Turning a 130mm hub into a 135 (O.L.D.)
 

I asked on here a few days ago about putting a 130mm hub into a frame designed for a 135mm unit, and the general consensus was that it was OK. However, it's sort of been bugging me, and i realized that a replacement 146mm axle complete with spacers, cones, and locknuts, would cost me about $10...

it seems like it would be worth the $10 and a couple of minutes fiddling just to have total peace of mind on the issue ;) Also, i contacted the maker of the frame, and they said it was 'probably okay, but not ideal'.. if i can have ideal for $10, i'll do it :p


So anyhow, my question is, am i correct to assume the following?

I should keep all the original hub parts (ie. cones, locknuts, etc), and simply replace the shorter axle with the new longer one, and then add a spacer or spacers adding up to about 5mm on the non-drive-side only.

I've already ordered the spokes and an asymmetrical rim, but i'm assuming this won't have much affect on that stuff...


Thanks,

Robin

BTW - the axle replacement kit i was looking at was like this one.. There appears to be a spacer that looks 5mm-ish included.

http://bobobox.net/~bobo/bikes/146mm-rear-axle.gif

If it were me, I would jump on it like "a duck on a june bug." Seriously, I think you will be fine, so long as you use a spacer with the proper length and ID.

It's actually even cheaper and easier than that. All you need is 5 mm of spacers to put on the left end of the axle.

141 mm axles work just fine with 135 mm spacing, absolutely no reason to replace the axle.

You will need to move the right cone and locknut over a bit so the axle sticks out roughtly evenly on both sides.

Sheldon "Cheap And Good" Brown

Thanks - that sounds even better. I'd heard rather conflicting prognoses from people regarding that scenario and the likelihood that it would lead to my early demise. A guy in a bike shop a couple days ago said that there wouldn't be enough protruding axle at all, and someone on the Rivendell Bleriot list said that Peter White had built him a wheel with a 130mm hub, but had only added 2.5mm of spacers because he was also concerned about the lack of protruding axle.


Your suggestion does make sense to me though, since it's not the protruding axle ends that the bike rests on (but rather all the stuff clamped by the QR).

It's also the most economical in terms of money and parts, so i'll go with it :)

I actually rode for quite a while on a setup where the axle did not protrude at all, it was flush with the locknuts. I did this to give a bit more axle adjustability on a fixed gear with vertical dropouts.

Never gave me a lick of trouble, but I only weigh 250 pounds...ymmv.

Sheldon "It's The Skewer" Brown

It's really not a problem because the protruding end of the axle actually doesn't take much of a load at all. Once you've got the skewer clamped down, the dropouts are squeezed onto the ends of the locknuts. The intense friction is what carries the load from the locknut to the dropout.

The load-path would look like this:

TYRE -> air in tube -> rim -> spokes -> hub-flanges -> bearings -> cone/axle/locknut -> dropout

How about going the other way? I'm toying with building a road bike wheel using a 135 OLD hub. Will I have to replace or shorten the axle or can I get by just removing 5mm of spacers?

You would need to cut the axle down. Otherwise the quick release won't be able to press on the dropout.

Sheldon "Longer, Not Shorter" Brown

Exactly. I've made the same conversion and had to cut 5 mm off the axle to keep the ends within the dropout faces.

BTW, axles aren't particularly hard and cut easily with a good hacksaw blade. Thread on a locknut before you cut so you can use it to chase the cut end threads when you remove it and file the cut end smooth. It's a 5 minute job if you take your time.

From a safety perspective the axle should extend at least halfway into the dropout.

I'm stunned that people are advocating anything less. Do it right. Ride safe.

Can you explain? In what situation would having less axle protrusion be dangerous?

The only situation i can think of is if your QR was not only untightened, but actually fell completely out. Then the wheel would slip out. However, even with the axle protrusions, it would probably still come out as soon as you hit a bump or something.

It sounds like a far fetched situation anyway.

Back to the spacer thing.. after trying several LBS'es and coming up empty handed, i went to a hardware store and got these washers. Not exactly an elegant solution, but they are more or less the right hole diameter (probably about 11mm on the inside), and two of them put together give almost exactly 5mm width. Dunno about there tolerances in terms of flatness though, but i'm thinking it's a fairly soft steel they're made from, so maybe they'll squish a bit between the harder steel of the locknut and cone?

http://bobobox.net/~bobo/bikes/washers.jpg

Axles extending into the dropout do two things. First, they help to align the wheel. Second they prevent shifting of the wheel if you hit something. Your thin skewer shouldnt be the only thing holding your wheel in place.

Just a quick update - the washers shown above turned out to be entirely the wrong inner diameter (the guy in the store told me 5/16" was just over 10mm, and i stupidly believed him...), but i finally located some at a friendly LBS.

I ended up making the rear hub something like 134mm. There is still plenty of exposed axle, and 134 seemed like a nice compromise for a 130 hub in a 135 frame.

The wheelbuild is almost complete (i discovered i was 2 spokes short mid-build, so i'll have to make a trip to the store again), but i'm expecting it should be fine. I'm using an asymmetrical rim - hopefully this won't end up being an overcompensation what with the rear hub being 2mm over from normal.