|gearing question for road newbie||reklar|
Mar 19, 2003 1:20 PM
|I got my first road bike last week (actually it is a
cyclocross, but i'm using it mainly for road riding).
And I've been able to go on a few road rides.
My gearing seems a bit high even on the road for me...
The rings are 50-39t up front and a 12-26 rear cassette.
I'm *reasonably* fit, but we have some long road (and MTB!)
climbs here in norcal, and I think I should be able to spin
up those hills. Instead I am grinding away--I guess I'm really
used to having a granny and spinning from my MTB riding.
Would going to a 12-30 or 12-32 cassette fix my problems? Would
I need to swap to a MTB derailleur? If so, will the STIs work with
that type of derailleur?
How much efficiency can be gained my switching out my 35c
cross tires to 23c or 25c slicks?
|definitely try the tires first. You won't feel a whole lot of||bill|
Mar 19, 2003 2:03 PM
|difference between 23 and 25, but either way you'll see a world of difference from 35 cross tires. It may be all you need.
A 12-26 rear should give you some pretty low gearing, although for very mountainous terrain and until you're more fit (if that's an issue -- you don't really say), it's not going to make it easy. Once you're more road-fit, you really should be able to get up most anything with that rear. Maybe not with a smile, but you'd get up it.
As to whether you can use your existing derailer with a bigger rear, I think you're going to have to tell the studio audience what you're running right now. I'm out of my league here, but I think that almost anything bigger than about a 27 in the rear is going to require something different from the standard road setup.
I guess I would change the tires and then train more before I started fooling around with any other equipment.
|re: gearing question for road newbie||laffeaux|
Mar 19, 2003 2:08 PM
|I live in the south bay, so if you're riding the same nor cal hills that I ride, you can forget about spinning up them with a double (unless you have really strong legs). I run a 38/27 combo on my 'cross bike with 32mm cross tires. Road tires are a bit faster while climbing, but nothing overly dramatic.
If you want to spin up Montebello Road (or similar) it's going to take a lot more saddle time or a triple on your bike.
|re: gearing question for road newbie||reklar|
Mar 19, 2003 2:20 PM
|I'm in the east bay...Mendenhall/Del Valle road, Morgan Territory, Altamont, etc...are typical rides. Don't know about Monte Bello road, but I have ridden MTB at most of the popular (and some not so popular) parks in the bay area.
Favorite MTB rides with a lot of climbing include Skeggs, Saratoga Gap, etc. I'm reasonably fit cardio wise at least, but could stand to shed some pounds (6'0", 190lbs).
I guess I'm just used to spinning up the steep fire trails and single track in my granny and 32t rear cog on my mountain bike.
I'm running an RSX derailleur in back right now...
|re: gearing question for road newbie||laffeaux|
Mar 19, 2003 4:08 PM
|I ride the same MTB trails as you and there are several hills that I can't spin up in my 24/34 MTB combo. I can think of a couple of climbs at Skeegs that fit that category, and Charcoal Road (near Saratoga Gap) definitely fits that category.
A double on a road/cross bike is a lot higher gearing than your MTB. Even though there is less rolling resistance, it hardly makes up for the gearing changes.
|re: gearing question for road newbie||reklar|
Mar 19, 2003 4:32 PM
|> A double on a road/cross bike is a lot higher gearing than
> your MTB. Even though there is less rolling resistance, it
> hardly makes up for the gearing changes.
That's what I was thinking!!!
Yeah, some of the climbs at Skeggs are technical. I can ride up Charcoal road, but that sure is one heck of a long boring and steep fire road. The table mountain singletrack ascent is worth it I suppose...
I'm not trying to take my cross bike to these places, but...I have to push a lot harder on the pedals of the road bike on the roads even around here it seems. I guess it is just "road gearing shock"! I think a different rear mech would help and will try that as well. There is no point in mashing if I can avoid it...(duck!)
|are you going to be a roadie or not? ;)||sievers11|
Mar 19, 2003 5:00 PM
|standard mtb - 42-22 front 11-32 back
standard road - 53-39 front 12-23 back
There is not enough gearing on an mtb bike, you will run out of gears fast...get a triple on the front so you have a 52-39-26ish mix if you are concerned about climbing. If you start messing with your current set up you are killing you top end.
|are you going to be a roadie or not? ;)||reklar|
Mar 19, 2003 5:19 PM
|> There is not enough gearing on an mtb bike, you will run out
> of gears fast
I'm not sure what you mean by "not enough gearing on a mtb bike".
Also, how would changing the rear cassette affect my top end? I would go to a 12-32 or 12-34 in the rear (from 12-26) so the jump between gears would be larger, but would my high end change?
Wouldn't a triple set me back some serious cash? In addition to new cranks wouldn't I need a different front STI and derailleur?
Admittedly I don't know a whole lot about this stuff, so please don't mistake my (insert adj here: e.g., innocent, stupid, ignorant) questions for beligerance... ;) I'm just learning...
|you didn't say what STI shifters you are using, but if they are||jiggs|
Mar 19, 2003 6:45 PM
|anything but dura ace, I bet they will shift either double or triple, dura-ace have a specific triple unlike the others as far as I know. You are right though, unless you have triple crank arms, you will have to buy a new triple crank. That might not be that expensive if you stay with something like 105 or even truvativ elita triple was on somewhere for 79 bucks. (plus 40 for the BB)|
|I'm using XTR RD, either 11/34 XT or 12/27 DA cassette &||jiggs|
Mar 19, 2003 2:57 PM
|it handles the large cog no trouble. The XTR rear derailler is almost same weight as Dura-ace. I use the 11/34 for climbing & the 12/27 for ordinary road riding. I have Dura-ace sti shifters, works great. I don't think a road cassette will handle more than 27/28T cog.
I just took off my Ritchey speedmax CX 30c tires and put back on my 23c slicks and they roll faster but I don't think there is a big difference climbing.
The other choice is to go triple on the front, but could be a lot more money. BTW XTR derailler is about $75.00
|Tire size and wheel radius||AllUpHill|
Mar 19, 2003 3:00 PM
|I would point out that, in addition to the easier rolling afforded by slick road tires over knobby tires, you'll be in effectively an easier gear. The difference in wheel (not rim, but wheel) radius between a 35mm cross tire and a 23mm road tire is fairly large -- large enough to feel like you've got lower gearing with the road tires.
I have the distinct sensation of slightly lower gearing when using my 19mm road tires over comparable 23mm tires. Someone will say I'm crazy to claim I can perceive a difference for only 4mm, but it's true.
|yes, UR crazy||cyclopathic|
Mar 19, 2003 3:43 PM
the diff in diameter is less then 1%. Add another 2% less power to roll and I am with you.
|not crazy and derailer note||sievers11|
Mar 19, 2003 4:13 PM
|just think about, when you are setting up a cycle computer, there is a mojor difference from 26 to 700 but also variation in circumfrence in tire sizes
You may not be able to go to a larger cassette in the back because of you derailer. A short reach derailer will only work up to like 26-27 max, a medium with work to 29-31, and a long reach with work with...well the max 32-34, but you will have to go to MTB cassettes.
On a personal note, I went from MTB riding to Road riding and was initially freaked out about the gearing...you will "grow" in to the new bike, but damn change your tires..you don't have a hybrid.
|not crazy and derailer note||reklar|
Mar 19, 2003 5:24 PM
|> On a personal note, I went from MTB riding to Road riding and was initially freaked out about the gearing...
Good to know! I think I'm suffering from the same shock....
> you will "grow" in to the new bike, but damn change your tires..you don't have a hybrid.
I have a cyclocross bike though, so the tires make sense for trail riding, yes? I definitely plan on going with different tires...from what I've read, the Michelin Axial Carbons sound like a good option. Thoughts? These will be on my Sun ME14As....
|not crazy and derailer note||laffeaux|
Mar 19, 2003 7:28 PM
|If you never plan on riding off road, 23mm tires make sense. If you want to do both on and off road, go with a 32mm tire.
Another trick for lower gearing is to put a 38 tooth ring on the front. Shimano does not make one, but others do. It's very common to see 38/48 rings on a CX bike. The 48 might not be enough on the high end for road rides, so you can leave your current big ring as is.
|One more set of options||Ray Sachs|
Mar 20, 2003 5:30 AM
|Folks have recommended going with an mtb rear derailure, like an XT or an XTR and running a 11-34 or 12-34 cassette. Good start. If that's all you need, you're good to go. If you need lower gears, but don't want to go to a triple (I personally think STI sucks with triples - you need to be able to trim the front derailure), you can go to a 110 bcd crank. These are harder to find, but they're out there and they seem to be making a bit of a comeback. With these, you can run down to a 34 tooth small ring. I ride with a 34-48 double and either use a 12-27 (for normal one day rides) or a 12-34 (for really hilly centuries or for week long supported tours or off road riding). The 34-34 low is lower than most road triples are set up for and the 48-11 or 48-12 is enough top end for most mortals.
You'll take abuse for not being a "real roadie" but that stops hurting waaaay before your knees if you don't have low enough gears :)
Mar 20, 2003 10:39 AM
|I'm not worried one bit about not being a "real" roadie...if I were I wouldn't have bought a cross bike! ;)
What is a 110 bcd crank? The only number I've heard referred to with respect to cranks is length (i.e., 175, 170, etc.)...
BTW, how much difference does crank length make?
|110 Bolt Center Diameter , is standard 5 bolt MTB crank (vs||jiggs|
Mar 20, 2003 11:45 AM
|4 arm compact) and there is good selection of ring sizes from 24T to 55T or more, from cheapos to XTR. I used this XTR 24Tfront ring with 11/34T rear for Mount Washington climb because I couldn't push the 39T ultegra.|| |