Adventure Cycling Association Forum

Bicycle Travel => Gear Talk => Topic started by: latifb on June 22, 2013, 12:19:31 am

 
Title: Touring crankset
Post by: latifb on June 22, 2013, 12:19:31 am
I just picked up a Salsa Vaya as an all around bike that I would also like to do some touring and to what degree I don't know yet. It came with a Sora triple ext BB with very high gearing for this kind of bike, 52/42/30 which I knew from the outset I would like to swap out for something like 48/36/26. The cassette is 11-32 9sp, and has microshift bar end shifters.
I'm looking at a couple options. There's a Sugino xd600  46/36/26 that's billed as a touring oriented road  or MTB crank which uses the old standard sq taper BB setup and then a couple Shimano mountain bike/trekking, the  Deore M532 and Deore M591 which come with external bearing BBs, both 48/36/26. Those setups run around $90 with the BB while the Sugino around $130 plus the cost of a new BB. I've been reading what I can but it can get so confusing especially with the issues of chainline.
Any advice would be greatly appreciated. The cost savings of the Shimano setups as well as the 48t large sprocket seem attractive but am I missing something here. I'll have my LBS do the install.
Thanks in advance
Title: Re: Touring crankset
Post by: DanE on June 22, 2013, 07:11:36 am
I believe the Sora crankset has a standard for a road bike 130 mm bolt circle. You might want to consider just changing your chainrings. You probably can't get a middle ring as low as what you are looking at with the MTB crankset. You should be able to change the chainrings yourself as they come off with an allen wrench and you will save bike shop labor charges. Not saying this is the solution but you might not have thought of this.

I saw these options on the Harris Cyclery Web Page: http://harriscyclery.net/product-list/parts-1400/chainrings-1405/chainrings-130-mm-bcd-1278/
Title: Re: Touring crankset
Post by: dkoloko on June 22, 2013, 10:36:27 am
The most cost sensible thing for you to do is swap your inner chainring for a 24 tooth chainwheel. If you change cranks, then you might as well go for a touring or mountain bike cranks that accommodate chainrings as low as 22 teeth. You could lower the large and middle chainrings you have; I wouldn't; not worth it. Chainline has little to do with size chainrings.
Title: Re: Touring crankset
Post by: latifb on June 22, 2013, 01:17:58 pm
Thanks for the suggestions. My original thought was to do just that, swap just the inner ring but the jump from 24 to 42 seems too big to me. I'm sure with the friction front bar end it would be physically doable. The 52 big ring is almost useless to me. I did a short 25 mile ride yesterday, flat with a lot of wind at times and never got out of the middle which is ok with me. My dedicated road bike is a triple with a 39t middle and I'm mostly always on the middle ring and I like it's ability to use most all the cassette cogs.If I were to change out two rings then the cost goes up and it may still be a compromise. The combo of 46or48/36/26 sounds the most useable at this point. I have plenty of time to work on this as there won't be anytime until perhaps the fall before I can get a chance to do any light touring.
Harris cyclery also has a Sugino XD500 which is 48/36/24 but $160 plus BB. The TA rings that Harris and Peter White sell sound like great rings but nearly as costly as swapping a whole crank out to get the same combos.
Title: Re: Touring crankset
Post by: RussSeaton on June 22, 2013, 02:51:16 pm
The simplest fix for you is to change the chainrings.  The outer two rings are 130mm bolt circle diameter.  You can put anything from a 60 to 38 on those two positions.  The inner ring is 74mm bcd.  It takes down to a 24 tooth.  You can change the outer two rings by just loosening an allen wrench, five of them.  To change the inner ring you have to take the whole crankset off the bike because you can only get to the inner ring from the inside.  And the inner ring only fits from the inside.  It can't go over the spider from the outside.  You could probably get some Sugino rings for sort of cheap.  Check the internet.  Maybe 48-38-24 rings.  Or 46-38-24 rings.  Put them on the crank and bottom bracket you already have.
Title: Re: Touring crankset
Post by: BikingBrian on June 22, 2013, 11:59:15 pm
The TA chainrings are nice, but you won't need anything that fancy, as the bar end shifter will shift anything. I have the Sugino cranks and they are perfect for touring. If you go that route, just watch which model crank you get, the lower end one has heavy steel chainrings.
Title: Re: Touring crankset
Post by: dkoloko on June 23, 2013, 10:06:44 am
The TA chainrings are nice, but you won't need anything that fancy, as the bar end shifter will shift anything. I have the Sugino cranks and they are perfect for touring. If you go that route, just watch which model crank you get, the lower end one has heavy steel chainrings.

While I choose alu chainrings, don't go overboard with concern with "heavy"; you're talking about a couple ounces. Some mountain bike/touring cranksets have just two out of the three rings steel. Some prefer steel over alu for inner ring.
Title: Re: Touring crankset
Post by: BikingBrian on June 23, 2013, 10:11:01 am
While I choose alu chainrings, don't go overboard with concern with "heavy"; you're talking about a couple ounces. Some mountain bike/touring cranksets have just two out of the three rings steel. Some prefer steel over alu for inner ring.

Agreed - just mentioning because I know of some people who have ordered the crankset and then were surprised it didn't come with alu chainrings.
Title: Re: Touring crankset
Post by: paddleboy17 on June 24, 2013, 01:13:16 pm
On a compact triple, aluminum generally is not strong enough for the small chain ring.  Sorry, but I got to use the correct terms.  With all of the mechanical advantage of a small front and a large rear,  you can generally create enough torque that aluminum teeth will not hold up.  So you really want a steel small chain ring.  The year I built my bike, the Shimano XT mountain crank had an aluminum small and large ring, with a carbon fiber middle ring.  That combo struck me as stupid, and I went with an LX mountain crank featuring the more traditional steel small, and aluminum middle and large chain rings.

If it were me, I would invest in a mountain bike compact triple crank set and the tools to do the job.  It sounds like the crank would be more that you want to budget, but the tools could be cheaper than what the dealer would charge you to do things. 

Tapered square is the classic way of doing things, but outboard bearing are real easy to install.  The Deore cranks should be just fine, and you might be able to just leave the old bearings in and keep the new ones as spares.  I would not worry to much about chain line, as the crank usually compensates for that.  There is something called Q factor (basically how far apart the pedals are) and that may be an issue if you have tight hips.  Since you have outboard bearings now, this probably is not an issue for you.
Title: Re: Touring crankset
Post by: dkoloko on June 24, 2013, 01:39:43 pm
On a compact triple, aluminum generally is not strong enough for the small chain ring. 

I don't know why should be more a factor with compact triple than with any other triple, but my thousands of miles experience touring with aluminum small chainring says strength is not a question. I suspect most who opt for steel instead of aluminum for small chainring do it for anticipated less tooth wear than for perceived strength.
Title: Re: Touring crankset
Post by: paddleboy17 on June 24, 2013, 01:46:10 pm
A compact triple has a 22, 24, or 26 tooth ring, with 22 being the most common. My understanding is that if you are a real pedal masher, then you can subject the front ring to severe torque levels.   As always, your experience may vary.  I think the following year, XTR went back to more traditional rings.
Title: Re: Touring crankset
Post by: RussSeaton on June 24, 2013, 04:11:25 pm
If it were me, I would invest in a mountain bike compact triple crank set and the tools to do the job.  It sounds like the crank would be more that you want to budget, but the tools could be cheaper than what the dealer would charge you to do things.

Why are you advising the author to throw money in the toilet?  Your advice is very expensive compared to changing the chain rings.  The mountain bike triple you recommend can get down to a 22 tooth inner ring.  He currently has a road triple crankset with 130mm bcd for the outer and middle positions and 74mm bcd for the inner ring.  He can put a 24 tooth ring on his current crankset.  There is so little difference between a 22 and 24 inner ring that its not worth talking about.  You're advising him to spend an extra $100 to get two less teeth on the inner ring.  Big waste of money.  Cheapest and easiest is for him to just leave the outer and middle rings alone at 52-42, and replace the inner ring with a 24.  $15 plus the labor of changing the inner ring.  Or he could spend the extra $60 and change the outer and middle rings to 48-38 or 46-38 for fun.  But changing the crankset is throwing money in the toilet and flushing it down the drain.

For fun I went to Amazon and typed in "Sugino chainrings".  Came up with a $15.23 24 tooth 74mm bcd ring, $21.70 for a 130mm bcd ring, and $33.25 for a 50 tooth 130mm bcd ring.  If you looked closer I'm sure you could find other tooth counts for about the same price as listed here.  So for $70 in rings the author can have a 50-38-24 crankset using the crank and bottom bracket he already owns.  Minimal labor to change rings.  Your idea of a new crankset would not get within $100 of the $70 listed here.  And not have much better gearing either.  What is the point of spending more money than you need to?

Also do a search on Amazon for "Vuelta chainrings".  Vuelta and Sugino are comparable.  I came up with a $79 total for Vuelta 48-38-24 rings.
Title: Re: Touring crankset
Post by: latifb on June 24, 2013, 05:41:07 pm
Thanks Russ for doing my homework or at least pointing me in the right direction. After getting confused looking at 110bcd rings I found the correct 130bcd rings on Amazon at the prices you found. I'm good with 38 for the middle ring and will likely do 48 for the big ring.I see these rings are not ramped and pinned but is that a non issue with friction front shifting?

Yesterday I was convinced I would go ahead and get the sugino XD500 48/36/24 from Harris for $160 plus $26 for sq taper BB. I can find a way to make it work but agree that it would be flushing an extra $100 or more down the can which could be used for all the rest of the touring gear I'll be needing.

Thanks for your input as well Paddleboy. I'm in no rush at the moment to make a decision. I'll be off to the LBS to get their input as well.
Title: Re: Touring crankset
Post by: paddleboy17 on June 25, 2013, 01:48:23 pm
Russ, touched a nerve did I...  :)

We all have to decide about what is important to us.  I will admit that I am a big fan of using mountain bike cranks on touring bikes.  At some point in you life, having that enhanced low end is nice when you are humping your stuff up a grade.

The OP (original poster) complained about the total range available on his current crank, not just the low end but the high end too.  Yes you can swap out rings (except when Shimano rivets them on).  The ramps and pins do improve shifting, but they also elevate the cost of the replacement rings.  I would still pay ~$100 for a high value mountain bike crank in the desired range than ~$70 for economy chain rings to convert the existing Sora crank to that same range.  Better shifting is worth ~$30 to me.  But every else is entitled to their opinion.

I once had a Tiagra triple which I think was a 30/40/50.  I did swap out the 30 and put a 26 ring in its place.  The dealer could only get a 26 ring, and I never checked to see if there were other choices.  As I recall, the shifting was not too bad, even with Tiagra brifters, but I ultimately wanted a little more on the low end and put an LX mountain crank in its place.  When I sold the bike I put the Tiagra crank back. 

The right crank for the OP is the one that meets his needs.  I don't know that the Sugino touring crank would be my first choice in an after market crank.  There is nothing wrong with Sugino or tapered square bottom brackets, but Shimano still calls the shots in the bicycle component world.  About 15 years ago Shimano started the transition from tapered square bottom brackets.  Right now Shimano pushes the outboard bearing cranksets.  At some point, sources for quality tapered square BBs are going to dry up.  There are lots of sources for new outboard bearing cranks besides Shimano.  As far as I know, all of the outboard bearings are interchangeable, so a new crank could mean useful spare parts.   

Either way, swapping rings or another outboard bearing crank really is something that even an novice can do.  And maybe just trying out a new little chain ring is worthwhile since the out of pocket cost is so low.

One final caution, going from 32/42/52 down to 26/36/46 (or lower) may also require a new front derailleur.  You will not know until after the swap.  Good news is that front derailleurs are pretty cheap.

Title: Re: Touring crankset
Post by: latifb on June 25, 2013, 03:09:08 pm
Thanks once again for a thoughtful perspective. Yes, I would like to gain the skills to do this work myself if I'm going to tour at almost any level.
What I like about the sugino 500 is the 24 low and 48 high, something I haven't seen in the MB cranks. I do also ride the bike unloaded and although the 52 is mostly still unusable for my fitness level I think 48 would give me a nice extended range.I'm thinking 24 is as low as I may need. 36 or 38 in the middle would both work with the edge to the 38 for the amount of unloaded riding I do.
Most of the MB cranks I've seen don't seem to have such a wide range. Admittedly there's a lot I haven't seen I'm sure.
Title: Re: Touring crankset
Post by: RussSeaton on June 25, 2013, 03:36:13 pm
I wholeheartedly endorse using mountain bike triple cranksets on touring bikes.  The 44-32-22 possible chainrings make lots of sense combined with the 11-32 or 11-34 9 or 10 speed cassettes available today.  More high gears than you need and low enough low gears.  Great.  But the person starting this thread already owns a Sora crankset and bottom bracket with 130mm bcd outer and middle rings and 74mm bcd inner ring.  So its cheaper and easier to just change the chainrings than to buy and install a new crankset and maybe bottom bracket too.  Putting a 24 tooth inner ring on his current crankset gets him a low of 24x32.  I toured Europe using that low gear so its low enough.  Cost wise he would be best to just replace the inner chainring with a 24 tooth and leave the 52 and 42 alone.  Just ride in the 42 and 24 rings all the time.  He has bar end shifters so he can shift anything fine.  If he wants to get crazy he could buy a new cassette for $34 from Nashbar and get 11-34 9 speed cassette.  Little bit lower gearing.  Not worth the money but...

Nashbar has Shimano XT cranksets in 44-32-22 for $200.  And a Race Face crankset in 44-32-22 with bottom bracket for $100.  So if he goes low cost he can end up with a mountain bike triple crankset for only about $30 more than replacing the chainrings  Worth it?
Title: Re: Touring crankset
Post by: dkoloko on June 26, 2013, 08:54:18 am
If it were me, I would invest in a mountain bike compact triple crank set and the tools to do the job.  It sounds like the crank would be more that you want to budget, but the tools could be cheaper than what the dealer would charge you to do things.

Why are you advising the author to throw money in the toilet?  Your advice is very expensive compared to changing the chain rings.  The mountain bike triple you recommend can get down to a 22 tooth inner ring.  He currently has a road triple crankset with 130mm bcd for the outer and middle positions and 74mm bcd for the inner ring.  He can put a 24 tooth ring on his current crankset.  There is so little difference between a 22 and 24 inner ring that its not worth talking about. 

I previously advised that the most economically sensible choice is to just change rings, so we agree on that. However, you error in dismissing difference between 22 and 24 ring as "not worth talking about". It is not the two tooth difference, but the percentage difference in gear inches that is determinative. It is significant enough to determine choice.
Title: Re: Touring crankset
Post by: staehpj1 on June 26, 2013, 09:30:28 am
I previously advised that the most economically sensible choice is to just change rings, so we agree on that. However, you error in dismissing difference between 22 and 24 ring as "not worth talking about". It is not the two tooth difference, but the percentage difference in gear inches that is determinative. It is significant enough to determine choice.

Yes a 12% change in gearing is definitely significant.  It is roughly comparable to the difference of shifting from the 30 to the 34 on the rear cluster.  So it basically adds the equivalent of one more gear lower. 
Title: Re: Touring crankset
Post by: RussSeaton on June 26, 2013, 07:41:19 pm
The person has a 11-32 cassette.  A 22x32 low gear is 18.2 gear inches.  A 24x32 low gear is 19.9 gear inches.  If you think you can tell a 1.7 gear inch difference in a gear, you're living in a fantasy world.  Yes the percentage difference is important.  But you somehow forget it depends on what number its a percent of.  I get 8.3% difference between 22 and 24.  8.3% difference of 20 gear inches is about 1.7 gear inches.  8.3% of 100 gear inches is 8.3 gear inches.  It depends on what gear you are talking about.  Big difference between small gears and large gears.  Have you ever thought that is why the small cogs on a cassette change by one tooth.  While the large cogs change by 3 or 4 teeth.
Title: Re: Touring crankset
Post by: mbattisti on June 26, 2013, 10:03:34 pm
I second paddleboy's advice, just swapping the smallest chainring for a 24.  the 24 to 42 jump was no problem on my wife's and my fully loaded tandem, which took us XC a few years ago.  I may suggest adding a n-gear jump stop to prevent the chain from dropping off that little gear.
Title: Re: Touring crankset
Post by: latifb on June 27, 2013, 12:27:58 pm
In my quest to find the best direction for me to go to get the gearing I think would be best a new question has arose which has been alluded to already.
The question is about the importance of ramps and pins for the outer and middle chainrings. I did talk with the mechanic at the LBS I purchased my Salsa from and all the single replacement rings he could find did not have ramps and pins which he thought would lead to poorer shifting even with my friction front derailleur setup. He admittedly wasn't experienced at setting up touring bikes.
So what are folks opinions on the importance of ramps and pins?
Thanks again for all the input so far. This newbie has a lot to learn.
Title: Re: Touring crankset
Post by: RussSeaton on June 27, 2013, 02:38:31 pm
Ramps and pins on the chainrings are good.  They help shifting.  Essential, no.  Helpful, yes.  You have a nine speed 11-32 cassette.  I suspect you will ride most of the time on the middle or outer ring and do all shifting with the rear derailleur.  Shift the front rarely.  So you could easily do without ramps and pins on the chainrings.  They help shifting but they cost more.  Your choice.
Title: Re: Touring crankset
Post by: latifb on June 27, 2013, 06:54:12 pm
Thanks Russ, you got it right about spending most of my time on the middle, and a much smaller time on the front although with a smaller big ring I'm hoping to be able to use that ring much more. I do ride unloaded on fun rides quite a lot. Whatever I finally decide to do you've all been a great help.
Title: Re: Touring crankset
Post by: Old Guy New Hobby on June 27, 2013, 07:59:25 pm
Quote
The person has a 11-32 cassette.  A 22x32 low gear is 18.2 gear inches.  A 24x32 low gear is 19.9 gear inches.  If you think you can tell a 1.7 gear inch difference in a gear, you're living in a fantasy world.

My granny gear is 17.9 gear inches. There are times when I'm glad to have it. It all depends on what you want.
Title: Re: Touring crankset
Post by: zerodish on June 29, 2013, 08:12:04 am
 Santana tandems makes a set they call their stump puller gears the are 24 38 48 Santana is the only company I trust to make a 38 tooth http://www.flickr.com/photos/63373992@N07/7111011835/in/photolist-bQnN5k-4Cs4Yb-4Cs4TN-4CiTE2-4CiTyT-4CiTJz-4CiTp8-4Cob8h-6hkcQA-bPDQoK-ayQuPB-bytiMq-3YMB56-9WGd8Y-6hgcLZ-6hkoNS-3dhDY8-bRpekZ-5EYta3-3VUgXh-jmoDY-jmoEV cog for a 130 mm bolt circle there is not enough metal to prevent it from breaking.
Title: Re: Touring crankset
Post by: latifb on June 29, 2013, 03:34:02 pm
I discovered something this morning that may have an effect on what I choose to do. I've assumed all along that the factory advertised spec for my Salsa is 52/42/30. When I talked to my LBS mechanic the other day he was looking closely at the big ring and noticed it was stamped 50t. Interesting. This morning I put on my magnifiers and counted the teeth on all the rings and found 50/39/30 which is the spec for the previous years model and does make much more sense. I still need lower gears but  just swapping the 30 for a 24 is the simplest way to go. I can only go down to a 38 on the middle with the 130bcd so that swap makes little sense. The 50 is still  too big but I spend so little time on that ring that maybe I can just let that go. 24 to 39 still seems like a big jump but much less than the 24 to 42 possibility.
Title: Re: Touring crankset
Post by: dkoloko on June 30, 2013, 07:17:40 am
24 to 39 still seems like a big jump but much less than the 24 to 42 possibility.

I shift from 24 to 49; no problem.