Shimano R600 chainset question

Asha

Asha

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Asha
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Presently have this bike http://www.giant-bicycles.com/fr-FR/bikes/model/tcr.1.double/7672/44566/#overview with a shimano R600 39 / 53 chainset along with a 10spd 12-27 cassette.

The bottom end gearing is a tad high for winter training in the hilly terrain where I live.

Is it possible to change the inner ring to a 34T and possibly the outer to a 50 ( i doubt a 34 / 53 difference will function properly will it?) or is it going to be a cheaper option to simpy replace the chainset for a 34/50 compact?

Any links to suitable chainrings and/or chainsets appreciated.............second hand in decent nick will do so long as all works correctly.
 
You would be better changing the gear cassette.
what about an 11-32 ?
 
Mr Bump said:
You would be better changing the gear cassette.
what about an 11-32 ?
Click to expand...

Mr Bump said:
12-30
Tiagra

http://www.probikekit.co.uk/bicycle...imano-tiagra-4600-10sp-cassette/10809999.html
Click to expand...


Cheers Paul, I've just calculated gear ratios and yes, bottom gear of 1.3 ( 39/30) would work fine as presently it's 1.44

Two questions......

1. Do you know what the cog sizes are throughout the range for that cassette?

2. More importantly, I presently have the 105 derailleur short cage.....is it going work with a 30T cog without jocky wheel / cog contact issues?

EDIT ;;;;ignore question one, I've just found the info!
 
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and you have the tool
 
on your original question - it's all down to the "bolt circle diameter" - i.e. the bolts that hold the chainring on. To get 34t at the front, it needs a maximum of 110mm BCD, anything larger than that, and the bolts would be where the teeth need to be.

To measure you're BCD, use this - http://www.wolftoothcomponents.com/pages/how-to-measure-bolt-circle-diameter-bcd

if you've a standard 110mm (usually referred to as a road "compact" BCD) with 5 bolts, then you CAN get a 34-50 combination, BUT the cost of a pair of genuine shimano rings would be as much as a replacement crank new (this goes through the range - i've got Ultegra on one bike and 105 on another, and it was cheaper to buy a whole new crank than the pair of rings) However, you can get cheaper rings - TA specialities do a "budget" range which may work.

Oh - and if you change the inner ring to a 34, you'll HAVE to go to a 50t on the big-ring, as the front changer only has a capacity of (depending on the 105 model) 15-16teeth or less... so 34+16 = 50T max. - Front changing with anything wider than that capacity will be "seriously compromised" - ie , half the time it won't work at all, and the other half it'll drop the chain or overshift.

For the terrain you've got around your way, I'd be throwing on the new 11-speed Ultegra and a GS rear mech, to drop a 50-34 crankset and 11-32T cassette - and probably still having to swap to SPD pedals so I could walk some of the hills... but that's a function of my lousy power/weight ratio.
 
I've got Ultegra 11 speed with 11-32 on my Scott Speedster 10
 
Mr Bump said:
I've got Ultegra 11 speed with 11-32 on my Scott Speedster 10
Click to expand...

Stills struggling on with 10-speed 6700 series here on the Dolan I'm afraid, apart from the 6800 chainset (which was cheaper than buying kosher replacement chainrings for the 6700 cranks...) - Hack/Crosser has 10speed 105 on it (and the old 6700 ultegra cranks with aftermarket rings - so I can switch the Stages powermeter between bikes fairly easily) - If I can ever get fit again and actually start giving it a worthwhile amount of mileage, then I'm thinking that it'll be 11s Ultegra Di2 (probably the next incarnation after the current one at the rate of progress I'm showing!)
 
I'm pretty happy with the setup I have on the bike but have just popped for some new wheels.

Mavic Cosmics from Merlin cycles with tyres and tubes for £251 delivered :)

they look Cosmic.

still cannot fit properly as waiting for chain tool to swap cassette, on rear.

 
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nice... This summers upgrade was going to be a pair of Shimano WH-RS81 C35's , but the past 6 months worth of health problems and the massive setback i've had in my riding, fitness and pretty much everything kind of made them a complete waste of time/money.
 
TheBigYin said:
TA specialities do a "budget" range which may work.
Click to expand...

Not sure I would brand TA as budget. Maybe Shimano on the other hand is overpriced?

TA have been around for many many years and produce seriously good kit, without the massive advertising budget the Shimano throw around, yet they are still there producing lightweight kit that just goes on and on. The reason I like TA stuff is that you can mix some of their chainrings with other brands depending on the configuration.

I have a TA chainring on a mega expensive Campag Record 11 Speed Carbon Fibre crank and bottom bracket set up (there are very specific reasons why this was needed). I also have a bike with a full TA set up that has been on that bike for over thirty years and is still going strong. At the end of the day the size of the front and rear mechs are crucial in being able to cope with differing chainrings and rear cogs as the spare chain required to float around that sort of set up needs to be compensated for when you change up. Take a look at a gear chart, to see where you are going and/or duplicating gearing.

Shimano gives very smooth changes due to the cut outs and design of the rings/cogs which assist with the chain climbing and descending from the larger cogs and chainrings. Most manufacturers these days have a similar system.

And yes as Paul mentioned you need appropriate specialist tools. Can be cheaper and quicker to tell the bike shop what you are after and let them get their hands covered in oil.
 
Oh, I know TA have a high profile - i've been around bikes since the "cyclotouriste" triple was the only game in town for a decent low gearing option as well ;)


What I meant was TA have a couple of different grades of chainwheels - the top flight ones are pretty much on a par price-wise as shimano 105 or the better aftermarket jobs - BUT they also do a range that aren't quite as expensive - think a pair for my old hack came in at around £40 for the pair.
 
TheBigYin said:
nice... This summers upgrade was going to be a pair of Shimano WH-RS81 C35's , but the past 6 months worth of health problems and the massive setback i've had in my riding, fitness and pretty much everything kind of made them a complete waste of time/money.
Click to expand...

I think a lot of what we as "road cyclists" buy vastly exceeds our real needs, I just like pretty stuff and to be fair earn a good amount of money.
The bike I bought the Scott Speedster 10 came in at well under 1k and with the finishing kit items still only stood me at about £1100 I had always budgeted for nice wheels and its currently sale time of the year :-)

The only thing I might do for winter is replace the front mech which is 105 with the ultegra version, also the brakes are a generic shimano model.
 
Thanks for all the detailed info guys.

I'm going to go with Pauls idea and sort out a 39 / 30 set up for the winter bike.

The 1.30 ratio will be fine as although i have a compact 34/50 ultegra set up with an 11-28 on the other bike, i very rarely see myself needing lower than the 23 cog even after à long day in the hills.

Nonetheless it's nice to have that security of àn easy gear or two to plod home if the legs pack up! Lol

I haven't shot à photo of my bike(s) in ages .....maybe i'll post one on here :)
 
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