nerdy question about gear ratios

I got back into cycling about 3 years ago and the incredibly heavy hybrid that I ride has got a nice spread of gears (48/38/28 - 12/14/16/18/21/26/32). For most riding I just keep it in the middle ring and use the 16, 18 and 21 with quite a high cadence (I unscientifically worked it out at about 90-95). The small ring with 21 copes with most hills, with the 26 being reserved for the most savage bits of all. I only really use the big ring if I'm going downhill.

Recently I've brought my old racer (which had been gathering dust in my Mum & Dad's garage for many years) back to life with a bit of oil and some new tyres and stuff. It's got 52/42 at the front and six-speed block of 15/16/17/18/19/20. I assume this was fairly standard (for racing, anyway) when I got it (way back in 1989), but it feels crazy to me now when I try to ride it. Using the big ring, you've really got to grind it out, rather than spin it the way I've got used to, and even in the smallest gear it's a nightmare trying to get up steep hills. I'm not sure if this is because I've just got a totally different riding style now or because I bought a stupidly narrow block nearly 20 years ago.

What's considered 'normal' nowadays? From what I can gather, it seems that most racers (with two chainrings, obviously) have a smaller small ring these days (say 38). What about the back? Seeing as they have nine or even ten speeds now, do people go for a wider range than before (i.e. do they keep something in reserve for the steep bits)?

I don't know that much about gear ratios, but my impression is that spinning is in vogue nowadays, which requires smaller chainrings. So you're probably right that most modern road bikes would have something smaller than 42 up front. A lot of single-speed riders go for a 40-something up front and something in the mid to high teens in the back as a good all purpose ratio.

As a practical matter, you could always get a new chainring or cassette for your old bike, or just get stronger.

that is a v weird freewheel. i cant even guess what thats designed for.

is it a thread on freewheel? yr probly stuck with something like 13-23 or 13-25. if you can find anything.

the standard for road ranges these days is a 39/53 and an 11-23 or 11-25. ime at least.

w/ compacts and 10spd cassettes, i see crazy wide gearing tho.

The standard road setups Hunter mentions are for strong racey types. My compact is 50/34 and I have a 12-27 cassette, because I am a big wimp who prefers spinning.

I use Sheldon Brown's gear inches calculator. Inputting your gears gives you a range of gear inches from 55.4 (42/20) to 91.5 (52/15). In comparison, my setup gives me a range from 33.1 (34/27) to 109.5 (50/12). So a hell of a lot easier for me to climb hills!

I tend to cruise out of choice in the low 70s in gear inch terms, which equates roughly to your 52/18 or 52/19 combos.

that is a v weird freewheel. i cant even guess what thats designed for.

I'm not sure because it's so long ago, but the more I think about it, the more I think I asked for it. I'd had a touring bike when I started racing when I was 15, which wasn't very useful (obviously I took off the carrier and mudguards and stuff) as the gears were really widely spaced. To make matters worse the BCF had some rule that stopped Juveniles (under 16s) from using high gears and they would measure out your top gear between two lines before the race and move the limiter until you were under the permitted maximum - this just ruled out one of my gears and left a big gap to my next one down (say from 15 to 18 for example), while everyone I was racing against had gears in the gaps (i.e. 16 and 17) which put me at a disadvantage. So when I got some wheels built for my 16th birthday I think I might have asked for as narrow a range as possible. If I did, then that was pretty stupid, as the gear restriction didn't apply to Juniors (16-18 year olds) and I was just about to move house to from a flat part of the country to a hilly part.

I have 13-27 (across 9) on my rear so that is possible in a standard short cage racing set up. You could look at replacing the front rings with a compact setup (probably need a whole new crankset). That would give you 50/34 rings.

I'm worried about opening up a whole can of worms if I start changing bits. Do you think I could get away with changing just the block or just the chainrings & cranks? Or do you think the bike shop would insist on changing the whole chainset in one go? The thing is, I expect all the components are obsolete nowadays: the rear mech is Suntour, the front mech Sachs Huret, the gear shifters are the old-fashioned levers on the downtube, I've got no idea what the chain is, and the block is something or other by Campag. If I ended up needing to replace everything it would probably be so expensive I might as well just buy a new bike.

I think in your situation the crankset is easiest to replace. Is you front mech braze on or band on? If it is braze on you may need to get a clamp to lower the mech down enough.

Ah jr gear restrictions explains it perfectly

(xpost) - not sure, the bike's still at my parents', but I could upload a photo later

if your downtube levers are non index, i think id just try to crack that freewheel off there and find an acceptable six spd freewheel thatll fit. you might even be able to fit a seven speed freewheel on there depending on what you have there.

trying to retrofit a compact crankset sounds like $ to me. youd still only end up with a gear slightly easier than your hybrid's 38/21. you could try to put a triple on, but then youve got r mech capacity issues

for example

Thanks for the advice, Hunter (and Ed). The downtube levers *are* indexed. Does that make it impossible or just difficult? I'm out of my depth here in terms of working out what I can/can't change, so here are some pictures if that helps...

Levers (Suntour GPX)
http://farm4.static.flickr.com/3013/2930125238_c09b22f1c7_m.jpg

Front Mech (Sachs Huret)
http://farm4.static.flickr.com/3042/2930125162_413bd78873_m.jpg

Rear mech (Suntour Cyclone 7000) & Block (presumably Campag, as the hubs and the rims are, but I can't actually remember)
http://farm4.static.flickr.com/3002/2929265917_ac7cd0d273_m.jpg

The whole thing:

http://farm4.static.flickr.com/3151/2930124942_5bd09d16d4.jpg

those same gpx shift levers came on my bridgestone rb1 in 1989! but they were 7 spd. anyways, as i recall they had two modes, pure index and "semi" index. semi index might give you some slop to make things more compatible.

suntour had some proprietary, non linear cogspacing in some of their 6 and 7 speed shit so i think yr best bet is to:

1. see if you can get that old freewheel off (it can be rather difficult, go to a pro if youre not familiar with it)

2. find a 6 or 7 speed freewheel that fits your rear spacing.

3. see if it works acceptably with yr suntour gpx shift lever

4. if the indexing thing is a problem, find some used friction shifters. there is a huge (10000 ppl) bike swap coming up here in denver, im rather confident i could find a pair of used friction downtube levers somewhere for cheap.

I love your bottle cage. Is your rear light attached to your rear brake?

Haha! I'm not proud of that cage. It's not a light - it's a reflector, and yes, removing it would mean taking the brake apart. Back in the day, my Dad refused to let me remove it, so it's a token nod to road safety. I suppose now I'm 35 I could get rid of it, but I don't think the extra weight/drag is going to affect me that much.

I've e-mailed the bike shop nearest where the bike is and they've said they could put on a 14-28 6-spd freewheel and new chain for about £22 which sounds very reasonable. Also, they could put on a compact chainset for about £70. I'm trying to find out if the indexing would still work.

Not so nerdy, but recently I changed out the front gear on my single speed to something larger thinking that I could go faster, but now I'm not so sure. I spend so much of my energy pedaling that I have no good impression of how fast I am going. The first night I used it I thought, This is great, I'm flying.

Is it possible that I'm consuming more energy but not going faster? Will my legs get strong enough to ensure that I definitely am going faster? When I first started using a single speed I was in a town with a lot of hills and I developed all kinds of new muscles just trying to go fast and climb them all and with the pulling up action on the cages. I hope that's the case with this new set up.

I've noticed that a couple of the bike collective type kids in the downtown area have their bike set up like mine with the larger front gear. It just seemed okay in theory, that I'd not only be faster, but that it was okay since Orlando is so flat.

can you do us a favor and count how many teeth are on your chainring (and also provide the rear cog teeth count as well)?

that would help us understand your question better imo.

Sure. I'll update tomorrow.

amazed that NB&S fits on a bike he got when he was 15!

also bamcquern: just pedal faster!

So tired from this new set up - I've had a headache since Friday, but it might be from other health issues (even though I figured it was dehydration and too much exercise and maybe not enough sleep).

I'm thinking it will get easier, though. I'll give you that ratio tomorrow and maybe Steve Shasta or someone else will have some insight.

bamcquern, you could be damaging your knees if your new set-up is too highly geared. Be a bit careful there.

Also, can I ask why you changed the front chainring and not the rear sprocket, which would have been much cheaper and easier?

amazed that NB&S fits on a bike he got when he was 15!

That's not quite the case, but I can see how my posts make it sound like that. The (not terribly interesting) chronology is: bought touring bike in late 1988 (age 15), starting bike racing in early 1989 (on a touring bike with mudguards/carrier etc. removed and completely inappropriate gearing), got set of Campag wheels made for my 16th birthday in the summer of 1989 (with the ridiculous 15-20 block on), bought new road bike (racer, not tourer) in early 1990 minus wheels (which I already had), gave up racing in 1991 just before going to university and leaving bike to gather dust for many years.

So I was actually 16½ when I got that frame, and I was pretty much done with growing by that point.

The front one had a crack in it and had to be changed. And there was some creaking and dragging in my bike that I thought was a set of bearings needing to be replaced and re-greased, but I only suspected it was the crank hub. It cost $15 parts and labor. I shopped around and found the place that the bike kids use.

I've been mindful of my knees. I think my knees are safer at faster than 1 pedal revolution per second, and I'm not sure I'm consistently besting that. I'll still get that ratio for you today.

Okay: 53 teeth in the front and 16 in the back.

rather big. ok, fuckin huge, imo.

anyway, so im working for a client in golden, co (no, not c00rs). i brung my road bike and rode up lookout mtn after work--not a hard climb, about 1200 ft of vert at 5%. anyway, a local youngster in full garmin/slipstream kit (who might be a devo racer) came by me at the bottom. he proceeded to climb for at least 13 minutes standing up. i then lost sight of him.

i assume his assignment was to climb the entire thing (a very respectable ~19 mins at that pace) standing up. 8^0. wow, GOOD JOB DOOD!

i ended up at just under 25 mins. :( suckitude.

53/16 is O_O - be careful! I prefer about 90rpm on fixed and geared, and even with my 48/18 set-up my knees have complained a fair bit.

i ride a 48/16 which is kinda O_O for SF (very hilly) but 53/16 is like another +.5 in gear inches.

Put another way, I have a 20-speed bike. 6.7 gear inches is like my 4th or 5th highest gear.

Orlando is hella flat and 53/16 may not be too crazy...

You guys were right. It's bad bad bad. Not only do I suspect that my ride times and possibly even top speed are slower, but I am starting to feel it in my knees, and it's only been a week. I have to change to something else as soon as possible.

I ride 46/17 on my fixed and it's justright for me