First roadie ride - pros and cons and questions...

[Spiderweb]

I have a short cage rear derailleur, and was struggling with a max 25t on the rear cassette (53/39 up front) You will be able to fit a 30t without swapping the derailleur, this is what the bike shop advised & fitted for me. You will need a new longer chain too.
Have you managed to get your Carerra into the biggest cog at the back yet?
I would sort that first and see how you get on.

 

[mjr]

I have a short cage rear derailleur, and was struggling with a max 25t on the rear cassette (53/39 up front) You will be able to fit a 30t without swapping the derailleur, this is what the bike shop advised & fitted for me. You will need a new longer chain too.

Isn't 28t the normal maximum for short cage rears? Sometimes 27t on the more drunken recent Shimano creations. 30t will often fit, but it may be worth taking a few measurements first... although I think you should be able to sell an unused cassette fairly easily for not much loss beyond postage.

 

[mjr]

Not checked - the tyres came hard and stayed that way so happy for now... to be fair it's only when rough surfaces and brilliant the rest of the time.

http://www.dorkypantsr.us/bike-tire-pressure-calculator.html before you hurt yourself or the bike IMO

 

[Spiderweb]

Isn't 28t the normal maximum for short cage rears? Sometimes 27t on the more drunken recent Shimano creations. 30t will often fit, but it may be worth taking a few measurements first... although I think you should be able to sell an unused cassette fairly easily for not much loss beyond postage.

I had read the Shimano info before hand which stated 28t Max for a short cage mech, it was the bike shop that advised a 30t would fit, it does without issue.

 

[mjr]

I had read the Shimano info before hand which stated 28t Max for a short cage mech, it was the bike shop that advised a 30t would fit, it does without issue.

Indeed. A good shop might know that a particular bike/mech combination works.

 

[SirDickieBird]

Got it in the big rear cog yes. Did the adjuster nut thing and seems to work but not been for a ride out yet to try in anger...

Going to pop in at bike shop to check out options

 

[Low Gear Guy]

Right - been out and done some counting...

MTB
Front: 42-34-?? (didn't count the granny)
Rear: 27-12

Carrera road
F: 50-34
R: 26-12

So...only 1 tooth difference 26 vs 27 from MTB so presumably similar ratio?

Would I get any benefit top or bottom end from a switch to 11-28?

Also the road tyres will have a larger diameter and circumference so each turn of the cranks will take you a couple of percent further on a road bike.

 

[gbb]

The road vibration aspect could be the fork design and material. I had a Raleigh Chimera with low end steel forks and a very straight fork, no curve or 'rake...and bugger it transmitted every bit of buzz and bump from the road. The Virtuoso forks appear similar visually. I got round it a bit by using gel tape and better gloves...note I said a bit. it was an absolute revelation when i moved to carbon forks on my next bike.
Lower tyre pressures will help as well but then you increase the possibility of punctures a bit.

 

[rugby bloke]

The road vibration aspect could be the fork design and material. I had a Raleigh Chimera with low end steel forks and a very straight fork, no curve or 'rake...and bugger it transmitted every bit of buzz and bump from the road. The Virtuoso forks appear similar visually. I got round it a bit by using gel tape and better gloves...note I said a bit. it was an absolute revelation when i moved to carbon forks on my next bike.
Lower tyre pressures will help as well but then you increase the possibility of punctures a bit.

I agree with this. When I am out on my Virtuoso I certainly have the dubious benefit of feeling every tiny bump and imperfection in the road. Hit a section of poor road surface at speed and you have to hang onto your fillings.

 

[Jody]

It depends on your rear derailleur.

A rear mech has two published numbers which you can find on the bits of paper that came with it, that you threw away/lost. You can find these on the web.

The numbers are:
Capacity, the amount of slack chain that the sprung cage can take up. Eg if you want to run 50/34 and 11-32 you need (Big ring +Big sprocket) - (Little ring + little sprocket) = (50+32)-(34+11) =37 teeth capacity.

The second number is max sprocket size.

You will find the published numbers are a bit conservative and people on here will tell you they've exceeded them successfully.

This is just the information I was after the other day but my thread got no replies to the question. Thanks @Dogtrousers

 

[SirDickieBird]

Thanks for all the advice. Ended up at bike shop the other day and he fitted and 11-32 cassette.

First impressions - that the 11 is quite a bit harder work than the 12. It's only one toot so thought it wouldn't be noticeable but 11/12 is 91.6% so does that make it 8.4% harder? Not sure on the maths there but presume 1 tooth at the bottom end makes more difference than say 32 to 33?

Hills at the weekend

 

[mjr]

First impressions - that the 11 is quite a bit harder work than the 12. It's only one toot so thought it wouldn't be noticeable but 11/12 is 91.6% so does that make it 8.4% harder? Not sure on the maths there but presume 1 tooth at the bottom end makes more difference than say 32 to 33?

Yes, it makes more difference. Compare setups at www.gear-calculator.com with a recent browser and scripting and wotnot.

 

[SirDickieBird]

The new cassette certainly helped on the hills. Got up them all without having to stop which is a start and having a 28 gave me options too. Only downside being the jumps between higher gears being a bit bigger.
Just need to get faster now...