changing front ring (double)

Rich-hill

HI All,

I am currently using a 11-28 with standard double front rings (53/39).
Is it possible to change the small ring on the front to something smaller without having to change anything else? If so how much smaller?

I find i use the large front ring all the time while on the flat, but run out of gears on some of the climbs around where i am. I could do with an extra one or maybe two.


If you could let me know fi this is possible.


Many Thanks
Rich

sloppyschleckonds

You may be able to put a 36 on the small front ring.

Rich-hill

This would be a huge help if it's possible.

Can anyone confirm if this is possible without changing any other component?

earthvspace4XTuUWcX

Depends on the PCD of your chainset, if 130 or 135 mm (the most likely) then 38 probably the smallest.

sigorman85

Why not try a 12-30? The extra few teeth really do help

thefd

You may struggle. The maximum difference between the teeth is 16. 50/34 has this. Currently the difference is 14 (53/39). Changing to 36 makes the difference 17. The problem is the jump between the two rings. Usually to run a 36 you need to make the big ring a 52.

I wouldn't risk it.

oldhairylegs

sigorman85 wrote:

Why not try a 12-30? The extra few teeth really do help

^This.

Much simpler solution and will do the trick nicely.

simon_masterson

So far as I know, the smallest inner ring you can get for a 130bcd Shimano chainset is 38t, and 135bcd Campag 39t - hence the existence of the compact chainset. The gap would be ok - prior to the onset of triples, some touring bikes had custom chainsets that allowed you to pair a smaller bcd 32t inner ring with a 50t big ring.

But the immediate solution to your problem is to get a wider range cassette.

Rich-hill

I will look at changing to a 12-30 rear cassette then.

Can the rear mech take the slack that 39-12 would give, considering it needs the length for 53-30?

It only feels like i need one more gear, my cadence just can't quite keep it going up some of the climbs i have locally. I'm sure with added fitness though this will come in time.

Thanks

gubber12345

I went from a compact to a 52-36 and its brilliant for me.keep an eye on fleabay or on facebook buy and sell cyclist only you might pick one up.best of both worlds and good range of gears for climbing.

John.T

Rich-hill wrote:

I will look at changing to a 12-30 rear cassette then.

Can the rear mech take the slack that 39-12 would give, considering it needs the length for 53-30?

It only feels like i need one more gear, my cadence just can't quite keep it going up some of the climbs i have locally. I'm sure with added fitness though this will come in time.

Thanks

It is only 1 link (2 teeth) more so you will probably not need to lengthen the chain at all so it will not have any trouble with the 39/12. Even adding a link, if you have to, will put the mech in the same position as with the 39/11.

stevenb

A 12-30 is an option.
If your rear mech is a short cage then you might need to change to a medium cage to accommodate the 30t cog and you might need 1 x chain link to add to the chain.

You dont want too big a gap between the inner ring and outer ring on the chainset.
A 36t inner ring is typically found on a 110BCD chainset as a 36/52 is the biggest 110BCD Ive ever seen.
Once you are on 53/39 you are limited to the cassette.
What about swapping out the chainset?

Rich-hill

I will use a 12-30 and see how i get on, my mech says it can take something that big.

I'm really liking the idea of 52/36.Is this all i need to buy?

http://www.ebay.co.uk/itm/2014-Shimano- ... 2c856b3322

How would i go about fitting the new chain rings?

simon_masterson

As long as you have the right BB, yes, that chainset will be fine. Fitting chainrings is easy - all you need is an Allen key and a chainring bolt tool to hold the back of the bolts.

John.T

If your current chainset is HT2 that one will fit straight in.

Rich-hill

My BB set is:

BB-Set
INT Dura-Ace SM-BB9141

If that helps. I have little understanding of bottom brackets i'm afraid

Rich-hill

So does my current BB allow me to purchase the above 52/36, alter chain length and get our riding? Or have i mus understood?

John.T

That is a press fit Hollow-Tech 2 BB. Those cranks will fit fine.