herst

Guys,

The other day I found an old schwinn mirada (looks like a mtb/touring type frame) in a dumpster near BU. The rims are totally wasted, but the frame is in working condition and it has horizontal drops. I want to convert this to a single speed MTB for singletrack riding in Western Mass and could use some advice on making a wheelset for it. IRO sells a SS MTB wheelset, but reading sheldon's site it seems like I can use any old wheelset with a cassette freehub pretty easily. Just to be sure, does this mean I could buy a new wheelset with a cassette freehub (which are typically $60-$80 cheaper on ebay), or just buy a used MTB from someone on CL, strip off the wheels and use that to make my bike a singlespeed?

Sheldon's site is pretty explicit, but I just wanted to check and see if anyone's done this on a MTB before and if they have any advice. thanks a bunch.

riderx

Yep. It's usually the cheapest way to get started.

bostontrevor

Head over to Bikes Not Bombs on Amory Street or Broadway Bicycle School in Cambridge. BNB in particular has a pretty decent selection of used wheels (as I recall, most of Broadway's are fronts, but you could give them a call).

Since you want to go SS, it's probably better to find an old mtb wheel (or current one from a low-end bike) with a thread-on freewheel cassette than a freehub. If you go the freehub route, you'll have to leave the wheel dished (ick!) and throw a bunch of spacers on the freehub body (double ick!). A classic thread-on will let you recenter the rim on the wheel and equalize spoke tension, stronger and better looking. You can do this yourself or have the shop do it for probably about $20 (plus the cost of the wheel).

Actually, it occurs to me that I have just such a wheel sitting around. If you want it, it's yours.

riderx

I disagree. A classic freewheel MTB wheel will be dished more than a cassette after you respace the axle to get the chainline right. Plus, the cassette hub lets you easily adjust the chainline.

I prefer freewheel SS wheels if you use an SS hub, but on the cheap the cassette wheel is the way to go.

bostontrevor

Why would it be more dished? I have one and as I recall it's pretty well spot-on center. Sure, you may be able to more easily get adjustment on a freehub body, but who cares? You only do it once.

herst

Is that just an aesthetic issue? If so, I'll post a picture of the frame and you'll understand why I'm not too concerned with having a nice looking rear wheel On a serious note, though, would using spacers make it easier to get chainline correct, or is adjusting a freewheel axle fairly easy? Asking out of general curiousity.


Dude, you're like my hero. Once I figure out this PM thing I'll send you one.


Or pay BBS $18 to show you how to do it, which is what I'll end up doing.

If I actually get this to work, I'll try to post some pictures so's other newbs can start on a little surer footing.

riderx

Chainline on a thread-on MTB freewheel is not in the proper place, so you need to shift the axle and spacers to get it right. Once you do that the wheel needs to be redished to get it centered again. Sheldon makes mention of it too.

For quick, cheap and dirty I vote for the freehub.

dobber

I hear Lance is doing pretty good on the tour riding a wheel with a bit of dish.

bostontrevor

I'll have to check my wheel when I get home, but in any event any reverse dish necessary to move a thread-on BMX freewheel into proper alignment will be less severe than that required to accommodate a freehub body.

Anyhow, the wheel I have is already setup for singlespeed use. It came off my Bridgestone when I built up my flipflop, so there won't be any work necessary.

herst, if you click on my name, you can send me a message.

bostontrevor

Yup, and lots of downhillers ride 'em too. But it's also true that all else being equal, a dishless wheel will be stronger. For example, that's why Ritchey has the Zero hub to allow you to build dishless multispeed wheels.

riderx

Sounds like we have a winner!

The only problem w/ the reverse dish is sometimes it need to be moved enough that the spokes the wheel was built with don't have enough thread to allow it to be dished properly. I've run into this once or twice.

herst

Hey, just wanted to pull this thread up from the dead for three questions, as I'm going into Broadway Bike School to build this up on Sunday.

1. Gearing: I've checked the chainrings on my cranks and will use the inner one which is 29T. I've ridden my friend's Kona Unit on the trails I'm building this up for and his 32x18 was almost perfect, although just a hair high. Haven't completely wrapped my mind around the important parts of gearing, but would 29 x 17 give me a roughly equivalent, although slightly lower gearing? Apologies for not doing my homework on this; feel free to just link me to sheldon if appropriate.

2. LBS (boston) tool store: This is more of a general question. I really like BBS, but my corporate job and their hours make it hard to go in and do the routine stuff. There's a bunch of good online stores for tools, but is there any LBS in Boston that actually sells a full line of bike tools (BBS doesn't)? I need silly things like a pedal wrench and a fourth hand.

3. Respoking the Wheel: First off, thanks so much to BT for giving me the rear wheel. I probably wouldn't have gotten off the ground on this project without it. However, the more I've read about redishing freewheels for SS conversion, the more I come across suggestions to respoke the wheel. I'm a bike mechanics newbie, but I'm very eager to learn; would this be a hard thing to do / how long would it take? I feel like it might be a good way to start down the path of wheelbuilding, but would love to hear opinions.

Anyway, I'm super excited. I'll post pictures of this beast when its finished.

bostontrevor

1. Sounds good. It's a pretty good climbing gear if you'll be doing a lot of that. On the other hand, if it's going to be mostly XC with only occassional climbs, go higher.

2. Broadway is open 10 - 5 on Saturdays, fwiw. Broadway doesn't sell tools? I've purchased some stuff from them but I guess they're not listed in Park's resellers list. Cambridge Bicycle is. They're just up Mass Ave (towards Central Sq) from MIT. Right near the intersection of Main & Mass Ave. Bonus, they're open 7 days a week and later than most shops.

3. Why respoke? In fact, it's quite possible that that wheel was built up as a SS to begin with. At any rate, the hub and rim are pretty cheap (especially that single wall rim) that I wouldn't dump anymore money into it. If you're going to rebuild, always fun, I would also think about picking up a new double wall rim for an extra $30 or so.

Thanks for the beer, btw. It was tasty.

herst

1. Good, thanks. Yeah this is all quick-paced singletrack in Amherst and Montague, the only pedaling is during quick climbs coming right out of descents.

2. Doesn't someone who posts on BF work at Cambridge? Just curious. Also, I live right down the street from International Bikes and they are listed on Park's website, does this mean they'll sell tools? They're a pretty surly bunch (the mechanics are really nice though), and the owner stopped talking to me after I decided to not buy a Lemond from him and showed up a week later with a fixed conversion, but right down the street is right down the street.

3. To get the spoke lengths even and spoke tension as high as possible? If you think I should get a new rim then I'll just a new hub too, but is jumping into wheelbuilding just going to be suicide? Should I, like, learn how to true one first? Anyway this is too far down the road to worry about now.

welcome

bostontrevor

Yeah, I've heard bad things about International, but yes, they are listed as a reseller so they'll sell you tools. The fact that Broadway isn't a reseller may explain why my tensiometer was a bit higher than I expected. Or maybe they only recently stopped, I don't know.

If you want, feel free to swing by my place and we can throw the tensiometer on the wheel and see what spoke tension looks like. Given the guy I bought it from and the cheapness of the components, I suspect it was a purpose-built SS wheel from junk parts in the bin, so it'll be as good as can be expected for something that cheap.

Building a wheel isn't hard (in fact my first build was not that long ago, the wheel that replaced that one, in fact--it seems like forever though since I've built/rebuilt a bunch of wheels since then for various reasons). But it would be good to get some experience truing first.

My advice would be to try out that wheel first. If you're not doing anything too gnarly then it should hold up fine. Beat it up, if it gets wacked out of true that's a good chance to get your truing skills up to snuff. If you completely trash it, well then you should build a new one.

The IRO mountain hub is great and inexpensive.

Sheldon Brown

1. According to my trusty slide rule, 29/17 is just a bit lower than 32/18. Note, however, that chain tension is inversely proportional to the chainring size, so a 29 is going to put a LOT of tension on the chain. This will lead to rapid chain/sprocket wear, and may also cause axle slippage issues.

2. We're not much farther from Allston than Broadway is, only about 6 miles or so. We carry a very large selection of tools.

3. Wheelbuilding is not nearly as hard as many folks assume, and it is generally a very satisfying experience. See my article on this https://sheldonbrown.com/wheelubilding

Sheldon "1, 2, 3" Brown
Newton, Massachusetts

Sheldon Brown

I'm afraid this may not be as useful as you might expect. Not sure if it's true of all of them, but at least some Schwinn Miradas used the very uncommon 584 mm (650B, also known as "26 x 1 1 2/") wheel size.

Due to the cantilever brakes, you won't be able to use 559 mm MTB wheels and get the brakes to work.

If the frame is in nice enogh condition, it might be worth building up a new 584 rear wheel for it. We carry the parts neeed. The 584 wheel size has much to recommend it for on/offroad use. I converted my own IRO Jamie Roy to this size.

See: https://sheldonbrown.org/iro

and: https://sheldonbrown.com/584

and: https://harriscyclery.com/584

herst

Guys, thanks a lot for the input. BT, I'm actually moving up into the JP area next week, so I'll PM you or something when I get up there.


Yeah, I know, but I caught that disease pretty quickly where you're always thinking two component upgrades ahead. Its the result of sitting in front of a computer all day where you can look at parts online at work, but you can't ride your bike. From what I understand its a fairly common affliction with no known rememdy. Still trying to figure out how I can get a stand into the office w/o anyone noticing.

Sheldon, thanks for the insight on the wheel sizing. I'm now kicking myself for having thrown away the old wheels without checking their size (rookie error--what can I say?), but if I can put the brake on its peg and get it to touch the rim, I'm probably OK, right?(sidenote: is there a more appropriate term for the post that comes out of the fork and rear of the frame that the cantilever slides onto?).

I'll check this once I'm home.

herst

Sheldon, you were correct: on friday afternoon I checked and the frame that I had did not fit a standard MTB wheel. However, disappointment leads to determination and yesterday I found a used MTB (Columbia Pro Mountain) in much better condition, which was my size with horizontal dropouts. The frame is actually really nice, much better than the schwinn and the fact that the wheels, tires and brakes are all in good conditional means that I'll actually end up spending less converting this to a single speed (I guess all I'll need is a freewheel and a new chain). What's really nice is that since the bike works, I've been able to take it over to a local park and try out different gearings.

I have a question related to chain widths that resulted from one of your comments, but I'll post a new thread, as this one has departed quite far from the original topic.

Edit: See https://www.bikeforums.net/singlespeed-fixed-gear/126691-ss-mtb-chain-width-options.html