Chainring gearing on my Trek

[mikeyw]

Guys,

I live in Harrogate which is near to the dales so fairly hilly to say the least once you get out into them, my Trek 1.2 is ok mainly for steady climbs but you have to work pretty hard on the steeper stuff and once you get to the 1:6 or 1:7 you can forget it. I'm doing the coast to coast soon and believe it'd be better to change my gearing.

I counted 53 on the large and 39 on the lower ring - does this seem correct ?

To be honest i never use the top ring but i guess if you just want to change one of them you have to do the inner one. Would taking that one down to say 34 be enough to get me up those steep climbs ?....i'm fairly fit and normally ride 20-35miles in the surrounding hills.

Rather not spend a fortune on a new set up but a reasonably priced straightforward change would be very much of interest.

Any advice greatly appreciated.

Mike.

 

[2Loose]

If you can change the inner ring for a 34, then that would make a big difference to your climbing.
Some chainsets cannot have their inner ring changed though, which would mean a complete chainset replacement to a compact double.

 

[Dave Davenport]

If you can change the inner ring for a 34, then that would make a big difference to your climbing.
Some chainsets cannot have their inner ring changed though, which would mean a complete chainset replacement to a compact double.

You can't run a 34-53 combination. You need to change to a compact chainset 34-50 is common and available from about £60, you'll just need to drop your front mech a bit and maybe take a link out of the chain.

 

[HLaB]

Sounds like you've got a traditional double mikeyw, when perhaps a compact double would be better. I don't know the compatibility engineering wise but for you as an individual, it'd probably be a too big step between the large and small rings. By all means if its engineeringly possible go for a lower chainring but I personally wouldn't like too big a step between the two rings, I'd prefer to fit a larger cassette to the rear.

 

[Tigerbiten]

What BDC is your crank, 130mm or 110mm ??

If you have a 130mm BDC crank then I think a 39 tooth inner ring is as small as you can go.
If you have a 110mm BDC crank then there is room to fit a smaller inner ring.
Look at your inner ring and see how much room you have between the fixing bolts and the teeth.
Does it look like you have room to fit a smaller inner ring ??

 

[jimboalee]

Spa Cycles will fix you up.

 

[Andrew_P]

Anyone help me with this?

I have a Marin 29er, which I am comfortable on, but I have found myself only really using gears 18 -24 cannot remember the last time I used the middle ring let alone the granny. I have been considering a race bike, but giving it some thought the main thing I am looking for would be better gearing, so how easy to change this over?


Shimano HG30, 11-32, 8 Speed rear cassette
TruVativ X-Flow C 3.0, 48/38/28

 

[mikeyw]

Hi Guys - thanks for the advice.

I'm afraid i'm not sure what a BDC is ? - the bike is a Trek 1.2 if anyone else knows ?

I found a reasonably priced
Shimano FC-R600 105 Compact 50/34 would this be compatible with my 2008 Trek 1.2 ?


Think 50/34 would probably be enough to get me up those climbs !


Just found the details on my 2008 bike :-


Drivetrain Shifters Shimano 2203 STI, 8 speedFront Derailleur Shimano 2203,Rear Derailleur Shimano Sora,Crank Bontrager Sport 50/39/30

Does this mean i could squeeze a 30 in the inside of my existing crank ?

Thanks again,
Mike.

 

[John Ponting]

Sounds like you've found the spec for the 1.2T(riple) rather than your 1.2D(ouble).

My Trek 1.2T is indeed 50/39/30 Bontrager with a square shaft.

I'm not sure what fitting the 105 chainset is.

***************
Just checked the Shimano TechDocs site - the 105 is NOT directly compatible. It comes with an integrated bottom bracket. Not a major task to remove the current bracket set and fit the 105 but best left to a shop if you do not have the correct tools.

http://techdocs.shimano.com/media/t...FC/EV-FC-R600-2596A_v1_m56577569830694005.pdf

 

[HJ]

What BDC is your crank, 130mm or 110mm ??

If you have a 130mm BDC crank then I think a 39 tooth inner ring is as small as you can go.
If you have a 110mm BDC crank then there is room to fit a smaller inner ring.
Look at your inner ring and see how much room you have between the fixing bolts and the teeth.
Does it look like you have room to fit a smaller inner ring ??

Um, don't forget this is Beginners a quick explanation of Bolt Circle Diameter (B.C.D.) is in order, so here is a link to Sheldon Brown to do just that.