Friday, September 23, 2011

Friday News And Views

29"er Specific Gearing?

I've written on this before, and I want to bring the topic back up for discussion again, but first- a quick recap for those who don't know what this is about.

When the 29"er came about, several good and bad things were noted right off the bat. One of the "bad" things was in regard to gearing. You see, your wheel size affects your end gear ratio. Late 19th Century cyclists would have been quite familiar with that concept, but with all the cassette gears and crank chain rings in between the pedals and the drive wheel these days, how a rear wheel affects final drive gear is lost on a lot of folks. Essentially, a bigger wheel is a "harder" gear, all else remaining the same. You go faster, but it is harder to get rolling, and harder to climb hills, etc. Make sense?

So, 29"ers, with their larger diameter wheels, were stuck using gear ratios optimized for smaller wheels. This left the low end of the range wanting. (Well, for some folks anyway. Bear with me here.) Suggestions to remedy the situation included getting a cassette with a 36T low gear, (got that now, huzzah!), and using a crankset with a 20-30-42 tooth chain ring set.

Now some will be about a millisecond from the comment button right now ready to pounce and tell me about Middleburn, or Action Tec, or whatever. Sorry folks. This has to do with those that control the market with OEM spec. Namely SRAM and Shimano.

Okay, and then there is the argument that says you need to lose weight, get fitter, pedal harder, yada, yada, yada. This doesn't apply here either. Yes, that is a valid point, but we're putting that "over there" for a minute, okay? Some folks "need" this lower gearing. Shimano and SRAM are not giving it to them. Close in the case of SRAM, but no cigar.

Historically, Shimano has been all over the board with regard to gearing on hybrids and mountain bikes. One thing is for certain, unless the Shimano company is going to sell "a lot" of product to OEM's, they don't really care what you and I think "mountain bike gearing" should be for any bicycle. They are a research and development company that specializes in forged metal products. They are not much for market research. They definitely do not chase "niches". Until most mtb's become big wheelers, (and that looks to be starting to happen), Shimano will not make a "29"er specific crankset. Heck, they don't even do a single speed crank set for mountain biking. And we all know how long that's been around.

SRAM is hedging its bets with 2X10 drive trains, and hoping that will become enough to make 29"er folks happy. Very soon they will offer what they are billing as crank sets good for 29"ers in a 22/36 configuration. Not low enough gearing, some will say, and I'd have to agree that it seems to be a lateral move. I mean, you can 2X a triple and practically get that gearing.

Nope! Until one of the big outfits does a 20-30-42, we'll continue to hear about this gearing thing for 29"ers.

Soul Ride
Here We Go Again With That Steel Thing...

Looks like another Milwaukee Bikes 29"er is headed over for testing and review. Ya know......another steel hard tail! 

I don't know how the new rig will compare,  but I nearly bought the old one after testing and reviewing it, I liked it that much. But....I sent it back. This one? We'll see. Check out Twenty Nine Inches for all the updates.

I'll just say that it is Fall, which is the perfect time to single speed, this bike will be a single speed, and Reynolds steel at that. If it rides anywhere as near to the older Milwaukee rig, it's gonna be good times in the woods!

It is great to just hammer the single track without fear of ripping off your derailleur when a stick gets caught bin your spokes. That happens a lot here in the Fall due to the windy days that knock down a ton of twigs, branches, and well......sometimes entire trees!

Those pesky twigs and branches get kicked up by your front wheel and wham!  (Not the George Michael "Wham!", but ya know.....a sudden bad thing kinda "wham" Well........I guess you could say those are both bad kinds of "wham"!)

Anywho.......yeah. Bad deal there when the ol' rear mech goes belly up into your spokes. I've been clear of that issue for more years than I care to count, but then again, I single speed most Fall seasons anymore! Now I've gone and jinxed myself, I suppose, but we'll see.

Okay, have a great weekend folks! Ride bikes, Take pictures!


Matt said...

I am less concerned with what the "big two" companies are pushing and more concerned with what 29er manufacturers are actually speccing. In this respect there seems to be very little interest in 29er specific gearing. I recently got an el mariachi and paid $150 extra to get 24/38 chainrings. By my calculations this gives me a similar granny gear to the 3x9 26er I was replacing. Salsa specced 27/39 on the same bike and search as I might, I could find only Specialised offering "29er specific" gearing. I can't speak for the cost to bike manufacturers, but "29er specific" gears are easily available, at least for 2x10, by putting whatever size chainrings you want on a standard crank. The gearing I have now is wonderful and I can't imagine why more 29er manufacturers, particularly the ones that pay such attention to detail in other areas, don't do it.

Guitar Ted said...

@Matt: Well, the reason most manufacturers don't spec "29"er specific gearing" is exactly what I said in the post- Namely that the OEM manufacturers, (SRAM, Shimano), don't produce that stuff. Can't spec what doesn't exist, (in large enough quantities that is easily available in the Far East)

And to be specific, even your gearing is not considered "29"er specific" by those who want the 20-30-42 triples, or 20-30 doubles.

I'm not one of those that advocates for this gearing, by the way, but I am saying that a very vocal component of 29"er riders wants this.

mw said...

i've always been satisfied with 'standard' gearing. when i switched from 26 to 29 it didn't really seem to matter much. also might be the case that my cadence is slowing as i age...

roy orbison rules

mw said...

i've always enjoyed 24-34-46 which was probably a bit low for 26 and is now a bit high for 29 but still works for me

Matt said...

@GT: I defer to your better knowledge of the industry, but I am surprised. There are 3x cranks floating around everywhere and you just need to put the right sized chainrings on them. I figured that a manufacturer could call up FSA or Race Face, etc and ask for a batch of chainrings in the right sizes, but I can see why that might be incorrect.

In fact, thinking about it, I recall a salsa rep saying they swapped to the alternator dropout because they could source it from Taiwan, which they couldn't for the previous solution. So if you can't get it cheap in Taiwan it might as well not exist as far as mass production is concerned.

On the matter of what constitutes 29er specific, surely that must mean parity with 26ers. It is too much to expect whatever combination a certain person wants :) There are no equivalents of 20/30 for the 26er world!

To match 24/32/42 26er you need 22/29/39 29er or so, and to match 27/39 26er you need 24/36 29er or so. Both these combinations can be put on 3x cranks.

So, what am I getting at. Well, I _wish_ manufacturers would spec 29er equivalents of the 26er gear ratios (even if it costs a little more) and you _can_ get it yourself with existing products.

Dave said...

Does the gearing really make that big of a difference?

On another note, is there anything different about the new Milwaukee rig?

Guitar Ted said...

@Matt: You must be using an old crank set, or older XTR, since "standardized" gearing for 26 inch mtb' has been 22-32-42, or 44T since the late 90's.

Equivalent 29"er gearing to this is the stated 30-40-42.

You can't bolt a 20T granny to a 64BCD inner 4 bolt pattern, thus part of the issue is that a new BCD standard would necessarily have to be used, (OR we could go back to old 5 arm compact cranks, but that's not likely to happen)

@Dave: The Milwaukee is now made overseas from Reynolds tubing. I haven't checked the geometry chart to see if anything else has changed or not.

Johann Rissik said...

What's wrong with 1x9 (32 : 11-32)?
;) It's nine times more giyahs than I'm used to.
Nice piece on the subject, GT.

shiggy said...

In a way, I agree with Shimano. It is all "mountain bike" gearing, because as soon as lower "29er" ratios are available somebody will spec it on a 26" wheel bike. Then if/when the user of that bike gets a 29er they "need" lower ratios yet again.

And yes, I miss the 94/58 BCD cranks that easily accept 20/30/XX rings (and I do still use a couple).

shiggy said...

Also odd that SRAM does not offer a (geared) mtb crank in 180mm. They do in all of their road cranks.

Matt said...

@GT I am doing the calculations for 10speed with a 36 tooth cog on the back. 22 granny ring was in the 7/8/9 speed days right?

Tim said...

MTBR posted about the "new" SRAM 29er gearing on FB. My comments:

"Lower gearing for 29ers? Are they bringing back 94/58 bcd 5 arm cranks? Woot! Simple solution."

"Oops, well, just read it and they gave us back the 22t that they took away last year. Generous. I'll keep my old 5 arm 20/30/41 on my 29ers, thanks for the offer."

flammpunkt said...

I've found that regular MTB mech don't fit my 29er Cielo becuase the cage is designed for a 66-69degree angle between the chainstay and seat tube.

I'm guessing that with 29er specifc gearing with it's smaller chain rings it will be even harder to get the mech low enough on the seat tube.

So in addition to the 29er specific chainset there would need to be a 29er epcific mech?