Cassette advice

68 lost souls

Looking for a little advice. Started cycling last year and still not great on technical/gear side of things. I have been riding a shimano tiagra 12-30 and recently picked up a turbo an trainer wheel. The trainer wheel has a 12-25 tiagra on it.

So knowing that, do I have to make any adjustment if I'm changing between the trainer and road wheels? So far all my maintainance has been done by my lbs as I have 2 years free service with them

I'd rather not have to change things as I'm a little worried to do it. The alternative I have been thinking about was upgrading my road wheel to a 105 or Ultegra in which case my question would be wether to go 12-25 or 12-30. A tend to ride a lot of hills and race triathlons rather than bike races.

Thanks

martin.mcevoy

Speaking from personal experience I recently upgraded an 11-25 to an 11-28 and have noticed a considerable difference on the hills. So if you are riding a lot of hills I would go with the 12-30.

XtotheZ

what do you have on the front?

68 lost souls

XtotheZ wrote: »

what do you have on the front?

It's a stock Trek 2.1, almost certain it's a 50/34

XtotheZ

68 lost souls wrote: »

It's a stock Trek 2.1, almost certain it's a 50/34

a 12 - 25 with 34 on the front is low enough to climb anything youll ever encounter in Ireland in my honest opinion

JonDoe

Go and buy yourself these tools

http://www.chainreactioncycles.com/ie/en/x-tools-chain-whip/rp-prod10184

http://www.chainreactioncycles.com/ie/en/cyclo-pro-series-cassette-lockring-remover/rp-prod7975

have a play about, bikes are simple you just need a few tools and try to keep things generic.

cdaly_

68 lost souls wrote: »

I have been riding a shimano tiagra 12-30 and recently picked up a turbo an trainer wheel. The trainer wheel has a 12-25 tiagra on it.

So knowing that, do I have to make any adjustment if I'm changing between the trainer and road wheels? So far all my maintainance has been done by my lbs as I have 2 years free service with them

You should not need to do any mechanical adjustment when swapping between wheels assuming both cassettes have the same number of sprockets (9sp/10sp). A bike that is set up for 12-30t will happily handle 12-25t.

Wishbone Ash

XtotheZ wrote: »

a 12 - 25 with 34 on the front is low enough to climb anything youll ever encounter in Ireland in my honest opinion

Have you had the pleasure of the Gap of Mamore?

ragazzo

Wishbone Ash wrote: »

Have you had the pleasure of the Gap of Mamore?

Just once. 42x23 back in the day.

Brian?

Wishbone Ash wrote: »

Have you had the pleasure of the Gap of Mamore?

How steep? Strava tells me 1.1km@12%. Very managable with a 34x28.

quozl

I don't think it's worth it to upgrade your cassette to 105 or Ultegra. The weight savings are small and durability goes down slightly.

As to whether you should move from a 12-30 to x-25, do you currently use your two lowest gears?
On a Tiagra 12-30 they are 27 and 30 teeth. So your new lowest gear on a 105 12-25 would only be very slightly easier (25) than your current 3rd lowest gear (24).

If you'd be happy with that then it's a good change as you'll gain a 16 tooth sprocket - which is a useful one IMO - and you'd have slightly smaller gaps between your low gears. If you'll miss those 27 and 30 teeth then it's a really bad idea

Wishbone Ash

Brian? wrote: »

How steep? Strava tells me 1.1km@12%. Very managable with a 34x28.

The Strava gradient doesn't seem to reflect it's brutality. When the Ras went through in 2012, An Post advertised it as averaging 21%. Ryan Sherlock described it as the toughest climb in Ireland and Britain.

68 lost souls

Thanks quozl. I have used the 27 and 30 a few times but I don't often find myself using them hugely, I reckon if I work on the engine the need for them should go away (am I only dreaming here). A smaller jump probably would make more sense as sometimes I find there is a very noticeable difference between some of the gears and cant find one that I am 100% happy with my cadence in.

Ideally for now I would like it if I can use the cassettes as they are and then hopefully I can get an idea of which one is better suited to me. I know I wont be comparing like with like if one is on the turbo and one is on the road. I was worried that the chain might slip off on the 12-25 if I changed all the way to the inside where I would have had the 30 or some damage say in the 16 which isn't on the 12-30?

After using both I reckon I should get a good idea of which to get either to upgrade the bike or change the turbo wheel? As I said was a afraid to use the 12-25 on the bike having it setup for 12-30. I am showing how naive I am when it comes to bikes right now I know.

quozl

The chain won't cause any problems being used on a 12-25 or a 12-30. It's already working fine with a 24 tooth sprocket on your 12-30.

The one thing to watch out for is that if one cassette is old and worn then it will rapidly wear a chain, which will then wear any other cassettes that chain is also used with. So make sure that both cassettes are in good condition.

You could have 1 chain per cassette but that's pointless hassle IMO as long as you just don't use an old cassette in the mix.

68 lost souls

Thanks again for the help.

The cassette on the turbo is brand new and the cassette on the road wheel has ashamedly probably not more than 1000km on it and has been regularly serviced but I will keep an eye on them as time goes by.

Brian?

Wishbone Ash wrote: »

The Strava gradient doesn't seem to reflect it's brutality. When the Ras went through in 2012, An Post advertised it as averaging 21%. Ryan Sherlock described it as the toughest climb in Ireland and Britain.

Right, that is a bit more gruelling than strava would have you believe.

I reckon a 34x28 would still see most regular cyclists over it though.

cdaly_

68 lost souls wrote: »

Thanks quozl. I have used the 27 and 30 a few times but I don't often find myself using them hugely, I reckon if I work on the engine the need for them should go away (am I only dreaming here). A smaller jump probably would make more sense as sometimes I find there is a very noticeable difference between some of the gears and cant find one that I am 100% happy with my cadence in.

I'm very attached to my 13-32 cassette. I took a 13-25t, split it (just use a drill bit to punch out the pins) and removed the 23t and fitted a 32t from an MTB cassette. I get a near linear top end with a lovely granny gear for the hills/walls...

nilhg

I went up the hill behind Hollywood in 34x27 and on up to the top of the Wicklow Gap mostly in 34x21 (PBs all the way) last Sunday morning, we dropped down into Laragh and had a cup of Coffee, then headed back the way we came, coming back up from the time we came out of the shelter and hit the steep bit in the middle and on right up to the top I was in the 34x30 and suffering, the difference was the wind, behind going East, in our face coming home, my attitude to gears is that I'd rather be looking at it than looking for it, but then I'm old and fat compared to most here I think:rolleyes:

XtotheZ

Wishbone Ash wrote: »

Have you had the pleasure of the Gap of Mamore?

Nope but it looks fun :eek:

I run a 39x25 and can get up local 20% gradients. That said there not as well known but still 1.3k at an average gradient of 10% and a max on 20 isnt bad either

ford2600

ragazzo wrote: »

Just once. 42x23 back in the day.

Manly stuff, similar gear to 34/19 for comparison.

Went up it both sides in August with 34/28. Found it tough but well doable, racing up it in your gears is a different ball game altogether

Iwernia

Brian? wrote: »

Right, that is a bit more gruelling than strava would have you believe.

I reckon a 34x28 would still see most regular cyclists over it though.

Yes, a 34x28 would see most cyclists over it but doesn't it all depend when you hit it, if memory serves me right you have roughly 80 miles in your legs when you hit Mamore on the Innishowen 100 tour, thats when you appreciate an extra gear.