Prototypes of TRP's DH-specific derailleur and shifter made their World Cup debut on Aaron Gwin's bike back in 2018, and several teams have been using the DH7 drivetrain between the tape this season.
The components are now available to the general public, marking TRP's first official step into the drivetrain arena. The shifter and derailleur were designed with extensive input from Aaron Gwin and his mechanic, John Hall; the derailleur even has a feature called the 'Hall Lock' that came from that partnership.
TRP DH7 DetailsDerailleur• Adjustable ratcheting clutch
• Hall Lock B-knuckle lock
• Carbon cage and upper link
• Weight: 281 grams (actual)
• Price: $179.90 USD
Shifter• Carbon fiber upper housing and advance lever
• Adjustable lever
• Weight: 111 grams (actual)
• $119.99 USD
•
trpcycling.com ShifterThe 7-speed shifter has grooved paddles to help provide extra traction and hopefully prevent any missed shifts. It's possible to shift up the cassette five gears at a time, while the release lever allows for one shift to a harder gear at a time. That release lever is positioned so that it can be reached by moving your thumb either over or underneath the advance lever depending on rider preference. The carbon fiber advance lever can be adjusted within a 40-degree range for an extra level of cockpit customization.
DerailleurThe feature that sets TRP's short-cage derailleur apart is the Hall Lock, the lever that's located to the left of the mounting bolt. Flipping that lever to the closed position effectively locks the B-knuckle in place, which keeps the derailleur from bouncing around and creating unwanted noise or chain movement. The tension of the Hall Lock is adjustable, and the lever allows it to be turned off for wheel changes or derailleur adjustments.
Along with the Hall Lock, the derailleur also has an adjustable, ratcheting clutch mechanism. The clutch adjustment is hidden behind the pulley wheel, which can make it a little tricky to get to without removing the wheel. It's a relatively fine adjustment, too, and an eighth of a turn can make a noticeable difference in how tight the clutch is. Other details include sealed cartridge bearing pulleys and a carbon fiber cage and upper link.
Ride ImpressionsI've put in five days of bike park laps aboard the DH7 drivetrain so far, enough time to get a solid feel for the ergonomics and performance of the shifter and derailleur combo.
Installation was quick and easy, and I appreciated the fact that there weren't any tiny screws to fumble with when performing a cable swap. The clutch mechanism provided plenty of tension to keep the derailleur's cage from extending forward too easily, although the ratcheting mechanism is audible if there's not much other noise going on – you can hear the cage return to its home position when the bike is unweighted. When I was bombing down the trail with a full face helmet on it wasn't as noticeable, but it's there. The Hall Lock worked as intended, holding the derailleur securely in place and away from the frame. How much difference it makes will vary from bike to bike, but the fact that it's adjustable is a nice touch.
The shifting feel isn't quite as light and refined as what you'll find with SRAM's DH drivetrain – it takes a little more effort to shift up or down, but each shift generates a positive 'click'. I got along well with the actual shape of the shifter, and it didn't take any time at all to get used to the positioning.
On my fifth day of riding I ran into an issue I haven't experienced in years – I went to add a little cable tension and noticed that the barrel adjuster had snapped off inside the shifter. I'm not exactly sure what the cause could have been – I hadn't had any memorable crashes or collisions, and the shifter itself is free of any scratches or other damage. It's a pretty easy fix, but it's still far from ideal.
It's great to have another competitor in the mix, and the DH7 derailleur does have several novel features that set it apart, but the price vs. performance ratio isn't quite enough to elevate it above the level of SRAM and Shimano's offerings. Still, it's going to be interesting to see what else TRP bring to the table in the future.
Mine was bouncing and I could have broken the chip where the adjustment bolt sits on.
Anyone else remember this?
In a magical theoretical world would a system where the chain could decouple for downhills and then reconnect when you need to pedal be perfect?
Some bikes does have a quite neutral kickback and are working similarly with or without a chain.
For others, when the chain is under tension (the upper part of the chain, so, either when pedalling or when braking), it does add some "new" characteristics to the suspension. It can be unwanted or it can be wanted by the frame's designer.
There is some brands that tried to reduce these things. Canyon had a prototype "freewheel clutch".
I don't know if they kept the idea.
If you really want to reduce the chain tension effect on the suspension, it's actually quite easy with modern tools to make a frame with just a little kickback so you don't have to worry about decoupling the chain. There is aslo a trend, bikes using pulleys and high pivots, that reduce the kickback but increasing antisquat and rearward travel. This can totally negates the kickback if you really want.
To help with the explanation, imagine a single speed, without derailleur. The chain would snap before the suspension start moving freely in the first cenario, the chain could drop from the cogs in the second cenario.
The ghost cog only helps with pedal kickback.
But, we're looking at a really small effect there. The clutch doesn't lockout the cage, it only makes it harder to move. It adds 20 Lbs or something like that to the chain tension (I don't remember exact values). Its way less than the tension of the upper links by at least a factor 15.
Difference between cluth and no clutch is less than bushing vs bearing in the shock's eyelets.
So you're not wrong but it's negligible
Look at the last "cavalerie" bike. They had to move the main pivot to have enough antisquat.
www.cavalerie-bikes.com
Their previous bikes are using a main pivot concentric to the output shaft of the gearbox.
I've reworded that passage for clarity, but even TRP's own literature sticks with the terminology I used.