PWRDbyTRD

I was wondering if there is anyway I could run a 53T chainring on my cranksets...they're Shimano FC-M445 Hollowtech. I want to remove the 44 and replace it with a 53T, but if I can't...how big can I go?

cryptid01

Shouldn't be a problem with the crankset, as long as the bolt pattern matches. Chainstay clearance may be an issue depending on your frame. You'll need to get a new/longer chain.

Waldo

^
It is a problem with the crankset as the bolt pattern is different.
48 is a big as you can go, and it could be tough to find one.

a2psyklnut

Not only that, but your shifting might be compromised. Going to a 48 tooth will require you raise the front derailleur. Then when you shift back to your (I'm assuming 32 tooth) middle ring, it'll drag on the back of the derailleur cage. This will be even worse when you shift to the granny gear (if you can at all).

If you want to improve your gear ratio for riding on the road, you are better off with a road cassette vs. a front chainring.

cryptid01

I thought he was just going for a top speed record.

PWRDbyTRD

it's all about a higher top speed, I actually would like to go to a road crank on the bike if at all possible. the 28/38/48 has been mentioned to me.

a2psyklnut

You're still better off with a new cassette. The bigger chainrings might hit your chainstays. Mountain bikes need more tire clearence and thus widen quickly away from the bottom bracket.

I'd get a tighter gear ratio for the rear vs. the new cranks. But that's just me. A guy who's been a bike mechanic for 20+ years (off and on).

PWRDbyTRD

I have an 11-32 in the back...I'm quite content with it, what if I went to a road crankset, like a 105 triple?

a2psyklnut

Without actually mounting it on your frame, I wouldn't even venture to guess, but yeah, a triple should work. You can also find some mtn cranks in a standard spider (not compact) that are 46/34/24.

The_Convert

sounds to me like you should get a 'cross bike

PWRDbyTRD

I was going this route til I was told the frame I wanted to get can't support more than a 46T....

The_Convert

Still doesn't make sense not to get one, seeing as 99% of cross bikes can have standard road gearing. You didnt see any others you liked in your price range?

Raiyn

He went to a boutique frame builder.

The_Convert

well there is clearly alot to that story i don't know.

Still doesn't make sence to me to mess with a mountain bike when there are tons of good off-the-rack cross bikes.

Raiyn

He's trying to find a solution that works for him.

PWRDbyTRD

haha...what is this supposed to mean Mr. Raiyn?

Raiyn

Small company non big name but good quality.

Waldo

You would need a new derailleur, as mtn derailleurs aren't going to work well with that setup. A new bb would be necessary to achieve proper chainline, and of course a new chain would also be required.

KrisA

Didn't the road forum just get through roasting some guy called 53-11AllTheWay saying that unless his name is Ulrich he doesn't need that gearing? Somehow I doubt you do either, your current 4:1 top gear ratio would be plenty high enough for any kind of sustained speed. I can only stay in my 4:1 top gear on my cross bike for an extended period if their is 0 headwind and I'm really pushing it.

Can bigger guys just push bigger gears at much lower cadence?

The_Convert

A 53t ring is standard on road and cross bikes. 53-11 wanted like a 58 or 60 ring

notfred

My commuter bike is a mtb frame with 44-11 as the highest gearing. I only use two gears on the bike most of the time: 44-11, and 44-12. 4:1 on a bike with slicks is not that high a gear ratio.

khackney

There are some guys around that will make custom chain rings any way you want. A fixie friend of mine had a really strong ring made for his "Poojoe". As for the derailer problem. You could go to a road front, bottom pull and use a cyclocross pull reversing pulley to work on a mountain frame. It's some rigging to go thru but it would work.

PWRDbyTRD

That's exactly it sir. I can't spin to 100+ rpm so I have to use a higher bigger gear. I am more of a masher than a spinner, my friend who I ride w/ spins at anywhere from 1.5-2x higher than me.

PWRDbyTRD

as far as mr. 53-11 I'm not saying that this is the ONLY gear I will be using, I just want the ability to jump into a higher gear, I constantly find myself having to use the top chain ring as my riding is improving. I don't like spinning high cadences, I'm not trying to break any speed record...it's just a question...I'm not asking to get flamed here, just looking for info.

Dannihilator

Just change the rear cassette.