Workshop tales, trials and disasters.
Maintenance tips, techniques and myths.
Technical discussion, description and outright lies
Hi, I took the chain and cassette off on the weekend for cleaning and inspection, it's a 2nd hand bike I've had a few years so I was interested to take a close look at the wear and tear as well as because it really needed a good clean.
I was suprised to discover that the back cluster ran from 12 to only 21, it's a 9-speed Ultegra set and I've been having some problems getting up some of the bigger local hills. I don't know why I didn't count it before but I always assumed it was at least 25 - my old bike had 28 on the back and 42 on the front, whereas this has 39 on the front and 21 on the back.
Given that I want to do some extended rides outside of Sydney e.g. Mangrove Mnt through to Windsor and others that all have significant hills, I really want to drop the gearing down quite a bit. I've looked at the Shimano options for this set and it looks like I can go down to either 25 or 27 as the lowest, I'm tempted to just leave it at 25 which would give me a lowest gearing of about 40" I think. Question is, what do you use (excluding race day bikes for less hilly sections) that will get you up anything you come across?
My touring bike is equipped with front chain rings of 22-30-42T and the rear ranges from 11 - 34T
I have Shimano on the front and SRAM on the rear. This will get me up most hills in Australia.
I have 30/39/50 rings and 12-26 cassette. IMO 39/26 is a low enough combo for any hill if you are relatively strong and riding an unloaded road bike.
A 34/50 compact crankset and 11-25 cassette is a good "hills" setup, lets you spin out a couple of lower gears while others are down to weight-lifting their bikes with the cranks.
I run 53/42/30 11-25 nine speed on my good bike. I never use the 30. I don't feel any holes in the 11-21 nine speed ratios.
On my commuter I run 53/39 11-21 seven speed and I get up the hill to Crows Nest no problems.
Got bored of my signature
52-42(Q-ring)-30 to a 12-26 cassette on my recumbent. So far I've climbed every hill I've attempted on it, but Perth is not very hilly.
Mangrove Mountain to Windsor ?
Can't say I've done that in one go, but have done most of the roads that would make it up.
I use a 53/39 and 12/27. On the hills on that route, I usu climb seated in the 39/24 combo or higher.
Having said that, there have been times I have been so stuffed that the 39/27 combo was welcome. Maybe it's psychological, but I like knowing I have the 27 there if I need it (though I very rarely use it).
Wow, I'd have thought tyre grip would be your main concern in that low gear when you're heading up a 1 in 2
I get up that hill ok myself on 39-21 (as I now know), it was the River Rd hill approaching Greenwich Road near Greenwich hospital that recently did me - I managed it but it was a close thing. I need to be able to get up those sort of gradients over longer distances.
Don't recumbents use much smaller wheels and therefore the final ratio would be very different? I see a recumbent pretty much every day on my walk home up the hill to Crows Nest (as mentioned previously), looks fast.
I'd probably do this ride over a w'end stopping at Wisemans ferry (it's suggested in a cycle guide book).
I'm thinking that the 27 is the way to go based on this and all the other posts. It won't leave huge gaps and might come in handy later in the day. Thanks for sharing your thoughts.
There are many more designs of recumbents than there are designs of "normal" bikes.
Mine currently has two 700c wheels on it. I should have specified my wheel size, so sorry for the confusion.
Will your current derailleur support a 27t sprocket?
I thought i read a recent thread on this site about someone having an issue running bigger than 26t on a modern shimano changer..
Anyone (with a better memory) recall this thread/issue?
I think Shimano road rear derailleurs are specced for sprockets up to 27T, but it's widely believed that's just because that's the biggest sprocket size on a Shimano branded road cassette and that they actually work fine up to 28T...
Me, I like to spin, on one of my recumbents (much like Graeme's, but with 26" wheels) I use a 52/42/30T triple with an 11-34T 9-speed cassette. With that gearing I can keep a cadence of 80+rpm going right down to 8.3kph if I really want to... My newer recumbent (also with 26" wheels) has a 53/39T double with a 11-32T 8 speed cassette and it's taking me a little while to get used to climbing at lower cadences on the steep bits.
I only use the 22T when hauling a loaded BOB trailer uphill.
I fall over otherwise as it's too slow a speed to stay upright.
There is only one BicycleWA.
In the end it worked fine, B-screw fully wound in, and avoided the big-big combo.
Didn't notice any shift quality issues either.
Actually I have read reports where you can run 30T at the back with no issues. Aside from turning the b-screw all the way in, you can get more clearance by reversing the screw, or simply get a longer one.
The issue is not so much with the big-big combo, but rather with the small big combo where the derailleur pulley wheels do not clear the large sprocket at the back.
I run MTB gearing - 11-32T rear and 22-32-44 on front. I never use granny gear (22x32) because keeping the front down becomes a major challenge.
I do use most of the others, though. I'm an old phart.
It's the adjustment screw at the 'b-pivot' where the derailleur attaches to the frame. It's used to adjust how close the derailleur is to the cassette, for best performance you want the jockey pulley to be close to but just clearing the cogs in all gears.
Edit: Sheldon's take on the subject.
On the previous bike, 38/50 at the front and 12-26 SRAM at the rear (9sp), and with the Argon 18, its a 39/53 and 12-25 (10sp).
I used an 11-28 for a hilly ride on the LeMond, and will probably resort to an 12-27 on the Argon soon, but trying to work on the engine over winter ....
Ok, thanks - that makes sense, I'm not sure if my old one has that adjustment (it's a Campag Record from the 80's) but it sounds like it should be fairly obvious if it needs adjusting once it's in lowest gear.
I'll fit the new one on the w'end - sadly it doesn't look like the weather will be much good for riding though.
I've changed recently from 12-25 to 11-23 with 39/52front. I don't really need the lowest gear except when I occationally do the lapstone hill which is 2.5km with about 150m of climbing, I went alright with the 23t gear and didn't really struggle any wore than before, I simply stand up when I no longer can spin. The reason I didn't go 11-25 is I like to have the extra ring in the middle when I am on the motorway.
I'm late to this thread, but I've just moved to 12-23 cassettes on both my bikes - both have 53/39 chainrrings. I ran a 12-27 cassette on my 9-speed Ultegra-euipped bike with no problems, although I did need to lengthen the chain when I first put the 12-27 on as I was replacing an 11-21 cassette on a used bike.
Litespeed Classic - 3Al/2.5V titanium tube set, Record 9-speed groupset, Open Corsa Evo CX
Alchemy Diablo - Columbus Zonal tubing, Ultegra 9-speed groupset, UltraGatorskins
Gitane Rocks T1 - U6 tubing, Deore/XT groupset, CrossMarks
Who is online
Users browsing this forum: No registered users