sizing a Jamis Aurora

[canadan]

I'm a newbie, about to buy my first real touring bike and I've already decided on a bicycle, Jamis Aurora but the closest store that carries it is 3 hours away (by bus / train). Moreover the stores that I can get to (in 3 hours) sell the bike for about $250-300 more than a couple of places that I've located on the East coast (> a thousand miles away) so I'm not likely to buy it from them.

I'm considering buying the bike from a remote store and have them ship it (they'll ship it for $125). Besides not having them around to help if something needs adjusting (I guess a local bike store could do that) I can't test it out to see if it fits. Then again, considering that I know exactly which bike I want to buy, my choices of frame size are fairly limited to start. A rough calculation on a website based on my height and inseam (5'8, 80.5cm respectively) tells me that I need a frame on the order of 54cm. The Jamus Aurora comes in 53cm and 55cm (the 2010 model seems to come in 54cm, but that's much more expensive and doesn't seem to have much improvement over the 2008 model). So now I just need to choose between those frame sizes.

How should I decide on a frame size? Is there a popular bike make, say canondale, (which I am certain to find locally) whose sizing is comparible to Jamis'? If so, maybe I should try that.

OR should I just take the trip to Chicago be willing to pay the extra cash to buy a bike there and get sized in person?

Any advice is appreciated.

thanks.

dan

 

[alfeng]

I'm a newbie, about to buy my first real touring bike and I've already decided on a bicycle, Jamis Aurora but the closest store that carries it is 3 hours away (by bus / train). Moreover the stores that I can get to (in 3 hours) sell the bike for about $250-300 more than a couple of places that I've located on the East coast (> a thousand miles away) so I'm not likely to buy it from them.

I'm considering buying the bike from a remote store and have them ship it (they'll ship it for $125). Besides not having them around to help if something needs adjusting (I guess a local bike store could do that) I can't test it out to see if it fits. Then again, considering that I know exactly which bike I want to buy, my choices of frame size are fairly limited to start. A rough calculation on a website based on my height and inseam (5'8, 80.5cm respectively) tells me that I need a frame on the order of 54cm. The Jamus Aurora comes in 53cm and 55cm (the 2010 model seems to come in 54cm, but that's much more expensive and doesn't seem to have much improvement over the 2008 model). So now I just need to choose between those frame sizes.

How should I decide on a frame size? Is there a popular bike make, say canondale, (which I am certain to find locally) whose sizing is comparible to Jamis'? If so, maybe I should try that.

OR should I just take the trip to Chicago be willing to pay the extra cash to buy a bike there and get sized in person?

Any advice is appreciated.

Part of sizing is cosmetic ...

How much seat post exposure do you want?

How much lower (if at all) do you want the handlebars to be than the top of the saddle?

Between the two frame sizes, 'I' would get the smaller of the two frames if I were you & adjust the fit with a longer stem (if necessary).

FWIW. The first picture is of my 52cm (c-c) Peugeot (54.5cm top tube) ... which is essentially the same size as the 53cm Jamis which is measured c-t.

The second picture is of my 53cm (c-c) OLMO (55cm top tube) which you can use for additional reference ...

I'm 5'9" ... the cranks are 175mm ... the top of the saddle is 28.25" above the center of the BB. You might have the saddle a little closer to the top tube, or not.

Of course, you may want MORE exposed seat post ... or, less.

Since the JAMIS Aurora is a "touring"/CX-type bike, you may-or-may-not actually want the 50cm frame if you are planning to use it for light touring.

 

[canadan]

Thanks for your advice. Unfortunately, I've been getting conflicting advice from all sources : friends who ride, local bike shops, not so local bike shops, internet forums. I finally decided (today) to just order a 55cm frame online. If it's too big, I'll just spend some time hanging from the ceiling by my ankles. That should lengthen my torso enough to reach the handlebars.

I'll post again with a status report once I get the bike and ride it for a while.

dan

 

[alfeng]

Unfortunately, I've been getting conflicting advice from all sources : friends who ride, local bike shops, not so local bike shops, internet forums. I finally decided (today) to just order a 55cm frame online. If it's too big, I'll just spend some time hanging from the ceiling by my ankles. That should lengthen my torso enough to reach the handlebars.

Well, as I stated earlier, a part of sizing is cosmetic ...

BUT REALLY, are you saying that 'I' am the only person who recommended that you get the smaller frame?!?

The slight variance in the top tube length doesn't matter because the difference can be readily adjusted with a shorter stem OR by raising the handlebars by using a hi-rise stem (if necessary) ...

BUT, did you look at the standover specs for the bikes? The standover height on the 55cm frame is a whopping-for-a-5'8"-person 32.12" (81.6cm)?

IMO, you should really have been choosing between the 50cm & 53cm frames rather than the 53cm & 55cm frames.

INCH/MM

SIZE CENTER of BB to TOP of TT EFFECTIVE TT LENGTH HT ANGLE ST ANGLE CHAINSTAY WHEELBASE FORK RAKE BB HEIGHT HEADTUBE STANDOVER

47 15.35/390 20.20/513 70.5° 74° 17.32/440 39.84/1012 1.97/50 10.83/275 3.94/100 27.52/699
50 19.56/497 21.06/535 72° 74° 17.32/440 40.24/1022 1.97/50 10.83/275 4.53/115 30.45/774
53 20.75/527 21.46/545 72° 73° 17.32/440 40.24/1022 1.97/50 10.83/275 5.32/135 31.40/798
55 21.57/548 21.65/550 72° 73° 17.32/440 40.43/1027 1.97/50 10.83/275 5.91/150 32.12/816
57 22.36/568 22.05/560 72° 72° 17.32/440 40.43/1027 1.97/50 10.83/275 6.50/165 32.74/832
59 23.15/588 22.44/570 72.5° 72° 17.32/440 40.63/1032 1.97/50 10.83/275 7.09/180 33.46/850
62 24.33/618 23.23/590 72.5° 72° 17.32/440 41.38/1051 1.97/50 10.83/275 7.67/195 34.33/872

 

[alfeng]

I want to buy, my choices of frame size are fairly limited to start. A rough calculation on a website based on my height and inseam (5'8, 80.5cm respectively) tells me that I need a frame on the order of 54cm. The Jamus Aurora comes in 53cm and 55cm (the 2010 model seems to come in 54cm, but that's much more expensive and doesn't seem to have much improvement over the 2008 model). So now I just need to choose between those frame sizes.

How should I decide on a frame size? Is there a popular bike make, say canondale, (which I am certain to find locally) whose sizing is comparible to Jamis'? If so, maybe I should try that.

BTW. If you still have 2-to-3 years of potential growth ahead of you (say, you're 16 years old) AND your mother is 5'8" & your father is 5'10" or taller, then the 55cm is probably the right frame size for you.

BUT, if you are done growing, then I guess I can't stress enough that the 55cm frame is probably too large for you ... particularly if you are going to use it for touring ... OR, CX riding ... OR, most riding.

If you're touring, in particular, and not using a trailer, then you don't want to lean a heavily loaded bike over as much as you will have to a 55cm Jamis Aurora when you stop.

Your Mates/whomever should have had you find any OTHER bike(s) whose standover is 32", etc.

FWIW. The attached pic is an older frame of mine whose standover is probably in the 32" range (28.5" between the center of the crank & the top of the saddle). The height is/was certainly fine when I am actually pedaling the bike because 'I' set it up for 'me' [including, using Cinelli 66 handlebars which have a deeper drop to compensate for the higher-relative-to-the-saddle stem height], but I definitely need to lean it to one side or the other when I stop -- I'm 5'9" tall.

 

[canadan]

Hmm, well that certainly does make me a little anxious.

You were not the only one who told me to go with the smaller frame. Two rider friends told me that if I am in doubt, to go with the smaller frame. Another rider, a little smaller than me, told me that he rides a 54 and he paid a lot of dough to get properly sized.

At that point it was 3-0 in favour of the smaller 53cm frame (I was even considering a 50 frame on reading your post). In addition, I had a line on a 2008 Jamis Aurora for $605 on closeout special. I went ahead and initiated the procedure to buy the 53cm.

The bike mechanic that I spoke with over the phone who was selling the 53cm Jamis took a bunch of measurements (height, foot, torso, inseam, arm length) asked me a bunch of questions (will you be using the bike for fully loaded touring - yes!!) and concluded that the 53 is slightly too small. He said that my foot hitting the paniers was a concern with a smaller frame. Considering that he was confident enough in his assesment of my needs that knowingly gave up a sale in telling me that, I trusted his opinion.

I took a 56cm bike from the local bike shop (not a Jamis dealer) for a test ride. It was a bike that the salesman chose for me that was his estimate of an appropriate size. I didn't have much to compare it to, but the ride was nice. It felt a little bit strained when I rode with my hands on the bottom part of the handlebars, but he said that that was my aggressive position and it was supposed to be a little less comfortable than the others.

So, that's basically the research on which I based my decision. Perhaps it was rash, but it's done. Like I said, I'll report again when I ride on it for a bit.

dan

PS I've long since stopped growing. In fact, I might even be shrinking.

PPS The geometry of the 2009 model (the model I bought) is different than that of the 2010 model whose specs you posted. I really don't have a feel for how these numbers translate to the feel of the bike, so the difference might be negligible but it does indicate that the standover on the 2009 model is smaller.

 

[alfeng]

Hmm, well that certainly does make me a little anxious.

You were not the only one who told me to go with the smaller frame. Two rider friends told me that if I am in doubt, to go with the smaller frame. Another rider, a little smaller than me, told me that he rides a 54 and he paid a lot of dough to get properly sized.

At that point it was 3-0 in favour of the smaller 53cm frame (I was even considering a 50 frame on reading your post). In addition, I had a line on a 2008 Jamis Aurora for $605 on closeout special. I went ahead and initiated the procedure to buy the 53cm.

The bike mechanic that I spoke with over the phone who was selling the 53cm Jamis took a bunch of measurements (height, foot, torso, inseam, arm length) asked me a bunch of questions (will you be using the bike for fully loaded touring - yes!!) and concluded that the 53 is slightly too small. He said that my foot hitting the paniers was a concern with a smaller frame. Considering that he was confident enough in his assesment of my needs that knowingly gave up a sale in telling me that, I trusted his opinion.

I took a 56cm bike from the local bike shop (not a Jamis dealer) for a test ride. It was a bike that the salesman chose for me that was his estimate of an appropriate size. I didn't have much to compare it to, but the ride was nice. It felt a little bit strained when I rode with my hands on the bottom part of the handlebars, but he said that that was my aggressive position and it was supposed to be a little less comfortable than the others.

So, that's basically the research on which I based my decision. Perhaps it was rash, but it's done. Like I said, I'll report again when I ride on it for a bit.

dan

PS I've long since stopped growing. In fact, I might even be shrinking.

PPS The geometry of the 2009 model (the model I bought) is different than that of the 2010 model whose specs you posted. I really don't have a feel for how these numbers translate to the feel of the bike, so the difference might be negligible but it does indicate that the standover on the 2009 model is smaller.

Well, if you ordered the 53cm frame, then I guess everything will be "okay"/(workable), but you had previously indicated that you had ordered the 55cm frame.

If you just ordered the frame on Saturday, then you can probably change it to a different size because I doubt it was shipped out, yet.

Now, there's no reason to trust me, but as far as the mechanic being concerned with your feet hitting the panniers -- THE GEOMETRY CHART INDICATES THAT ALL OF THE JAMIS AURORA FRAMES HAVE THE SAME LENGTH CHAIN STAYS -- 440mm (17.32 inches).

BTW. You didn't indicate (which means the guy who was sized for a 54cm frame probably didn't indicate) if that 54cm size was c-c or c-t OR c-to-the-top-of-the-seat-tube (which is how I think Trek actually measures their frames just to describe a third sizing option). No offense, but that would be like suggesting that you chose a particular shoe size because it was the size that someone else you know wears that size!



BTW/FWIW. Touring frames & CX frames (i.e., frames with cantilever brake bosses) are usually (but, not always) sized ONE SIZE smaller than the same rider would choose for a ROAD frame ...

• The primary reason is the BB height is often higher on a CX/touring frame than on a Road frame ... and, that raises the standover height.
  
  
• A secondary reason is that CX/touring tyre choice is often larger, and that also raises the standover height.

 

[canadan]

Well alfeng, I can't say I like being chided but I really do appreciate your clear, direct and experienced input. You might save me from making a big mistake.

I talked it over with my friend ( who feels the same way you do). He suggested a possible reason that the mechanic missized me. It might have been my fault. I measured my inseam from the ground to my crotch. I read about how to take that measurement for bicycles online. Is it possible that the mechanic assumed that inseam was measured as a tailer would: from the bottom of my pant leg to the crotch? If so, my reported measurement would exagerate my size and that would explain his judgment on the 53cm frame being too small for me.

Anyway. I'm going to try my best to change my order from a 55cm to a 53cm. I just hope that it's not too late.

Thanks again for your posts. I'll let you know how it goes.

dan

 

[canadan]

Well alfeng, I can't say I like being chided but I really do appreciate your clear, direct and experienced input. You might save me from making a big mistake.

I talked it over with my friend ( who feels the same way you do). He suggested a possible reason that the mechanic missized me. It might have been my fault. I measured my inseam from the ground to my crotch. I read about how to take that measurement for bicycles online. Is it possible that the mechanic assumed that inseam was measured as a tailer would: from the bottom of my pant leg to the crotch? If so, my reported measurement would exagerate my size and that would explain his judgment on the 53cm frame being too small for me.

Anyway. I'm going to try my best to change my order from a 55cm to a 53cm. I just hope that it's not too late.

Thanks again for your posts. I'll let you know how it goes.

dan

Well, I just received my 53cm 2009 Jamis Aurora today. It seems like the right size for me. Thanks for your advice.

dan