How to go from down tube shifters to STI on an old road bike?
January 1, 2006 10:25 PM   Subscribe

Road bike fix-er-uper question! The short of it is I want to upgrade an old cannondale road bike from down tube shifters to STI. Is it economical vs. dropping the cash on a whole new bike? Where to get started learning how to do us?

The long of it: I've been riding a nice triathlon bike for years and years now. I have had this beater roadbike that i ride in bad weather, and just for a change every once in a while. I love the feel of road bikes (vs. the tri bike geometry) and want to ride it more but the down tube shifters are a p_a_i_n.

I dont want to drop the cash on a whole new rig, as i don't mind riding this trusty old steel beast. Looking at shifters on looks resonable, but I have no clue about if STI is compatible with the old shifting equipment on this beast. Where to get started? Advice? Should i just shut up and save the pennies for a new rig?
posted by joshgray to Sports, Hobbies, & Recreation (9 answers total) 1 user marked this as a favorite
Take your bike to the local bike shop. They will actually be able to tell you exactly what you need and whether your bike is worth cost x because they can see the bike.

I've been amazed at the number of times I have done hours of research and gone in prepared to buy an expensive new part. I'll walk out of the shop with a 4 dollar bottle of oil/antioxidant/whatever and my bicycle will be in tip-top shape.
posted by mr.dan at 10:38 PM on January 1, 2006

What component group is currently on the bike? How many speeds? How old?

I've upgraded before, and with the right parts, it sometimes works. If you let me know what you are currently running, I can help you figure out what you'll need.

Have you considered the low-tech solution of a bar end shifter?
posted by tumble at 10:39 PM on January 1, 2006

If your derailleurs are compatible with a current STI lever, it's a pretty straightforward parts-swap. If not, it's a more expensive parts-swap.

It is conceivable at that point that you might come out ahead buying a new (or new-to-you) bike instead of buying the parts, but it's still a bit of a stretch.
posted by adamrice at 6:08 AM on January 2, 2006

You will probably need new shifters and new derailleurs, plus a new cassette. Most downtube shifters are 7 speed or less, and the new stuff is 9 speed, having different spacing, hence the new cassette and new deraillers. The front derailleur may be OK, but that is the cheapest part. Frequently you will also need your rear wheel redished, which involves putting in new spokes and changing the offset of where the rear cassette sits with respect to the hub, as the new cassettes are a tad wider. You can probably get basic parts for about $300, but your LBS (local bike store) is going to want $100 to $200 in labor, less if they do not need to redish the wheel. Of course you can pay a whole lot more for high end components. Given what you will pay in labor, it probably pays to take a step up or so from basic components.
posted by caddis at 9:22 AM on January 2, 2006

A general truism is that the most expensive way to buy a bike is in parts.

That said, being a bit careful with parts selection, you probably can get the bike you want for a reasonable price.

How many gears on your rear cluster? Measure your rear spacing. To save the most money, you want to keep your rear wheel.
- Less than 7, and it's probably not worth keeping (so upgrade to a 7). This means a new rear cluster, new chain, new front derailer, minimum. Note that upgrading to a 8 speeds or more means a new rear hub/wheel.
- For 7 or 8, look for a mid-ninties NOS (new old stock, new parts never used) shifter set on ebay. Alternately you can get a Shimano Sora brifter for about $150ish new. For true Shimano action you need to buy the Tiagra level or higher though.
- 9-speed (or higher) get a Sora/Tiagra or a low end Campy---at 9 Campingolo and and Shimano are almost perfectly interchangeable, they aren't at 7 or 8. I prefer the Campy shift mechanism, myself. If you want to go higher, seriously consider a Shaminglo mixed group to get the best of Japanese and Italian engineering.

Note that if you change your rear cluster, unless it's ancient, or unless you've changed the read hub, you probably don't need to change your rear derailer. Rear derailers don't care about speeds. You will need to change your front one though. Most front chainrings should work with 7's or 8's, but you may need new ones if you go 9. Shifting will be very difficult on older unramped rings if you go 10. Sevens and eights use the same chain, 9s and 10s both have individual, narrower sizes.

Brakes. Not really part of your question, but you may also want to think about upgrading your brakes. Older bikes had a longer brake-arms than new ones do, so-called long-reach brakes. Measure the reach, the distance from the brake mount point to the rim. If you have older "long-reach" brakes, you can still use new calipers with a drop bolt (the above link sells one).

I'll say again, used and new-old stock parts off eBay are probably your cheapest option. Also, poke around discounters like pricepoint and the returns and sale items from Nashbar/Performance.
posted by bonehead at 1:39 PM on January 2, 2006

One other point: there's really no reason to go 8-speed unless you get a killer deal. 8-speed parts are probably the hardest to find, and you can put a much more common 9- or 10-speed system on the same rear hub. Note however, that if you do get a good deal on an 8-speed shifter, you can use it to shift a 7-speed cluster (I've done just this) to save a bit of money.
posted by bonehead at 1:43 PM on January 2, 2006

One last point, we've all been writing as if you have a cassette freehub, you may have a freewheel (screw-on) hub instead, especially if the bike is quite elderly or was a budget model. Read about the difference here. You can get new freewheels up to 8, but by far the most common are 6s and 7s. If this is your bike, I'd go with a 7-speed freewheel and then proceed as the 7-speed freehub option above.
posted by bonehead at 1:53 PM on January 2, 2006

Jeez, just strip off the front and rear derailers. Put them in a desk drawer. Take the downtube shifters off and make key fobs from them. Get rid of one of the two front chainrings (I'm assuming it's a double). Make a wind chime from that. Remove the freewheel, if it's a freewheel, replace with a track cog. Shorten chain and ride. If it's a cassette hub, sell the rear wheel on Ebay and buy a cheap track wheel. Viola, budget fixed gear bike. Shifting is way over-rated, particularly with brifters.
posted by fixedgear at 2:34 PM on January 2, 2006

... Shifting is way over-rated ....
posted by fixedgear at 2:34 PM PST on January 2 [!]

posted by caddis at 4:19 AM on January 3, 2006

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