bluefoxicy

So I'm able to push my bike up a really steep hill at around 4mph in the lowest gear I have, at a slow cadence. At what I'm guessing is 90RPM, I get about 8mph? My daily commute is full of tons of steep hills, so this is becoming somewhat relevant; the strip of mountain path is irrelevant, I can power through that on my small crank gear in 2-4 easily enough, although getting up there is almost enough to make my heart explode in my 1:1 ratio lowest gearing.

https://www.performancebike.com/bikes...0_20000_400296

Shimano HG-50 8spd 13-32
FSA CK-200 52/42/32
700c wheels

My lowest ratio is 1:1 (32:32), and I want something lower. From what I can surmise:

• I can't just throw on a 9 or 10 speed cassette and chain without a new derailleur and shifter
• Customizing the gear set is possible, but there are trade-offs
• Could also mess with the crank

Shimano sells an HG-40 cassette (I have the HG-50) that goes 11-34 rather than 13-32, which gets me both higher and lower gears on an 8 speed. Of course, it goes from 34 to 26, which is crazy. The difference would be like 5% anyway, 1:1 to 0.94:1.

The other options seem to be something like a 28-38-48 crankset instead of a 32-42-52. Mountain bike cranksets seem to be 22-32-42. A 28-38-48 seems like it'd give a lower gear than the current crank into an HG-40; but I'd sacrifice the 52/13 ratio for a 48/13. I rarely use the 52 tooth gear on the crank, but that's due to lack of experience; I really don't know how fast these go either, although I'm sure there's a formula somewhere to go f([gear ratio],[Wheel size],[Cadence]) = [Speed] and the theoretical speed consideration is at 80-90 cadence. The difference here would be around 12.5%: 1:1 to 0.875:1.

The last possible consideration is that a 9 or 10 speed deraileur of similar quality to my OEM part would cost around $50, a cassette would cost around $50... it's really not that bad to upgrade the parts, costs about as much as a good saddle. Seriously, the cassette on there is a $25 cassette, I don't have an expensive bike. Still, that would take me up to a 36 tooth gear, 0.89:1 on my current crank, so changing the crank would accomplish the same thing.

Of course all considerations come down to "does this part fit my bike in the first place?"

At this point I'm facing a paradox, really. I think I'm best off doing nothing until I've gained more experience; but exactly at this point of minimal experience, I'm lugging myself up hills that are killing me, forcing me to a crawl at an ungodly slow cadence, and so I want/need/whatever a lower ratio specifically because of my lack of experience.

I'm thinking my best option would be to change the crank, and then if I still want a lower gear then go with a 10 speed 11-36 tooth crankset. That should take me from 0.78:1 up to 4.36:1, where I'm currently 1:1 up to 4.72:1 (I think my smallest gear is 11 teeth, not 13). When it comes down to it, all that stuff would cost around $200 total if I went all the way; and of course I'd keep the OEM parts and put them back on when I want another bike, sell the bike, and if I've got this much crap lying around my next bike will probably be one I build. At this point though I think just the crank change would do it...

Also of note: any time I look at options for the parts I have, it tells me that the information on my bike is WRONG. That 32-42-52 crank is of a model offered in 30-42-52. My HG-50 13-32 gear set... near as I can tell, it's offered in 11-(28,30,32). I should sit down and count the teeth on the gears and figure out what I actually have. I bet my fork isn't even carbon fiber (everyone else lists it as aluminum).


Thoughts?

Al1943

First confirm that the smallest chainring is a 32 or a 30, count the teeth. It would be fairly simple to replace the smallest chainring with a 28 or maybe smaller. A crankset with chainrings closer in size will shift smoother than a crankset with big changes in size. Your middle chainring at 42 teeth is fairly large by today's standards. You may want to consider a 39 tooth middle chainring with a smaller small (granny) chainring. The middle chainring in a triple crankset well work better if it is designed to work in a triple, with ramps and pins to assist lifting the chain from the smallest to the middle chainring. Suggest you check to see what optional chainrings FSA may offer. A new crankset like you have mentioned may be a good idea, 28-38-48 is a good combination, most of us really do not need a 52.
Changing to a 9 or 10-speed cassette would require new Shimano shifters, cassette, and chain. Your old derailleurs should work fine unless the rear is Dura-Ace. The shifters are the most expensive part of that conversion.

bluefoxicy

I'm rather certain I don't need a 52, because the speed at 90 cadence for 50/11 is 34.2mph (Sheldon Brown's calculator says so) versus 31.5mph for a 48/11 (the MegaRange 8 speed is 11-34). This is not a huge concern for me, since I never make it up there anyway and my commute is all along 25mph speed limit roads anyway (and too many hills); there's not a lot of places I'm going to want to be at 35.

Interesting that I can change crankset gears; although a whole new crankset is easier and might be cheap, though I'd imagine it'd be somewhat more expensive than just getting new gears. Then again, I wouldn't have to worry about the difference between 175mm, 173mm, and 170mm cranksets. Still, you say having the rings closer in size is better; if I start dropping the lower and middle, I'll want to drop the higher as well, so I think a new crankset is better in this case than changing the rings.

The crank might be a good enough change for me, though I'm tempted to go with the crank and gear even though it's only 2 gear teeth difference.

10 Wheels

All you need to do is change the 32T Chain Ring to a 24 tooth.

I started with a 52/42/30. My friend changed the 30T to a 24T and I have been good ever since.

canopus 

At 90RPM in your 32/32 would be 7 to 8 mph. 50 to 60 RPM will give you around 4 mph.

A 32/32 on 700X28c wheels and 170mm cranks is about a27" gear (For each full crank revolution you travel 27"). That's really quite low for a road bike unless your in the mountains. If you need something lower than you could either replace your 32 with some like a 28 (23" gear) or a 26 (21" gear). That is in touring gear territory. Going to a 34 in the rear is only going to give you an extra inch so I wouldn't consider a cassette change that big of an improvement. A 26t front should make a big difference. If your still having problems after that its going to come down to conditioning for the climbs.

Al1943

If you buy a complete crankset try it before changing anything else.
You still haven't confirmed that the smallest chainring is a 32, count the teeth.

bradtx

bluefoxicy, The good part of just changing chainrings is that there is no BB length issues with a new crankset that may or may not have different backspacing (automotive term I know, but not all cranksets position the chainrings in the same place).

Brad

bluefoxicy

Interesting.

That leaves one problem of course: google is being unfriendly with "crank gear" "Crank cog" "bicycle cog" "bicycle crank cog" "bicycle crank gear" etc. Cranksets are way easy to find.

I assume BB is Bottom Bracket... okay, what I read about that seems not relevant to your concerns, so I need to find other sources of information to fill an information gap before I go buying crap. Or maybe go to a bike shop and ask them; turns out there's a couple good ones around here, the one I was going to sucked horribly.

Al1943

The correct term is "chainring" (used to be "front sprocket"). In the back you have "cogs" in a "cassette", or in some cases cogs on a "freewheel" (used to be "rear sprocket").

Barrettscv 

According to the Performance bike link, he has a FSA CK-200 52/42/32 as stated.

He should install a 28t small chainring as his first and cheapest modification.

Al1943

But in the last paragraph of the OP he says: "Also of note: any time I look at options for the parts I have, it tells me that the information on my bike is WRONG. That 32-42-52 crank is of a model offered in 30-42-52."

bluefoxicy

Yeah, and I also noticed I have a 13 tooth gear on something not offered in 13-32. But then Google tells me that there are OEM Shimano HG-50 cassettes that are 13-32, which apparently you can't buy in that configuration aftermarket. I'll have to count the teeth next time I sit down and check out the bike. Cleaning the dirt off might be useful too; my frame is all muddy.

Kimmo 

The 24t chainring sounds like the easiest way to sort it...

Although perhaps the best way is to get a compact crankset (28/38/48) for better shifting and a better spread of ratios... it also gives you the opportunity to go to a different crank length.

If you're 5'10" or over and can spin pretty well like me, you may wonder where 175mm cranks have been all your life when you try them...

berner

I,ve just re-geared my own bike to be able to do some light touring in New Hampshire mountains. Based on comments from Barretscv in another thread, which also is in sync with advice given here by others, I first replaced a 30T chainring with a 26. It took a bit of adjusting but shifting seems fine and made an immediate and noticable difference. Then I cobbled a 30T cog onto a cassette that previously only had a 26T cog. Gear inches now are about 24.5 and I'm a happy camper.

bluefoxicy

Mine's 175, I was actually considering going to 170 since those seem to be readily available. I'm 5'9.

I also figured out that my comfortable cadence is apparently around 100-ish, not 90... well, I figured out my mph for gears and it's like, this gear is 7.6mph@90, I'm going 8.5mph, etc. A week ago I was too slow so I started using lower gears... this is the result, now I'm too fast?

roberth33tiger

the commonly used term "gear inches" does not mean "how far the bike travels for 1 turn of the crank". to get the distance traveled, you have to
multiply "gear inches" by pi (3.1416)

fietsbob

I Use a 26t 3rd chainring, on my 52, 42 .. 26, given favored , 10 and 16t differences .
Have 2 different Campag Triples, Other one a 50,40,24..
both shipped with a 30t innermost chainring ..

as result, I've got several New 30t 74BCD chainrings, take offs.

if any one wants one .

bradtx

"... this is the result, now I'm too fast?" --bluefoxicy

Sort of... It's good to experiment with riding style. I've read alot of comments that spinners should use shorter crank arms. Maybe so, but I like to spool up to 100 RPM now and then and use 175 mm crankarms on my distance road bike. When in a long distance lope I'll generally run 60-80 RPM. You may like a 170 mm crank arm, it's worth experimenting with. I like kimmo's advice about the 28-38-48 crankset (I'm going to swap my T bike to that with 170 mm crank arms), again it's something worth experimenting with and I have one sitting in a box.

Cycling doesn't get any better than when you have your fit and gearing right.

Brad

bluefoxicy

Lots of people with wide spreads here, 26 42 52 I've heard multiple times.

I've confirmed and yes, my crank says 42/52 on the outside and 30T on the smallest gear. Largest chainring seems to be an integral part of the crank somehow; haven't looked closer but I think it's ganged to the middle one.

So I'm at 30/42/52, going to 28/38/48 is going to make a 6% difference and doing that plus a megarange is a 11.6% difference total. Also I think my highest gear really is 13, and the MegaRange gives me an 11, so overall the change would actually give me a higher gear in the end. Then again, now I'm wondering on 26/38/48 or 26/38/50.

Of course, if it shifts well enough, dropping that smallest chainring is all I really need. If I'm not going uphill, I'm on my middle ring. I worry about how well it'd shift though; the chain already fails to shift occasionally anyway, and it's slipped between my crank and frame a few times now. Last time I backpedaled when it started rattling (in neutral! It was between two gears and not shifted properly onto either! It was slipping off more on top, backpedaling feeds from the bottom where it was almost right) and managed to get it to catch. This is usually trying to come up from 30T to 42T. Didn't think you could complete a shift by backpedaling.