How hard is it to add gears to a bike that previously had none?

May 2, 2007 7:52 PM

How hard is it to add gears to a bike that previously had none?

So, I have a wonderful bike, the '06 Bianchi Castro Valley. It's tons of fun to ride. Since I live in Chicago and don't need tons of gears, I like that it only has changeable gears in the back and not in the front (i.e., there's a rear deraileur, but not a front one). But, suppose I one day wanted to add gears to the front. How hard would that be? I know the same frame is used on the Volpe, but the Castro Valley frame doesn't seem to have the little braze on doohickeys to guide the cables down. How would things work, then?

posted by rbs to sports, hobbies, & recreation (22 answers total)

In theory it shouldn't be difficult, but in practice it is, just because it is not cost effective. Parts are not sold economically for this sort of custom work, and the labour would be quite expensive.

All is not lost, though. If you slap on a Shimano Megarange rear derailleur and cassette, you could achieve close to the range of gearing that you wanted without burning too much money.
posted by randomstriker at 8:10 PM on May 2, 2007

Hm, the poster stated clearly that he has rear gears, randomstriker. I'm going to ask my friend who has a bianchi fixed gear. in theory, aside from parts and labor, this should be doable, unless you have to make any changes to the frame.
posted by phaedon at 8:16 PM on May 2, 2007

I believe it may be possible to find clamp-on doohickeys.
posted by unSane at 8:17 PM on May 2, 2007

You can get clamp-on derailleurs and swap out your front cranks to add gears, but randomstriker is right, it isn't cost effective. To do it right (which a Bianchi deserves) would mean you need brifters+cranks+derailleur+a new chain. This would probably run $300-$400 for the parts if you got deals on eBay, not counting labor. You would expect to spend WAY more than that if you wanted to go all top-of-the-line Campy parts.

Solution: Own multiple bikes. Welcome to the club. Just try to leave room in the garage for a car, or your significant other gets mad.
posted by jtfowl0 at 8:33 PM on May 2, 2007

You'll need a "clamp on" front derailleur, not a braze on. This will clamp onto the seat tube.

You're going to need clamp-on cable stops. Once you have those you can route a cable from your left shifter to the front derailleur.

Now for the left shifter: the easiest method would be to stick a bar-end shifter into your handlebars and keep your left brake as it is. As far as I know, Shimano doesn't sell the left STI lever by itself, but a pair of bar-end shifters isn't that expensive, and you can sell the unused right one on ebay.

Finding the clamp-on cable stops will be the crux.
posted by spikeleemajortomdickandharryconnickjrmints at 8:33 PM on May 2, 2007

Looking at the specs, you would need:

Clamp-on front derailleur (these come in a few sizes measured by diameter, so you'd have to measure the circumference of your seat tube and divide by pi).
Double or triple crankset
Integrated brake lever/shifter
Chain

Figure, for new parts, about $30 for the derailleur, $115 for the shifter, $50 for the crankset, and $30 for a chain. Grand total: $225 plus labor, plus cables and housing.
posted by The Michael The at 8:37 PM on May 2, 2007

Oh yeah, a new crankset plus probably a new bottom bracket. I doubt that your single-speed bottom bracket is going to work with a double crankset.

You have the right type of chain (9 speed) already, just make sure it's long enough to accommodate the the gearing combination which uses up the most chain (biggest cog on the back, biggest ring on the front, you should never ride like this but you want to make sure you can shift into this accidentally without breaking something).
posted by spikeleemajortomdickandharryconnickjrmints at 8:37 PM on May 2, 2007

Plenty of clamp-on derailleurs and adaptors available on ebay.
Just make sure you get the right size(s). Don't forget cranks!
posted by fidgets at 8:37 PM on May 2, 2007

N.B. the prices I just quoted come from various sites, particularly universalcycles.com and a google search for "left tiagra shifter."
posted by The Michael The at 8:39 PM on May 2, 2007

i think the hard part would be finding the parts and/or getting someone to braze cable guides onto your frame. clamp-on cable guides exist, but tracking down the right one and installing it in such a manner that doesn't interfere with the existing cabling will be tricky. also, if there is only a bottom-pull derailleur available for that drivetrain, you're also going to need to figure out a way to route that front derailleur cable around your bottom bracket, which might involve drilling holes and brazing. if there's a top-pull derailleur you can get you could mount the cable along the top tube, but you'll need at least 3 clamp-on cable stops, possibly of different diameters, and you're still going to have to worry about interfering with your existing cabling.

oh yeah, assuming you get the derailleur/cable guide issue sorted out, you'll need a new shifter, cranks, chainrings, and likely a chain as well.
posted by the painkiller at 8:43 PM on May 2, 2007

rbs, its highly unlikely you need to actually "add gears" to your bike to attain a desired result.

You can muck around with clamp on cable guides, front derailleurs, and changing out your crankset and bottom bracket (not to mention adding new shifters, etc.) or you can just figure out your specific needs and address them by changing the gearing options you have.

1. You can install a smaller or larger chainring on your crankset.

2. You can swap your cassette for one with a taller or shorter range.

Between the two of these minor adjustments you should be able to get whatever gearing you like out of your bike for a given terrain.

You'll need to do a lot more research on gearing which beyond what AskMe can really help you with (hint: google around and read about mountain bike gearing) plus you'll need to plan ahead for your usage. But in the end this is a lot more simple and cost effecting then trying to build your bike into something that its not.

This is all moot if you never leave Chicago with your bike.
posted by wfrgms at 9:10 PM on May 2, 2007 [1 favorite]

Oh yeah, you'll need to add or subtract chain when you make these changes and you're rear derailleur will probably need adjustment.
posted by wfrgms at 9:12 PM on May 2, 2007

I concur with those who say that adding chainrings isn't cost-effective.

You may consider buying the more expensive parts used if you can find a bike shop that sells used parts -- not sure if Chicago has one.

Also, the bike has a reasonable gear range for a 9 speed bike. The top end is as good as or better than what you'd have on a mountain bike, and the low end, well, it wouldn't be enough to get you around San Francisco. Adding a cassette with a wider range would certainly help that though.

If you're hard-core, just get another bike -- with gas prices where they are, it'll pay for itself in no time. Happy trails.
posted by bicyclingfool at 10:10 PM on May 2, 2007

More bikes!
posted by beerbajay at 10:14 PM on May 2, 2007

As only one other commenter has pointed out, the bottom bracket (that's basically the axle that your chainring & crankarms are sitting on) is not going to be wide enough to fit any more gears.

I say that with 99% surety. There's a slight chance that Bianchi is using the same BB on the Volpe as the Castro Valley, but I can't make sense of the site and that doesn't seem likely.
posted by coolhappysteve at 10:49 PM on May 2, 2007

What wfrgms said. "Adding gears" to the back by swapping your cassette would be the easiest. Honestly, the bike has a gear-inch range of about 99 to 42. That's pretty good for the bottom except for steep hills. The top end? Well, you won't be racing the thing but if it's really, really high speed you want you've got the wrong bike.

Note on the following: the prices here are really wild-assed guesses as I do almost all my own bike work and hunt around for good parts prices. The technical details are pretty good, though.

If hill-climbing's a problem, a wider-range cassette would run from 20-50 bucks and could increase your climbing ability drastically (the bike comes with 26 teeth on the biggest cog; you can get cassettes with 34 teeth that keep 11 on the smallest one so your top speed would be unaffected.) The bad news is you'd probably have to swap out the rear derailleur too as I think the one that comes with your bike has a stated capacity of 27 teeth. You can usually push this a tooth or two but much more probably not. So another fifty bucks or so for a 9-speed ATB rear der'r. Add another 5 to 15 bucks for a new chain.

Work involved would be minimal for an experienced wrench -- maybe an hour -- so you'd be looking at maybe ~$150 total (?) including new parts. If you have a shop willing to work with you, maybe they could substitute used parts (not the chain) and save some bucks.

If you think the bike's too slow in high gear you're probably a very strong rider but anyway you'd have to swap out the front chainring as the 11-tooth small gear on the cassette is about as small as they get. A bike shop would tell you what they could do here but hopefully they could replace just the ring and chain rather than the whole crankset. Pretty cheap ( maybe 50-75 bucks, all-up?) for just a new ring and chain. Maybe, I dunno, 20-30 bucks more for a new, inexpensive but decent single-ring crankset? Hopefully there's sufficient clearance for a large single chainring without having to swap out the bottom bracket for something wider.

Yes, you could add gears to the front but that means a double-ring crankset, almost certainly a wider bottom bracket, front derailleur (clamp-on), front shifter (I'd just use a bar-end or clamp-on -- it's good enough for Lance) and cable guides. Seriously, you could do it (at least I could do it and I'm pretty much a klutz but I have a lot of tools,) but there are several non-trivial aspects (e.g., selecting the correct bottom bracket, selecting front crank rings so you don't exceed rear der's capacity, cutting cable, etc.) So, it wouldn't be a no-brainer if you aren't comfortable working on bikes. The bottom bracket especially is a huge deal. And a shop would probably charge you more than it would cost to get a decent used bike with the new gearing you want.

So yeah, more bikes sounds like a really good answer too.
posted by Opposite George at 11:14 PM on May 2, 2007

It's definitely do-able. If the bike were mine, I would wait until the paint has started to get a bit trashed and the components a bit shagged out. Then I would take it to my friendly local framebuilder and have them braze on a left-hand cable boss and the required guides under the BB. Easily done. A nice new powerdercoat costs less than 100 bucks here in Australia, so I'm sure you could find somewhere there to do it.

Since you've waited until the components are a bit shagged (and maybe you've scratched up those levers a few times anyway) you won't baulk at a new pair of Tiagra or 105 brifters. Add a front mech and you're almost home.

As for the naysayers who reckon you need a new bottom bracket... I'd take a guess that the cranks on this bike *are* effectively double cranks and that the single chainring is bolted in the inner position, with a smooth guard in the outer position. If you can find a bike co-op you may well be able to experiment with swapping a double crankset onto the existing BB. And even if you have to get a longer BB, it's not a big deal. Bike shops can swap a BB in 5 minutes.

Your bike - which looks lovely, BTW - has a huge advantage pver almost anything else in the market today: it's steel. Steel is durable. But more importantly, steel is repairable. Adding cable guides, cable stops, more bottle mounts, hell - even disc brake mounts, is entirely do-able. If you wait until you're looking at replacing the bits anyway, the cost of adding gears will be absorbed in the regular maintenance.

Hell, if you were in Melbourne, I'd do it for you for the cost of a 6-pack of good beer.
posted by tim_in_oz at 12:58 AM on May 3, 2007

a new brifter is not necessary - one can insert a bar-end shifter.
posted by entropone at 7:02 AM on May 3, 2007

As others have said, it'll be kind of spendy to update this bike to front and rear shifting. I would not consider brazing on cable stops unless I had a real hard-on for that finished appearance—you can get clip on cable stops.

A less conventional way to approach this would be with a mountain-drive, a shiftable planetary gear built into a crankset/bottom-bracket combo part. It allows for insanely wide gearing, and doesn't involve any cable runs. But expensive.
posted by adamrice at 7:18 AM on May 3, 2007

The first thing you have to answer is why you want more gears. To get up steeper hills? To go Faster? Both? To reduce the difference between each gear? All or some of these?

To get up steeper hills, you reduce the size of the front ring, increase the size of the rear sprockets, or both. The cheapest option is to just get a smaller front ring. With a single ring this is a problem because the chain can easily be thrown off the ring without a front derailleur or guides on the ring to restrain it. Getting a different casette with bigger sprockets for the rear is more expensive, because you'll most likely need a new rear derailleur with a longer arm to take up the extra chain required as well.

To go faster, just do the opposite - larger front ring or smaller sprockets at the back (best option is the former). The penalty is that your lowest low gear will be less low.

To increase the range of gears, you could get a wider spread of sprocket sizes at the rear. The Shimano MegaRange casette is an option here. They're a bit of an open secret, not outrageously expensive and excellently designed. You'll need a new rear derailleur to accomodate it, of course. The jump between each gear will be larger. You might find that less comfortable.

To get a wider range of gears for hills and speed, and without increasing the jumps between them, you're into adding chainrings, as discussed above, so I'll not labor it, just agree that the cost might not be worth it.

Unless... how much do you need indexed gears? If you can live without indexing, many older bike shops might have parts bins containing what you need at a fraction of the cost compared to modern parts. Another way to keep the cost down is to use clamp-on downtube shifters and regular brake levers. The good news is you've a nicely standardized steel frame that older parts should fit without bother.

Also, check under your bottom bracket for a front mech cable guide. Even though your bike is sold with a single front ring, I wouldn't be surprised if the guide was there, anyhow. Manufacturers often use the same frame across different models.
posted by normy at 7:54 AM on May 3, 2007

Harris Cyclery sells a modified Bianchi singlespeed with an internal hub. Unfortunately, it's not available mail order. It's a handy proof of concept though.

Internally geared hubs are wonderful and avoid, at the cost of a little weight and efficiency, all the hassles of deraileurs and exposed gears. This is a benefit even when you're not talking about kludging together deraileur mounts on a bike that wasn't built with them.

I had a Sturmey-Archer 8-speed hub built by them a few weeks ago for $300 with the shifter included. It bolted right into the frame and *zoom* instant eight speed!
posted by stet at 10:43 AM on May 3, 2007

You guys and gals rock. Thanks!
posted by rbs at 3:18 PM on May 3, 2007