30t cassette

[paxterg]

Could I use a 30t cassette with Shimano 105 5700 short cage derailleur?

 

[DCLane]

There needs to be a maximum range between the cogs, so I can get an 11-28 to work but it'd need to be 13/14-30.

Adding a rear derailleur extension to the rear mech would mean 11-30 would work.

 

[Mark pallister]

Could I use a 30t cassette with Shimano 105 5700 short cage derailleur?

Yes ,you might need to adjust the b screw
ive just done it no problem

 

[Racing roadkill]

Depends on your crankset. 50-34 will work. 52-36 should work. 53-39 probably won’t work, without some issues at max, or min ratios. If you get any issues, try something like this
https://www.sjscycles.co.uk/gear-spares/aluminum-rear-derailleur-hanger-extender/

But be aware your existing chain wrap may not be sufficient, so you may need a longer chain.

 

[paxterg]

I have a compact crank, I'm looking for the best gearing for the Fred Whitton in June. A 28 would probably do but a 30 would be nicer!

 

[DCBassman]

Surprising what you can get away with, though...
Have 52-42-30 running to a Sora 3300 medium cage, and running 11-34t on a hanger extender. Expected it to complain bitterly , but it just...works.

 

[CXRAndy]

I have a compact crank, I'm looking for the best gearing for the Fred Whitton in June. A 28 would probably do but a 30 would be nicer!

You will need more than that come end of the day, unless you are quite light

 

[roubaixtuesday]

You will need more than that come end of the day, unless you are quite light

Nah, I'm 85kg and got up the Hardknott on 34/28 last year.

Only just, mind.

Edit: To answer the OPs question, it's very likely but not certain that you'd get away with a 30. No way to be sure except by trying.

 

[Stompier]

Go for the biggest range you can get away with. If you think you'll be ok on a 28 or a 30, then get a 32. If this means getting a new rear mech, then it's probably worth it for the event. You can always sell it afterwards. FW is not to be underestimated, especially for first timers.

Oh and weight (as mentioned upthread) - in isolation - is completely irrelevant.

 

[Venod]

I have run a 32t with a short cage 105 with no problems,

 

[paxterg]

I've ordered a 28, just to be on the safe side, I'm around 70kg but hope to be around 65ish when the event come round, hopefully I'll be OK!

 

[Stompier]

I've ordered a 28, just to be on the safe side, I'm around 70kg but hope to be around 65ish when the event come round, hopefully I'll be OK!

32 would be 'on the safe side' not 28 - but it's your decision, obviously.