core and center section, which is not economical in most cases at a $/gr level (eg the difference between a DT Swiss 350, 240, and 180 hub - same mech, but more machining of the hub shell).
The diameter of the TA is mostly there for fork stiffness. On a QR, it only takes a 5mm rod to safely your fork together and a 9mm shell around that rod to support it vertically. On a good lightweight TA, they ditch the handle, machine down the center section ( “butting” if this were a frame tube or spoke), which doesn’t do much but spin the threaded side of the bolt and do the work of a 5mm pin. It might also be hollowed out more, meaning you need to support the piece better and run the machine slower, which is just harder to machine, so you can’t run the factory as fast.
I’ve got a 60gr 12mm DT Swiss TA and a 25gr ebay one from J&L. 20gr of that was the handle, 5gr is the thinner wall, and 10gr of that was the extra machining of the TA center. In your hand, it’s clear the lightweight TA is still not very fragile.

I understand your point but time and time again, marketing managers + spec chasers have dictated what engineers and product managers should offer to “be competitive.”

For years the bike industry has chased light weight. I can think of many examples of how that has resulted in recalls or catastrophic failures on products that were “not very fragile” or engineered in the right way to product a safe product. (Stella Azzura stems, Prima 199 bars, many of the 1990s cranksets that were engineered by folks that came from NASA or other parts of the aerospace industry, Campy cranksets, Time pedals, Mavic wheelsets, a few FSA products, a generation of Easton EA90 stem faceplates, etc.)

I don’t mean to imply that chasing light weight will automatically lead to catastrophic failure. I just feel like chasing lightweight adds to the risk factor. On top of that, purchasing light weight from ebay also increases one’s chance of buying light weight counterfeit.

The thing that scares me about light weight and not to expensive TAs is something that I’ve observed first hand: poor thread cutting or rolling and that leading to a TA that loosens enough to be “floppy.”

My brain runs the scenario like this:
loose TA (LTA)
loose wheel (LW)

LTA = LW
LW + bump = nick on TA. (NTA)
NTA = compromised TA (CTA)
CTA + bump = broken TA (BTA)
BTA = injury
injury = JRA.

:wink:

I’ve got some of these on the way for my new TCR SL :slight_smile:

Maybe you’re not considering about the whole system here. The TA exists in a Fork/endcap/Hub sandwhich, with the wheel bearings riding on the TA, the end caps help with lateral loading. In a QR, you’ve got the QR holding the whole thing together laterally, but the endcaps and an interior axle supporting it vertically. Inside that QR hub, is effectively a Thru Axle pipe, most of those are about 1-2mm in wall thickness.

Currently, light TAs aren’t all that light! I bought one just to clean up the front of my bike. A Shimano DA 9000 front axle is 34gr with (1) end caps ( 16gr end caps on the other side) - so 18gr axle. DT Swiss lists their (ebike) 12mm TA unit as 29gr. My unit is ~20gr.
They’re all made out of basically the same material. The weight savings here is from saving 9gr of material out of the center of the bolt, which is only there to reduce bending loads, which there are very little there for a whole host of reasons.

You’re basically comparing:
QR: 9mm front end cap + for a 5mm skewer. That end cap is threaded onto a (on a Shimano QR front hub) 9mm with ~1-2mm wall thickness +
TA: 12mm hollow shaft with ~3mm wall thickness (recalling my 20gr lightweight TA) ~5mm bore (based on the 6mm allen key needed) in the loaded bearing area and 1.5mm thick in the reduced center . The fork is the exact same width.

The TA drop out also have cups built in, to vertically support the end caps, should things get real. If things go wrong, that 5mm QR is going to get leveraged apart much faster than my 12mm TA because of the maneuvering room in the dropouts there. You can test this yourself at home by putting putting a QR almost all the way in and buy putting a TA almost all the way in and putting a little vertical load on the bike. You’re going to have an extra second to deal with a sheared TA.

As for things, unscrewing… as mentioned the TA dropouts are cupped and will support the hub end caps for a sec. I think both 12mm TA and QR end caps are ~20 in outer diameter. These work to manage bending forces on the axle and to slow down the face plant when the axle system gives way. If it loosens, that axle will get pinched if it moves off axis pretty quickly up due to end cap tolerances and the axle isn’t incentivized to move laterally because of the vertical load being applied. It will be a very very slow accident.

Weight reference
https://www.sjscycles.co.uk/hub-spares/shimano-duraace-hb9000-front-hub-axle-unit-y28e98040/?geoc=US .
https://r2-bike.com/DT-SWISS-Thru-Axle-FW-RWS-Plug-In-Road-with-Lever-12x100-mm-E-Thru
https://www.ebay.com/i/303086817157?chn=ps&var=602018382007&norover=1&mkevt=1&mkrid=711-117182-37290-0&mkcid=2&itemid=602018382007_303086817157&targetid=924107596967&device=c&mktype=pla&googleloc=9033151&campaignid=9241643027&mkgroupid=96862021434&rlsatarget=pla-924107596967&abcId=1141156&merchantid=101810961&gclid=EAIaIQobChMIp_HYqdbb5wIVBdbACh2mBgt_EAQYASABEgI9KfD_BwE

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I dig the Syntace axles the most, though a little more complex than the others I own.

i like your response. :smiley: