from Rookie’s keyboard,
Hello, friends
A while back, I made a post praising downtube shifters. I stand by my statements, but at the same time, it’s possible that some rookies out there have old bikes and would like to upgrade to something more modern like STI type brifters.
The good news – it’s possible.
The bad news – it’s expensive.
Needed Components
A conversion from downtube shifters (DTs) to brake-shifters (BSs) demands the following parts:
1. STI Shifters or an equivalent (#captain_obvious)
The new shifters are the most expensive purchase on the list.
The cheapest STI shifters that I know are Shimano Tourney 2/3×7.
Most places have them around USD 80-120 (depending on whether they’re on clearance).
If you want more speeds (e.g., 8, 9,10), the price goes up severely.
If the bicycle isn’t particularly expensive, the brake-shifters could end up costing more than the bike’s value on the second-hand market.
Brake-shifters cost 1/8th of a kidney because they’re seen as a premium product and include a multitude of small parts that have to operate under great stress.
7 speeds are the minimum. But if you have the money, you can go for 8, 9, or even a 10-speed cassette as long as the rear hub can accommodate it.
Unless you want a 1x drivetrain (or keep the front downtube shifter), you will need a shifter for the front derailleur too.
If you run a double crankset, you can use either a 2x or 3x shifter.
If you have a 3x shifter and a double crankset, you will have to heavily limit the travel of the front derailleur via the limit screws.
2. A new cassette
Unless you’re already using a modern cassette, you will need a new one with up-to-date spacing between the cogs.
This is necessary because brake-shifters use index shifting and therefore pull the cable a pre-determined amount with each click.
If the cassette has a different cog pitch (the center-to-center distance between two adjacent cogs) than the current models, the shifting won’t be as good.
3. A New Rear Hub (possibly)
It keeps getting “better”, doesn’t it?
The conversion will require a replacement of the rear hub in the following scenarios:
a. Old 5-6-speed System
If the bicycle uses an old 5-6-speed system, a new modern hub will be needed. (It may be cheaper to buy a new wheel altogether.)
b. 7-speed Specific Hub
If the bike has a hub designed for 7-speeds, and you want to run a cassette with more speeds on it, you may still need a new rear wheel.
This isn’t always the case. Some 7-speed hubs can actually accommodate 8, 9, or 10-speed cassettes.
If the 7-speed cassette is installed with a spacer at the back, then the hub is wide enough to work with more gears.
If there’s no spacer, and the 7-speed cassette covers the entire hub, a new wheel will be necessary.
The Frame Could Be Too Narrow For The New Wheel or Hub
Some 7-speed hubs have an O.L.D. of 126mm.
O.L.D. refers to the usable part of the rear hub and is essentially the distance between the outer sides of the hub’s locknuts.
The O.L.D. of modern road wheels is 130mm when using caliper brakes and 135mm when relying on disc brakes.
A retro frame designed for 126mm O.L.D. hubs won’t be able to accommodate a new hub built for wider cassettes with more cogs.
If the frame is made of steel, it could be “cold set”/bent to accept a wider wheel.
However, this adds another step to the process and complicates it even further.
4. A new Rear Derailleur
If the rear shift ratio of the current rear derailleur does not match that of the new models, the rear mech will have to be replaced too.
The rear shift ratio shows how much the rear derailleur moves for every millimeter of cable pulled or released by the shifter.
For example, the rear shift ratio of Shimano 9-speed road derailleurs is 1.7.
For every millimeter of cable movement initiated by the shifter, the derailleur moves 1.7mm.
If the rear shift ratio of the derailleur is 1.4 for example, then the shifter will fail to control the derailleur as expected.
Consequently, the shifting experience will be poor because the derailleur will keep moving the chain to the wrong places.
Note: Suntour’s Accushift rear derailleurs are incompatible with Shimano’s index shifters due to the different rear shift ratio and cassette spacing.
However, if the derailleur is Suntour and made before the Accushift area, there’s a great chance that it will work to a satisfactory level with an indexed Shimano system.
5. A new front derailleur
The front derailleur may have to be updated too as it may index poorly with the new shifters.
6. A new chain and chainrings
If the chain is worn or you want to move up to 10 or more speeds, you will need a narrower model.
You will also need thinner chainrings.
7. Downtube cablestoppers
The shifters have to be replaced with downtube cable stoppers which will also play the role of barrel adjusters.
Most models attach to the downtube shifters bosses via an M5 bolt – the same size used for the bottle cages.
8. New Cables + Housing
The brake-shifters will need new brake and gear cables as well as housing for those.
While it’s possible to use some of the old stuff, it’s always best to install a set of new cables and housing when changing shifters for better accuracy.
10. Bar Tape
There’s a very high chance that you will need new bar tape due to the different cable routing.
If the bicycle is old, chances are that the bar tape is worn out anyway.
11. A new Bottom Bracket (Possibly)
If the bottom bracket is positioning the chainrings too far away for the new front derailleur to reach them, you will have to replace the spindle with a shorter one (if possible) or the entire bottom bracket.
12. Tools
If you plan to do the conversion yourself, you will need the following set of tools:
- Cable + housing cutters
- Cassette removal and installation tool
- Chain whip
- Chain Breaker
- A set of Allen keys
- Philips screwdriver
- Crank Removal Tool (if you’re going to replace the bottom bracket)
- Bottom bracket tool(s)
- Wrenches
- Pliers
- Insulation tape (to install the new tape)
If you count on a bike shop to source the components, you will pay even more because they’ll charge you a retail fee without looking for special discounts online.
The Total Cost of The Conversion
The table below contains the required parts and their estimated price in a situation when you have to replace the greatest number of components.
The actual price will depend on the shop from which you’re buying, but in most cases, it will be close to the values below:
| Components | Price |
| Shimano Sora Di2 STI ST-R3000 | USD 155 |
| Shimano CS-HG400-9 Cassette | USD 20 |
| Shimano WH-R501 28″ Rear Wheel | USD 85 |
| Shimano Sora RD-R3000 9-speed Rear Derailleur | USD 26 |
| Shimano Sora FD-R3000 Front Derailleur | USD 25 |
| Shimano Sora FC-R3000 2×9-speed cranks | USD 77 |
| Downtube cable stoppers | USD 15 |
| 9-speed chain | USD 15 |
| Bar tape | USD 8 |
| Cables + housing | USD 15 |
| Total: | USD 441 |
As you can see, this conversion could end up costing you a ridiculous amount of money.
Lower The Price of The Conversion
Below are a few options that will help you save money:
1. Buy second-hand parts and do the work yourself
You may find some good offers on Facebook’s market place or sites for used items.
2. Stick to 7-speeds
7-speed brake-shifters are the cheapest (unless you get scammed). Unfortunately, they’re getting hard to find.
3. Switch to a 1x Drivetrain
If you switch to a 1x drivetrain, you won’t need a second brake-shifter and a front derailleur. The downside is that your gear range will be highly limited.
4. Keep One of the Downtube Shifters (a very smart choice)
Using a downtube shifter for the front and a brake-shifter for the back is a high IQ way to save money and combine the best of both worlds (index+friction shifting) all while preserving the gear range.
– Some genius
This set-up eliminates the need for a front brake-shifter and reduces the bike’s weight too.
Many people love front friction shifting because you can easily “trim” the derailleur and prevent “chain rub” against the cage.
Lance Armstrong had a similar set-up (downtube shifter front + STI back) for some races. The goal was to save weight (about 100 grams), avoid chain rubbing, and reduce the chances of dropping the chain.
Time
The duration of the process depends on how many parts you have to replace.
Scenario 1: 7 Speeds
If you want to preserve a 7-speed system, the steps will be as follows:
1. Remove the old bar tape, detach the brakes, and take down the old shifters.
2. Replace the cassette with a 7-speed one spaced properly for modern index shifters.
If the current hub cannot accept a modern 7-speed cassette, it will have to go too. The cheapest way is to simply buy a new wheel.
3. Put on the new shifters
4. Replace the rear derailleur
5. Reattach the brakes
6. Install the shifting cables
7. Install a new chain and test set-up.
8. Adjust the limiting screws on both derailleurs.
Scenario 2: 7+ Speeds
If the frame can accept a modern 130mm hub, the process of upgrading to more speeds will be similar.
The only difference is that you will need brake-shifters and a cassette designed for more gears.
If the frame is too narrow, you will have to cold set it to 130mm or live with a 7-speed system.
Note: Cold setting can be done only if the frame is made of steel. Other materials do not tolerate it.
Every Case Is Different
Due to the high variety of retro bicycles, it’s difficult to predict every problem that you could run into. It will be helpful if you prepare yourself mentally for surprises.
Maybe Buy a “New” Bike
Given the investment, it may be wiser to buy a new or second-hand bike that already has STI shifters.
My experience
As I said in the beginning, I like downtube shifters. They work for me. But I’ve done this conversion once a for a client.
We had some 7-speed STI shifters on sale, and I convinced the client to use them instead of spending a fortune on 10+ speeds. Since he had a retro road bike with a 7-speed freewheel on it, the final result was decent.
But if you are planning some massive upgrade from an ancient 5-speed model, I wouldn’t bother.
But hey,
The decision is always up to you.
Until next time,
Rookie
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