Installing a bigger chainring
Comments
-
the jump will be too big between the two rings. It's already big at 16t. Your front mech (depending on which one you have) will probably have a 16t capacity (Shimano) so it's already at the maximum. You might be able to squeeze a few more teeth but I can't say if 53t is possble, as I haven't tried.
You could go 36/52 and keep the same jump?Facts are meaningless, you can use facts to prove anything that's remotely true! - Homer0 -
The jump from 53 to 34 will be too big plus the 'bcd' will be wrong, your compact will have a 110mm spider whereas a 53t chainring almost always has a 130mm.
Furthermore, a 50/11 is about the same as a 53/12, there's not much in it...0 -
assuming you now have a 12 on the back, when you next get a new block you could go to an 11. this will give you a much bigger difference than going from 50 to 53 up front.
the real question is how often are you spinning out your current gear?regards,
dbb0 -
Bhima I told you it would not be possible
, If I remember rightly I wanted to do something similar and was told the same thing. 0 -
-
PS, if you're good enough to want a 53t, get a 53/39 chainset, if you still need a 34t inner ring, get a triple so you can have both big and little gears.
Anyway 50-11 is plenty good enough for beyond 40mph, at which point you probably go faster by maintaining a proper aero tuck in which you won't be able to pedal anyway.0 -
hmmm..... this is very odd! It's got to be possible!
My mate's got his bike round my house now and he has the following gear configuration:
34/53 on the front
11/32 on the back
I've counted the teeth myself - it must be possible! :shock: He bought the bike off someone who'd done the upgrade from 34/50 a few months ago and contacting that guy to find out what he did is difficult, as he has now moved to another country. :?
Not too sure which front/rear mechs he has - I guess mine would be designed specifically for a particular range... Can you get ones designed for bigger ranges?
I don't want to get the 39t - or a 36t - as I like the 34 and have only 23 as my largest rear sprocket - so it would be a nightmare going up hills with a 39 - i'm no Contador/Mancebo! Hit a few 20% hills the other day and struggled because the lowest gear was so.... massive! Last thing I want to do is make it worse! I would get a cassette with a larger range, but it's brand new, so I have no intention of changing it just yet. The current lowest gear is making me push harder on the hills anyway, so it's kind of a good thing that I have the 34/23 combination.
A tripple would cost me quite a bit - as i'd need a new shifter. Not sure my frame would even allow it actually... :shock: Because of the exchange rate fluctuations, my LBS has doubled the price of the shifters in the past 4 months! :shock: I do love climbing at 130RPM+ though, so maybe I might try out my mates bike (with a tripple) in the peaks and see if it's actually possible to fit one on my frame...
dbb - I do have an 11 on the back. On the flat, I do hit 30mph+ at 100rpm and wish I had a higher gear sometimes, so this is the reason I want a bigger chainring.0 -
Bhima wrote:
dbb - I do have an 11 on the back. On the flat, I do hit 30mph+ at 100rpm and wish I had a higher gear sometimes, so this is the reason I want a bigger chainring.
You'd be pushing 40mph if you're doing 100rpm in a 50/11, and you can spin faster still if needs be. I trained on a compact over winter and I only ever span out if we had a really strong tailwind and everyone kept the bunch tight. If you're going to race however i'd recommend getting yourself a 53/39."A cyclist has nothing to lose but his chain"
PTP Runner Up 20150 -
ShockedSoShocked wrote:Bhima wrote:
dbb - I do have an 11 on the back. On the flat, I do hit 30mph+ at 100rpm and wish I had a higher gear sometimes, so this is the reason I want a bigger chainring.
You'd be pushing 40mph if you're doing 100rpm in a 50/11, and you can spin faster still if needs be. I trained on a compact over winter and I only ever span out if we had a really strong tailwind and everyone kept the bunch tight. If you're going to race however i'd recommend getting yourself a 53/39.
Sheldon Brown's Gear Calculator says:
50x11 @ 100rpm = 35.5mph.
A 39x27 = 28.0 gear inches
A 34x23 = 28.8 gear inches
therefore you can get as low a gear as you have now on a 39 ring and you still have the option of a lower gear with a SRAM cassette which go as low as a 28 so I wouldn't discount the suggestion on the grounds of the cassette at the back as this about the easiest thing you can do to adjust the gear range that you have available to you and can easily be swapped about to give you the best range of gears appropriate to the type of riding you do.
Get the chainset that is most appropriate for the type of riding which is most important to you (which is not necessarily the same as the type of riding you do most) and use cassettes to allow to do the range of riding that you want to do.0 -
If you can push 35mph at 100RPM why want bigger gears?, I'm sure I seen a thread where you stated your min cadence was like 100 and max over 200? One one gear I got 40mph at like 170RPM, no need for a bigger chainring.
I think I mioght buy another chainset though (39-53), and depending if it's a hilly or flat ride I can alternate between that and the 34-50
I'm thinking I'd be ok now with a 53-39, the other day I went out into the peaks with Bhima and on one quite steap bit I was getting up in 50-23 gears, granted it was only 5-6mph, going into the 34ring only gave me an extra 3mph though.0 -
just buy a 110mm BCD c/ring and see if it works
Stronglight do a 52t
http://www.dotbike.com/ProductsP5085.as ... RACK%3dDDI
TA do anything between 40t and 61t
http://www.dotbike.com/ProductsP2143.as ... RACK%3dDDI
just don't blame us if the shifting is rubbish and the mech rubs like crazy
Facts are meaningless, you can use facts to prove anything that's remotely true! - Homer0 -
I think the point is: it CAN be done (a 53-34 combo), but it's not recommended.
Last year I rode a 50-34 all year and it was great for all the hills (I live not that far from you and ride some of the same hills, plus some bigger ones!). I just replaced my chainset with a regular 53-39 and while it is now harder and slower going up those same hills - it is still possible! (Plus I only have one leg - so if I can do it, anyone can!).
And - if you want to race as you have stated - then you certainly should be strong enough to ride a regular 53-39. You may find it a bit of a struggle at first - but it will only make you stronger in the long run.
Why risk the possibility of drivetrain failure, improper shifting, chain falling off, etc, etc?0 -
willhub wrote:If you can push 35mph at 100RPM why want bigger gears?
Unfortunately races often go a good 10mph (and more) above that speed on occasion. If you're already spinning your biggest gear at 100+ rpm when it comes to a sprint and every else has 1 or 2 sprockets left you're going to be left for dead.
If you're young and fit (which by the sounds of it you are) you'll hardly notice the jump putting on a standard chainring. Plus you roll along a lot better on the flat then on compact."A cyclist has nothing to lose but his chain"
PTP Runner Up 20150 -
admittedly, it has been many years since i raced.
and 45 mph = 72 km/hr
i don't recall hitting that as a top speed in many sprintsregards,
dbb0 -
ShockedSoShocked wrote:willhub wrote:If you can push 35mph at 100RPM why want bigger gears?
Unfortunately races often go a good 10mph (and more) above that speed on occasion.
Downhill maybe, I doubt many Amateurs in the UK are hitting above 40mph in a flat sprint.0 -
redddraggon wrote:ShockedSoShocked wrote:willhub wrote:If you can push 35mph at 100RPM why want bigger gears?
Unfortunately races often go a good 10mph (and more) above that speed on occasion.
Downhill maybe, I doubt many Amateurs in the UK are hitting above 40mph in a flat sprint.
Downhill or a strong tail wind (or both at the same time!)
Also bear in mind that a 4th cat could potentially be up there with Elite/Pro standard riders, so it's not outside the realms of possibility."A cyclist has nothing to lose but his chain"
PTP Runner Up 20150 -
From what I say the averages for races are like around 30mph constant.
If you can hit 35mph at 100rpm then you would be hitting 70mph at 200rpm, so I cant see you struggling on a sprint.0 -
willhub wrote:If you can hit 35mph at 100rpm then you would be hitting 70mph at 200rpm, so I cant see you struggling on a sprint.
:?:"A cyclist has nothing to lose but his chain"
PTP Runner Up 20150 -
ShockedSoShocked wrote:willhub wrote:If you can hit 35mph at 100rpm then you would be hitting 70mph at 200rpm, so I cant see you struggling on a sprint.
:?:
:?:0 -
when did you last pedal at 200rpm?regards,
dbb0 -
willhub wrote:ShockedSoShocked wrote:willhub wrote:If you can hit 35mph at 100rpm then you would be hitting 70mph at 200rpm, so I cant see you struggling on a sprint.
:?:
:?:
I don't think it quite works like that. Otherwise we'd all be Chris Hoy."A cyclist has nothing to lose but his chain"
PTP Runner Up 20150 -
ShockedSoShocked wrote:redddraggon wrote:ShockedSoShocked wrote:willhub wrote:If you can push 35mph at 100RPM why want bigger gears?
Unfortunately races often go a good 10mph (and more) above that speed on occasion.
Downhill maybe, I doubt many Amateurs in the UK are hitting above 40mph in a flat sprint.
Downhill or a strong tail wind (or both at the same time!)
Also bear in mind that a 4th cat could potentially be up there with Elite/Pro standard riders, so it's not outside the realms of possibility.
It equals track 500 m WR of Chris Hoy or 200 m WR of Theo Bos... :roll: :roll: :roll:0 -
So if it's 35mph at 100rpm what is at 200rpm?
Obviously it's not possible to get to 200rpm in that gear due to wind resistance...0 -
Am I alone in thinking that Bhima was mistaken when he claimed he was hitting 200rpm on a ride? Is 200rpm even possible/practical on a road bike? For any length of time?
As for speed - I have not gone faster than 40MPH - and that WAS downhill with a tailwind and pedalling flat out!0 -
Perhaps I need to get my speedo checked then!
Either that or I just don't go as fast as you! But I have some weight on me to carry momentum, plus a very good bike and aero wheels and I'm pretty certain that I haven't seen my speed get over 40mph recently!
Next time I'm out riding with someone else who has a speedo I'll check against their speed to make sure mine is calabrated properly. I would certainly be happy if I was indeed going faster than my readouts! Would make the 5MPH I go up hills a little easier to stomach. 0 -
-
I'm with the guys urging you to stick with the 50 tooth big ring and maybe, maybe, you might be able to spin out a 50-11(downhill or maybe, maybe monster tailwind). 50-11 is a monster gear as far as I'm concerned and of very little use to many riders. It's taller than a 53-12 and there aren't many of us that can push one of those for long. So a 53-11
is basically useless. My advice is that IF you can spin a 50-12 for any length of time then go for 50-11. You won't spin it for long.
Dennis Noward0 -
maddog 2 wrote:the jump will be too big between the two rings. It's already big at 16t. Your front mech (depending on which one you have) will probably have a 16t capacity (Shimano) so it's already at the maximum. You might be able to squeeze a few more teeth but I can't say if 53t is possble, as I haven't tried.
You could go 36/52 and keep the same jump?
FWIW I have used DA with a 50-33 and not had problems.
Dennis Noward0 -
I can get to 28-44mph on top gear, depending on wind/surface conditions (on the FLAT).
So your calculations are not going to work perfectly when the conditions change.
I need the bigger ring, simply, so I can push harder and get stronger. Even in a headwind, when going 28mph, I could do with a bit more resistance to get the legs BURNING! :twisted:
Of course, I could just find a hill, but the advantage of being able to go beyond 45mph on some downhill sections/in a tailwind will be an added advantage.
Willhub, don't you have a 26 on the back? When you'd burst past on the hills the other day, I was under the impression I had a 25 and, now that i've counted 23, I can stop feeling so unfit from being beaten by someone 2 years younger!
Oh, and 200RPM is certainly possible. Did a roller race today where I registered at 224 at one point!0
