double to Triple

ram038

I currently have a double crank on my bike and I am thinking of changing to a triple. I have noticed that on my rear shifter that there are three index clicks when I change from 53 to 39 crank. does this mean that the bike is by default set up for a triple using a double, if so does that mean that i can change the crank to a triple with no other adjustments needed or ne parts bought. I hope this makes sense , bottom line is I am struggling on what i think are modest climbs and would like a lower gear to help me get up those climbs. If it helps i have a lemond reno 2007

John.T

Are you on Shimano. If so then the extra click is the trim set to help stop chain rub on the cage. You may still have a triple shifter if it is 105 or lower. You will need to slacken the cable off to check this. You would also need a longer cage rear mech and a longer chain with a triple.

ram038

John.T wrote:

Are you on Shimano. If so then the extra click is the trim set to help stop chain rub on the cage. You may still have a triple shifter if it is 105 or lower. You will need to slacken the cable off to check this. You would also need a longer cage rear mech and a longer chain with a triple.

Rear bit is a 105. i have aked Lemond bikes if it is possible to convert to a compact and they said no because the BCD ona a compact is 130 as oppose to 110 on a double. Can anyone verify if this is the case or know a way around the BCD incompatability.

aracer

You can change to a compact, but that will involve a whole new chainset, rather than just changing the rings (which is where the size incompatibility comes in).

star_rover

You can pick up a tiagra compact chainset for about 35 quid. Depending on your bottom bracket, that should be all you need.

maddog 2

change to comapct is much cheaper

to do it properly

triple
- chainset
- rear mech
- front mech
- BB (probably)
- STI (maybe)

compact
- chainset
- BB (maybe)

ram038

star_rover wrote:

You can pick up a tiagra compact chainset for about 35 quid. Depending on your bottom bracket, that should be all you need.

basic question i know but what part is the chanset?

ram038

duh next questions is

is there a standard bottom bracket type if not how do you kno which bb your bike has?

andy_wrx

A bit of confusion here - you say you have 52 & 39 front rings on your bike (the rings and the pedal arms are the 'chainset' btw), a 105 'rear bit' (rear mech/rear derailleur I assume) and you've asked Lemond about converting to a compact and 'they've said no because the BCD on a a compact is 130 as oppose to 110 on a double'

A bit of Googling appears to show your bike has this spec
LeMond Reno 2007
Shifters: Shimano Tiagra STI
Chainset: Bontrager Select with 53/39 tooth rings
Gears: Shimano Tiagra front and Shimano 105 rear derailleurs
- is that right ?

With this spec I think...

Triple
- you'll need a triple chainset (three rings on the front)
- you'll need a long-cage rear mech (triples need long-cage, you'll currently have a short-cage one for your double)
- you'll *maybe* need a new front mech
- you may or may not need a new BB (bottom bracket), depending on what chainset you get and whether it's compatible with your current one, but triples tend to require a wider BB than doubles if it's the 'traditional' sort
- I *think* (I'm fairly sure but not certain - someone else confirm ?) your STI's (shift levers) will be OK, because I think Tiagra will do double or triple (the three clicks you're getting now are big-ring, little-ring and little-ring-trim-click, but there will be a fourth one there for the inner ring on a triple which you're not getting to at the moment)

Compact
- you'll need a compact chainset (smaller 50 & 34 rings on the front : your double has a 130BCD so the smallest ring you could possibly fit is a 38, a compact has 110BCD - the bolts are closer to the centre - so you can have a 34 little ring)
- your short-cage rear mech will be fine
- your front mech will be fine, but will need adjusting lower for the smaller 50 & 34 rings
- you may or may not need a new BB, depending on what chainset you get, as above
- your STI's will be fine
- you might want a new cassette : what do you currently have ? 12-23 or 12-25 ? To get lower still you might want to try a 12-27 cassette

- and either way, if you're doing all this, I'd replace the chain too
- maybe the gearshift cables too, if they are worn/corroded

No insult intended, but from some of the questions you're asking, replacing all this sounds like it might be more of a job than you're used to, so there's also the cost of labour to get the bikeshop to do it.

ram038

andy_wrx wrote:

A bit of confusion here - you say you have 52 & 39 front rings on your bike (the rings and the pedal arms are the 'chainset' btw), a 105 'rear bit' (rear mech/rear derailleur I assume) and you've asked Lemond about converting to a compact and 'they've said no because the BCD on a a compact is 130 as oppose to 110 on a double'

A bit of Googling appears to show your bike has this spec
LeMond Reno 2007
Shifters: Shimano Tiagra STI
Chainset: Bontrager Select with 53/39 tooth rings
Gears: Shimano Tiagra front and Shimano 105 rear derailleurs
- is that right ?

With this spec I think...

Triple
- you'll need a triple chainset (three rings on the front)
- you'll need a long-cage rear mech (triples need long-cage, you'll currently have a short-cage one for your double)
- you'll *maybe* need a new front mech
- you may or may not need a new BB (bottom bracket), depending on what chainset you get and whether it's compatible with your current one, but triples tend to require a wider BB than doubles if it's the 'traditional' sort
- I *think* (I'm fairly sure but not certain - someone else confirm ?) your STI's (shift levers) will be OK, because I think Tiagra will do double or triple (the three clicks you're getting now are big-ring, little-ring and little-ring-trim-click, but there will be a fourth one there for the inner ring on a triple which you're not getting to at the moment)

Compact
- you'll need a compact chainset (smaller 50 & 34 rings on the front : your double has a 130BCD so the smallest ring you could possibly fit is a 38, a compact has 110BCD - the bolts are closer to the centre - so you can have a 34 little ring)
- your short-cage rear mech will be fine
- your front mech will be fine, but will need adjusting lower for the smaller 50 & 34 rings
- you may or may not need a new BB, depending on what chainset you get, as above
- your STI's will be fine
- you might want a new cassette : what do you currently have ? 12-23 or 12-25 ? To get lower still you might want to try a 12-27 cassette

- and either way, if you're doing all this, I'd replace the chain too
- maybe the gearshift cables too, if they are worn/corroded

No insult intended, but from some of the questions you're asking, replacing all this sounds like it might be more of a job than you're used to, so there's also the cost of labour to get the bikeshop to do it.

Thanks for your time and effort, the info is exectly what i was looking for. No offence taken as I am totally ignorant regarding bikes which is why i bought a Double and not a triple\compact. I have no intention of doing this myself but I would like to be prepared when I go to my LBS and not get ripped off because of my lack of knowledge.

thanks again..

star_rover

ram038 wrote:

star_rover wrote:

You can pick up a tiagra compact chainset for about 35 quid. Depending on your bottom bracket, that should be all you need.

basic question i know but what part is the chanset?

If you were to buy the Tiagra compact you would then buy the Tiagra Hollowtech 2 BB cups (they are about £15).
This is the chainset http://tinyurl.com/2qyble
You might also need a new chain, as someone has already said. But your front mech will be fine.

This seems the easiest way to achieve what you want, rather than messing about with buying chainrings, etc.
If you still find you need a lower gear try a 12-27 cassette, again as already suggested.

I did the same thing with my Lemond Tourmalet, swapped the double for a compact, all I bought was the chainset and chain.

ram038

star_rover wrote:

ram038 wrote:

star_rover wrote:

You can pick up a tiagra compact chainset for about 35 quid. Depending on your bottom bracket, that should be all you need.

basic question i know but what part is the chanset?

If you were to buy the Tiagra compact you would then buy the Tiagra Hollowtech 2 BB cups (they are about £15).
This is the chainset http://tinyurl.com/2qyble
You might also need a new chain, as someone has already said. But your front mech will be fine.

This seems the easiest way to achieve what you want, rather than messing about with buying chainrings, etc.
If you still find you need a lower gear try a 12-27 cassette, again as already suggested.

I did the same thing with my Lemond Tourmalet, swapped the double for a compact, all I bought was the chainset and chain.

This seems the easiest option thanks. did you find that the change from the double to Compact made much of a difference on hills?

star_rover

It does make a difference. Not a huge amount, but enough. If you find you need a wee bit more help, try fitting 12-27 cassette (your bike probably has a 12-25 at the minute), which will give you an even lower bottom gear.

John C.

Before you buy, check the cost of a whole new Groupset. It may work out cheaper and you would then also have your old Group for a winter bike or you could sell on.