Detrained? Dodgy bike?

Hello. Quick question - I’m no bike mechanic but want to know if there’s something up with the bike.

Testing hasn’t been frequent of late but I did a solid half monty in mid dec. A few ups and downs in training in Q1 but I hit April at a level where every workout I ran at +5%. I did 9H at +5%, an hour’s run the next day and AVDP @ +5% the day after. Feeling good and even my notes say “retest time”.

I was away for a week in late April. I managed no cycling but some surfing (upper body wasn’t happy) a couple of easy runs (weather was hot, I struggled). Whilst I was away I left the bike in the shop for a full service - it’s been on the trainer for 6 months, I felt it needed a bit of TLC.

My first ride back felt awful. Sluggish, like I could barely move the pedals. I was exhausted from travelling so put it down to that. I gave up after 10mins of z2.

Since then I managed a Holy Week/van Aert back to back (it felt ok, but at target power and they’re not tough) And TBTIWT but at +0%. It was pretty hard.

Half Monty today. I was feeling good. FTP -7% and MAP -3% to the December numbers!

I also note that having not dropped a chain in about the last 12 months I dropped it 8 times during the Holy Week.

Have the ****ed up my bike? I don’t care if my numbers have gone down, but I’m a little perplexed giving I was absolutely smashing them a couple of weeks ago. I wouldn’t have expected fitness to drop like that. Life stresses,travel, etc etc are also to beb remembered of course, but I felt good today and HRV/RHR have been steady.

Do I just go back and ask them to check ti out? It doesn’t sound odd, but it feels it.

TLDR: I want to make sure they’re nothing wrong with the bike. It is the bike or me?


Well, the dropped chain is likely related to the shop service… everything else it’s too hard to know what’s going on. Have you ridden it outside to see if it feels off (if you ride outdoors :rofl:)

If you take the chain off do the cranks spin freely? Worth checking in case something has happened with the bottom bracket / chainset

Did you give them the trainer to service with your bike, or did you put the back wheel on and then have them service it? And is your trainer a wheel-off or wheel-on trainer?

Even with the exact same cassette on a smart trainer, it can still fit different than your actual rear wheel cassette. Took my bike to the mechanic and it shifts flawlessly on the rear wheel when I’m out on the road, but when I put it on my trainer it doesn’t exactly line up anymore. May need to re-index your gears for your trainer. Or, did they put on a new chain, but you’re still using the old worn cassettes?


You make a good point. Trainer is a Kickr Core, put the wheels back on for the service.
They did replace the chain (I wasn’t expecthing them to, it seemd ok to me to be honest, I’m not 100% convinced it wasn’t an easy bit of margin for them), but the casette on the Kickr is most definitely not new.

I’ve never had any problem with shifting on the trainer - itendical casette and the spacing/indexing hasnt always been perfect (I also do 99.9% in erg mode).

To @jesawdy’s question. no I haven’t had the chance to try the bike on the road if I’m honest. That would always be my first test before putting it back on the trainer but time and weather havent really bbeen in my favour (I know that’s a poor excuse).

Thanks for the responses!

I previously had a really old and worn drive train and over time my chain started dropping more and more. Got to the point where the big ring dropped the chain if I rode anywhere close to threshold and I had to ride only in the little ring.

At first I replaced the chain and rear cassette, but if anything that made it drop even more. So just a short time later I replaced the front rings and that solved it. New chain and new cassette and rings means happy bike and happy me.