You are hereForums / By Discipline / Mountain (off road) / MTB Gear / I know its an old topic but...
I know its an old topic but...
NB: Originally posted elsewhere on the Global Riders Network and appears via syndication.
Advice on drivetrains..
My current SLX rear cassette is on its way out and am thinking about getting rid and also removing the front mech for simplicity purposes.
The question is a 34t or 32t single chainring, combined with a 11/36 rear cassette.
My local trails are Terrey Hills 50k+ with Red Hill thrown in for good measure.
I ride up the Maybrook & Manly Dam big hill climbs generally in granny gear, will I be walking with the new conversion.? or just don't worry about it, accept the fact I am 45 and need the extra help.
Any advice is appreciated
W
- Login to post comments
- Bookmark & share
Tags
I had a 28 widget with a 34 on the rear of a 26in wheel, I recall that it was perfect for Red Hill, Maybrook was a pain but doable (even not easy in granny sometimes). I think I could push a 30 if I had one, but a 32? perhaps, a 34?? I'm not so sure I'd enjoy that around Red Hill.
Try ride the dam in the middle ring the whole way and then see if you want a 32 or less.
I do all my riding with a 32 front (with an MRP 1.X) and an 11-34 cassette. Serves me well off road in Glenrock, Awaba and places like that.
I had 34 front and 36 rear at the rear. I need to walk the last bit of long trail. before I had double ring from 24/36 prior to 28/40. The first upgrade make me struggling at the beginning but my leg got used to it after several month. It is very good training. And now I try to use the highest possible gear in normal day.
I think you can try to stay middle ring and avoid 2 biggest cogs at the rear this weekend. Then, u should feel what is like. If u have the heart rate monitor, u should see the difference!
BTW, I just ordered 42 wolftooth cog last week. I aim to do more uphill training and races as well. Just can't wait my leg to build up.
One last thing is around 200 or 300 buck between shimano m9000 and off market 1x10 setup. I decided to go for 1x10 setup simply because of extra 2 tooth while keep 34 at the front. It make sense to go for 32 front and 40/9 rear and move to 34 if u like.
I've just gone from a 33 to a 34 up front with a 11-36 at the rear and 175mm cranks. It was fine for Red Hill and MD.
I've had a wolftooth 30 chainring for about 12 months, I run out of top end sometimes, but I could basically climb almost anything (fitness allowing) with 11/36, however to make some little pinch climbs a tiny bit easier without getting out of the saddle I've just installed a wolftooth CG40 on the back. Certainly an improvement but not essential.
It's not a super cheap option with about $160- for the 2 rings and likely you will need a new chain. Also picking the right chain length with a 40 (or 42)Giant Cog and rear suspension is tricky, there is little room for error. Too long and my medium derailleur is wrapping back too far, but too short and you run out of forward movement on full rear suspension travel and will bust your rear derailleur.
Overall its a nice simple system, and cheapish ($80) to just experiment with a front ring to start with. If your not worried about spinning out your top speed, a smaller ring would likely be more comfortable and as a bonus gives a great improvement in bottom bracket clearance.
If it helps, I recently upgraded from 1x9 34f 11-34r 26" to 1x10 34f 11-36r 27.5" and mainly ride the northern beaches with occasional events. Setup is a widget front and now a shadow plus RD, no other chain protection although have used MRP 1.x in the past with the 1x9
In the past I've never had an issue around the dam etc but needed a lower gear on 100km events when the legs were tired. With the 34f-36r combo I did the 3 ring circus recently and it was the perfect range, on the fastest fire roads I just ran out of gearing and was spinning at a tad over a hundred RPM and I was able to ride the steepest climbs (halfway hill) in the lowest gear. For the dam I only need the middle 8 gears so it's right in the range
I had planned on getting a 40t rear extender sprocket but based on the circus I'm going to save my money for now. I think a 1x10 setup can meet all of the needs of the average rider 95% of the time so I'll be sticking with it
My general rule on this is usually "go as low as can" - because its very rare that you think "Jeez - I wish I had a higher gear" on an MTB...
32x11 is still a pretty big gear for off road riding, although on the road you would spin it easily.
34x11 is better on the road, but 34x36 is a big gear to be climbing with.
If it helps (and I'm not getting into the whole 'xxx like a girl' debate) - but my missus runs 32x11-36 on her MTB that she commutes on and also takes off road every now and again (it went to Rotorua with no problems), and she isnt a super strong rider by any means.
indeed; I never ran out of top gear with 28x11 up red hill and yes 28 makes me sound soft.. then well I guess I am.
28 is probably too low for Terry Hills (long, center) but I don't recall running out of top gear around the dam as well.
Yep an old topic and a perennial one with no clear answer as "it all depends". I'm 68, used to love climbing when younger and whatever gearing was on the bike was used. If struggled then just use it and get stronger - but after around 50 and expecially after 65 strength isn't going to increase, but will decrease. Coupled to this you have the factors of your weight, power, leverage (leg length), crank length, etc. etc.
So right now on my 29r I've probably got the lowest gearing available with a 36 large front ring - 36/20 front rings and 11/40 rear (One up components 40t on an XO cassette
) and I don't think you can get lower as the rear derailleur cant handle a 20 front 42 rear. Using a 1x10/11 just doesn't make sense for me. I'd be walking up anything over 20% grades and have a cadence of 130+ on a downhill, i.e. on every ride.
So to get the best gearing for you, only you can work it out. Is a 2 x 10/11 really that much of a problem? Do what has been suggested, workout which of your current ratios is the same as a 32f x 36r and use that to climb. Then do the same for a 30 and 34 T front ring. (note a 29r is around 11%(?) higher gearing than a 26r with the same ratios)
PS; if you really want to experiment try a much shorter crank length, most are 175, try a 165 or shorter 145 (if you can find one) it can be quite surprsing the effect
. (google 'short crank length' especially if you have knee issues or see http://powercranks.com/cld.html ) There are better 'scientific' based studies available. But for alternative view see http://www.nettally.com/palmk/Crref.html
Work out what upper and lower gears you'd be losing going 1x and on your next ride don't use them and see what its like. While I was deciding to go 1x11 I stopped using highest and lowest gears to see what it was like.
I ride like an old biddy and run a 32 front with an 11/32 cassette on a 29er. Just ride for a month without shifting the front out of the middle ring and see what breaks first, your legs or your will.....
I've gone with a 32t Wolftooth on the front and found with the 11-36 it's perfect for Red Hill and the Dam. It necessitated a slight change in riding style. From spinning in the 22/36 up the steep climbs to attacking them with a little more speed and aggression.
I've had to add a 42t to the rear cassette though for the long climbs in places like Cascades. Recommend it.
Cheers
try here
http://gears.mtbcrosscountry.com/#26I1I1
It'll make you stronger on the climbs. You'll be surprised what you can push when you have to.
I changed from 3x9 to 1x9. Brilliant.
The 'defeat' of getting of your bike will push you more than you thought possible. Do it do it do it...
(Now I have a 32t up front for me on a 29er... initially had a 30t widget up front on my old 26er. That was good to start)
Thanks guys most helpful.
My current setup is 24/38f with a 11/36 on the back. The problem is having such a difference in gearing on the front I found myself only really using the 3rd or 4th lowest rear cogs and changing between large/small front.
The gear ratio chart helped heaps, easy to compare what Ill loose and gain (cheers Carlosdjakal)
The 30t/32 look the go, will ride for the next few weekends in the third lowest as advised and go from there.
Cheers all
W
OK I'm officially soft.
I seem to spend a lot of my time spinning 39/28 these days and dirt/mud/rocks concern me.
Mont Rouge this weekend? I'm going to go look for my mojo.
I'm keen on checking out the freeway to the lake. When are you thinking?
I tried 155 mm cranks (I made them by drilling and retapping an 175 mm set that had been stripped out by a PO). I found them exhausting to ride: it feels like your spending 10 times the energy to maintain your usual pace. They ended up worse for my knees because I had to pedal so hard to try and keep a decent average speed.
http://www.bikesmithdesign.com/Short_Cranks/
I'm pretty sure that the laws of physics say shorter cranks just need different gearing and the crank length is more about how long you legs are or what your used to, but personally I've not tried them. I do get annoyed that all cranks are the same length. To build up a bike for my 11yo I had to go to the expense of getting cranks shortened (the guy at bikesmith offers a great service and has some interesting stories and advice on his website). Everything else on a bike seems available in a myriad of sizes and here we are going on about relatively minor gearing changes, but cranks come in 2 sizes "long" or "longer".