triple chainset upgrade advice

paddyeds

Hi Chaps,

Looking for some solid advice, I currently ride a scott speedster s50 which I am generally happy with.
I live in a pretty hilly area and when the legs get tired find the granny cog useful.
I now however feel the need to upgrade the chainset and really fancy a Hollowtech or similar setup.

Currently It has a Bottom Bracket Truvativ 07BB 68/108
Cassette (Rear Cogs) Sram PG-850 12-26 T
Chain KMC IG 51
Crank Truvativ ISOFLOW 3.0 54x42x30 T

setup and I would like to fit possibly a Shimano Tiagra 4503 Hollowtech II Triple Chainset.
As this is within my budget of under £100.
I do however have concerns of the change in ratio's as the Tiagra is 50 / 39 / 30T

My question for you knowledgable guys on here is whether or not I would notice a significant difference between the 54 and 50 large ring and the 42/39 on the middle ring??
Also is the upgrade justified. The reason for change is that the chainset does'nt seem to run true and no matter how the front mech is set, the truvativ seems to enjoy dropping from the middle chainring to the small when under load and on the largest cog on the rear cassette.

I have fitted the M590 Hollowtech Chainset to my mtb and am very happy with that setup.

Any advice gratefully received

Cheers

Paddy

paddyeds

Anybody???

CarlosDSanchez

Hi, I'm currently going the other way, from a 48/38/28 tripple to a 50/34 compact on my sirrius. What I did was work out the gear inches of my "favorite" gears and then compare them to what I'd get with the new stuff I was considering. If you find that you use gears outside the range you'd get with the tiagra tripple then I'd look for something different which will give you what you use.

tenor

54/12 is a massive gear. 50/12 is equivalent to 54/13 so try using that gear and see whether you feel it is too low for your style of riding.
As an alternative, GB Cycles are selling Campag Chorus triples in 53/42/30 at 40pounds (allow another 30 for B/B).

paddyeds

Thanks for the advice guys,

it really is hilly around my locality where 90% of my riding is done so a triple is for me over a compact i think

Tenor, i must admit I hadnt realised how big a gear 54/12 is and having looked at a lot of bike specs on the net most of them seem to have 50/12 as their biiggest gear.

I also must admit that I only ever really hit the big gear when going downhill so 50/12 will probably be fine.

Decision made will go for the Taigra as there are some really good deals on it at present.

Thanks for the advice guys

Cheer

Paddy

willbevan

to aswer your other question about a 42 or 39.

I prefer a 42, as I find it naturally fits my self selected cadence and routes I ride.

I think you just have to try (or work out the gears you like as above and see what matches)