TallRider

Is there any reason (other than convenient availability) that a respaced/redished freewheel-hub rear mtb wheel is less desirable for a singlespeed mtb than a cassette-hub rear wheel using a single sprocket and spacers?
The only downside I can think of for the respaced/redished freewheel-hub rear wheel is that there's more exposed axle sticking out beyond the bearings on both drive- and non-drive-side of the hub, increasing the bending moment on the axle. The dropouts of my bike are spaced at 132.5mm.

I came by a large old Diamondback mtb frame from the early 90's - welded steel, horizontal dropouts and no derailer hanger (the bike came with a cheap Shimano rear derailer with a "claw" type attachment). Perfect for conversion to a singlespeed mtb. The frame is heavy but should be extremely durable.

The bike came with 21-speed gearing and I'm debating whether to just use the rear wheel (mounting a single sprocket with spacers on the cassette) or to find a freewheel-hubbed mtb rear wheel, and respacing and redishing it for proper chainline with a singlespeed freehweel.

pyze-guy

Use the wheel you have, less hassle and ready to go with. I have a s/s wheel with this setup. Easy to switch cogs and get a good chainline this way.

dutret

better then both... A single speed freehub.



You'll be fine with what you have for now.

TallRider

Right, right. Note that I asked "is there any reason (other than convenient availability) taht respaced/redished freewheel-hub rear mtb wheel is less desirable for a singlespeed mtb"

You've just said that the cassette is conveniently available. But you're right (and it's a worthwhile point) that there are multiple levels of convenience - using the wheel I already have, but also ease of changing sprockets and adjusting chainline.

My reason for wanting a freewheel-hub rear mtb wheel is the elegance and dishlessness of the wheel. (That said, a 132.5mm-spaced rear hub is pretty near dishless already).

dirtyphotons

i'd say all other things being equal, that the closer-to-symmetrical dish of the freewheel hub would make it slightly stronger and thus more desirable. but that is based on thoughts, not on personal experience.

i'd agree that either should be quite good.

12XU

I'm lame, have access to employee discounts, and prefer a cleaner look so I went with the Phil Kiss Off hub, but there's no problem with going to a cassette hub using spacers and a cog. It's much more convenient and less expensive to switch ratios, especially if you'd be going with Eno freewheels like me..

Aeroplane

I use a regular XT hub with a stack of spacers. It works fine. While a dishless wheel is stronger, 99.99% of geared mountain bikes run on a standard freehub rear wheel, so it can't be that bad.

goldener

use what you have. unless you are doing super crazy off road and/or hucking your freewheel hub will be fine. if it ever breaks, then buy a cassette wheel.

if you are just comutting and other city use on the bike everything will be tits.

max-a-mill

wider spaced hub flanges will lead to a stronger wheel build....

but then why not just ride your wheel now; and if you destroy it go for something stronger next time.

blickblocks

A SS specfific wheel will do you better, since dishing weakens a wheel considerably.

jim-bob

You'd be surprised how well those weak-ass dished wheels hold up.

blickblocks

Still, he has the option to get a bombproof wheel. Why not take it?

shogun17

If you don't get a single speed specific freewheel hub (eg. an old thread-o 7 speed or whatever is NOT SS specific) then it would be better to go for a freehub because there will be twice as many bearings supporting the axle, and if you go hopping over anything or down any bumpy descents, then the chances of a bent axle will be much MUCH less (which the OP mentioned. Especially with 135 spaced frames). I have bent 2 axles on non-singlespeed specific freewheel hubs over the past 6 months (both 135 spaced.). Granted they were crap to begin with, but I only weigh 140lb.

TallRider

Well, that settles it for me. Bearings further outboard definitely is something that's good about using cassette hub on a 132.5mm-spaced frame. I've converted standard freewheel hubs to singlespeed on road bikes, but that's with 124mm-spaced rear dropouts. And of course, riding on roads with less chance of major impact placing bending moments on the axle.

Aeroplane

Maybe you just suck at riding?

I know a LOT of folks who freeride and do all kinds of ridiculous stuff (DJ's, etc.) on normal 135 hubs. Nobody has to replace a wheel every 3 months. If you've got a wheel, use it. That's what is great about going SS, is that you don't really have to buy anything new, you can just use stuff you've already got.

dutret

have freehubs changed since the last one I bothered to take apart or are you counting the bearing in the freehub body itself?

1 set of bearings on the non drive side.
1 set of bearings on a removable cup on the freehub
Some inside the freehub that don't count cause they don't touch the axle.

TallRider

Aeroplane, by "normal 135 hubs" are you talking about freehubs, or about 135mm-spaced normal freewheel hubs? The latter has a lot of exposed axle which is susceptible to bending in off-road riding, and it seems like it would be even more of a problem for freeride and the like. mtb-singlespeed-specific freewheel hubs are different because the flanges (and bearings) are spaced further apart for the sake of
a) mtb singlespeed chainline being further outboard than road ss/fixed
b) less exposed axle subject to bending moments

dutret is correct - freehubs have two sets of bearings that are relevant to this question - the ones that the axle turns on. The bearings inside the freehub body are irrelevant to this question.

It is worth pointing out that Shimano freehubs are much superior to Campagnolo in this regard, because both drive- and non-drive-side bearings are at the ends of the axle, whereas Campagnolo freehubs have the drive-side bearings in the same spot that they were with freewheel hubs - the Campy hubs don't have a problem with broken axles because they overbuild the things (comparable to Phil freewheel hubs) but it's still a less good design.
Here's an article by Jobst Brandt with simple diagrams indicating the location of bearings:
https://www.sheldonbrown.com/brandt/free-k7.html

Aeroplane

"Normal 135 hubs" meaning your average 135mm freehub, for a multi-gear bike.

Yes, it's probably "even more" of a problem for freeride and like, but my point is that the problem is extremely minute. Unless you are casing every landing and not absorbing anything with your legs at all, you probably won't have to worry about wrecking your wheel.

shogun17

I'm talking about a 135mm freewheel hub, not freehub. freehubs are much harder to bend axles on because the bearings in contact with the axle are spaced much, much wider. An extra 30mm is enough to stop a bent axle. A freewheel hub made for 7 speed is a pain, because the bearings and flanges are so narrowly spaced (yes, normally they would be 126 or 130, but this one came as a 135).

Sorry Dutret, my mistake, freehubs space the bearings out wider, the extra bearings have nothing to do with it.

shogun17

This is on my crap beater bike, which I use for standing-uphill start training and other forms of sprint building techniques (roadie). I haven't bent anything on any other bike (BMC SL01, XtC, etc).

BoozyMcliverRot

timcupery.......one other advantage with the cassette freehub is you can run 2 or more cogs in the rear. im running a 16t and a 18t on the rear of my SS

TallRider

I thought I was pretty clear that I was talking about 135mm-spaced freewheel hubs being potentially a problem because of exposed axle. Just a miscommunication, and shugun17 explained the reasons more.

I'm going to just, for now, get a singlespeed conversion kit and run one or two sprockets on the freehub, along with spacers.