Chainring
- Thread starter twitchboy
- Start date
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lol yes, but I mean in terms of what's on the bike? I have just switched from a singlespeed road bike to a singlespeed moutain bike. I understand that these are different types of bike for different purposes and they have different types of components. However, I was not expecting to have to cycle the mountain bike so much harder to reach the speed and acceleration that I did on my road bike. Yes, the tyres are chunkier and but in terms of weight there is no difference between the bikes. The only difference is the size of the chainring.
My road bikes chainring is 42t but my new mountain bikes chainring is 32t. Is this the most likely reason why my mountain bike requires more pedal power to reach the same acceleration and speed as my road bike? If so, can a new chainring be easily added to a mountain bike to remedy the situation? The mountain bike is the charge cooker. Great bike BTW. http://www.wiggle.co.uk/charge-cook...d||pkw||pmt||prd|5360675322uk&dest=1&curr=GBP
My road bikes chainring is 42t but my new mountain bikes chainring is 32t. Is this the most likely reason why my mountain bike requires more pedal power to reach the same acceleration and speed as my road bike? If so, can a new chainring be easily added to a mountain bike to remedy the situation? The mountain bike is the charge cooker. Great bike BTW. http://www.wiggle.co.uk/charge-cook...d||pkw||pmt||prd|5360675322uk&dest=1&curr=GBP
You can't compare chainrings by themselves. they are just part of the total leverage system which includes the chainring, rear sprocket, wheel size and crank size. vary any of these and the leverage will change and thus your acceleration will be different. Need to google gear tables to make comparisons.
Cheers Keith
Cheers Keith
A not too complicated starting page.
http://www.whycycle.co.uk/buying-a-bike/bike-jargon-buster/bike-gears-explained/
http://www.whycycle.co.uk/buying-a-bike/bike-jargon-buster/bike-gears-explained/
Andrew_Culture
Internet Marketing bod
- Location
- The People's Republic Of Suffolk.
Yes, but only if you hate your knees.
gds58
Über Member
- Location
- Colchester
I presume that they belong to Sir Chris but even those monster thighs pale into the background next to those attached to German Sprinter Robert Forsterman!! and no this is not a photoshopped image!
You are correct and yeah that picture is impressive/ scary- I was at work at the time so cautious over what I was typing into google image search!
Andrew_Culture
Internet Marketing bod
- Location
- The People's Republic Of Suffolk.
I saw them at the Velodrome, they made me feel a mix of admiration and nausea. They didn't help him win.
gds58
Über Member
- Location
- Colchester
Poor bloke looks deformed! I reckon he must have to spend a fair bit on specially tailored trousers!!
Old Plodder
Living at the top of a steep 2 mile climb
- Location
- Surrey/Hants border
First off, your mountain bike likely has longer chainstays which will give it the feeling of being less responsive.
Secondly, your tyres will create more drag to be overcome, more rubber in contact with the road & lower tyre pressure.
Are the cranks the same length, usually a road bike has 170mm or 172.5mm whilst mtb's have 175mm.
Single speed mtb's come with a 52" gear because riding offroad on dirt is 'harder', i.e. more drag from the surface & the tyres.
Single speed road bikes normally come with gears of between 60" & 70", have thin tyres with high pressures creating as little drag as possible.
Yes, you can change the chainwheel of your mtb, but there will be a limited choice, probably 42t, (or maybe 46/48t).
It will depend on where & how you want to ride your bike as to which will be best for you.
wheres_my_beard
Über Member
- Location
- Norwich
Acceleration and speed are quite different things, and equally the gradients and surfaces you are likely to tackle on the MTB are likely to be very different to those on a road bike. There's always going to have to be a compromise between various factors, and that will be down to personal preference, strength and endurance.
With the different gearing you have referred to on the same bike, the smaller chainring should give you faster acceleration, but a lower top speed at your maximum cadence over a given distance, where the larger ring will be a little slower off the mark with the same effort, but will be able to achieve and maintain a higher speed at the same cadence. Saying that MTB riding is often in small bursts of high cadence riding to get speed up quickly, with tight turns and hard braking so fast acceleration is essential, where as road riding is much smoother and likely to try and maintain a higher speed, and lower cadence over greater distances so needs quite different gearing.
I can't imagine many mtbs ride with anything close to the gear ratios of road orientated single speed bike. A recommended base ratio is 2:1, which would mean 32/16, or 52 inches, as mentioned above. Just in terms of cost, it would be cheaper to stick with your chainring, and tinker with the sprocket if you need to adjust your speed or acceleration, or build up strength for acceleration or spinning endurance if you want to go faster.
With the different gearing you have referred to on the same bike, the smaller chainring should give you faster acceleration, but a lower top speed at your maximum cadence over a given distance, where the larger ring will be a little slower off the mark with the same effort, but will be able to achieve and maintain a higher speed at the same cadence. Saying that MTB riding is often in small bursts of high cadence riding to get speed up quickly, with tight turns and hard braking so fast acceleration is essential, where as road riding is much smoother and likely to try and maintain a higher speed, and lower cadence over greater distances so needs quite different gearing.
I can't imagine many mtbs ride with anything close to the gear ratios of road orientated single speed bike. A recommended base ratio is 2:1, which would mean 32/16, or 52 inches, as mentioned above. Just in terms of cost, it would be cheaper to stick with your chainring, and tinker with the sprocket if you need to adjust your speed or acceleration, or build up strength for acceleration or spinning endurance if you want to go faster.
