Saturday, November 26, 2022

Cervelo Aspero: PRO PLT Carbon Road Handlebar

On the Cervelo Aspero gravel bike, I have been using the PRO Vibe Aero Superlight handlebar since the beginning. At that time, the plan was for the Aspero to serve as a dual purpose road and gravel bike, as seen from the two wheelsets that I had.

Later on, after I got the Focus Paralane as a road bike, the Cervelo Aspero was converted to be a dedicated gravel bike with a front single drivetrain. One of the more recent change was to GRX Di2 shifters which work really well for gravel riding.

All the while, the handlebar used was the PRO Vibe Aero Superlight handlebar, which is OK for road riding but not really ideal for gravel. I have some issues with the design of the PRO Vibe handlebar, such as the teardrop bar shape in the drops, and the non-compatibility with standard Garmin computer mounts.

Therefore, after much consideration, I decided to change the handlebar to a more conventional round type, to improve the ergonomics and avoid all the downsides of the PRO Vibe Aero handlebar.

At the same time, I wanted to avoid or minimize the internal routing needed, as it takes more work to route hydraulic hoses and Di2 cables through the handlebar.

Finally I chose the PRO PLT Carbon Handlebar, which is relatively lightweight, with less internal routing and a normal round clamp section on top.

New PRO PLT Carbon Handlebar

These handlebars are 40 cm wide, with a standard oversized clamp diameter of 31.8 mm.

Not the top level PRO Vibe model, but the lower PLT model.

Compact shape, with a very standard 80 mm reach and 130 mm drop.

Pretty good drop shape, but the top area where it starts curving down seems too gentle for a smooth transition to the shifter hoods.

Unfortunately there is still some internal routing on the underside of the handlebar. But at least this is much easier to route than the PRO Vibe Aero Superlight handlebar.

This handlebar weighs 230 grams, not a weight weenie type. But probably safer and more reassuring for gravel riding.

Warning label not to add clip on aero bars onto these handlebars, as the walls are probably not strong enough to support clamps.

Terrible sticker which tore apart when removing, along with lots of glue and sticker residue that took me a lot of time to remove. A very negative experience, can't imagine the bike shop having to spend so much time to clean this up.

After that, it was time to remove the old handlebar from the bike, before installing the new handlebar and the shifters on it. At the same time, I will not be using the integrated EW-RS910 Junction A inside the bar end any more, but using the Di2 Info Display SC-MT800 instead. It will essentially be the same Di2 wiring layout as on the Focus Paralane.

Similar Di2 wiring layout as on the 1x11 speed Focus Paralane.

Since both the old handlebar and new handlebar has some internal routing, I needed to disconnect the hydraulic hose from the shifters. This is the downside of having internal routing, where it is more troublesome to change handlebar or make adjustments.

For Shimano road hydraulic shifters, there is a flanged connecting bolt that needs to be screwed into the resin Bracket. The torque on this bolt needs to be within 5-6 N.m, to avoid a leaky connection or a cracked Bracket.

Torque wrenches usually have a 3/8" or 1/4" square interface to the hexagon socket, but not with open wrenches. I have always been tightening this flanged connecting bolt by hand feeling, without knowing the actual torque. Extra care needs to be taken to ensure the bolt is not over-tightened.

I recently learnt that there is a tool called a crowfoot wrench, which you can see below. It is like an adapter which is attached to a standard square interface torque wrench.

Size 8 crowfoot wrench for 1/4" torque wrench, which needs to be attached at 90 degrees to the torque wrench for accurate torque readings.

Here is how it is used. The open crowfoot wrench allows the flanged connecting bolt to be tightened using a standard torque wrench.

GRX Di2 shifters installed onto the new PRO PLT carbon road handlebar. Note that I can attach a standard cycle computer mount from Cycliq, and also the Di2 Display onto the round handlebar.

View from the front. Cycliq Duo Mount for the Cycliq Fly12 Front Camera + Light if needed.

Side view of the transition from the shifter hoods to the handlebar. Not a smooth transition, due to the shape of the handlebar.


At the newly opened bridge that crosses over Hillview Avenue.



Latest bike component specifications. Note an additional 200 grams of weight mainly due to the PRO Stealth Off-Road saddle and the Redshift suspension stem.

I think it will be quite a while before I modify anything else on the Cervelo Aspero, as I don't have anything else lined up as of now (Nov 2022). It is a very good gravel bike which I really like, and I can't really find anything else that needs an upgrade. In fact, this PRO PLT carbon handlebar change is not really necessary, just something that has been bugging me for quite some time now.

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