Image 1 of 7 Fernando Gaviria (Quick-Step Floors) wins the opener, Peter Sagan (Bora Hansgrohe) second and Marcel Kittel (Katusha Alpecin) third (Image credit: Tim de Waele/TDWSport.com) Image 2 of 7 Warren Barguil (France) crashes at the 2018 elite men's Worlds road race, and subsequently abandons the race (Image credit: Bettini Photo) Image 3 of 7 A battered Fabio Aru climbs Balcón de Bizkaia with his UAE teammates during stage 17 at the Vuelta (Image credit: Getty Images) Image 4 of 7 Louis Meintjes (Dimension Data) (Image credit: Tim de Waele/TDWSport.com) Image 5 of 7 Edward Theuns (Sunweb) (Image credit: Bettini Photo) Image 6 of 7 Lisa Brennauer (Wiggle High5) wins Lotto Thuringen Ladies Tour (Image credit: Lotto Thüringen Ladies Tour) Image 7 of 7 Alberto Bettiol lost his wheel on some gravel (Image credit: Bettini Photo)

Last week we cast our eye back to the 2017-2018 transfer window and looked at the moves that had paid off over the course of this season. This week, we're looking at those that didn't.

Whether it's adapting to the new environment, new teammates, a new calendar, or simply a lack of form for whatever other reason, there a number of high-profile riders who, wearing fresh colours, haven't lived up to the high expectations they set for themselves in previous years.

Marcel Kittel (Quick-Step Floors to Katusha-Alpecin)

How the mighty have fallen. Marcel Kittel was on top of the world this time last year. He'd just ended the season topping the victory rankings, with 14, and had struck no fewer than five times at the Tour de France. After two seasons with Quick-Step, his annus horribilis of 2015 seemed a distant memory, yet little did he know that something similar was just around the corner.

Kittel signed for Katusha-Alpecin for the start of the 2018 season. Since then he has won just two races, struggled to build an effective lead-out train, fallen out with team management, and succumbed to an illness that required him to call time on his season in August.

Kittel's move to the Russian team was tied up with their sponsorship deal with Alpecin - the German shampoo company teaming up with the nation's star rider and bearer of most-discussed hairstyle in the WorldTour seemed like a natural fit - but it wasn't like Kittel had the luxury of choice. In fact, his departure was precipitated by the rise of Fernando Gaviria, who, with his four wins on his Grand Tour debut at the Giro d'Italia - not to mention him equalling Kittel's end-of-season record of 14 wins - had established himself as the Belgian team's lead sprinter for 2018.

Kittel pulled on the red of Katusha and, with Fabio Sabatini having refused to follow him from Quick-Step, set about building a lead-out train with Marco Haller and Rick Zabel. The early signs were far from encouraging at the Dubai Tour and although there were some improvements in Abu Dhabi, Kittel left the Middle East without a customary early-season win. Things looked to be back on track when he swapped Paris-Nice for Tirreno-Adriatico and struck twice, but he wouldn't win again all season.

The Tour de France was where Kittel would truly be judged but his best finish was third on the opening stage - behind Gaviria no less - before he left in the mountains after missing the time cut on stage 11. Things turned sour when Katusha DS Dmitry Konyshev labelled Kittel 'egotisical' and criticised him for staring at his phone during meetings.

Kittel returned in August, but abandoned both the BinckBank Tour and the Deuschland Tour before ending his season early due to health reasons. "It is not so easy to find the cause for my bad feeling on the bike, unfortunately," he said. "Luckily, there is no virus involved, but it is clear that my body simply needs peace and quite right now."

The 2018 season was another annus horribilis for Kittel, few will be writing them off. As he showed three years ago, if anyone knows how to come roaring back, it's the German.

Fabio Aru (Astana to UAE Team Emirates)

The sullen, forlorn expression on the face of Fabio Aru was an all-too-common sight in 2018, a season which saw the Italian veer yet further from the promise he once showed.

Aru turned pro with Astana at the end of 2012 after winning the Giro della Valle d'Aosta and, after helping Vincenzo Nibali to Giro d'Italia victory in 2013, he was on the podium himself as soon as 2014. The following year he won two stages and finished second overall in Italy, before winning the Vuelta a España later that season. Aru then spent two years targeting the Tour de France but - despite winning a stage, wearing the leader's jersey and finishing fifth overall in 2017 - he switched back to the Giro in 2018 as he left Astana for pastures new at UAE Team Emirates.

Aru injured his leg at the Volta a Catlunya but returned to finish sixth overall at the Tour of the Alps, a result that hardly made him a Giro favourite, but certainly didn't rule him out. The writing, however, was on the wall as Aru fell away on Gran Sasso d'Italia on stage 9, and he continued to haemorrhage time until he quit the race on stage 19.

Medical tests would suggest dietary intolerance and a surplus of training at altitude and Aru skipped the Tour de France in order to prepare for the second half of the season. Yet, the Vuelta a España didn't go much better. He was in and around the top 10 for the first half of the race but shipped time in the Asturias mountains. He was left cursing his bike and his bad luck as a blocked chain caused him to crash at speed on stage 17, and he trudged home in Madrid in 23rd place.

Aru lifted himself for a couple of Italian autumn classics before pulling the curtain down on the sorry season at the Tour of Guangxi. He said the motivation was still there but did admit: "I can't wait to hit reset."

Warren Barguil (Sunweb to Fortuneo-Samsic)

Warren Barguil to Fortuneo-Samsic was one of the most high-profile transfers of the last window. The Frenchman had just won two stages and the mountains jersey at the Tour de France, but he was soon quitting the WorldTour to drop down a division to Pro Continental level.

After a subdued couple of the seasons in the wake of the early flare he'd shown, Barguil appeared to have rediscovered himself as a rider and the move to the French team - based in his native region of Brittany - was all about tapping into that, even if it appeared something of a gamble.

It certainly didn't pay off, as Barguil spent the entire campaign way off his swashbuckling best. Having been brought in as the talisman for the French team, he didn't win a single race. He struggled gamely at the Tour de France, repeatedly infiltrating the breakaway on mountain stages, but the spark of 12 months ago simply wasn't there, and his best finish was 14th on a sprint stage. Despite finishing second in the mountains classification, Barguil couldn't quite pinpoint a reason for his lack of form in 2018, variously hinting at personal as well as health problems. There were also equipment problems as he was spotted riding a non-sponsor bike, soon after which the team ditched Look and linked up with BH.

In essence, though, there were no real excuses, and Barguil, having signed a three-year deal with Fortuneo, quickly needs to rediscover his old self if the transfer isn't to be seen as a case of wasted talent.

Louis Meintjes (UAE Team Emirates to Dimension Data)

The homecoming party turned out to be a damp squib. Louis Meintjes started his career at Dimension Data - then MTN-Qhubeka - in 2013, and was touted as a possible first African winner of the Tour de France. After finishing 10th at the 2015 Vuelta a España, the South African left his 'home' team for the Italian Lampre-Merida - which became UAE Team Emirates last year - and helped himself to back-to-back eighth-place finished at the Tour de France.

His return to Dimension Data at the start of this season came with the announcement of a three-year project, which had Meintjes on the top step of the 2020 Tour de France podium. The 26-year-old would, they said, target the Giro d'Italia in 2018 in order to gain experience away from the Tour before returning as a more complete rider. However, the Grand Tours - and the season as a whole - were a washout for Meintjes in 2018, in what was a dire season for the team as a whole.

Meintjes was anonymous in the early part of the season, and his 20th place at the Tour of the Alps certainly didn't bode well for the Giro. Meintjes said he'd had no injuries or illness, explaining that "sometimes your body responds, and sometimes it doesn't."

It didn't respond at the Giro, as he gave away time on the first summit finish on Mount Etna and continued to slip until he lost 25 minutes in a split on stage 10. Things didn't improve, and he eventually pulled out after stage 16 citing illness.

Meintjes then switched his focus to the second half of the season and the Vuelta a España, but that didn't go much better. He had finished ninth at the Vuelta a Burgos to provide some cause for optimism but he reached Madrid in 58th place. A brutal crash on a stage 14 descent had left him reeling but in truth he was already out of the equation, 24th and eight minutes down.

Meintjes once seemed a picture of consistency as he rode to those top 10s at the Tour - in a style that hardly won him many fans - but he found none of it in 2018. That 2020 project may need some revision.

Lisa Brennauer (Canyon-SRAM to Wiggle-High5)

After spending six years with variations of the same set-up, Lisa Brennauer made the switch to Wiggle-High5 for this season. Along with Kirsten Wild, she was a major signing for the team, who were looking to fill gaps in the roster after some high-profile departures.

There were some flashes of success for the German, such as the defence of her Thuringen Ladies Tour title and time trial victory at the national championships, but ultimately her season wouldn’t live up to expectations.

Having delayed the start of her season to compete in the Track World Championships, where she just missed out on a medal in the individual pursuit, Brennauer’s spring campaign was hampered by illness. There were a couple of close calls but Brennauer didn’t notch up her first win of the season until stage 4 of the Thuringen Ladies Tour.

After taking the German TT title, bronze in the European Championships road race was another highlight – though not in team colours. The remainder of the season proved disappointing with second in the team time trial at the Madrid Challenge the best result. With Wiggle-High5 due to fold at the end of the year, Brennauer will ride for WNT-Rotor next season with the hope that she can find success in her new team colours.

Edward Theuns (Trek-Segafredo to Sunweb)

Edward Theuns left Trek-Segafredo for Team Sunweb for the start of 2018 and was designated as their leader for the spring classics. One year into a two-year deal, the contract was ripped up with mutual consent and now the Belgian is on his way back to Trek.

Theuns had shown considerable promise both at Topsport Vlaanderen and at Trek, with strong Classics showings as well as an ever-improving sprint finish, and had bounced back from a severe back injury at the 2016 Tour to finish top 10 in Paris-Roubaix in 2017. He has appeared blunted throughout 2018 and the season will go down as something of a waste.

Theuns, it seems, just never clicked with his new team, and a press release was issued in which both parties insisted they had 'differing visions' of the sport. "There is a certain way of working that is typical for that team," Theuns later explained. "They get a lot of nice results, and for many riders it will work well, but for some people it does not fit. I did not come to Sunweb to be gone after one year, but in the course of this season it turned out that we had different ideas about many things."

Theuns now returns to Trek-Segafredo hoping to pick up his career where he left it 12 months ago.

Alberto Bettiol (EF-Drapac to BMC Racing)

Another rider who has returned 'home' after a one-year experiment away. Granted, the BMC team had no sponsors in place until late summer and is now taking on a new identity as the Polish CCC Team, but Bettiol lost his way slightly in the red and black and is retracing his steps to set about building on what had been some very strong foundations.

Bettiol turned pro with Cannondale in 2014 and moved under Jonathan Vaughters' tutelage when the team merged with Garmin in 2015. Riding at the WorldTour from the age of 20, the Italian grew up fast, and he had something of a breakthrough season in 2016 - albeit almost by stealth - as a string of high placings in major one-day races earned him a place in the top 10 of the WorldTour rankings and went some way to saving a miserable season for the team. There was more of the same in 2017 but no victory, and Bettiol moved to BMC as EF-Drapac scrambled to find a sponsor to keep the team afloat.

Touted as an important support rider for Greg Van Avermaet, Bettiol was unable to perform in the spring classics, posting a string of DNF's, and his season was disrupted by a collarbone fracture at Liège-Bastogne-Liège, which took him out of the Giro d'Italia. Bettiol did not make the Tour de France team, and the second half of the season was also thrown out by another collarbone fracture, this time at the Bretagne Classic. He returned in October but was unable to have any impact on the autumn Italian classics - races where he would expect to perform - and drew a line under his season by signing the contract that would bring him 'home' to EF.

"Alberto showed great promise when he was with us," said Vaughters in announcing the deal. "He was climbing near the best at the 2017 Tour de France, and he was a key part of our Classics team. He got a bit derailed in 2018, but we are going to get him back on track."