Force11-28 Cassette Choice

[Lou N]

All,

I recently purchased a 2008 Specialized Tarmac from a guy who was in much better shape and he has smaller cassette on the bike than I push on the hills around here. I would like to replace it with a SRAM Force 11-28.

The rear derailleur is a SRAM red and the bike has Roval wheels. I notice there are several types of 11-28 cassettes which one should I be looking for in terms of a Force cassette?

Thanks,
Lou

[redondoaveb]

Pg-1070

[DrSmile]

You may need to add links to your chain or you'll snap your Red rear derailleur.

[LC]

PG-1050 is would work just as well and cost less.

[Lou N]

All,

Thanks for the recommendations I will look into both suggestions. I checked the cassette on the bike today and it's an 11-24. How do I know if I would need a longer chain?

Thanks,
Lou

[fun2none]

All,

Thanks for the recommendations I will look into both suggestions. I checked the cassette on the bike today and it's an 11-24. How do I know if I would need a longer chain?

Thanks,
Lou

Quick & Risky method:
With the bike mounted on stand, start with chain on big ring and in the middle of cassette
Slowly turn cranks with low force and start down shifting (move chain up cassette to larger cogs). If you make to the 28 without seizing up or jamming, you chain is ok.

Safe method:
Follow directions from park tool, Shimano, or Sram for chain sizing. Split chain and wrap it around big ring and largest cog while routed outside of rear dérailleur. Match to nearest link then add one link.

[MickM]

Hi

You can use the formula below.

L = 2 (C) + F/4 + R/4 + 1

L = Chain length in inches. Round the final result to closest whole inch figure.
C = Chain stay length in inches, measure to closest 1/8” in decimal.
F = Number of teeth on largest front chainring.
R = Number of teeth on largest rear cog.

e.g.
L = 2(16.25) + 53 / 4 + 25 / 4 + 1
L = 32.5 + 13.25 + 6.25 + 1
L = 53

[looigi]

Another way. If the chain is the correct length now, going from a 24 to 28 cog will add two teeth or one complete link to the required length of a chain since the chain only goes half way around it. (a complete chain link comprises two outer plates, two inner plates, two pins and two rollers.)

[Lou N]

Thanks all. Once I get ready to install the cassette I'll take some measurements. I assume adding a link or two should be relatively straightforward.

Lou

[vettracer]

You might want to consider the 12-28.unless you live in a hilly area and like to fly downhill.

The 12-28 eliminates the 11 and adds the 16 tooth cog which is much more useful for most riders.

[Lou N]

Vettracer,

I live in the Denver area, there are quite a few hilly rides around here, thus the 11-28 choice. The cassette has arrived, I hope to get it installed this weekend.

Thanks for the suggestion,
Lou

[Lou N]

All,

I installed the new SRAM 11-28 cassette today with no trouble. However, it appears the chain is too short. With the chain on the large chain ring the the largest of the two rings on the cassette are not usable.

I realize it's not a good idea to ride with the chain crossed over like that anyway, but I do trust that I will remember not to shift that way and break the derailleur.

Is there a way to add links to a SRAM chain or do I need to purchase a new chain?

Thanks,
Lou

[DrSmile]

Assuming you have a connecting link already, all you need are some chain links and another connecting link. Any bike shop should have spare chain links. If you change your own chains you try to find uses for all the small lengths of leftover links you have after a while, like making keychains, bottle openers, or picture frames with them!

[LC]

Buy a new identical chain then you can steal two links and still have plenty left over for the time you need a new chain.

[Lou N]

All,

Thought I would follow up with the results of a few hours in the garage yesterday. Actually it appears hat this chain is long enough. I adjusted the B screw on the derailleur and that seemed to be what was holding things up. The chain now moves through all the cogs without issue (except for some rubbing at the extremes).

I have to go back and reset all the adjustments on the derailleurs front and back, but I think it will be ok.

Thanks again,
Lou