Change Front rings and Casette?

[bennydorano]

I have an Ultegra/105 Bianchi, 50/34 & 12/25. I'm thinking about possibly changing to 52/39 (or close to) and maybe 11/28 on the back. How big a job are you talking here, I take it a good bike mechanic can do this? ( I ask as I left a previous yoke into my LBS to get a new casette on and it was never the same again and I'm going to have to look about for someone to do if for me). Would those gear ratios be ok? I take I should stick to Ultegra/105 (or better) components

 

[Herzog]

A cassette change is easy (you'll need a new chain as well). However, your rear mech might not be able to cope with with the 28 tooth rear sprocket (check the Shimano tech documents).

You'll have pretty much the same low gear (around 37 gear inches).

 

[festival]

Your rear mech will cope with 28.

You havent said why ?

 

[battered]

Any bike mechanic can do this, it takes minutes. An hour tops, in total. If a mechanic messes this up he's a muppet. The only snag is that you need a pile of special tools so it's not a good place to start DIY bike maintenance. You need a chain tool, a chain whip and cassette socket to change the cassette, a crank puller and then a peg spanner for the rings themselves. That collection of tools will cost you more than an hour's labour in a bike shop.

 

[Herzog]

Any bike mechanic can do this, it takes minutes. An hour tops, in total. If a mechanic messes this up he's a muppet. The only snag is that you need a pile of special tools so it's not a good place to start DIY bike maintenance. You need a chain tool, a chain whip and cassette socket to change the cassette, a crank puller and then a peg spanner for the rings themselves. That collection of tools will cost you more than an hour's labour in a bike shop.

That's true, though next time the OP will have the tools to replace cassette, cut a chain etc. In the long term tools are a good investment.

 

[4F]

That's true, though next time the OP will have the tools to replace cassette, cut a chain etc. In the long term tools are a good investment.

Agreed, I replaced my chainset at the weekend and it took 30 mins. Much more satisfaction than paying someone to do it and you can never have too many tools.

 

[bennydorano]

Your rear mech will cope with 28.

You havent said why ?

Maybe my gear selection is rubbish, but I find I dont use the small ring except for really nasty hills. I always seem to be changing gear and I've a mate with 30 years experience who tells me he'd use maybe 3 gears on any spin - so I reckon I'm doing something badly wrong. I've a dodgy knee as well so grinding in the big ring is probably doing me no good in the long term. So I think if I have the 39/42? smaller ring I could spin instead of grind while still maintaining a decent speed? Maybe I'm badly off the mark???

Is keeping the 50 and adding a 39(or a 42) an option without changing everything else? Although it's a personal thing what would ratios would people recommend?

 

[4F]

What you are essentially doing is changing from a compact set up to a double. Everyone is different so you should take how many gears your mate is using with a pinch of salt

My double set up is 39 / 53 and I find it fine for riding around flat Suffolk however if I had some serious hills to contend with then I would prefer either the compact set up you currently have or having a triple.

 

[festival]

This reply might be a bit late now but, I would suggest you stick with the compact chain set & 12/25 and train to pedal at an increased cadence.

The aim is to pedal faster when you need to accelerate without having to change gears, much like a track rider will spin quicker to go faster while still using the one gear.

When you have achieved a proficiency at this, you will be able to use bigger gears without straining, therefore go faster, less gear changing and less stain on your knees