PedallingATX

my beater bike is a 1991(ish) Specialized Sirrus. It's a 3x7 w/ Suntour Edge components. Unfortunately, these components suck, so I'm ready to give them up.

The rear hub is a freewheel style hub, so it has threading to put a SS freewheel on it. The problem is, according to Sheldon and others, if I thread a BMX freewheel on there, the chainline will be way off.

Apparently I need to re-dish the wheel and re-space the rear axle.

How hard is this to do? I've trued wheels before, but I've never built them completely. Would I have to buy new spokes?


And just b/c threads w/o pictures suck, here's what my bike COULD look like if it were properly taken care of and had a double crank instead of a triple.

Squirrelli

I converted my old Norco road bike to a SS, I thought the chain line will be all messed up but it ended up nearly perfect, just had to move the spacer a bit. You should thread the BMX freewheel on just to see if your chainline is straight. If not you might want to take it to a bike shop or one of those bike workshop to learn how to dish a wheel.
I hope what I said was helpful...

bbattle

Vixtor says helpful things.

Are you planning on using the triple crank or will you replace that? Triples require bottom brackets with longer spindles so the chainrings clear the chainstay. That will make getting a good chainline harder. When you replace the triple crankset as I urge you to do, get a new bottom bracket as well. I recommend the Sugino RD and matching bottom bracket.

You can see in this pic, the rider chose to use the inside ring on his crankset. Most likely a 39T so he's probably tooling around at 6 mph, spinning a cadence high enough to churn butter. Not good.


Note the ironic method of locking the bike. Padlock to one spoke. Then there's the broom handle bars. And I suppose that top tube protector is to keep his jeans polished as he waits for his frappaccino at the Starbucks drive through.

Beware the slippery slope of cheapness.

mihlbach

Try threading on a BMX freewheel and using the middle chainring. You may find that the chainline is already close enough not to bother redishing. If the chainline is only off by a few mm, you can move the freewheel outboard a bit by putting a freewheel shim or metal spacer or two behind the freewheel. Just make sure you leave enough threads for the freewheel. You should easily be able to get your chainline within 7 mm which will be good enough, probably much closer than that.

RoyIII

Get one of those kits to just use one of the sprokets you already have on the rear and use your middle chainring. You can adjust the chainline with spacers and you save $$$.

the_don

That's a bit of sly Jackassed tarck rider of the day action right there!

See mods! Without the thread, people will just post this stuff randomly in other unrelated threads!

PedallingATX

i wanted to keep the triple crankset b/c I'm really trying to do this cheap. I plan on removing the unused chainrings. Originally, I wanted to take off the granny gear and the biggest gear and just leave the middle one. I'll see what kind of chainline that gives me and go from there.

mihlbach

Its a freewheel hub, not a freehub, so a SS conversion kit will not work.

cs1

At 51 I've done lot's of really bad things. Which one are you refering to?

powers2b

Last Friday night on W25 & Loraine.

Enjoy

powers2b

You read my mind....careful in there.

Enjoy

frankenmike 

Redishing is actually not so hard. The first step is to figure out how far sideways you need the hub to go- some trial and error should give you a pretty good idea. Next, remove your axle locknuts, giving you access to the spacers. Move a spacer(pick one that is half the thickness of the distance you need to move- should be one or two options) from the drive side to the non-drive side. You will need to move your cones a little bit in order to have the same amount of axle protruding from both sides- make sure your bearings are appropriateyt tightened. Reinstall the locknuts. At this point, your hub is in the right spot, but your rim is off to one side. Center and true the rim. Good to go!

mihlbach

In theory its very simple. However in practice it can be tricky for someone with no prior experience, depending on the preexisting condition of the wheel. Older wheels are often poorly tensioned and out of true to begin with and may have frozen nipples or other complications. That may not be the case, but if it is, its probably better to not mess with it too much if you can get a reasonable chainline.

Yellowbeard

In my opinion, re-dishing the wheel is a very simple job provided you know how to true one. When I did it, my wheel lasted three days before every spoke went loose. I retensioned it from scratch and it's been perfectly fine since.


Every one of those three-bolt cranks I've seen is a 52/42, so I'd say the gearing is the only good choice this dude's made.

TejanoTrackie 

Redishing a wheel properly w/o a dishing (centering) tool is not very easy and I don't recommend doing it, regardless of how much experience you have re-truing wheels.

frankenmike 

I agree. BTW, the bicycle itself can function as said tool with the addition of a zip tie.

antiaverage

I've used a bicycle as a truing stand, but never a re-dishing tool. Where are you putting that zip tie?

Cynikal 

On the seat stay to use for a gauge. I would use 2 if it were me. Also, do you have a co-op in your area? they will have the tools.

Yellowbeard

I've made impromptu dishing gauges out of cardboard and out of wood before, too.

frankenmike 

On the stay. To guage the dish, flip the wheel.