Why is my new bike slower than my old one? Aero?
Discussion
I have a fancy aero bike and I am a lightweight. Compared to my friend who is bigger/heavier and on a similarly weighted round tubed bike I tend to have a slower top speed on the decent by 1 or 2 mph. My trick therefore is running higher gearing and then pedalling downhill to make up the difference. What I do notice is once up to speed my bike takes a lot longer to slow down..
Not sure if that is relevant but hey...
Not sure if that is relevant but hey...
okgo said:
Lets just make clear that a 30mm difference in stems is not going to be costing you 10kph LOL
Of course it isn't, but combined with the ridiculously shallow drops on the standard bars it makes quite a big difference to the tuck position you can adopt when descending. Also, yes, I am very skinny! Always have been, and no amount of pies, toblerone or fondue seems to make a difference to it
syko89 said:
Is it not mainly the lighter wheels making the difference?
Less unsprung weight so its harder to keep the momentum up going downhill? Or am I talking rubbish?
There's no suspension, that makes the whole bike unsprung! Less unsprung weight so its harder to keep the momentum up going downhill? Or am I talking rubbish?
Unsprung weight tends to cause issues around handling, on vehicles with suspension. The weight of the wheels would more likely be noticeable under acceleration or braking. Matt_N said:
How do the top tube lengths compare?
How does the bar height compare?
Bar height is the same at the top as I took a couple of spacers out on the new bike to get a bit lower (drops are lower on the old bike as the bar is deeper). Not sure on top tube lengths, they are similar but I'm not at home so can't check at the moment.How does the bar height compare?
I've ordered the new bars and stem, will throw myself down the side of the nearest Alp once they're fitted and report back.
Try using the same wheels on both bikes. Rolling resistance can make a hell of a difference. A friend has an identical tandem - and they drop like a stone when pointing DH - to our with different wheels and his is considerably faster despite their team being lighter and a lot smaller. It just rolls and rolls - I'm convinced he's fitted a jacking oil system and is running ball-less bearings
If you're running your new, narrower tyres at the same pressure, then you'll have a larger contact patch, will you not?
Need to up the pressure in a narrower tyre.
http://sheldonbrown.com/tires.html#pressure
Need to up the pressure in a narrower tyre.
http://sheldonbrown.com/tires.html#pressure
jamiebae said:
Bar height is the same at the top as I took a couple of spacers out on the new bike to get a bit lower (drops are lower on the old bike as the bar is deeper). Not sure on top tube lengths, they are similar but I'm not at home so can't check at the moment.
I've ordered the new bars and stem, will throw myself down the side of the nearest Alp once they're fitted and report back.
Fair enough, just when you mentioned one bike had a 100mm and the other a 130mm, that's quite a difference and was wandering if that was due to just what they came with or trying to match effective length.I've ordered the new bars and stem, will throw myself down the side of the nearest Alp once they're fitted and report back.
Matt_N said:
Fair enough, just when you mentioned one bike had a 100mm and the other a 130mm, that's quite a difference and was wandering if that was due to just what they came with or trying to match effective length.
It's just what they came with. I bought the new bike online and it's marketed as more of a fast city bike than a racer, hence shallower bars and a shorter stem. My old bike was back in the UK when it arrived so I didn't get a chance to A/B test them but it has now become clear that although it's not uncomfortable the new bike isn't as good a fit for my body shape as the old one was.So maybe the bike is slow, or I just don't get on with it. I took my old bike to work today and cycled home, the first time I've ridden it properly since I got the new one. Lots of PRs, a KOM and a much faster average speed later something is clearly wrong.
This is a flat ride (42m elevation in 16k) so maybe if I try a climb then it might make a difference with the lighter weight of the carbon bike but the 30T cassette on the old one means it's not quite a fair fight there either.
I'm on the verge of selling it, and putting it down to the fact that I just don't get on with the bike - it has been serviced by the LBS, and I'm happy with my position on the bike, I'm mechanically competent and can't find anything wrong with it so I'm not sure what else to do. Luckily I have all the original parts so can put it back to standard spec and hopefully get my money back as it was very heavily discounted when I bought it.
So, the plan I formulated on the way home is to order a 2015 Genesis Equiblibrium disc frame (the new one now has a carbon fork), 11 speed Shimano 105 groupset and some TRP HY/RD calipers, and re-use the carbon wheels and new finishing kit from the old bike. The cost of all of the new bits should be covered by selling the Eastway bike and I get the bike I wanted in the first place but was too tempted by SRAM Force and lots of carbon at a bargain price.
Anyone care to talk me out of it?
This is a flat ride (42m elevation in 16k) so maybe if I try a climb then it might make a difference with the lighter weight of the carbon bike but the 30T cassette on the old one means it's not quite a fair fight there either.
I'm on the verge of selling it, and putting it down to the fact that I just don't get on with the bike - it has been serviced by the LBS, and I'm happy with my position on the bike, I'm mechanically competent and can't find anything wrong with it so I'm not sure what else to do. Luckily I have all the original parts so can put it back to standard spec and hopefully get my money back as it was very heavily discounted when I bought it.
So, the plan I formulated on the way home is to order a 2015 Genesis Equiblibrium disc frame (the new one now has a carbon fork), 11 speed Shimano 105 groupset and some TRP HY/RD calipers, and re-use the carbon wheels and new finishing kit from the old bike. The cost of all of the new bits should be covered by selling the Eastway bike and I get the bike I wanted in the first place but was too tempted by SRAM Force and lots of carbon at a bargain price.
Anyone care to talk me out of it?
okgo said:
You might as well throw £500 off the Severn bridge for all the difference its going to make.
What on earth are you on about? How can one bike be THAT much slower than another over such a short distance?
On any given bit of road I can hold 3-4kph more on the old bike than the new one, it just seems easier to hold a higher speed on the flat as well as downhill. Maybe I need to play a bit more with my position on the new bike and see if that helps because you're absolutely right, there is no rational explanation for me being much faster on an entry level £600 bike than a £2k carbon one which is theoretically 'better' in every possible way.What on earth are you on about? How can one bike be THAT much slower than another over such a short distance?
hew:Gearing is pretty much the same, compact chainset with a 11-28 10 speed on the new one and compact and 11-30 8 speed block on the old one.
As I see it, there are two possible issues - one is that the BB isn't spinning as smoothly as it should be (no noises or noticeable resistance though) or my position on the bike is way off and is stopping me transmitting as much power to the pedals.
The new bars and stem have certainly helped, and I'm more comfortable on the bike now, but it still hasn't fixed the fundamental problem that I don't seem to be able to ride this one as fast.
As I see it, there are two possible issues - one is that the BB isn't spinning as smoothly as it should be (no noises or noticeable resistance though) or my position on the bike is way off and is stopping me transmitting as much power to the pedals.
The new bars and stem have certainly helped, and I'm more comfortable on the bike now, but it still hasn't fixed the fundamental problem that I don't seem to be able to ride this one as fast.
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