2015 Nicolai Helius AC 650b

I fell in love straight away

This bike is our first 2015 model year Helius AC 650b frame. I visited the Nicolai factory in Germany for the first time in March 2014 and I'd been in there for only a few minutes when I spotted this bright yellow colour in a welding booth. I'd never seen a Nicolai this colour and it turned out to be an experimental finish they'd been playing with. They call it semi permeable glaze, it's available in green, yellow, red and orange and in the daylight it's a really vibrant colour. The best bit is the transparency, you can see through it into the welded frame, the workmanship in these hand built aluminium frames still visible. 

I already had one of the first 650b versions of the Helius AC, this arrived in autumn 2013 and having been a longstanding Nicolai dealer I've had a few of their bikes over the years, mainly Argon hardtails and an early Helius CC and 26 inch wheels Helius AC. The 650b bike was something else, I'd always stayed away from 29ers as the geometry always felt like a compromise on suspension bikes. I realised that 650b was here to stay, so getting another 26" wheel bike would be a narrow minded step. I was disappointed, my worries about the geometry, bigger wheels and lack of manoeuvrability vanished straight away, the bike felt fast, nimble and just what I wanted.  

When I visited the factory in 2014, we had a meeting to discuss the 2015 range, what they were happy with and where they felt changes were needed. Nicolai had done significant development work on their new suspension platform, the Ion, particularly the Ion 16 which they released at Eurobike in 2013. Although similar to the existing Ion 18 and 20 in suspension linkage design, they decided that the Ion 16 would be a new dawn in their pivot design. Since they started they'd always used a adjustable needle roller bearing or bush design on all their pivots. This has always worked efficiently but was prone to wear due to lack of maintenance and general abuse. 

For the Ion 16 they redesigned the shock links and main pivot bearing to be fitted with double sealed angular contact bearings. They also brought the  frames up to current standards with a ZS44/56 head tube, post mount 180mm rear disc mounts and internal cable routing for stealth/covert style dropper seatposts. In 2014 Nicolai upgraded the Helius TB to include these same features, leaving the AC as the last to feature the old pivot design. 

In the meeting we agreed on some small changes to the AC. Although the TB and Ion 16 were bigger sellers in Germany, it was my feeling that the AC 650b was perfect for UK trail riding, light enough to ride all day but with enough travel to tackle Gravity Enduro events. So the 2015 AC came with 140mm rear travel, upgraded pivot bearings and a main pivot position optimised for single chainring use. 

Build Specification 

Frame 2015 MY Helius AC 650b
Colour Semi Permeable Yellow Glaze
Size Large
Rear Shock Fox Float X
Fork Fox 34 Stealth Series
Headset Chris King Inset 2
Stem Thomson X4 70mm
Handlebar Easton Haven Carbon
Grips Hope Lock On
Seatpost Thomson Covert dropper
Clamp Thomson
Shifter Shimano XTR M9000 Right Hand
Rear Mech Shimano XTR M9000 GS
Cassette Shimano XTR M9000 11-40 11 Speed
Chain Shimano XTR
Bottom Bracket Hope Stainless
Crank Shimano XT with Works Components 34 narrow wide chainring
Brakes Hope Tech 3 E4 183F/183R
Wheels Moonglu Custom Hope Pro 2 Evo 28h / Arch EX 650b / CX Ray Spokes
Tyres Continental Mountain King / X King 2.4 Protection Tubeless


The XT crank will be upgraded to Hope Technology's new crankset once it becomes widely available. 

For anyone that would like to see a Nicolai in the flesh, this bike is on display in the shop most of the time. Please call in at any time to have a look, we're happy to talk Nicolai.  

Moonglu | Blog | Nicolai Bikes | Helius AC 650b 

February 02, 2015 by Neil Dunkley