stebie

Hello everyone, I've been reading this forum for quite a while now but I never got around to posting anything.

So anyway, I was thinking of stripping my unused mtb and making a hybrid out of its frame. I'm looking for a comfortable ride on flat roads without missing much of speed, but versatile enough so that when I come across a hilly area I won't be out of breath before I reach the top. There will be minimum off-road riding.


I want to check whether it is okay if I did something like this:

Shifters: Ultegra
Cassette: XT, 11-34T
FD: Ultegra (since XT can't fit anything above 48T)
RD: Deore XT
and
Crank option 1: Ultegra 52-39-30
Crank option 2: XT 48-36-26, replace 48T with 52T


I'm checking on the drivetrain first since I guess the other parts shouldn't have much of a problem compared to this..?

And yes I'm going to use a drop bar.

pastorbobnlnh 

Good question. Gearing for a particular bike is usually a matter of;

a) location
b) rider's fitness
c) amount of weight to carry or haul

If you live in a flat area and generally want to go with a high pace, consider something like the old fashioned "half step plus granny" crankset. Use the Ultegra crank and replace the the 39 with a 48, for a 52-48-30. This way if you encounter light to moderate winds the 48 tooth provides the lows you will need. When you come to a hill, the granny gets you up the climb.

Best of luck with your build.

mikeybikes

Any of those gearing options will work. I recommend playing around with various chainrings and cassette combos.

Sixty Fiver

28/40/48 mated to an 11-34 cassette here... gear range is 20.5 to 108 gear inches which gives me as low a gear as I will ever need and a top gear that matches my vintage road bike and I will probably change that 40 out for a 42 or 44 to bring me closer to having a half step gearing.

Using the 48 addresses chain wrap issues as a 52 tooth ring was never really intended to be used with an 11-34 and the gear inches I lose on top are only ones I would use on high speed descents.

I would use the XT crank and rings... you will be able to climb walls with this and still have a really decent top gear with a 48:11 and you might opt to change that middle ring to a larger one to set up a half step which is really nice for flatter riding.

Panthers007

I have an XTR FD on my hybrid - and it's labeled as being for no larger than a 46 - 48T chainrings. I'm running an Ultegra triple 53 - 39 - 30 crankset. Works flawlessly.

stebie

Thanks for the input guys Looks like there are no major compatibility issues.

Just a few questions here,

1. What is gear range?
2. How do I calculate for half step/granny gearing?
3. How low is low and how high is high? 30:34? 52:11?

Sixty Fiver

https://www.sheldonbrown.com/gears/

Consider 20 gear inches to be almost as low as anyone would ever need and a gearing folks use on extreme off road trails where the grades will exceed almost any you see on the road... this is a 28:34 on a 26 by 1.5 wheel and tyre.

At the top end 100 gear inches is what a sport or recreational rider might use and competitive riders will use a higher top gear, primarily for high speed descents, this is where a 53:11 makes a difference and works out to 125 gear inches with a 622:20 wheel and tyre.

You can input your chain ring sizes and cogs and see how your gearing range works out from a low to high point and look at how much overlap you get between gearings.

Your wheel and tyre size has an effect on your gearing... smaller wheels need higher gear ranges to match the top gearings you get with road wheels and tyres and road gearing tends to be higher sicne these ultra low gears are not needed unless you are doing loaded touring.

kaliayev

I used to run a XT FD on my tourer with 50-39-30 gears and no probs as well. However, I was using Shimano bar ends. Not sure if STI,s would work as well.

stebie

Question: Would the chain be long enough for 52T front + 34T rear?

Wanderer

Probably not - but you won't know until you assemble everything..... A new one will be any length you need......

Surfindixon

Hi. just my tuppence:

I was under the impression that the max big chain ring that an XT Long Cage RD was designed to handle was a 48T although I'm not 'gear savvy' enough to tell you what the impact of utilising the XT Long cage RD would be (there might not be any...I just dont know) although Panthers007 testimony that his Ultegra solution with the XTR FD has no adverse impact on his system would suggest that there may be no negative impact.

My hybrid is:
XT Long Cage RD
with 11 - 32 cassette
and Shimano Deore 48/36/26

and I'm riding in similar terrain by the sounds of it.

I'm sure one of the more gear savvy members of the community can allay my concerns regarding the XT LC RD