12-30 cassette

MonkFunk

Hi

Recently bought an ex-demo Vitus Decium which came with a 12-25 Tiagra cassette and 105 5700 derailleurs. Full spec below:

http://www.vitusbikes.com/2012-road-bik ... ifications

The 34/25 isn't enough for the hills on my commute so I wanted to get a cassette with a bigger range and found that there is a 12-30 tiagra cassette. Will this fit with the derraileur and chain I currently have? Or would I need to stick to 12-28?

Thanks

danmitch

I just changed from a 12-27 to a 12-30 with a 105 5700 rear mech, details here and it has worked very well.

There is enough capacity on the derailleur but I suspect you may have to change the chain adding a couple of links and you may need to make minor adjustment to the derailleur. There are differences in frame geometries, specifically the exact positioning of the derailleur hanger, but I suspect it will be fine. In my experience it is better than going for a triple.

Dan

Sir Velo

What sort of hills do you have on your commute, the link to the bike suggests you have a compact on the front so I would have thought that unless your commute is the Fred W route you would be OK. At least after a couple of weeks.

SV

MonkFunk

@ Dan - thanks for that, very helpful.

Regarding the commute, there is one hill in particular that is a problem. It's half a mile long and gets progressively steeper so near the top it is around 15-16% gradient. I want to enjoy the commute rather than endure it and am happy to spend £20 on a new cassette to get a wider gear range. I can always swap back in future if necessary.

maddog 2

I've fitted three 12-30 cassettes recently to mates' bikes, all running std road rear mechs and 34/50. All worked okay but one needed the chain a link shorter than ideal, and the tension screw on max, but it worked in the end.

vorsprung

I have a 12-27 on my best audax bike, I've seen these 12-30 on offer at chainreaction, must get one next time I buy something else.

Not for general use but for if I ever try the Pendle 600 or something

chrisaonabike

I'm similarly planning to switch my Tiagra 12-28 for a 12-30.

My chain is about 2200 miles and seven months old - should I replace it as well, or is it not likely to have worn much? It's not as if I do Cav-stylee sprinting on it

binkybike

I've gone in the opposite direction, I found the 34-30 combination too low a gear, on the shallower stuff I never needed it and on the steep stuff my cadence was never high enough to generate enough speed to stop me wobbling all over the road. I found a 12-28 cassette much easier to get on with and with improved fitness the latest I got was a 12-27.

not sure the above is much use to original poster but I've written it now...

maddog 2

replace the chain if it is stretched. Buy a chain checker tool or measure it with a ruler. The tool is much easier.

t4tomo

ChrisAOnABike wrote:

I'm similarly planning to switch my Tiagra 12-28 for a 12-30.

My chain is about 2200 miles and seven months old - should I replace it as well, or is it not likely to have worn much? It's not as if I do Cav-stylee sprinting on it

If you puting on a new cassette then always put on a new chain at the same time - you might need to anyway as you prob need a longer chain if putting on a bigger big sprocket. That way the cassette and chain "wear" together. an old chain on a new cassette with wear the cassette quicker.

MonkFunk

Cheers for the advice. Ordered the cassette on Monday from CRC and it arrived yesterday. Fitted it with no problems. Didn't need to adjust anything. B screw was fine and and the chain even fitted and would shift in to big/big (not that you'd want to but nice to know it will go without jamming the drivetrain!). Took the bike out for a quick spin and the shifting seems good and the spacing between gears seemed fine. Very happy with the result.

ratsbeyfus

Glad to hear it worked... I'm putting one on my cross-bike with a road compact on the front. Should be able to spin up the ickiest hills this winter I'm hoping.

greasedscotsman

For what it's worth, just fitted one to my Dura Ace 7900 compact setup and appears to work OK.

Grill

Keep in mind that Shimano states you'll need a GS (medium cage) rear mech as the SS (short cage) is rated to 28 max. Doesn't mean you can't fit a 30, but if things go wrong you won't be covered by warranty.