TimJ

Planning for my rob roy I have some questions on wheels.

First of all- nutted rear axle. Is it necessary? W/ the track dropouts and a chain tensioner, wouldn't a qr work fine or maybe a bolt-on skewer (my favorite)?

Hubs- In the realm of affordable hubs what is there? Surly at 135mm? Formula? Is that it? Are the only options really just track hubs with spacers?

And generally, what sort of spoke count would be considered minimum yet tough? (for a 175lb guy)

thanks.

dirtyphotons

lots of people get away with quick release, i'd use a mountain skewer and clamp that sucker down. probably goes the same for locking/bolt on skewers.

the rr is spaced so that normal road wheels will fit fine. if you're going ss and not fixed i'd highly recommend just using a tough road wheel and spacers rather than a ss specific wheel. you'll save money and weight.

i don't think you should have any troubles with 32 spoke wheels, you're better off spending the money getting them built by someone you trust.

TimJ

A road cassette wheel is going to be lighter? Wouldn't the freehub be just as heavy as a little more shell? I don't like that idea, I'd prefer to have a wider dish. Do ss cx racers use road cassette wheels?

dirtyphotons

your reasoning is spot on, the lightest freehub wheel is heavier than the (theoretical) lightest ss wheel. but the reality is that you're much more likely to find a light set of road wheels at a good price than a set of ss wheels at the same weight.

some of it has to do with the fact that many ss specific (surly, formula, etc.) singlespeed hubs are basically just modified track hubs (as you suggested) and track hubs tend to be heavier, for whatever reasons.

also the multitude of geared wheels on the market for many decades have driven down the weight and cost of multispeed hubs where ss hubs (with the exception of bmx, who also don't put a huge premium on weight) haven't enjoyed the competition for that extended period of time.

so a formula with a bmx style freewheel on it is likely to be heavier than an equivalently priced freehub with spacers and a cog.

i can't speak for the pro ranks but many amateur cross racers use the freehub/spacer setup to great success.

TimJ

I've got a nos suntour xcpro freewheel hub. I wonder if the flange spacing is wider than a modern road hub? I'll have to check that out. I think I'm gonna build the wheels myself.

mrkaztro

How much weight are you really trying to save? 175lbs is not super heavy yet in your shoes I go with the ss specific hubs probably high flange too. It'll be a stronger and stiffer wheelset. You can save weight else where.

mihlbach

Track hubs are mostly heavy because of the solid steel axle and steel track nuts. The Dimension/Novatech/Nashbar/Ben'scycle track hub is a basic streetworthy track hub (with 130 mm spacing, so it will fit on the Rob Roy) with a hollow axle that weighs 270 grams and is now available at Nashbar for $24. I imagine that weight includes the track nuts. Note that skewers are almost never included in freehub weights, so you have to account for that when comparing. Other budget track hubs, like Formula or Surly are well over 300 grams because they have solid axles. Take any of those hubs and swap out the solid axle and track nuts for a hollow axle-skewer setup and you'll have a hub weight that is comparable to a freehub.

Because of the lack of dish in the rear wheel of a fixed gear or singlespeed wheel, it will be much stronger than an equivalently spoked freehub wheel. For this reason you can theoretically build a lighter wheel with fewer spokes. If you use a basic road/cx hub in the front and a rear track hub with a hollow axle and skewer replacing the solid axle and track nuts, you should easily be able to build up a very strong clincher wheelset that is less than 1500 grams and much much cheaper than any freehub wheelset of the same weight.

TimJ

So I's was checking out surly and they have their new hubs in 135mm QR, free/free, which is very cool. I'd prefer 130 but it sounds about perfect. And cheap.

bonechilling

The biggest reason to use a single speed cassette hub is, for me, chainline. With a cassette hub and a few spacers, basically any BB will work, because you can just slide the cog around until it's right-on. Oh, and it's lighter and cheaper.

TimJ

So I've been doing some research and figured surly hubs (at least in the rear w/ QR not solid axle) w/ velocity aerohead rims, 32 in the rear and 28 up front, w/ brass nipples and double-butted spokes would be the cheapest lightest wheels I could probably build.

But I was thinking, how different is that setup, really, from the standard iro wheels? How much weight could I really expect to save over an iro set? Any educated guesses? Or suggestions?

fyi- I want to race the wheels I make so I'm trying to get them as light as I can without spending too much $$.

mihlbach

I don't know the weight of the IRO wheels specifically, but they probably are not much different from many budget singlespeed/fixed gear wheels that are commonly available. All of these tend to be well over 2000 grams. The solid axles, track nuts, 32-36 straight gauge spokes, and heavy rims all contribute.

I'll bet that the build you proposed above will be at least 500 grams lighter than a stock IRO wheelset. Probably even more if you use a lightweight front hub rather than a track hub. Unless you are a total clyde you could even loose a few more spokes in the rear and still have a very strong wheel. I'm 205 lbs and I have a 32 spoke surly/mavic singlespeed wheel that is beyond adequate. A 28 spoke ss wheel is going to be stronger than a 32 spoke freehub wheel because of the lack of dish. Instead of a Surly hub, you could get a Miche or other hub thats available in 28 hole.
Also, when you swap the solid axle in the rear hub for a quick-release, don't weight-weenie out on the skewer, because with the horizontal track ends on the IRO frame you will need to really clamp that mother down.

TimJ

The surly's, I believe, have wider shells than something like a formula hub which can fit in track spacing (120) or up to 130, so I think the surly, which is a mtb hub intended for 135 spacing, would be the strongest with the least dish. I don't know what using a track hub would look like but I would imagine it would have to be dished a little to the drive side for the chainline? I just don't like that idea, but maybe I'm wrong about it.

Regarding the rear end I'm thinking a hollow axle w/ bolts would be the way to go, but that'd be a conversion I'd have to do myself. But I suppose a good shimano skewer would probably work fine, I just wonder how much weight it'd save over a solid axle and nuts, really. If it's negligible then there's really no point.

Thanks for the input.

mihlbach

I was under the mistaken impression that you were thinking of using a Surly track hub rather than the 135mm spaced MTB hub, which does have a different chainline. Either a track or mtb ss hub would work with a symmetrical dish. You would just have to work out the chainline difference up front with the crank/bb. Track hubs will give you a standard 42mm chainline which you can easily achieve up front with a SS crank such as the IRO. You can buy track hubs that are spaced to 130mm, which would also work with the IRO frame, which has 132.5 mm spacing. What crank were you thinking of using?

Heres another idea...get a ss freehub with an adjustable chainline like this (https://www.nashbar.com/profile.cfm?c...%2FRear%20Hubs) and work out the chainline to be the same as the diskbrake mount on the other side. Then bolt a sprocket on the diskbrake mount and have a ss/fg flip flop hub.


As for solid versus hollow axles...the Novatech/Dimension/BensBikes (etc.) track hub is reported to be 270 grams. The Formula/IRO/Harris (etc.) hub is reported to be 330 grams. The only significant difference that I can see between these hubs is that one has a solid axle and the other has a hollow axle. So I would imagine you would be saving roughly 60 grams per wheel by using a hollow axle. I'm not sure if a steel skewer would weigh more or less than a pair of nuts, but I imagine the nuts are slightly lighter.
In reference to your original question about IRO stock wheels versus custom built wheels, the bigger weight savings will probably come from lighter rims (open pros), and fewer/butted spokes.

TimJ

I haven't decided on a crank yet.

Let's see, ben's bike hubs are 34.5mm Flange Width, surly's mtb free/free is C-T-F (L or R): 38.5mm. So I guess that means flange to flange on the ben's is 69mm and surly is 77. Not a huge difference. Hmmmm.

Ben's I could get in cool anodized green. Hmmmm. But they're only 32 hole and only sold in pairs, apparently.

I guess it comes down to chainline and if I want to definitely have a 28 up front. Ultimately, crankset-wise, I'd like something with guards on it and I suppose a road crankset would be more accomodating. Lots to think about.

mihlbach

The Nashbar track hub is the same thing and they are sold individually...but no green.

TimJ

Honestly the green is a major selling point to me. I've never had cool anodized hubs... now's my chance!

mihlbach

Brainstorming different custom wheelbuilds can be a lot of fun.
The wheels for my SS Rob Roy will be a set of black Surly track hubs, laced to Mavic CXP33 rims (32 hole), with double butted spokes, radial front and 3x rear. Not the lightest wheels, but certainly strong enough. I'm hijacking them from my fixed gear road/track bike, which is going to get a new set of wheels.

TimJ

So I wanted to let folks know I got a pair of Sun M14A rims today from Ben's and they do not have eyelets. I believe this is because they are silver. They were much cheaper than the black ones and I guess that's why.

So FYI - Sun M14A silver rims don't have eyelets.

Oh well...