Gear ratios

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Davidwd
Posts: 76
Joined: 1 Aug 2015, 7:42am

Gear ratios

Post by Davidwd »

I have a single front chainring of 38 teeth and a rear sprocket 9 speed 12-36 teeth. I am going to reduce the front chainring to 36 teeth. My question is will this give me enough range of gears to ride the velodyssey? My climbing gear will be 36 front 36 rear. I will have 15kg of luggage the bike is a kona dew deluxe.

Thank you
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foxyrider
Posts: 5284
Joined: 29 Aug 2011, 10:25am
Location: Sheffield, South Yorkshire

Re: Gear ratios

Post by foxyrider »

if its not low enough you can always push!
Convention? what's that then?
Airnimal Chameleon touring, Orbit Pro hack, Orbit Photon audax, Focus Mares AX tour, Peugeot Carbon sportive, Owen Blower vintage race - all running Tulio's finest!
tatanab
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Joined: 8 Feb 2007, 12:37pm

Re: Gear ratios

Post by tatanab »

The only person who knows is you, or maybe somebody who rides with you.

The route you've asked about is essentially flat or rolling until you get to the final peninsula where it is a bit more choppy. I do not know the specific route involved but I have ridden roads over the whole length carrying about the same camping load as you've described in your other post and not needed to gear as low as your bottom gear - which is not to say I did not have lower gears, I just did not use them. I'm a recreational rider in his mid 60s who really should ride more. So I reckon you should be fine. Don't worry, go and enjoy yourself and learn from your own experiences.
Davidwd
Posts: 76
Joined: 1 Aug 2015, 7:42am

Re: Gear ratios

Post by Davidwd »

tatanab wrote:The only person who knows is you, or maybe somebody who rides with you.

The route you've asked about is essentially flat or rolling until you get to the final peninsula where it is a bit more choppy. I do not know the specific route involved but I have ridden roads over the whole length carrying about the same camping load as you've described in your other post and not needed to gear as low as your bottom gear - which is not to say I did not have lower gears, I just did not use them. I'm a recreational rider in his mid 60s who really should ride more. So I reckon you should be fine. Don't worry, go and enjoy yourself and learn from your own experiences.


Thank you, I have just booked the ferry crossings so no going back now!
JohnW
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Joined: 6 Jan 2007, 9:12pm
Location: Yorkshire

Re: Gear ratios

Post by JohnW »

Davidwd wrote:I have a single front chainring of 38 teeth and a rear sprocket 9 speed 12-36 teeth. I am going to reduce the front chainring to 36 teeth. My question is will this give me enough range of gears to ride the velodyssey? My climbing gear will be 36 front 36 rear. I will have 15kg of luggage the bike is a kona dew deluxe.

Thank you


I honestly don't think that you'll really benefit from two teeth difference on the chainring. On 700c rims, 36T front and rear will give you a 27" (nominal) bottom gear, which is quite low, but only a little lower than your existing bottom gear of 28.5" - you may not feel it.

To get to a significantly lower gear - one that you'll really benefit from, I think you'll need a smaller chainring than 36T. A 34T ring would give you 25.5" - which even then is not a great drop from your existing. I don't know what chainring sizes you can get for your chainset, but a 32T ring would give you a 24" bottom gear. However then your top gear would be 72" - which is quite a drop from your existing 85.5". You may find the revised top gear a bit restrictive.

Cost may come into this of course, but in your position, if needing a significantly lower bottom gear, I'd be going for a 28/38 double chainset which would give a really good bottom gear of 21" without sacrificing my top gear. But that's just me.
pwa
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Joined: 2 Oct 2011, 8:55pm

Re: Gear ratios

Post by pwa »

A 27" bottom gear is not quite as low as I would like with that load, but its not too far off ideal. Just be willing to stop and take a breather if the climbs get a bit too much. Hope it goes well.
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al_yrpal
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Joined: 25 Jul 2007, 9:47pm
Location: Think Cheddar and Cider
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Re: Gear ratios

Post by al_yrpal »

Your ratio gives you a 27" gear (wheel diameter x ratio). On a touring bike I like to have a sub 20" gear. For that you need a smaller chainwheel

Al
Touring on a bicycle is a great way to explore and appreciate the countryside and towns you pass through. Make a difference...
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