spinnaker

Didn't want to steal the other thread on gearing so I figured I would start my own.

I am looking at the Jamis Aurora.

https://www.myjamis.com/SSP%20Applica...cat_grp=road_9

Looks like a lot of bike for a decent price.

I am not a good hill climber. And I am not getting any younger. My current tourer is a road bike that I have fitted with a 24T granny and 11-32 cassette. It does me fairly well though there are times when I wish I had something a little lower.

The granny on the Jamis is 26T which I want the LBS to swap out. I might also ask them to swap out the 11-28 cassette for an 11-32 or should I go to an 11-34?

Will those stock deraillers handle that range?


Any thoughts on the stock crank itself?

Cyclist0094

That rear Tiagra derailleur has a rated capacity of 30 tooth max rear cassette sprocket. You would need to swap it out for a 34 tooth rated Alivio RD M430 or a Deore Rd-M615 which is rated for a 36 tooth cassette sprocket. That crank is probably Ok but I'm not familiar with the recent FSA cranks.


https://bike.shimano.com/publish/cont...-.rd_road.html
https://bike.shimano.com/publish/cont...mountain.html#

spinnaker

Thanks velonmad. So basically I need to get them to swap out a MTB RD?

Is the Deore Rd-M615 fairly price compatible with that Tiagra? Not that it matters that much just want to know so I know what I am in for when I talk to the LBS.

Any thoughts 32T vs 34T?

RhinoDave

A buddy of mine just picked up an Aurora at our annual swap meet. It was last years model (2013) and he got a pretty good deal ($500) He just swapped out the rear cassette to a 11-32 without changing the Tiagra RD. We had to screw the B screw in a ways but it is shifting good without any binding. Based on what you stated as needs, if you change out the RD to a MTB long cage, I would go ahead with the 11-34 instead of the 32. No compatibility issues with the 9 spd stuff and bar end shifters. I'm 66 and more than a little soft around the middle so I use mountain gearing on both my Tourers along with road triples on the cross and road bikes. I'm getting 17.5 GI with a 44-32-22 and a 11-34 and 700-32 tires. At the speed I've had climb some of our hills in NE Mich. I've developed a very good sense of balance. I even managed to ride up Mifflin rd. and over to Dravosburg fully loaded before the GAP was completed.

Cyclist0094

Sounds like Rhino Dave has a better grip on that setup. I would guess there is probably a $25-30 difference in price between the two derailleurs? I have a 34 tooth low cog (8spd cassette) on my touring bike since 2006 and I haven't ever wished I didn't have it . I remember a long hill near Coaticook Quebec I climbed two years ago I would have loved to have a 36t!

sstorkel

I'd run a gear calculator before making a final decision. It looks to me, for example, like there isn't a whole lot of difference between a 24-tooth chainring and a 26-tooth chaining nor between 32- and 34-teeth cogs in the rear. Based on that, I'd be tempted to stick with the stock 26-tooth chainring and install an 11-32 cassette, which shouldn't require a rear derailleur swap. If the 26-32 combo isn't low enough I'd suggest more pre-tour training, but you could always swap in the 24-tooth chainring to get a slightly lower low gear.

RhinoDave

I should probably also add that I have an 11-32 on the back of my Axis with a Tiagara derailleur. The front is a 52-42-30 FSA Gossamer crankset with a 105 derailleur. The issue comes in the chain length. If the chain is shortened enough so that the lower chain doesn't hit or interfere with the jockey pulley when in the small ring/ small cog combination then it is not long enough to go up onto the big ring/big cog combination without binding up. I have never seen a need to use this combination so I keep the chain short because I have ended up on the small ring/small cog before but usually not on purpose. This difference would be even more pronounced if you went to a 24 or 26 tooth inner ring. I tried an 11-34 just for fun and it is too big. It shifted up okay but there was some slight binding between the jockey pulley and the cog.

cyccommute 

The FSA Alpha Drive is a 104/64 BCD which means it can take an inner ring as low as 20 teeth (you can find them on Fleabay and Amazon). Although I'm a proponent of going as low as possible, a 20/28 would be lower than a 26/28 by about 3 gear inchs (19 gi vs 22 gi). I would suggest getting a 9 speed mountain bike rear derailer to make life easier and you can get a 20/34 (16 gi) low unless you wanted to go really silly and get a 36 tooth low but even I think that's absurd

MMACH 5

If you're buying from an authorized Jamis dealer, they can order past year models. The 2010 Aurora comes with an 11 - 34 cassette. Its cranks are 50/39/30 so you might still decide to change that small one out. Keep in mind, if you order a past year model, you'll also get about a third off the regular price.

spinnaker

LBS called Jamis is out of any previous year models.

spinnaker

Forgive my ignorance but what is a 20/28? I know 20 is the teeth count correct? What is the 28? You are not talking double rings 20/28? Because 28 for the large ring seems awfully small.


The Aurora comes with a triple 48/36/26T.


Ah or are you matching low gear in front with low gear in rear? 20T front - 28T rear? Just comparing the ratio?

spinnaker

And I am correct in my assumption that any good LBS will swap these out for me (of course I would cover any increased cost)? I would think they should be able to make use of the stock components?

MMACH 5

Wow, bummer. I got my 2010 Aurora Elite, last year and they had a number of past year models on hand. My LBS could even log into the Jamis warehouse database to see what sizes were available.

sstorkel

I wouldn't assume that. Shops in my area would want to charge you MSRP for upgrade parts, give you a reduced rate on installation labor, and return any stock parts to you... If the bike you're buying is expensive ($2500+) and the upgrade parts are costly (ex: Shimano Ultegra or Dura-Ace) they'd probably waive the installation fee.

cyccommute 

Yes, just comparing the ratio. The convention is to put the front chainring first and the rear cog on the cassette second. If you are going to calculate gear ratios, gear inches, gain ratios, etc., you divide the number of teeth on the crank by the number of teeth on the cassette and then multiply by whatever factor you need to multiply by.

The chainwheels on most cranks can be changed rather easily. The FSA Alpha does come with a 48/36/36 but the size of the inner bolt circle diameter or "BCD" is 64mm which means that you can put as small as a 20 tooth ring on the crankset. 20 tooth rings are rare but not impossible to find. 22 tooth rings are easier to get but would give you a little higher low gear.

It's simple enough for you to do it. You need a 5mm Allen wrench and you can do it before you put the crank on. If you get the external bearing crank, it's easy to remove the crank to change the rings.

spinnaker

Thanks for the advice.

fietsbob

+1 You can always change components if the frameset is a decent fit.

Jamis is the trade-name brand of the importing distributor .

they contract out the manufacturing.

the component manufacturers ship what goes on the bike .. to the assembly line company
in Asia for the low wages cost .

don't like the stock gearing? change it.

spinnaker

I checked with the LBS. They said they would work with me on swapping out part for part. I'd just need to cover any increased cost which is fair.


The only issue is that no one seems to have one in stock where I can ride one so I will have to buy sight unseen. Touring is not all that big here. They tout it as a commuter too but that has just been catching on in the past few years.

Tourist in MSN

I think you meant to say something else.

fietsbob

Normal for a customer service oriented shop

spinnaker

Found another shop that had one one stock. Went for a ride today. Pretty nice ride. Top tube seems a bit on the short side. Seemed sort of cramped but maybe if I moved the saddle back a bit it will be OK. It was pretty amazing saddle height was almost perfect and I never gave them my stats nor have they seen me before. Well the owner may have seen me before. I bought my Schwin there about an eon ago. Back when Schwin made a decent bike.

The other thing I know I will miss is my b-levers, I have them on on road bike. I felt myself reaching for them. Maybe I can add them. But the geometry of this bike makes it a lot more comfortable to ride in the drops or on the hoods.


They also said they would work for me but I did not get a warm and fuzzy from that shop. Owner out of shape and help out of shape. Obvious neither one rides.

fietsbob

Oh well , it is a basic thing , pick the shop First then the brand of bike amongst their offerings ..

out of shape, you mean you prefer all young fit racer types?


takes time to learn depth of information of all the stuff on the market these days

snow on the ground is a handicap out there, I hear.. rather than die being hit by a sliding automobile
I'd take the Bus .

cramped ?, fit a longer stem..

spinnaker

No they don't ride period. I am not in the best of shape but I look like a young racer type by comparison. And I am 55, with a lousy diet and plenty of weight to drop this summer.


The bike actually has a an adjustable stem. I wish I would have looked closer. Though mine is adjustable and it really adjusts the riding angle more or less and not so much the reach.

fietsbob

not much I can do from the west coast ..

67 years old I just ride around town, to get places ..
help at the LBS in the high summer when the hundreds of cyclists are riding down the Pacific Coast.

at the end of my 50th year , I moved here after spending most of '97 on my bike riding
from southwest Ireland , to north east Scotland..
having a few Pints along the way

VT_Speed_TR

Hey Spinnaker,

i can check my local shop, the Old Spokes Home, who sells Jamis bikes. They may have one in stock since they are big on touring. You could drop on over and you could try some snow biking on my fat bike! I'll stop in Monday, they are only 2 blocks from work. Though everytime I stop in I spend money :-)

Oh, even though those coastal folks are afraid to bike in the snow, Burlington is teeming with bike commuters all winter. We know how to bike & drive in snow.