Large Chainring Sizes - 55T 56T

[MexicanBunyip]

I'm currently riding a 53T chainring on my 10speed. Id like to upgrade to a 55 or 56t chainring.

I mostly ride long distances on flat land in one straight line to work and back.
Main reason for the switch is I want more power and also I make out at a certain speed on downhills pedalling.

Id like to keep my momentum increasing as I increase speed while pedalling.

Would this be the best option and also what chainring would you recommend with a 5 bolt dura ace crank. I saw some online called DriveLine on ebay. Are they any good?

[MexicanBunyip]

Max out^

[LateStarter]

I'm currently riding a 53T chainring on my 10speed. Id like to upgrade to a 55 or 56t chainring.

I once rode with a rider who did "BIG" distances, he was doing a 1,000km and I just a 200, I managed to hang on for about 45kms till he disappeared into the distance, about one of his bikes

"..One of my three bikes (Trek Cronus CX) is set up with an 80-73-53 chain-set bought off the shelf from Greenspeed who make recumbents out at Knox. The big rings are easy enough to find, the challenge is in getting them on the bike – getting a rear frame that can actually take the cog, and getting the right derailleur hanger height on the front and jockey wheel drop on the rear..."

https://cyclingtips.com/2015/05/miles-a ... ar-record/

I don't believe Greenspeed manufacture in Australia any more but you might find some bits from dealers

[P!N20]

Haven’t we done this before? viewtopic.php?f=12&t=104001&p=1524458#p1524458

[Andy01]

I would have to wonder if such a small increase is really worth the effort ?

Even 56T from 53T is a 5.6% increase, so if you are doing 50km/h now, you will get an extra 2.8km/h, which could be achieved with a slight increase in cadence (probably something like going from 80rpm to 85rpm).

[rkelsen]

Define "max out".

53/11 at 90 rpm = 55kph, which is quite fast on a bike. If you can't crank it up that much, then you might want to focus on increasing your cadence first? I dunno, just thinking out loud.

Would this be the best option and also what chainring would you recommend with a 5 bolt dura ace crank. I saw some online called DriveLine on ebay. Are they any good?

They'll fit as long as they're the same BCD. They might not look as good, because they're not 'styled' like the DuraAce ones, but they'll fit and will probably work. Then there might be some tuning to get it shifting smoothly, eg: You might need to move the FD up and possibly lengthen the chain, play with cable tension, etc.

[foo on patrol]

56x12 is good enough for 100kmh down hill, without over extending yourself.

Foo

[Derny Driver]

Normal cadence is somewhere between 80rpm and 100rpm. Let just say you pedal at 90. If you need 56-11 on your long rides, you would be travelling at 58kph. Without wanting to sound rude, I highly doubt you could do that for 100 metres let alone 100km at that speed.
I suspect you probably ride at around 32-35kph, at a cadence of 50-55rpm. Very poor technique.
The best professional cyclists in this country don't ride around with 55 or 56 tooth chainrings on their bikes. That's because they know how to pedal properly.
But you can ride however you want, so go ahead if you wish to.

[Duck!]

If you're set on a 54t+ chainring, you will need to pair it with a 42t small ring, otherwise your front shifting will go really up the fritz.

Also, the main reason the pros use "oversize" chainrings isn't for absolute speed, it's to gain snippets of efficiency by straightening the chainline, and getting a higher useable gear in the middle of the cassette.

[MattyK]

If you're set on a 54t+ chainring, you will need to pair it with a 42t small ring, otherwise your front shifting will go really up the fritz.

Also, the main reason the pros use "oversize" chainrings isn't for absolute speed, it's to gain snippets of efficiency by straightening the chainline, and getting a higher useable gear in the middle of the cassette.

...whilst averaging 55kmh in a time trial.

A slightly larger gear will make very little difference to your descending speed, where you are probably burning 1000+W of gravitational potential energy into wind resistance.