Can some one explain these gears...
Discussion
Hi, I'm a bicycle idiot; can some one explain these gears please
it's a road bike with 700c wheels and the gears are 12-24 (compact) on the back and 42-53 on the rear.
does this mean my bike is set of for flat, hills or a combination? I ask because I live in the middle of the pennines and these hills are seeming bleeding impossible!
it's a road bike with 700c wheels and the gears are 12-24 (compact) on the back and 42-53 on the rear.
does this mean my bike is set of for flat, hills or a combination? I ask because I live in the middle of the pennines and these hills are seeming bleeding impossible!
12-24 (compact) on the back and 42-53 on the rear.
They are not a compact set of gears
12-24 will be on the wheel so high geared and not good for hills
42-53 again high geared and not good for hills
If you are looking for compact gears they should be around 34-50 front
Rear will range between 11 and 32 depending on the make
They are not a compact set of gears
12-24 will be on the wheel so high geared and not good for hills
42-53 again high geared and not good for hills
If you are looking for compact gears they should be around 34-50 front
Rear will range between 11 and 32 depending on the make
by compact I meant two ring. I guess I got my terms wrong!
ok, so it's rubbish gearing for hills. Given that I live next to the tour de france route I will need a different gearing.
would this be good on the back instead?
http://www.ebay.co.uk/itm/SHIMANO-11-32-8-SPEED-MO...
is it likely just to bolt straight on, or do I have to be careful to get the right type or something? will it work with my chain? should I stick to motorbikes?
ok, so it's rubbish gearing for hills. Given that I live next to the tour de france route I will need a different gearing.
would this be good on the back instead?
http://www.ebay.co.uk/itm/SHIMANO-11-32-8-SPEED-MO...
is it likely just to bolt straight on, or do I have to be careful to get the right type or something? will it work with my chain? should I stick to motorbikes?
"Compact" = usually 34/50, sometimes 36/50 at the front.
"Double" = 39/53, 42/52, various other options at the front.
I >think< that cassette will fit - Shimano 8-speed is all the same hubs iirc. And it will help.
Do you know how to change it though? You need special tools to get the freewheel off.
"Double" = 39/53, 42/52, various other options at the front.
I >think< that cassette will fit - Shimano 8-speed is all the same hubs iirc. And it will help.
Do you know how to change it though? You need special tools to get the freewheel off.
OP,
What gears do you have? The name will be on the rear deralleaur. The number of gears at the back is also important. If in doubt, take a photo and post it =)
Most road bikes can't do a 32 rear gear, not with a big ring up front. SRAM and Shimano both do a long cage version of the rear deraliur (for triples etc) that can, but most bikes are supplied with "short cage" rear mechs that will max out at 28 or so.
What gears do you have? The name will be on the rear deralleaur. The number of gears at the back is also important. If in doubt, take a photo and post it =)
Most road bikes can't do a 32 rear gear, not with a big ring up front. SRAM and Shimano both do a long cage version of the rear deraliur (for triples etc) that can, but most bikes are supplied with "short cage" rear mechs that will max out at 28 or so.
Some Gump said:
OP,
What gears do you have? The name will be on the rear deralleaur. The number of gears at the back is also important. If in doubt, take a photo and post it =)
Most road bikes can't do a 32 rear gear, not with a big ring up front. SRAM and Shimano both do a long cage version of the rear deraliur (for triples etc) that can, but most bikes are supplied with "short cage" rear mechs that will max out at 28 or so.
its a shimano sora setup.What gears do you have? The name will be on the rear deralleaur. The number of gears at the back is also important. If in doubt, take a photo and post it =)
Most road bikes can't do a 32 rear gear, not with a big ring up front. SRAM and Shimano both do a long cage version of the rear deraliur (for triples etc) that can, but most bikes are supplied with "short cage" rear mechs that will max out at 28 or so.
pic as requested
wiggle said:
Top Features of the Shimano Sora 9 Speed Rear Derailleur
The 9 speed Sora derailleur features an advanced light action for low-friction shifting up or down the cassette and is compatible with all 9 speed frivetrains.
•Wide link design for increased rigidity and precise gear shifts•11-tooth pulleys for reduced pulley wear and chain noise•Pulleys feature sintered alloy bushings for smooth-running performance•37 tooth total capacity, rear sprocket size range 11-32T
I run a compact front (50-34), and 11-28 rear. I am bad at hills, but go in the peaks a lot. I still have to use my smallest combo sometimes, but get by. 34*28 is 31.9 inches.The 9 speed Sora derailleur features an advanced light action for low-friction shifting up or down the cassette and is compatible with all 9 speed frivetrains.
•Wide link design for increased rigidity and precise gear shifts•11-tooth pulleys for reduced pulley wear and chain noise•Pulleys feature sintered alloy bushings for smooth-running performance•37 tooth total capacity, rear sprocket size range 11-32T
If you can fit the 12-32, then your bottom gear is 42*32, which is 34.5".
That means your bottom gear is somewhere between my lowest and 2nd lowest combo. IMO you can get by on this, unless you intend to spend the whole time on the steepest hills you can find.
The comments above relate to the 9-speed version of the Sora rear mech. Yours looks like an 8-speed Mech. I'm not convinced it would be happy with a 32 tooth large sprocket.
You could fit an 11-32T or 12-32T cassette and, if the 32 tooth sprocket interferes with the rear mech., split the casette, remove the 32T sprocket and add a spacer, and use it as a 7-speed casette with a 28T largest sprocket (you'd need to reset the rear mech limit screw to avoid overshifting into the position formerly occupied by the 32T sprocket).
Alternatively, fit something like a 11-28 or 12-28 cassette and reduce the chainring sizes. You can fit a smallest inner 'ring of 38 teeth with the chainset you have, and then perhaps fit a 48 tooth or 50 tooth outer 'ring.
Alternatively, just swap the chainset to a 'compact double' with 'ring sizes 34 / 50.
You could fit an 11-32T or 12-32T cassette and, if the 32 tooth sprocket interferes with the rear mech., split the casette, remove the 32T sprocket and add a spacer, and use it as a 7-speed casette with a 28T largest sprocket (you'd need to reset the rear mech limit screw to avoid overshifting into the position formerly occupied by the 32T sprocket).
Alternatively, fit something like a 11-28 or 12-28 cassette and reduce the chainring sizes. You can fit a smallest inner 'ring of 38 teeth with the chainset you have, and then perhaps fit a 48 tooth or 50 tooth outer 'ring.
Alternatively, just swap the chainset to a 'compact double' with 'ring sizes 34 / 50.
Bugger! I could have sworn that i counted 9 last night...
Anyways, this might help:
http://www.bikeforums.net/archive/index.php/t-4178...
Anyways, this might help:
http://www.bikeforums.net/archive/index.php/t-4178...
Rouleur said:
Disco You said:
You're probably best off changing your chainring(s) rather than your cassette.
You can't put compact rings on the OP's chainset, he'd have to change the whole thing which will get expensive. It's the ideal solution though.ok, so i'm losing what you guys are saying slightly. so here is my understanding...
I assume I should be changing the front gears rather than the rear to make it easier, so...
.
I have taken off the big ring at the front which was dead easy to do, and it looks like the smaller ring could become the bigger ring, then I get an even smaller ring. BUT
measuring the distance between the bolt holes, it's 76.4mm which an ebay seller listed as BCD 130mm
Then I have a think about it. the 40 ring which is the small one i pretty much as small as you can get with this BCD. Meaning that if I wanted a smaller chainset, then I will need a whole new chainset and pedal thingies(crank?)... Which I assume isn't all that cheap.
A quick check of ebay confirms this.
So I'm back to the rear gear cassette (are my technical terms getting better?)
have had a look at the back, and there's no way I'm getting this off. says shimano dura-ace hyperglide Lock 40 nm
so this must be the tool to remove it: http://www.ebay.co.uk/sch/i.html?_sacat=0&_fro...
so after all that, here is my question:
If I buy this: http://www.ebay.co.uk/itm/Shimano-CS-HG31-8-Speed-...
can I chop and change the different gear rings on it and on mine, or are they in a certain order, or are they fixed?
I assume I should be changing the front gears rather than the rear to make it easier, so...
.
I have taken off the big ring at the front which was dead easy to do, and it looks like the smaller ring could become the bigger ring, then I get an even smaller ring. BUT
measuring the distance between the bolt holes, it's 76.4mm which an ebay seller listed as BCD 130mm
Then I have a think about it. the 40 ring which is the small one i pretty much as small as you can get with this BCD. Meaning that if I wanted a smaller chainset, then I will need a whole new chainset and pedal thingies(crank?)... Which I assume isn't all that cheap.
A quick check of ebay confirms this.
So I'm back to the rear gear cassette (are my technical terms getting better?)
have had a look at the back, and there's no way I'm getting this off. says shimano dura-ace hyperglide Lock 40 nm
so this must be the tool to remove it: http://www.ebay.co.uk/sch/i.html?_sacat=0&_fro...
so after all that, here is my question:
If I buy this: http://www.ebay.co.uk/itm/Shimano-CS-HG31-8-Speed-...
can I chop and change the different gear rings on it and on mine, or are they in a certain order, or are they fixed?
Edited by Efbe on Thursday 8th August 23:17
I'm in a similar position - http://www.ukcyclingevents.co.uk/events/wiggle-men...
I'm on a 25+ year old alloy bike with 8 speed Campagnolo 12-23 cassette with 42+52 front chainring (double?).
Have not 'road' cycled for while, past couple of weeks have been refamiliarising with above old friend (which is very comfortable on flats and downhills).
LBS not keen to acquire/change cassette, and it looks like only option (for my rear cassette) is 13-26. So am going to just push on, missing that lower gear, and looking forward to top of hills and flats.
Will then make a decision on if I want to spend money on old bike or change. Or just stick to off road.
(have forgotten how much I had enjoyed the acceleration and speed though).
<> <> <>
EFBE - Below website calculator may help understand your ratios (and appreciate the overlap of gears whilst changing between front chainrings (yours is 42/53)
http://www.bikecalc.com/gear_ratios
I'm on a 25+ year old alloy bike with 8 speed Campagnolo 12-23 cassette with 42+52 front chainring (double?).
Have not 'road' cycled for while, past couple of weeks have been refamiliarising with above old friend (which is very comfortable on flats and downhills).
LBS not keen to acquire/change cassette, and it looks like only option (for my rear cassette) is 13-26. So am going to just push on, missing that lower gear, and looking forward to top of hills and flats.
Will then make a decision on if I want to spend money on old bike or change. Or just stick to off road.
(have forgotten how much I had enjoyed the acceleration and speed though).
<> <> <>
EFBE - Below website calculator may help understand your ratios (and appreciate the overlap of gears whilst changing between front chainrings (yours is 42/53)
http://www.bikecalc.com/gear_ratios
It is possible to find 'Standard double' sized chainrings that will fit onto a 'Compact' crankset, with the smaller BCD. I know because I had a pack in my hand at Fatbirds in Norfolk, but I chickened out of buying them because they were quite expensive. I don't think it works the other way around, because the bolt holes on the larger 'Standard' crankset are too far out from the centre to allow a set of 'Compact' rings to fit. The front dérailleur will work with compact or standard rings, it just needs to be slid up/down the seat tube to 'mesh' correctly with the teeth of the chainrings that are fitted, and a corresponding change needs to be made to the clamping point on the cable.
On most rear cassettes, the smallest three/four 'cogs' (higher gears) are usually permanently joined together, with the remainder of the larger (low gear) 'cogs' coming separately in the pack. As such, it is possible to 'mix and match' the lower gears to achieve a 'custom' cassette on which you decide where the larger gaps between ratios should sit. This will most often mean buying more than one cassette and having some wasted 'spare' cogs. I have no idea if you can order separate component parts of rear cassettes from Shimano, but a decent LBS should be able to answer that question, or pass the query up to the distributor (Madison?).
Short answer (and cheapest option) is to take the advice of the LBS, or consult the Shimano data sheets you should find online, and fit the largest 'cog' your rear dérailleur can cope with, on an off-the-shelf cassette. If you buy a Shimano replacement, with the same numbers of cogs at the same spacings, you may not even need to adjust your indexing, simply purchase, fit, and forget. Most expensive option would be to buy a complete new 'compact' groupset and replace everything, or even just replace the whole bike with something more suited to the task. Personally, I'd recommend trying the cassette first. Either it works, and you love it, or when you come to sell the bike you can point to the 'brand new cassette, recently fitted - invoice to prove' on the ad
On most rear cassettes, the smallest three/four 'cogs' (higher gears) are usually permanently joined together, with the remainder of the larger (low gear) 'cogs' coming separately in the pack. As such, it is possible to 'mix and match' the lower gears to achieve a 'custom' cassette on which you decide where the larger gaps between ratios should sit. This will most often mean buying more than one cassette and having some wasted 'spare' cogs. I have no idea if you can order separate component parts of rear cassettes from Shimano, but a decent LBS should be able to answer that question, or pass the query up to the distributor (Madison?).
Short answer (and cheapest option) is to take the advice of the LBS, or consult the Shimano data sheets you should find online, and fit the largest 'cog' your rear dérailleur can cope with, on an off-the-shelf cassette. If you buy a Shimano replacement, with the same numbers of cogs at the same spacings, you may not even need to adjust your indexing, simply purchase, fit, and forget. Most expensive option would be to buy a complete new 'compact' groupset and replace everything, or even just replace the whole bike with something more suited to the task. Personally, I'd recommend trying the cassette first. Either it works, and you love it, or when you come to sell the bike you can point to the 'brand new cassette, recently fitted - invoice to prove' on the ad
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