Few questions regarding changing chainset

xbox gamer

Hi all,


I'm a newbie with a few questions. I've a Carrera TDF and the current double chainset of 52/39 (along with the weight of the bike) isn't great for climbing. I want to change to a compact double chainset and i found a cheap shimano 8 speed one online to avoid changing everything on the bike. I want to know:

• Whats the difference in the crankarm lengths? I currently have a 170mm for a 58cm bike and the ones available for the chainset are 170mm and 175mm. Being 5ft 11", i should be 172.5mm (according to the charts) so which one shall i go for?
• Will i need to change the bottom bracket or will the current one do?
• Do i need to change the chain to suit the comapact chainset?

I know these may be stupid questions, but i'm sure somebody can answer them and maybe even suggest something better. I know the other option is to change the cassette but i don't want to go down that road due to lack of 8 speed cassettes with 11 teeth cog.

Many thanks,

Niall

The chainset in question http://www.parker-international.co.uk/16483/Shimano-2350-8-Speed-Compact-Chainset.html

victorcarrera

Its unusual to see 170 cranks on an off the shelf 58cm frame but I do it myself.
I am also 5' 11" and a bit and I use 170 on a hybrid triple, 172.5 on a compact training bike and 175 on a standard double race bike. I prefer the shorter cranks for training and spinning and the longer ones for racing.
The new crankset you have shown is square taper so it depends on what is already on the bike for compatibility.
Its all 8 speed so no need to change the chain, but you might have to take a link out of it.
If the existing BB is square taper you will also need a crank extractor and a torque wrench to do a proper job. If it is not you will need more specialised tools.

xbox gamer

Thanks Victor,

It seems that i should probably stick with the 170mm as i'm just cycling to keep fit at the moment. When the need to race starts itching, i'll get a better spec bike with 175mm.

Hopefully the bottom bracket is the same, saving all the hassle, as i'll give it a go at changing the chainset. Its one way of getting to know your bike.

Thanks again for the info.

Paul Kiernan

xbox gamer wrote: »

The chainset in question http://www.parker-international.co.uk/16483/Shimano-2350-8-Speed-Compact-Chainset.html

Cheaper here, and only €6 delivery. The Carrera is square taper too so just remove old cranks and fit new. See this. You will need the tools though! This from Halfords probably has everything.

xbox gamer

Paul Kiernan wrote: »

Cheaper here, and only €6 delivery. The Carrera is square taper too so just remove old cranks and fit new. See this. You will need the tools though! This from Halfords probably has everything.

Thanks Paul,

That offer gives me food for thought. Didn't realise that it would be cheaper elsewhere, although they are out of stock. Might be worth holding out for it considering the brother wants one too.

Looking at the info., it seems to be an easy job to remove the chainset. Is that true? Also after looking at the Halfords toolkit, is there a need for the toolkit or would ordinary tools do?

happytramp

xbox gamer wrote: »

Thanks Paul,
Looking at the info., it seems to be an easy job to remove the chainset. Is that true? Also after looking at the Halfords toolkit, is there a need for the toolkit or would ordinary tools do?

It's not hard. But the one thing you will certainly need is the crank extractor. About €10 most bike shops places. You may also need a 14mm socket wrench and a regular adjustable wrench.

http://www.youtube.com/watch?v=c4r8PwKxAOM

Regarding the tools in general, if this is the only thing you plan on doing you might be alright with just the crank extractor. I started the same way (removing crank too) but bought more tools as I needed them (freewheel/cassette remover, Bottom bracket tool etc) It was fine but ultimately cost me a lot more than getting a specific bike tool set in the first place.

Paul Kiernan

You won't get the cranks off without the correct tool! This one will do.

You'll also need a full set of Allen keys 2mm to 8mm (or even 10mm).

If you do go for a complete tool set this might be a better buy than Halfords.

xbox gamer

happytramp wrote: »

It's not hard. But the one thing you will certainly need is the crank extractor. About €10 most bike shops places. You may also need a 14mm socket wrench and a regular adjustable wrench.

http://www.youtube.com/watch?v=c4r8PwKxAOM

Regarding the tools in general, if this is the only thing you plan on doing you might be alright with just the crank extractor. I started the same way (removing crank too) but bought more tools as I needed them (freewheel/cassette remover, Bottom bracket tool etc) It was fine but ultimately cost me a lot more than getting a specific bike tool set in the first place.

Thanks happytramp,

It seems too easy. I think i'll just get the crank extractor and start my tool collection that way, as i have a few normal tools already.

xbox gamer

Paul Kiernan wrote: »

You won't get the cranks off without the correct tool! This one will do.

You'll also need a full set of Allen keys 2mm to 8mm (or even 10mm).

If you do go for a complete tool set this might be a better buy than Halfords.

I have a multi tool kit that contains the allen keys, so i thinks the only thing is the crank extractor as I have the other normal tools.

Just one question, how good are Rose Versand at delivery? They're more than €20 cheaper (for two chainsets) and although it will be in stock in two weeks, do they have a long delivery time? Don't want to be waiting around too long when the weather is getting better and there are hills to climb

Lumen

xbox gamer wrote: »

Just one question, how good are Rose Versand at delivery? They're more than €20 cheaper (for two chainsets) and although it will be in stock in two weeks, do they have a long delivery time? Don't want to be waiting around too long when the weather is getting better and there are hills to climb

Rose generally take about a week to deliver in my experience. Slower than Wiggle.

Paul Kiernan

I've had no problems with Rose delivery, usually arrives within the week, most of the UK retailers take nearly as long.

Just realised you may need a chain tool and a chain link to break, shorten and remake your chain. I'd try it without breaking first though and see if the derailleaur can take up the extra slack. Even if it can't, you can still use the bike but you won't be able to use the smallest rear cogs while on the smaller front ring.

xbox gamer

Thanks for your help Paul and Lumen. Just after ordering the chainset and extractor from Rose bikes. Found it very cheap, now just have to play the waiting game like a child at Christmas