Bicycle modification question.

I have a big cruiser bike. Aluminum frame so it's light, big seat for my fat ass, sized well for a 6'2", 270# guy. Kind of a fat bike for a fat guy. I like the bike, except for one thing. It's a single speed and it's in overdrive all the time. Is it possible to convert it to a multi speed. Not necessarily 10+, I'd be happy with 3 or so.

My only concern is it's a cheap Chinese bike from Walmart. Are bike shop parts going to fit? I've also got a broken pedal that needs to be replaced. Is there an industry standard for bikes? There aren't any shops that are close to me so are there any online shops that are recommended?

The bike in question. (Not mine, but the same.)

You'll spend the value of the bike in converting. That's a coaster brake up (it appears), so you'd have to buy:

New rear wheel Cassette/freewheel for that wheel Rear derailleur that works on a slotted dropout Shift lever Cable Chain

...and as I type this, I realize there are no bosses brazed onto the frame for cable stops, so that's what will make this impossible.

Would something like this work?

Link

gamby wrote: ...and as I type this, I realize there are no bosses brazed onto the frame for cable stops, so that's what will make this impossible.

Cable stops shouldn't be too hard to fab up. I'd have to clamp them to the frame, but that's pretty easy to build.

The bike was $80, a set of tires would damn near be worth more than the bike.

Toyman01 wrote: Would something like this work? Link

Good find! It would, but you'd have to get a rear wheel built around it. I dunno what that would run.

You could do an internal gear hub to gain some gear range. You'd still need to get a new rear wheel or re-spoke the rim with the new hub.
Cheaper solution - put a bigger rear sprocket on; keeps it a single speed. You probably have an 18t now, maybe find a 20 or 22t to drop the ratio somewhat.

Edit: blast! Toyman beat me to the punch.

It's not impossible with the right internal gear rear hub, but you'll be dropping somewhere between $500 and $1000, and that's buying used parts. If you want to look into it a Shimano Alfine is the kind of thing I'm talking about. Oh, and you'll need to learn to ride without brakes or get real creative on handbrake placement.

On the bright side, three speed versions of a similar bike can be had for much less most of the time....

Well, this is GRM, where thousands get dumped into Yugos.

Of course buying another gear-equipped bike would make more financial sense and you could end up spending close to $200 on this, but it's a project--and projects are fun.

gamby wrote:

Toyman01 wrote: Would something like this work? Link

Good find! It would, but you'd have to get a rear wheel built around it. I dunno what that would run.

I actually laced/strung/built a wheel about 100 years ago and straightened a bunch of them. My father was always, a you broke it, you fix it kind of guy. Time consuming, if my memory serves me.

Would that hub fit in my wheel. Is there a standard for bike spokes or is every manufacturer different?

gamby wrote:

Toyman01 wrote: Would something like this work? Link

Good find! It would, but you'd have to get a rear wheel built around it. I dunno what that would run.

hey, excellent find! It's the budget version of the stuff I was talking about and even has the brake. Having a rear wheel built around it could probably be done by the right shop, or possibly even by NIagara Cycles if they have someone on staff. I'd think you could get out under $300, which might be breakeven on another bike. If you like the one you have, hey..

Every wheel/hub combo is different but there are common sizes. Biggest worry would be the axle length being close enough to fit in youe frame without spreading it too much.

Toyman01 wrote:

gamby wrote:

Toyman01 wrote: Would something like this work? Link

Good find! It would, but you'd have to get a rear wheel built around it. I dunno what that would run.

I actually laced/strung/built a wheel about 100 years ago and straightened a bunch of them. My father was always, a you broke it, you fix it kind of guy. Time consuming, if my memory serves me. Would that hub fit in my wheel. Is there a standard for bike spokes or is every manufacturer different?

Then it becomes a question of the number of holes in the hub equaling the number of holes in the rim. If they match, I'd take both to a bike shop, along with the original wheel, and talk to their wheel builder about proper spoke length.

Go for it.

ultraclyde wrote: Every wheel/hub combo is different but there are common sizes. Biggest worry would be the axle length being close enough to fit in youe frame without spreading it too much.

Meh, I've spread three oldschool (steel) bikes for newschool rear hub spacing. Steel will bend/spread with a little coaxing and very little drama. This assumes it's wider in the first place.

It looks like the rear sprocket is a 15T and the front is a 39T.

Is there a "ideal" ratio for bikes?

Toyman01 wrote: It looks like the rear sprocket is a 15T and the front is a 39T. Is there a "ideal" ratio for bikes?

That's purely subjective. There's no "right" answer. I run a 46/20 on my singlespeed with 700c wheels and 700x35 tires. Happy medium for my spinner-leaning tendencies.

This can help compare ratios: http://sheldonbrown.com/gears/

If you're happy with the current gear ratio on your bike, stick with something close to that. However, a 2-tooth difference on a rear sprocket is a big difference.

...and again--be sure the rim spoke holes equal the hub spoke holes.

What size tires are on the bike? If 24 or 26" just get an old 3-speed rear wheel, cable, and shifter and call it done. I probably have half a dozen of each in the barn at my mom's from the bicycle phase my brother and I went through 30 years ago. Any friendly LBS should be able to help you out.

A little more digging finds this.

http://www.niagaracycle.com/categories/sturmey-archer-awc-3-speed-hub-36h-coaster-brake-with-trim-kit

3 speeds, the right number of spokes. I'm not 100% sure about the length but it looks to be close.

Sturmey is a solid name in geared hubs. If your rim is a 36hole that should be doable.

Can't you buy a used Electra townie for the conversion cost?

Or this. http://www.bikesdirect.com/products/Mango/macaw_cruisers_al-7.htm For $229

You guys are overthinking this. Hit up the garage sales and find some neglected bike with a 3-speed hub for $5-$10 and swap the wheels over. The rim width will probably be narrower, but if you're not out riding trails it shouldn't be a problem. Hopefully your frame has a brace between the 2 seat-stays pre-drilled for a caliper brake...though I'm 100% confident you can resolve the problem if it doesn't.

In reply to petegossett:

The odds of finding a 26" 3-speed wheel are pretty slim.

Find a cheap 3-speed bike at a yard sale, swap rear wheels.

In reply to gamby:

It must be a regional thing, I have a pile of them. Unfortunately I'm guessing it would cost $20-$30 just to ship the wheels.

I thought of the old 3-speed solution as well (there are a fair few of them around here), but note that it is very likely that the original wheels are 26" decimal, while the old 3-speed will almost certainly be 26" fractional, meaning new tires will be necessary if you go that way.

I would do a cog swap before going through the work of a 3 spd conversion. A 39/15 is a pretty tall gear - essentially a "beach-cruiser" gear meant for slow pedaling on flat bike paths at the shore. Finding a rear cog shouldn't be too difficult, but you'll need to determine if it's a cassette style or a (likely) thread-on. Might need a new, longer chain.