Shimano road drivetrain differences

This article covers the actual differences between Shimano road groupsets. ‘Road’ here refers loosely to a bike with drop handlebars, as opposed from one with flat handlebars.

Shimano organises these in rank order, from worst/cheapest to best/most expensive:

1. A050 (7 speed, no brakes specified)
2. Tourney A070 (7 speed, rim brakes)
3. Claris R2000 (8 speed, rim brakes)
4. Sora R3000 (9 speed, rim brakes)
5. Tiagra (10 speed) 4700/4720 (rim/hydraulic)
   GRX RX400 (10 speed, hydraulic ‘gravel’)
6. 105 (11 speed) R7000/R7020 (rim/hydraulic)
   GRX RX600 (11-speed hydraulic gravel)
7. Ultegra (11 speed) R8000/R8020 (rim/hydraulic)
   Ultegra Di2 R8050/R8070 (electronic shifting, rim/hydraulic)
   GRX RX810 (11 speed hydraulic gravel)
   GRX Di2 RX815 (11 speed electronic shifting hydraulic gravel)
8. Dura-Ace R9100/R9120 (11-speed rim/hydraulic)
   Dura-Ace Di2 R9150/R9170 (11-speed rim/hydraulic)

However, there is not necessarily a performance difference between successive levels (often just weight). This article discusses the differences.

Brake/shifters

The biggest difference between a ‘full groupset’ (Claris or above) and Tourney & A050 is in the brifters.

Firstly A050 was introduced as bottom-of-the-line in 2002. They use handle-bar mount thumb shifters:

These are indexed on the right-side, for seven speeds. The left side uses friction, that is to say you’ll have click until it shifts into the right spot.

Shimano don’t make a cheap brake-only drop-bar lever, so a bike fitted with this design will have some other brand’s brakes. Obviously these shifters are very cheap, and you’ll find them fitted typically to bikes with very week components.

The Tourney A070 brifters are a full combined ‘STI’ brifter, based on the 1999 Sora 3300 brifters, which were in turn introduced as an ergonomically inferior version of the higher-end brifters. This is not terrible, but it does mean that rather than being able to shift from the drops, the down shift lever is instead located near the hoods. In addition, A070 does not have internal cabling, and this will help mark it out as older compared to the ‘full’ groupsets. For the reason of the very old brifters, Claris should be considered a big upgrade on A070.

notice the downshift lever on the end of the main lever on the Claris (and higher), which is located near the hoods on the Tourney

The Claris R2000 & Sora R3000 brifters are identical apart from being 8 vs 9 speed, though Claris is typically supplied with a non-stainless steel shift cable. This is a consumable item you should replace fairly regularly, so it should not be a concern. They weigh around 500 grams.

The Tiagra 4700 brifters are similar, but are 488 grams and 10 speed. Shimano claims these brifters are ‘SLR EV’. R2000, R3000 and 4700 should all have similar performance to previous generation 105 5800.

The 105 R7000, Ultegra R8000 & Dura-Ace R9100 levers are a newer generation with slightly different ergonomics. Dura-Ace has better-quality internals, which might result in longer-term durability, but there doesn’t seem to be much difference initially. However Ultegra & Dura-Ace get carbon fibre levers, which might be nice in cold weather. They weigh only 438g and 365g respectively, whereas 105 is similar to Tiagra at 482g.

Rear derailleurs

The Tourney A070 derailleur, used for A050 & A070, uses a different design from all the others, with larger jockey wheels, based on a mountain bike design. Although this is a good design, the RD is made from steel and plastic, and has a maximum rear cog size of only 28t. This means you’ll probably find this derailleur with a triple chainset, in order to get the low(ish) gears beginners need.

The Claris (R2000) & Sora (R3000) rear derailleurs are almost identical, using the same jockey wheels. Both have plastic A-knuckles, and are mostly steel. However the outer link on the R3000 is aluminium. There really is no difference between these, both are basic and functional, and much better than the Tourney.

The Tiagra (4700) rear derailleur is aluminium & steel (no plastic). It uses similar jockey wheels to the Claris & Sora. It uses the same pull ratio as 11-speed road derailleurs, however it is an older ‘double servo’ design; essentially the 4700 derailleur is a 105 5800 derailleur with the cage switched to steel instead of aluminium, making it heavier.

The GRX RX400 rear derailleur is more like a mountain bike derailleur, as it contains a clutch (so it’s slightly heavier than the 4700) and uses the ‘Shadow’ pulley design including Deore T6000 cage, and will work with 11–36t cassettes. It also uses the 11-speed pull ratio.

The 105 (R7000) rear derailleur uses the Shadow design, common to R8000 & R9100 as well. It’s still got basic jockey wheels, and there are some extra plastic parts compared with the (older) Tiagra design. It’s not obviously a better constructed derailleur than the Tiagra, but it is around 43 grams lighter, and it is claimed that the Shadow design is more durable.

Ultegra (R8000) is very similar to 105, but the jockey wheels are now improved, the derailleur hanger axle is aluminium and so is the P-axle. This makes it 25g lighter & gives better performance.

There is no GRX RX600 derailleur — technically RX400 or RX810/RX812 will work, but the RX810 & RX812 are the ‘11-speed’ models (even though they are interchangeable between RX400, 4700 and all 11-speed road/gravel RDs.

These models are similar in quality to Ultegra, though the RX812 is based on the M8000 Deore XT RD. RX812 is intended for an 11–42t 1x setup, and has been modded with an M8000 long cage to go beyond this. RX810 is a more conventional-for-road double, with a 11–34t cassette.

The Dura-Ace (R9100) is better finished with nicer bolts & axles all-round, and extra carbon fibre parts. This saves 42 grams over Ultegra. However it is not likely to offer any efficiency gains. The R8000 is more than sufficient.

Front derailleurs

The Tourney front derailleur design is again an older one, similar to previous generations of Claris, and distinct from the others.

The Claris front derailleur uses lots of steel and is relatively heavy at 143 grams to the Sora’s 117 grams. The newest Claris R2000 is updated compared to earlier ones being ‘long arm’ hence shifting better. So too is Sora. Tiagra just saves a few grams and has no performance benefit. There’s no advantage here.

The Claris, Sora and Tiagra triple front derailleurs lack the ‘long arm’ as that comes from Dura-Ace/Ultegra/105 9000/6800/5800 series, which had no triple.

The 105, Ultegra & Dura-Ace front derailleurs are the next generation redesigned front derailleurs and improve front shifting and setup for braze-on frames. Ultegra and 105 are all-but-identical while Dura-Ace uses bearings so might be more durable/smoother in the long run.

The GRX 400 and 810 front derailleurs are based on these designs, but are designed for a smaller chainset (30/46 or 31/48 rather than 34/50). There’s very little difference between a 10-speed and 11-speed chainset, but essentially these front derailleurs are the same quality, just slightly better suited to different chainsets.

Caliper brakes

The Tourney brakes are ‘Super SLR’, whereas Claris and Sora are ‘New Super SLR’. However you may often find other brands of brake on Tourney bikes.

Brakes are similar with no difference between Tiagra, Sora & Claris, all around 180g in weight.

Ultegra & 105 are not lighter, but they are better using ‘SLR EV’ design. The Dura-Ace brakes shave about 30–40 grams off using ‘unobtainium’ parts.

Hydraulic shifters & brakes

The market for hydraulic brakes on road bikes is fairly new, and Shimano is still trying to milk it, so you can’t yet buy Sora or Claris hydraulic shifters. Sometimes manufacturers will fit cable disc brakes to the same shifters, but these typically won’t be Shimano models.

The Tiagra 4720 & 4725 shifters are updated models based on the 105/Ultegra/Dura-Ace. There is not much to choose between Tiagra & 105. The older RS405 levers might be still found on some bikes- they are much less ergonomic. Both 105 & Tiagra weigh around 620g the pair.

Ultegra is 554g, and Dura-Ace 538g. The 4725, R7025 and R8025 models are for smaller hands.

The Ultegra, RX810 & 105 calipers are identical and weigh 286g. The Dura-Ace weigh 256g but don’t offer any performance benefits at all. They are however supplied typically with titanium-backed brake pads, but these are consumables and interchangeable. The Tiagra & RX400 calipers are the same weight/ body as 105/Ultegra/RX810 but uses resi pistons instead of ceramic. This means slightly worse heat dissipating performance, but this would only possibly be relevant on long descents.

Apart from this rotors aren’t really a groupset part, but the Dura-Ace (RT900), Ultegra/RX810 (RT800) & 105 (RT70) rotors have an aluminium core to conduct heat a way. Each saves around 10g on the next model down by use of more aluminium in structural areas. The 105 rotors lack the fins which are said to help with heat dissipation. Tiagra/RX400 may use RT64 rotors, which don’t have heat-dissipation fins or aluminium core, and weigh around 20g more.

Cranksets

There are bigger differences with cranksets than with most other components.

Firstly, the Tourney crankset uses riveted (non-removable) chainrings made of steel. It also uses the older/heavier (but very serviceable) square taper bottom bracket. The weight may be as high as 1.3kg. There are both 50/39/30 and 50/34 models. Note that with the 50/34 model, you will have a low gear of 34/28, which will be quite hard for beginners climbing hills.

In some cases manufacturers may specify the non-series RS200 crankset on Claris bikes. This is essentially the previous generation Claris chainset, with square taper bottom bracket. This is a 50/34 model.

The full (R2000) Claris crankset is either 50/39/30 (334 + 120 + 85g) or 50/34 (330 + 63g), with solid crank arms. The chainrings are steel, except for the 50t, which is steel and plastic. The total weight of the double crankset is 1080g, inclusive of 258g for the solid crankarm.

Sora is the same, but aluminium and plastic for the 50t. The double crankset weight is 980g.

Tiagra uses aluminium & GFRP 50t rings, aluminium 39t & 34t rings, and steel 30t rings. Double chainrings are 225+ 31, triple are 233 + 96 + 84. The double crankset weight is 927g.

105 has no triple chainset. The chainset is quite different from lower units, in that the arms are hollow. This reduces weight to only around 710g.

The RS510 chainset is commonly specced as a downgrade on otherwise 105-equipped bikes. This is essentially a Tiagra chainset, i.e. solid crank arms and heavy chainrings. The weight is 908g.

Ultegra has hollow outer chainrings, and is supplied with aluminium chainring bolts, saving around 7g. The Ultegra chainrings (112 + 34g) are cross-compatible with the 105 chainset. The weight is around 675g.

Dura-Ace has slightly lighter chainrings and other weight is reduced to 614g.

The GRX chainsets are slightly confusing but can be summarised as follows:

• RX600–1 and RX810–1 use the same chainrings, which are described as 11-speed, but in fact there’s no difference at all between an 11-speed and 10-speed 1x chainset. There are 40t and 42t chainrings. RX810 has hollow crank arms, while RX600 is solid. This means 644g vs 743g.
  As an example, you could use the RX 1x chainset with a 11–42t 10-speed cassette, and the RX812 ’11 speed’ rear derailleur.
• RX600–10 and RX600–11 are the same thing as each other but with a very slightly different outer chainring (inner ring is the same). These weigh 810g and are 46–30t. Solid crank arms.
• RX810–2 is a 48–31t double chainset with hollow crankarms weighing 710g.

The chainsets correspond more to Tiagra and 105 in their weight/construction, not Tiagra and Ultegra.

All the groupsets are supplied with high-quality HT2 bottom brackets, however there’s a 15g saving between the BB supplied with Claris/Sora/Tiagra/RS510, and Ultegra/105, and 12g more saved going to Dura-Ace.

All of the cranksets should shift well, but clearly there are substantial weight savings at 105 level, unless your manufacturer cheaps out with the RS510 instead! Top-level cranksets claim higher stiffness as well.

Cassettes

The Tourney A070 will typically come with a freewheel design, not a cassette. This means a different rear wheel, which won’t be as durable typically as freehub designs. In addition, the range is only 14–28t, which gives a relatively hard bottom gear. There is also 12–28 cassette, which lacks the nickel plating of the full groupsets, so will be less durable, though this is not such an issue as you can always replace cassettes as consumable items.

The Claris, Sora, and Tiagra cassettes are basic designs made of steel. All three use Shimano’s Hyperglide system.

The 105 cassette uses a ‘spider arm’ to reduce weight for the three largest cogs. This only saves about 20g.

The Ultegra cassette saves about 33g more by using lighter weight material for the spider arms, and adding a second spider arm assembly for the fourth & fifth cogs.

The Dura-Ace cassette further reduces weight (58g) by using titanium for those five largest sprockets.

The shifting performance of all the cassettes is similar, but the higher ones save a small amount of weight for extra cost. Many users, considering cassettes a consumable, will prefer the cheaper cassettes.

Chains

Chains are not really a groupset item, but Claris uses 8-speed HG71 chain, which weighs 324 grams, as 8-speed is the widest chain. 9-speed HG53 chain, for Sora, is 299g. Deore/Tiagra/RX400 10-speed HG54 chain is narrower still, at 273g.

11-speed chain HG601 (‘105’) and HG701 (‘Ultegra’) weigh 257g. Both compared to cheaper chains claim Teflon roller link plate treatment, but the HG701 adds it on the pin link plate as well. The HG901 chain is 247g thanks to hollow pins. There’s also Teflon on the rollers.

All these chains are consumables. A cheaper clean, well-lubricated chain will work better than a poorly maintained expensive one.

Conclusions

Of course everything comes down to price. With money no object, Dura-Ace is the best. But Ultegra is almost identical and costs much less. 105 is identical in terms of its basic function, but the rear derailleur is not as good quality as the Ultegra, although this is not a big deal in that it’s a cheap and easy replacement if/when you wear it out. So 105 is also an excellent choice.

The Tiagra 4700 groupset is older and due an update, in which case it may become more attractive. The front derailleur is a different design which still works well, and the crankset is significantly heavier (though heavy cranksets are often specced on 105 bikes). In addition, the caliper braking is weaker. However, as the hydraulic brake performance is very similar between all the groupsets, hydraulic Tiagra is a more appealing prospect than its caliper counterpart.

The Sora & Claris groupsets are not that much different from higher end groupsets, although they use generally lower grade materials. Sora is more-or-less ‘9-speed Claris’, so Claris has definite appeal in that this is ‘enough groupset’, whereas even lower grade groupsets may fall short. The main way Shimano differentiates Claris is with its very heavy outer chainring.

For example, the Trek Domane Al Disc bike for 2021 is $1050 (Al 2 Disc) with the RS200 square taper crankset and Claris, and Tektro cable disc brakes, and the Al 3 Disc is $1250 but comes with full Sora. The Al 4 Disc ($1600 has Shimano Tiagra hydraulic disc brakes, and the Al 5 Disc has upgraded hubs & 105 drivetrain ($1800).

From Canyon, the Endurace Al Disc 6.0 and 7.0 are identical except that the 6.0 uses Tiagra hydraulic and the 7.0 105 hydraulic. In addition, the 7.0 has a carbon seat post, and the price is $1500 vs $1900.

Often on new bikes the Ultegra & Dura Ace are sold with carbon fibre frames and other higher end components. However there’s nothing to stop you using them on cheaper bikes.

The Tourney groupset is outdated in many ways, including the typical use of a freewheel in most cases, older brakes, old brifters, and heavy crankset. However if you are on the tightest budget then a cheap bike with Tourney might fit the bill. A Tourney spec on a major brand bike would be crazy, however, as you’d certainly be better off with a cheaper brand and Claris.