Single Rear Gear with Double Chainring and shifters
 

Hello Guys,

I have set up a time trial bike single gear its very fast 50t chainring and 14t rear. However, the new ironman race route in my location requires crossing a bridge with obviously inclined slope. I'm used to going uphill but it burns significant amount of energy. Btw, the new route has 3 loops which makes it a little disadvantage on my part going up and down the bridge 6 times. Having experienced this, I was thinking maybe putting a double chainring like 52t & 36t with front shifters would decrease the tension for the climb? Do you think this is possible? I'd appreciate your input.

Thanks!
Max

Single Rear Gear with Double Chainring and shifters
 

On Wednesday, August 8, 2018 at 6:48:15 AM UTC-4, Max Nosugar wrote:
Hello Guys,

I have set up a time trial bike single gear its very fast 50t chainring and 14t rear. However, the new ironman race route in my location requires crossing a bridge with obviously inclined slope. I'm used to going uphill but it burns significant amount of energy. Btw, the new route has 3 loops which makes it a little disadvantage on my part going up and down the bridge 6 times. Having experienced this, I was thinking maybe putting a double chainring like 52t & 36t with front shifters would decrease the tension for the climb? Do you think this is possible? I'd appreciate your input.

Thanks!
Max

It's possible but you then need to put a front derailler and something to take up the slack for when you go from the big chainring to the small chainring.

52 x 14 = 100.4 gear inches. Don't you find that a bit hard on the flats too?

Cheers

Single Rear Gear with Double Chainring and shifters
 

Yeah it's hard when there's an inclined slope but can be tolerated on flats. What's the recommended gear size for both front and rear on this condition?

Single Rear Gear with Double Chainring and shifters
 

On Wednesday, August 8, 2018 at 8:06:45 AM UTC-4, Max Nosugar wrote:
Yeah it's hard when there's an inclined slope but can be tolerated on flats. What's the recommended gear size for both front and rear on this condition?

The late Sheldon Brown stated:

" Gain Inches Meters
52/19 Fixed 5.45 71.2 5.70 General road use
52/20 Free 4.90 64.1 5.13 Road...when I'm tired, or hilly areas.
42/30 Free 2.64 34.4 2.75 Off-road.

Gearing is a very personal matter, and it is difficult to give good specific recommendations for someone I haven't actually ridden with.

The best gearing for you depends on a large number of variables, including:

Your weight
Your strength
Your endurance
How far you'll be riding in a day
How hard you're willing to push
How much baggage you'll be carrying
The steepness of the terrain
The nature of the road (or off-road) surface

There is no magic formula for this, only experimentation will let you determine what gearing suits your needs.

You might find my online gear calculator useful for comparing with your present gearing. http://www.sheldonbrown.com/gear-calc.html

Generally, for street use, with a freewheel, I would recommend a gain ratio of around 5-5.3, for instance, a 42 tooth chainring with a 16 or 17 tooth sprocket."

Using Sheldon's gear calculator and his recommendation of a 5 5.3 gain ratio the rear cog when used with a 50 teeth chainring would be either 19 teeth = 5.2 gain ratio or 20 teeth = 4.9 gain ratio. I guess that's recommended so that one doesn't wreck their knees.

Hope this helps.

Cheers

Single Rear Gear with Double Chainring and shifters
 

I totally agree with you mate, thanks very much! I think it would all depend on one's strength. I usually go uphill with a fixie coz I had no choice..lol

But I'm at a disadvantage during a race coz it eats alot of my energy during the bike leg and will not have enough left to run. But I love my set up so I'm sticking to it than a normal road bike. I just need to modify a few things.

So putting a front derailler is possible correct? So I can install double chainring.

Single Rear Gear with Double Chainring and shifters
 

Max Nosugar wrote:
I totally agree with you mate, thanks very much! I think it would all
depend on one's strength. I usually go uphill with a fixie coz I had no choice..lol

But I'm at a disadvantage during a race coz it eats alot of my energy
during the bike leg and will not have enough left to run. But I love my
set up so I'm sticking to it than a normal road bike. I just need to modify a few things.

So putting a front derailler is possible correct? So I can install double chainring.


I don't think that the combination of a fixie (non-freewheel rear hub) and
front derailleur will work. Once you put on the front derailleur, you'll
need something in the back to take up the chain slack, and as soon as
you've done that, really weird things will start happening when you stop
pedalling and the hub is trying to pull the pedals around.

Single Rear Gear with Double Chainring and shifters
 

I thought so, Im wondering if this has been done before. I looked around and found no pictures of a fixie with a double chainring/derailler.

Single Rear Gear with Double Chainring and shifters
 

On Wednesday, August 8, 2018 at 10:29:48 AM UTC-4, Max Nosugar wrote:
I thought so, Im wondering if this has been done before. I looked around and found no pictures of a fixie with a double chainring/derailler.

OOOS! I forgot that it was a FIXED Gear bike you were thinking about doing this with. I'd say it's a very bad idea at best and a nasty accident waiting to happen at worst.

Cheers

Single Rear Gear with Double Chainring and shifters
 

On 8/8/2018 5:48 AM, Max Nosugar wrote:
Hello Guys,

I have set up a time trial bike single gear its very fast 50t chainring and 14t rear. However, the new ironman race route in my location requires crossing a bridge with obviously inclined slope. I'm used to going uphill but it burns significant amount of energy. Btw, the new route has 3 loops which makes it a little disadvantage on my part going up and down the bridge 6 times. Having experienced this, I was thinking maybe putting a double chainring like 52t & 36t with front shifters would decrease the tension for the climb? Do you think this is possible? I'd appreciate your input.

Thanks!
Max


There's one path to do fixed gear change:
http://www.sturmey-archer.com/en/pro...ail/s3x-silver

Any other option is overly complex, unreliable, possibly
unsafe or (as with a two-sided wheel) ungainly.

If that's what you need, the SA S3X, or vintage ASC, suits
perfectly.

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

Single Rear Gear with Double Chainring and shifters
 

Thanks guys! I actually set up a track bike on the road. So yeah I wasnt thinking if it was a good idea. Appreciate your responses.

Its cool to have a 3 speed rear hub for fixie now. So getting this will allow me to convert fixie into a road bike of some sort? Correct?