cheers its not so much the energy bit its more of the speed at which I climb when I got to the climb on Thursday I was fine the climb destroys me it down to fitness I think. looking at our watt to kg we pretty close on the flat I think we similar weight but u destroy on the climb same on the last mountain coat
Team BKool CycleChat
- Thread starter Peteaud
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gbrown
Geoff on Bkool
- Location
- South Somerset
The point of a Compact (50/34) chainset is mainly for the lower gears, the difference in the top gears from a normal double chainset is much smaller.
Going back to a double (53/39) from a compact (50/34) will increase gearing in the big ring by 6% as 53/50 = 1.06, if you are spinning out in the big ring on a compact the most you will get is a 6% increase in speed (and only if you can still spin out with the 53).
However, upping the small ring from a compact to a double reduces the low gearing by almost 15% (39/34 = 1.147)!
This is why compact chainsets are popular now, as you lose little on the high end (where you can freewheel anyway) but gain a lot on the low end which can help on the steep climbs, especially for heavier or less fit riders.
I know that Shimano do a 52/36 chainset to try and find a compromise in the middle, but the best solution is to choose the gearing for the profile of the course, as the pro's do. If there are no steep climbs and a lot of descents then why not use a 53 (or even higher if you can find them), on the climbs choose a chainset to give you a low enough gear to get up! Swapping chain rings would not be worth it for us mortals, so unless you can afford two bikes for the trainer it's not really an answer.
One good compromise on a trainer bike (since the weight of the bike is irrelevant) is to get a larger rear sprocket, such as a 11-32 to give back the low gear you lose by moving the front from a compact 50/34 to a double 53/39. At the low end 39/32 (1.21875) is much the same gearing as 34/28 (1.2142857), but at the high end 53-11 gives you that 6% increase over 50-11.
Personally, I soft pedalled on the long steep descents and got my breath back for the climbs, where the power expenditure was not wasted overcoming wind drag!
I tried tucking in to go faster, but it didn't seem to work on the trainer ...
Cheers,
Geoff
Going back to a double (53/39) from a compact (50/34) will increase gearing in the big ring by 6% as 53/50 = 1.06, if you are spinning out in the big ring on a compact the most you will get is a 6% increase in speed (and only if you can still spin out with the 53).
However, upping the small ring from a compact to a double reduces the low gearing by almost 15% (39/34 = 1.147)!
This is why compact chainsets are popular now, as you lose little on the high end (where you can freewheel anyway) but gain a lot on the low end which can help on the steep climbs, especially for heavier or less fit riders.
I know that Shimano do a 52/36 chainset to try and find a compromise in the middle, but the best solution is to choose the gearing for the profile of the course, as the pro's do. If there are no steep climbs and a lot of descents then why not use a 53 (or even higher if you can find them), on the climbs choose a chainset to give you a low enough gear to get up! Swapping chain rings would not be worth it for us mortals, so unless you can afford two bikes for the trainer it's not really an answer.
One good compromise on a trainer bike (since the weight of the bike is irrelevant) is to get a larger rear sprocket, such as a 11-32 to give back the low gear you lose by moving the front from a compact 50/34 to a double 53/39. At the low end 39/32 (1.21875) is much the same gearing as 34/28 (1.2142857), but at the high end 53-11 gives you that 6% increase over 50-11.
Personally, I soft pedalled on the long steep descents and got my breath back for the climbs, where the power expenditure was not wasted overcoming wind drag!
I tried tucking in to go faster, but it didn't seem to work on the trainer ...
Cheers,
Geoff
bobinski
Legendary Member
- Location
- Tulse Hill
I would love to Rick but my knee has flared up again. So, I will have to wait until tomorrow and see how it is and then perhaps chase a few ghosts. Have fun all
Randyberlin
Guru
- Location
- Sitka, Alaska
I'm awake and drinking coffee.I'll be there if it's a go.
burndust
Parts unknown...baby
Aye right
Likewise - been in the garage most of the day and think I'd prefer a big feed and a lie down!
bobinski
Legendary Member
- Location
- Tulse Hill
Likewise - been in the garage most of the day and think I'd prefer a big feed and a lie down!
Frigging lightweights
Well, 4th go on the new Bkool Pro and it has broken - not impressed!!
I was halfway up Alpe D'huez and there was a sudden clanking, grinding noise and it seized up. There is stuff rattling around in there and shards of metal fell out when I turned it upside down so looks pretty catastrophic!
I guess I will have to package it back up and send it back to Wiggle for a replacement but it doesn't exactly fill you with confidence of the build quality...
I was halfway up Alpe D'huez and there was a sudden clanking, grinding noise and it seized up. There is stuff rattling around in there and shards of metal fell out when I turned it upside down so looks pretty catastrophic!
I guess I will have to package it back up and send it back to Wiggle for a replacement but it doesn't exactly fill you with confidence of the build quality...
Sorry guys, bailed on the climb - still not feeling 100% after this weeks non-biking exercise. Once my own ghost when past me I knew the game was up! 
Will rest and do a mountain goats stage tomorrow I think.
not the first time I've heard of that and likely wont be the last either!
I had to get mine replaced too but once you get a good one they seem to last well! Hope you get sorted swiftly - I dont think I could do without mine now!
Will rest and do a mountain goats stage tomorrow I think.not the first time I've heard of that and likely wont be the last either!
I had to get mine replaced too but once you get a good one they seem to last well! Hope you get sorted swiftly - I dont think I could do without mine now!Sorry guys, bailed on the climb - still not feeling 100% after this weeks non-biking exercise. Once my own ghost when past me I knew the game was up!
not the first time I've heard of that and likely wont be the last either!
Thanks Rick - I hope it's sorted quickly too. I was just getting used to the idea of being able to train through this rubbish weather - and looking forward to the next chain gang ride!
All that power Bridgy...
