Changing Road Bike Gearing

[crashley]

I ride a 2011 Specialized Allez with 52/39, 13-26t 8spd gearing.

What's the best way to give me a little more top end? Can i simply swap the cassette to say a 11-25t or is there a better way of doing it? Changing the chainring to a 54 doesn't look feasible, tho' happily stand corrected. Presume in both cases, new chain required?

Cheers
Ash

[Seight_Returns]

Cassette change easiest and most viable option.

Existing chain should be fine unless worn - rear mech should take up the slack, worst case take a couple if links out.

[Disco You]

crashley said:

I ride a 2011 Specialized Allez with 52/39, 13-26t 8spd gearing.

What's the best way to give me a little more top end? Can i simply swap the cassette to say a 11-25t or is there a better way of doing it? Changing the chainring to a 54 doesn't look feasible, tho' happily stand corrected. Presume in both cases, new chain required?

Cheers
Ash

Why do you need more top end? You won't spin that ratio out until about 37mph, assuming 110 cadence...

[Smartboy]

How did you work that out? I'd be interested in seeing what speed I should be expecting to reach before spinning out. I don't have a cadance (sp?) sensor, but I do have a speedo so I'll get an idea if I need to work on leg-speed.

If I feel like I am at the max spinny-ness with my legs, but still 10mph below the calculated max, then I'm obviously not able to spin my legs quickly enough.

[Disco You]

Smartboy said:

How did you work that out? I'd be interested in seeing what speed I should be expecting to reach before spinning out. I don't have a cadance (sp?) sensor, but I do have a speedo so I'll get an idea if I need to work on leg-speed.

If I feel like I am at the max spinny-ness with my legs, but still 10mph below the calculated max, then I'm obviously not able to spin my legs quickly enough.

http://sheldonbrown.com/gears/

[greggers]

Disco You said:

Why do you need more top end? You won't spin that ratio out until about 37mph, assuming 110 cadence...

Yeah, how did you work that out...? To my calculations you won't hit 37mph until spinning at 120, which is frankly a ridiculous cadence.

You can take it from me, he needs more gearing. I ride with him and while he's spinning like a lunatic I'm at a decent cadence when around the 28mph - 30mph mark

[AndrewO]

Wanting more downhill speed ?

I don't remember pushing that sort of ratio on the flat.

[Kermit power]

A 52/13 combo would be doing 31.3mph at 100rpm cadence.

[lynus2004]

As mentioned above a new cassette will be easiest, It is pretty simple to put a new chainring on but you will get a bigger benefit going to a 12t than you would by putting a 53 or 54t chainring on the front.

Neither would require a new chain.

[okgo]

greggers said:

Yeah, how did you work that out...? To my calculations you won't hit 37mph until spinning at 120, which is frankly a ridiculous cadence.

You can take it from me, he needs more gearing. I ride with him and while he's spinning like a lunatic I'm at a decent cadence when around the 28mph - 30mph mark

You are right, 37 mph = 120 rpm, which is quite spinny.

BUT to ride at 29 mph in his biggest gear is 95 rpm which is not spinning like a lunatic in anyone's book I don't think.

[anonymous-user]

How long are you maintaining 45 km/h for though? I'd be breathing through my arse after 30 seconds of that on the flat never mind a gentle undulation or two...

[thiscocks]

The classic 'im too fast for my bike' thread

[HereBeMonsters]

pablo said:

How long are you maintaining 45 km/h for though? I'd be breathing through my arse after 30 seconds of that on the flat never mind a gentle undulation or two...

On a long descent it's entirely feasible to run out of gear for accelerating out of the bends.

[greggers]

It's so we can match our bikes to one another, we like to hold hands when we ride and the difference in gearing makes it difficult.