Axle Size

[Drozdster]

The top pic shows a front axle from a Trek Dual Sport +2, the bottom pic is from a Specialized Vado. The Trek is about .200" in diameter and is solid, while the Specialized is .440" diameter but is hollow. Not sure if the strength is the same but the Specialized sure feels sturdier. Does anyone know which style is most prevalent on the majority of ebikes? Is one style any better than the other?

 

[Stefan Mikes]

The Trek axle is for a fork with the axle tightened with a nut (actual size 135 x 5 mm) while the Specialized is probably a 15 x 100 mm thru-axle. These are totally different systems, and any discussion "sturdier or not" makes no sense, as it is the fork build that determines using either of them.

By the way, the thru-axle is only a binder for the fork to squeeze it at the hub bearings, and it does not transfer any other force whatsoever. Specifically, the thru-axle is not in contact with the wheel hub at all!

 

[PDoz]

The Trek axle is for a fork with the axle tightened with a nut (actual size 135 x 5 mm) while the Specialized is probably a 15 x 100 mm thru-axle. These are totally different systems, and any discussion "sturdier or not" makes no sense, as it is the fork build that determines using either of them.

By the way, the thru-axle is only a binder for the fork to squeeze it at the hub bearings, and it does not transfer any other force whatsoever. Specifically, the thru-axle is not in contact with the wheel hub at all!

The thru axle braces the forks and modern axles make a massive difference! Possibly not noticeable for a road bike, but when you're bouncing of rocks , turning and braking at the ....we now have 20x110 axles for seriously silly people

Oh, and if you still need convincing about 15 mm axles - check out the thread on those onld axles coming undone under braking

 

[Stefan Mikes]

check out the thread on those onld axles coming undone under braking

I do not think the Dual Sport+2 has the QR dropouts. Trek is using a kinda funny proprietary solid thru-axles of small diameter, that's it.

Not your usual 9 mm QR dropout.

 

[Drozdster]

Yup, this is what it looks like.

 

[rochrunner]

The Trek axle is for a fork with the axle tightened with a nut (actual size 135 x 5 mm) while the Specialized is probably a 15 x 100 mm thru-axle.

The Vado SL uses a 12mm front axle, which is closer to the .440" that the OP measured. This, by the way, is causing me issues in spec'ing out a set of custom wheels. While there are a number of front hubs available in the 15x110mm "boost" size for MTBs, there are not many in 12x110mm, which is sometimes called "road boost" (the 12x148 boost rear hub is more common and not an issue).

 

[Nubnub]

When I wanted to go tubeless on my 4.0, the only off the shelf tubeless ready boost wheels were the ones from the 5.0. When I received those, the front hub was actually a 15 mm diam but provided with a 12 mm axle and a sleeve with a nominal 15 mm od. Makes sense from a parts/supply standpoint to make everything 15 mm I notice Jenson USA also has a boost front wheel they specifies 12/15 mm x 110. So it probably includes a sleeve as well.

 

[Stefan Mikes]

(the 12x148 boost rear hub is more common and not an issue).

Still, the 12x142 mm is far more popular!

 

[rochrunner]

When I wanted to go tubeless on my 4.0, the only off the shelf tubeless ready boost wheels were the ones from the 5.0. When I received those, the front hub was actually a 15 mm diam but provided with a 12 mm axle and a sleeve with a nominal 15 mm od. Makes sense from a parts/supply standpoint to make everything 15 mm I notice Jenson USA also has a boost front wheel they specifies 12/15 mm x 110. So it probably includes a sleeve as well.

That's interesting. I suspect that many (most?) hub mfrs do it that way. I also noticed a lack of suitable wheelsets but anyway am having them custom built, which is a lot of fun. In addition to spec'ing the brands and models of the components, there's also options for spoke count and lacing pattern (two-cross, three-cross, etc.). I'm using Onyx Vesper hubs and they do come in the required boost sizes.

 

[Stefan Mikes]

custom built, which is a lot of fun.

Welcome to the club I had to design and make a replacement rear wheel for my Vado. The wheel is all DT Swiss.

 

[rochrunner]

Welcome to the club I had to design and make a replacement rear wheel for my Vado. The wheel is all DT Swiss.

This is what I had built for my Cannondale Synapse road bike in 2014. That bike had white and blue accents and these wheels really set it off with the blue anodized hubs and spoke nipples. I was tempted to do something like that for my SL but since the bike is all silver and black, it might be a bit much to add color to the wheels. It was easier back in those days too because there was basically one standard for hubs, all rim brakes, etc. About the only technical choice was selecting for a Shimano or Campagnolo cassette!