|bout to make the plunge - nead gearing advice||wolfereeno|
Dec 16, 2003 3:40 PM
|Planning on finally buying the Pista this week. I'm an FG newbie - never even rode one before. But I'm pretty sure I'm going to love it. I mainly want it for training but also as something I can get around the city on from time to time.
So I'm sitting here with Sheldon Brown's gear ratio calculator and trying to figure out what kind of gearing I want. I need to be able to handle moderate hills and also NYC city traffic accellerations but would also like to be able to hit a speed of say 20mph or more just to keep up with people.
I took my regular road bike out for a few laps in Central Park today to try to find a comfortable gearing for its mix of flats and smallish hills. I was pretty comfortable in a 42x14=81" gear. My 42x13=87" was a bit tough up the hills but I could get used to it.
When I got home I started looking through the old messages on this board and see that I'm looking at gears that are a lot bigger than maybe they should be. Other people are in 60-70" range which I didn't even consider today.
I'm fairly fit for over 40 but not really that fast. I love climbing but sometimes have to resort to my 30x27 to get me to the top.
Over the past two years I've been trying to focus on riding higher cadences rather than churning gears. But sometimes my habit is still to churn.
The Pista comes with a 48t front ring. Am I crazy for thinking I should get a 16t for the rear? Is it better for training/fitness to think more like 18-19? I'm not sure I could make it down a hill without riding the brake. Not sure I could hold a 120 cadence for long. Or is that the point - ie to learn to?
Looking forward to learning to ride those perfect circles...
TIA for your advice.
|If you have to sometimes resort to 30x27||LC|
Dec 16, 2003 4:50 PM
|then how are you going to push a 48x16? I know there are riders strong enough to push that gear, but they typically don't need a 30x27 on their geared bike no matter how big and steep the hill. Until you know better yourself I would advise you to stay with gearing of not more than about 70 gear-inches or 48x18 in your case.
If you need to use the brake to keep from spining out, then use it! The more you ride your fixed the better your spin will get and 120 rpm will soon be no big deal.
|re: bout to make the plunge - nead gearing advice||ukiahb|
Dec 16, 2003 5:19 PM
|The advice I saw said to go for 65-75 inches, so I set my bike up at 70" and that works really well, have not felt a need to change it...and I'm also 40-something FWIW.|
|what I did ..||Steve Young|
Dec 16, 2003 5:47 PM
|I don't know if this will be helpful or not - but here are my experiences as a fairly recent convert to Fixed.
I ride predominantly flat trails. Dead flat as the default route runs along the SF BAy with about 60 feet total altitude change in a 20 mile route.
My fixie came with 48x16. I didn't ask for anything else as I didn't know any better. This works fine on still days but when it is very windy this gear is a real battle into a headwind.
After a few hundred miles experience I fitted an 18 on the back which I found to easy (except on very windy days). I have now settled for a 46 on the front and a 16 on one side and an 18 on the other (it's a flip flop hub). On the flat route I use the 16, when I stray into more undulating country (I don't do hills yet) I switch to the 18. If you can get a flip flop hub as part of the deal (I'm not sure what the Pista spec is) then that enables you to hedge your bets to some extent. I'd highly recommend it.
My overall advice would be to go with gear somewhat lower than 80". High 60's low 70's in terms of gear inches would be where I would aim for in a slightly hillier area (I occasionally bail on a 30x27 up serious hills too). However ideal is going to vary between people - Changing gear is a bit cumbersome and typically costs 20 notes give or take but it's cheap and easy enough that experiemnting is worthwhile.
|go for the lower gearing||wooden legs|
Dec 16, 2003 10:45 PM
|most everyone i know who rides a fixed for commuting / on roads is in the 42x15 / 44x16 / 48x18 range. shoot a bit low and it will help you with cadence as well as being better suited to less than ideal conditions like rain, headwinds and seep hills. if you're riding in traffic a lower gear also helps you slow faster (huh? i think that makes sense) which can be crucial in swimming through rush hour and dodging motorists.|
Dec 17, 2003 7:56 AM
|For CP or a quick jaunt out to Nyack, I find that 48x18 works for me. I'll spin up to about 160rpm going down state line hill on 9W but can still manage to keep my cadence in the 50-60rpm range coming back up. I've used 48x16 in the park but the 16 is a little tough once I get out of the city. 48x18 lets me cruise at around 19mph at 90 rpm. You'll be surprised how quickly you'll develop the ability to hold higher cadences for longer. One thing I do notice is that I am more likely to push my heart-rate up going down-hill than up. Up-hill it seems like the momentum of the pedals makes climbing easier. I suppose that this is because I have no choice but to grind it out.|
|Really hard to say what's right for you||cmgauch|
Dec 17, 2003 8:48 AM
|but the 48x18 sounds reasonable to me. On my geared roadie my lowest gear is a 39x21. If I ever put a cog on the "flop" side it'll likely be an 18. Now I suffer with a 48x16, but I really like it on the flats/downhills.
I haven't done the Nyack ride on the fixed yet, I'm in northern NJ & ride mostly Passaic & Morris counties on my fixed.
Whatever gear you choose, you'll be OK w/high rpms (150+) after a few hundred miles.
|Split the difference||KEN2|
Dec 17, 2003 9:00 AM
|Why not split the difference and go for a 48x17? That gives you around 75 gear inches. I'm 55 and reasonably fit, and I ride rolling hills terrain with a 46x16 (77 inches). You can always stand up to climb when the cadence gets too low.|
|Thanks to everyone, you guys are awesome. (nm)||wolfereeno|
Dec 17, 2003 10:11 AM
|Whats involved with changing the rear cog?||wolfereeno|
Dec 17, 2003 1:25 PM
|What do I need to change the rear cog - I've got a chain whip but what's holding the gear in place?
And when you go from something like a 16 to an 18, do you have to add links back to the chain - or does the horizontal dropout have enough play for that kind of change?
|Whats involved with changing the rear cog?||LC|
Dec 17, 2003 2:01 PM
|It is threaded on. you need a lockring tool to remove the lockring, and then a chainwhip to unthread the cog. It tightens as you ride the bike so it will be very tight.|
|Changing the rear cog....||gspot|
Dec 17, 2003 2:06 PM
|To change the rear cog... you need to use your chain whip to remove the cog after you remove the lockring...
The lockring is reverse threaded.. and you need a lockring remover to do this... *or* tap it very carefully with a hammer and screwdriver in one of the openings to loosen it and remove.
this is the less desired method.. as you could very easily damage your lockring...
as for chain length.. and dropout adjustment.. I don't know. its hard to know unless you see the bike in person... and where the wheel is in the dropout...
(there are probably way to do this with mathematical formulas and such... but i don't know them...)
|Whats involved with changing the rear cog?||climbo|
Dec 17, 2003 2:07 PM
|removing the lock ring and then taking off the cog with a chain whip.
Depending on where you are on the dropout and what you need to do, 16 to 18 or 18 to 16, that's one full chain link which should be OK if you can set it up right the first time. If you start with the 18, when you go to the 16 you'll need to slide the wheel back a little so make sure you have half the wheel starting closer to the front part of the dropout.
FY, I run 42x15 in central NJ which is 77 gear inches, almost the same as a 48x17 coombo.
|My experience.||Steve Young|
Dec 17, 2003 2:11 PM
|You need a chainwhip and a lockring removal tool (The wheel is held in pace against backpedalling by a lockring). The type of tool you need will likely be affected by the type of lockring but a Park HCW-5 tool works for me - if you look through some of the recent posts with a search someone posted a picture of this a week or two back.
If you have a few miles on the wheel and have never before removed the cog you may be surprised at how tightly it is on the wheel. Once you have removed the lockring (should be easy enough), if you find that you can't loosen the cog with a chainwrench it is possible to reapply the lockring loosely (make sure it has enough threads engaged to avoid damage) and then back pedal from a slow and then an increasing speed until the cog breaks loose.) As a disclaimer - this worked for me but I'm not sure if it is recommended.
It's not often mentions but I would also wear some gloves to protect your hands the first time you remove the cog ! (I'm still healing from not doing this:)
A change between 16 and 18 on the back was accommodated on my rig with no problem - I would be surprised if it can't be accommodated by your drop-outs but I think that will be predicated on the current position of the wheel.
When you reassemble it all make sure the lockring is tight. This may necessitate riding a bit after everything is reassembled and then stopping without backpedalling. If you resnug the lockring at this point you can be confident that the cog is tight (enough)
|Shouldn't someone at least mention crank arm length?...||TFerguson|
Dec 28, 2003 2:20 PM
|Going from a 165 to a 175 crank arm is equivalent to about 1 tooth in back.