Entry level commuter bike?

[garage sale GT]

You may find that if you change to a ROAD triple -- the 9-speed Ultegra comes with a 53/42/30 combination, BTW -- and still need/want a higher gear, that a 54t or 55t time-trial chainring will more than suffice.

I went looking to upgrade my Raleigh MTB crankset. Check Amazon under "Shimano, FC-2203, 175mm, 52-42-30T, Square Taper, Crank Set". It's fifty bucks. You still won't have as much top end as a bike with 52/11 and 700c wheels but you'll be close. You may not need all that top-end gain unless you ride to work in tights and then change.

They also have a steel one for a square taper bb if you want to save some bucks. I could even send you a pie plate which fits a Shimano freewheel so it would match your crank!

 

[sideshowbob]

My hands get numb when i ride more then 30 minutes. I assume a c/f fork would reduce this. The c/f seat post is to reduce weight. The switchback weight a ton!

 

[sideshowbob]

I searched amazon and alot of the cranks are over $100. Is the issue, the crank arms are the wrong length or a bigger sprocket won't fit? I've thought of changing the cassette to a 11 tooth. Would it work?

 

[garage sale GT]

It should take an 11; I would be surprised if it didn't already have one, unless it's a freewheel. Freewheels don't go smaller than 13.

Try getting slicks and upping your cadence before buying a crank. 44/11, 26" wheels, and 60 crank rpm should be good for 18MPH.

I think you would have to be a pretty well trained cyclist to be able to push an upright MTB faster than that when you were either wearing your work clothes or carrying them on a rack.

 

[sideshowbob]

My gearing is 48/13 with 559-1.50. The crank teeth do show alot of wear. I average 12 mph with stoplight/stop signs. I have dnf on 2 out of 2 novice group rides. I have no idea if a 11 would fit the wheel.

 

[alfeng]

My gearing is 48/13 with 559-1.50. The crank teeth do show alot of wear. I average 12 mph with stoplight/stop signs. I have dnf on 2 out of 2 novice group rides. I have no idea if a 11 would fit the wheel.

Okay, the rear wheel that comes on a "stock" Mongoose Switchback (as pictured, but your's may be a different color) apparently has a freewheel rather than a cassette ... and, you would need a different rear wheel to use an 11t cog ...

IF your fork is "solid" (vs. suspension), then there isn't any reason to change it unless you are going to change to 700c wheels, IMO.

Anyway, you can probably get a NEW rear wheel which has a "freehub" that will accept a cassette for under $50 ... of course, you can pay much more.

The cassette will cost you between $20-and-$120 depending on which one you select (you should be able to get an 8-speed 11-32 cassette for $20 on eBay -- the spacing on the 8-speed & 7-speed is essentially the same ... since you are in Florida, set your derailleur to handle the 11-28 cogs).

As garage sale GT notes, a 44/11 combination will give you the gearing that you want ... since you currently have a 48t large chainring, so much the better.

IF you are adventurous/knowledgeable -- or, have a friend who knows how to lace up a wheel -- you can have your current rear rim relaced onto a replacement hub for $20-to-$80 (for the hub) + cassette.

At some point, the cost of changing over a lot of components can become prohibitive vs. buying a different bike ... better to make minimal changes to your current bike ... if you were to put a ROAD crankset on your bike instead of a different wheel, you could probably re-use/re-sell it later IF you ever sold the Mongoose and got a new bike ...

There are a lot of USED bikes on eBay which have either 700c or 27" wheels (the latter are considered to be obsolete, but will be suitable if the price is right) -- there are less tire choices, now, for 27" wheels, but the selection is suitable for non-competitive riding.

The more you ride, the more you will get a sense of how well-or-poorly your current bike fits -- e.g., the distance between the saddle & handlebars, in particular -- and, that knowledge will help you if you ever decide to get a different bike in the future.

 

[garage sale GT]

I bet your rear axle is bent. Freewheel hubs are too fragile to even consider using.

I got a used 27" bike but updated it with a cassette style wheel for the strength, not for the ability to use 11T. They will all have freewheels more or less.

I would recommend purchasing a new rear wheel if you want a cassette, if the rest of the bike is worth saving. You could find one for $40, and a cassette for $20. It would not be lower quality than a fairly modern, freewheel style MTB as only cheap ones still come with freewheels.

That said, I still think the best route is to raise your RPM, maybe get some toeclips and straps or find an SPD shoe on clearance. Ideal cadence is 60-90RPM. If your top speed is limited by having to pedal so fast that your torso starts bobbing up and down, then you need a crank. If, however, you can't maintain your speed at 60 RPM, it will only get worse with a bigger crankset.

 

[sideshowbob]

I'm considering getting a 52 tooth crank ($28 shipped) and putting the old 1.95 semi slick on the back. I assume the crank would fit on the switchback.
Alloy, 130/74mm bolt circle, 170mm arms, square taper interface. Brand new. Rings are steel, 52/42/30T
I've never thought of increasing my cadence. I do spin out ( run out of gear) going down hills. I mostly ride in high gear on flat terrane