Ratio 1×13 Upgrade Kit

Ratio is a British company that produces parts to modify drivetrain components, which expands range or provides extra shifting capabilities. The 1×13 Upgrade Kit enables the use of SRAM shifters with a 13-speed Campagnolo Ekar cassette. The kit makes access to the Ekar shifting range more affordable but, while it is less expensive than an Ekar groupset, it’s still not what you would consider cheap.

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Ratio 1×13 Upgrade Kit – Technical details

A new ratchet, M2.5 bolts, and a set of jockey wheels are included in the 1×13 Upgrade. It is compatible with mechanical drop-bar shifters with SRAM 1×10 and 1×11. If you want to use a 1×10 shifter, you’ll also need the Ratio Cable Spool.

SRAM-compatible components include Force 1, Rival 1 and Apex 1 shifters, and rear derailleurs, as well as 1×11 SRAM mountain bike derailleurs. If you choose the MTB rear derailleur, you will also need a Ratio Cable Fin and possibly a Ratio Rear Exit Cable Stop, depending on frame cable routing.

Finally, the Campagnolo components required are as follows: an Ekar cassette and chain, a 13-speed compatible chainring, and a rear wheel with an N3W freehub.

With all of the requirements, existing parts, and probable costs, it’s worth considering whether simply upgrading to a Campagnolo groupset would be a simpler and maybe cheaper option.

Ratio_1x13_Upgrade_Kit_Parts.jpg, by Matthew Page

The biggest appeal will be for those who currently have a compatible SRAM drivetrain and are looking to expand the range. SRAM 1×11 uses a 10-42T cassette that offers a 420% range, while the widest Ekar cassette option is 466% (the extra two gears keep the gaps between gears smaller). Ignoring the cost of SRAM components and assuming you already have them fitted, a Campagnolo Ekar cassette costs £234, the chain is £38 and a freehub costs around £60, depending on the wheel brand. A full Campagnolo groupset costs £1,500 and you’ll still need to throw in an N3W freehub, so there’s a significant saving.

Ratio_1x13_Upgrade_Kit_Ratchet.jpg, by Matthew Page

A SRAM AXS electronic groupset with a “mullet” setup, combining AXS drop-bar shifters with mountain bike Eagle AXS cassette and a rear derailleur, would be one possibility for increasing range. You’d have to decide between a 10-50T (500%) or 10-52T (520%) cassette. For a gravel SRAM option, the AXS XPLR groupset is 12-speed with a 10-44T cassette (440% range). The e*thirteen Helix Race 11-speed, another alternative and by far the cheapest choice, offers a 9-46T (511%) range, although the jumps between the sprockets are going to be big.

To fit the parts, the right-hand shifter has to be disassembled to remove its standard ratchet and bolt. It is not a job that you should attempt to complete quickly and I would suggest doing it in a clean area as the parts are small and easily lost should you drop them. I finished the job in about 30 minutes after watching the fantastic video supplied by Ratio. The instructions and video are great, however, I would only recommend attempting the job if you have some mechanical knowledge. The jockey wheels are much easier to install – you just have to make sure they are fitted the correct way around.

Ratio_1x13_Upgrade_Kit_chainring.jpg, by Matthew Page

I used a 38T, 5-arm Ratio Ring for the test, which is 12/13 speed compatible. Ratio also makes a direct-mount chainring for SRAM three-bolt or eight-bolt crank arms.

Ratio 1×13 Upgrade Kit – Performance

After years of testing various bikes and components, I still think the Campagnolo Ekar cassette (9-42T option) has the best ratios for general gravel use. The ratios and changes between each sprocket suit my riding style, with closer ratios near the bottom for faster areas and wider spacing near the top for climbs and slower sections. Ekar also avoids using the massive bail-out gear of the SRAM mullet setup.

Ratio_1x13_Upgrade_Kit_Internal1.jpg, by Matthew Page

Ekar isn’t perfect and I have been using it since it was first released. After a lot of riding, I found that it is very sensitive to cable wear and tension, and the shifter design won’t suit everyone. There are very few options for replacement brake pads, with the Campagnolo-branded pads being very expensive. It has proven to be durable, and, after 5,000km of regular use, I am still using the original cassette and chain, with barely any chain wear. Some might question the nine-tooth sprocket, arguing it isn’t as smooth or efficient as a 10 or 11T sprocket, but anyone using the 9T sprocket for extended periods would consider sizing down in terms of the chainring.

SRAM 1×11 isn’t perfect either, with the major drawback being a hazy shift action caused by having up and downshifts on a single shifter.

With the 1×13 kit fitted, it was good to ride with the range that the Ekar 9-42T delivers, supporting my view that it is the best choice for gravel riding. Despite shifting smoothly in the work stand, I needed to make some adjustments to the cable tension. It took some tweaks, both up and down, to get a perfect shift. A completely straight mech hanger will also be essential and should be checked before fitting.

Ratio_1x13_Upgrade_Kit_Internal2.jpg, by Matthew Page

I needed a few hours to adjust to the movement needed in the shifter but the action feels identical to that of a typical SRAM mech with a rather vague shift feel. This is because the gaps in the ratchet are smaller, so it will take some time to adjust to the amount of movement needed for each shift. Once I was happy, it was reliable and remained so throughout testing.

In terms of overall performance, the Ratio 1×13 kit combines the advantages of both groupsets, offering a greater range but it does have its drawbacks. The shift action is vague, which needs precise finger inputs to get right and you’ll need to get the cable tension spot on for smooth operation.

Ratio_1x13_Upgrade_Kit_Complete.jpg, by Matthew Page

Ratio 1×13 Upgrade Kit – Verdict

If you do not already own a compatible SRAM groupset, I don’t think it is a cost-effective purchase. When you consider how small the Ratio ratchet is and the asking price, it seems quite expensive, yet there is currently no other company making comparable parts. Both a complete Ekar groupset and an SRAM AXS electronic groupset will set you back more than £1,000.

Is the Ratio 1×13 a worthwhile purchase? There are a lot of ‘ifs’ in my view. If you already own a SRAM 1×11 (or possibly 1×10) groupset, wish to increase the range and number of gears, are capable of the mechanics required to install it, can justify the cost of very small parts and Ekar components, and wish to stick with a mechanical groupset, then the kit works well.

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