Road Cycling - steep climbs

yesterday i tackled a 20 deg, more or less, climb for about 45mins.. Actually this must be the steepest road I climbed..

Although I enjoyed it a lot, the pain was almost unbearable..

My easiest gears are 42T-23T. With this combo, i was doing 10-12kmh @ about 45rpm cadence.. In my fitness level it is impossible for me to spin with those gears at 20deg inclines..

What can I do about this?

I can replace my cogs, but I still have the derailuer limit of 27T right? I have a Shimano 105 rear der. and currently have a 12-23 cassette.

If I replace my small ring to a 38T, would it make much difference?

Thanks.:D

I don't know if you can get a 38 on but, I do know you can use a 39t chainring- also you can use a 26t low gear on your cassette for sure !!, ( maybe even a 27 or 28, but doubtful).

Ride Easy
Pat

Going to a very normal 39 x 26 setup will make a huge diffrence.

20 degree hill? That works out to a 36.4% grade. Are you sure about that number?

Originally posted by pucci
Going to a very normal 39 x 26 setup will make a huge diffrence.

20 degree hill? That works out to a 36.4% grade. Are you sure about that number?

sorry, i must have been mistaken on my estimate, i didn't realize my estimate was too steep..

But here's my computation, I used my calculator now..:D

Slope is about ===== 1.8 - 2rise, 7run. I based this on a concrete fence running parallel to the road.. the blocks are visible (unfinished), I counted that in every 7 blocks run, there was a 2 block rise..

that's a 28% grade.. Is this even legal?

these are back roads, roads that were only accesible to 4x4 vehicles, until now since the road is paved.

I'm impressed... that's a 22.2% grade! And in a 42x23! No roads here in the US are built at more than 18% otherwise the material would be succeptable to sliding back down on itself.

Assuming a 700Cx23 wheel, a 42x23 works out to 48.0 gear-inches (3.6 ratio). A 38x23 works out to 43.4 gear inches (3.2 ratio). Now I don't know what that does as far as pedal effort is concerned. You may want to play with the tools downloadable from here (http://www.xsystems.co.uk/machinehead/).

Originally posted by dexmax

Slope is about ===== 1.8 - 2rise, 7run. I based this on a concrete fence running parallel to the road.. the blocks are visible (unfinished), I counted that in every 7 blocks run, there was a 2 block rise..

Ummm... Are you sure the blocks were square?

Originally posted by pat5319
I don't know if you can get a 38 on but, I do know you can use a 39t chainring- also you can use a 26t low gear on your cassette for sure !!, ( maybe even a 27 or 28, but doubtful).

A 38T is available in both 110mm and 130mm BCD so you can get it on the arm. I don't know how it will effect shifting though. I don't think it'll be a problem going one tooth lower in the front since a 39T shifts fine. You might need to avoid small-small if the rear derailleur can't tension that combo. And yes, you should be able to run up to a 27T rear. A 28T might even be possible. Some people claim that you can go all the way up to 30T if you avoid the upper two cogs when in the big ring. I'm running a 12-27 rear and 39/53 front.

Originally posted by dexmax
yesterday i tackled a 20 deg, more or less, climb for about 45mins.. Actually this must be the steepest road I climbed..

Although I enjoyed it a lot, the pain was almost unbearable..

My easiest gears are 42T-23T. With this combo, i was doing 10-12kmh @ about 45rpm cadence.. In my fitness level it is impossible for me to spin with those gears at 20deg inclines..

What can I do about this?

I can replace my cogs, but I still have the derailuer limit of 27T right? I have a Shimano 105 rear der. and currently have a 12-23 cassette.

If I replace my small ring to a 38T, would it make much difference?

Thanks.:D

I would suggest changing out your rear cluster. You can get a 26 or 28 big cog. That would have more effect then moving to a 38 chain ring. To get much more in the way of gearing, you almost have to go to a triple chain ring and a mountain bike rear cluster.

I doubt you grade is 20 degrees. It might be 20%. But 20% grades are really rare. I have ridden a couple but you really have to look for hills that steep and the steep part was pretty short.

Can you go around the hill? :D

Originally posted by dexmax
yesterday i tackled a 20 deg, more or less, climb for about 45mins.. Actually this must be the steepest road I climbed..

Although I enjoyed it a lot, the pain was almost unbearable..

My easiest gears are 42T-23T. With this combo, i was doing 10-12kmh @ about 45rpm cadence.. In my fitness level it is impossible for me to spin with those gears at 20deg inclines..

What can I do about this?

I can replace my cogs, but I still have the derailuer limit of 27T right? I have a Shimano 105 rear der. and currently have a 12-23 cassette.

If I replace my small ring to a 38T, would it make much difference?

Thanks.:D

Now THAT! is a hill where you need a triple.

Originally posted by dexmax
Slope is about ===== 1.8 - 2rise, 7run. I based this on a concrete fence running parallel to the road.. the blocks are visible (unfinished), I counted that in every 7 blocks run, there was a 2 block rise..

that's a 28% grade.. Is this even legal?

to do an accuracte measurement of percent on a hill you must know how much it rises in a given mile/kilo

i.e. 500 ft rise in 1 mile of course ~ 9%
150m in 1 km of course ~ 15%

the only accurate way to measure this is either by a topo map or a GPS with an altitude measurement. :)

well, i went again yesterday and now i was paying attention to the grade..

there are parts that go up to, i think 20%, but mostly it is 10%-15%..

The blocks that i made as a reference were about 9"x16". So that part that had the fence parallel to the road was ((9x2)/(16x7) x 100) about 16%, not 20% something because i assumed it was square.

Anyway, thanks for all your suggestions.. I am thinking or replacing my inner chainring, and modyfying my cogset...

What are your thoughts about this..

12-13-15-17-19-21-23-26.
my current config is 12-13-14-15-17-19-21-23. So all i have to do is take out the 14T and add a 26T. Is this possible or am I too cheap? :)

I am concerened about the 3T difference on the last 2 gears.

Originally posted by dexmax

What are your thoughts about this..

12-13-15-17-19-21-23-26.
my current config is 12-13-14-15-17-19-21-23. So all i have to do is take out the 14T and add a 26T. Is this possible or am I too cheap? :)

I don't think this is possible. Check out the breakout of an HG cassette sometime. The last 3 cogs are usually a single unit as is typically the middle two as a seperate unit and the four smaller cogs being loose. It might be cheaper to just get a whole new cassette. How does a 12-27 (12-13-14-15-17-19-21-24-27) strike you? Yes, I know there's some large 3T jumps in the upper portion but honestly, would you normally use them for anything except hills?

Originally posted by khuon
I don't think this is possible. Check out the breakout of an HG cassette sometime. The last 3 cogs are usually a single unit as is typically the middle two as a seperate unit and the four smaller cogs being loose. It might be cheaper to just get a whole new cassette. How does a 12-27 (12-13-14-15-17-19-21-24-27) strike you? Yes, I know there's some large 3T jumps in the upper portion but honestly, would you normally use them for anything except hills?

thanks.. I really should get a new cassete..

Originally posted by dexmax
I am concerened about the 3T difference on the last 2 gears.

A 3-T difference between large cogs is fine......actually that's not much of a jump, but a 2-T difference between two small cogs is a sizable jump in gear inches and is outright annoying....

Originally posted by dexmax
...Anyway, thanks for all your suggestions.. I am thinking or replacing my inner chainring, and modyfying my cogset...

What are your thoughts about this..

12-13-15-17-19-21-23-26.
my current config is 12-13-14-15-17-19-21-23. So all i have to do is take out the 14T and add a 26T. Is this possible or am I too cheap? :)

I am concerened about the 3T difference on the last 2 gears.


Quite possible... if you are able to find individual cogs at your LBS. Or you could do the same by mixing parts from 2 or more cassettes. See http://www.sheldonbrown.com/k7.html for details on cassette construction.

You may have a 105 or HG-50/70 cassette, in which case the largest 6 or 7 cogs are bolted or riveted together. Simply unbolt them (2 MM Allen bolt) or cut off the rivet (metal saw) and you'll have a bunch of loose cogs and spacers to assemble the way you want. If you have a higher-end XT cassette, the 3 or 4 largest cogs are assembled on a common spider, which would mean that, for example, the 19-21-23 would be stuck together.

So you could get rid of the 13 or 14, or if you rarely use the 12, you could buy a start-up 13 (to replace the start-up 12). At the end, just install a large cog.

How large? I would suggest you buy a 28 or even a 30, as your derailleur is able to reach to 30. (BTW, the only reason Shimano states that its road derailleurs handle a 27 is that they don't make any "road cassette" with larger gears than that.) The jump from 23 to 28 or even from 23 to 30 won't be as crisp as the jump from 21 to 23, but you just need to ease the pressure on the pedals for 2-3 seconds and it will shift flawlessly. How big a jump? I'm a fan of big jumps at the beginning because these are gears we rarely use.

By the way, stock MTB and touring gearing is often 11-13-15-17-20-23-26-30-34 and nobody complains about poor shifting. My rear cassette has 12-14-15-16-17-19-21-25-32 and the 7-tooth jump is NOT a problem.

Regards,