Arenberg Shimano 105 Di2 12 Spd

It's neither sluggish nor razor-fast - more of a versatile middle ground. This road speed rating is tuned for paved riding - think steady fast tempo and easier acceleration. It ends up here thanks to all-round road tires that balance speed and comfort, an aero-leaning setup that reduces drag at higher speeds, and a solid drivetrain that supports efficient riding.

Overall on climbs: 3.3/10. Within Road bikes, it ranks below average. On climbs, the lowest gear feels moderate. In numbers, the low gear is roughly 27.0 gear inches. On the ‘easier low gear’ scale, it sits around ~58% versus similar bikes. Gear inches is basically “how easy is the easiest gear”. Lower numbers help you keep your legs spinning on steep bits. It can climb, but you’ll likely prefer smoother pacing on longer hills. Build kits can differ by size and spec level, and not every detail is published by every brand, so use this as a practical guideline.

In race-focused terms, that 7.2/10 aero rating suggests that it balances some streamlining with versatility so it sits comfortably in the all-rounder lane. In everyday language, it’s a balanced middle ground: some streamlining, but not an extreme aero setup. Tyres around 28mm fit a faster road setup and usually keep drag in check. Specs can vary by market and model year, so the summary follows the strongest published signals. It’s a middle-ground feel: not the fastest possible in the wind, but not holding you back either.

Balanced fit - a neutral road posture that suits most riders. As a race-oriented bike, it encourages a lower, faster position. Mostly geometry-based, with a small category-based estimate.

Main reasons for the fit flexibility result: Because the bar and stem are separate, changing reach or bar shape is usually straightforward. Also, Cable routing is on the simpler side, which helps adjustability. So we classify it as Adjustable.

Comfort comes out to 3.0/10, which usually translates to a firm ride. So it’s tagged Firm overall. It’s running about 28 mm tires on 700c wheels, and narrow tires usually mean higher pressure, so more buzz comes through on chipseal and broken pavement. The posture is race-leaning (posture 7/10), which tends to feel more direct, especially over rougher sections.

This bike is best when your rides stay on clean tarmac. The tire size is around 28 mm, which is typical for fast road setups. Wheel choice (700c) fits the kind of surfaces this bike targets.