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SM+ question: 700x35c -or- 700x38c for Chicago year round commuting?



 
 
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  #31  
Old April 2nd 08, 09:24 PM posted to rec.bicycles.tech
[email protected]
external usenet poster
 
Posts: 3,751
Default SM+ question: 700x35c -or- 700x38c for Chicago year round ?commuting?

someone wrote:

You are absolutely right, Sir! It IS bent!!


Bent seatposts are a sad fact of my cycling life.


Thomson Elite posts are a sure cure, though they are expensive by
seatpost standards. I have used an almost 12" exposed section of
27.2mm Thomson post when my weight exceeded 400 lbs., and that
post never failed.


Another option that should work fine for you (at a more appealing
price point) is the Kalloy 350mm 4130 heat-treated chromoly steel
post. Oddly, these are not as resistant to bending as Thomson
posts, but they are more than strong enough for your application.


How does a seat post fail in one month of use? Bad steel? Bad
match with the frame? Both?


Long extension with a laid back seat angle plus a good sized rider.
It's basic lever physics. In a perfect world Electra would sell a
24" version of this bike, but as it's a one size fits all deal,
you're going to have to find a post that's stronger as you're out of
the expected "range" that it's supposed to fit.


Bending is not failure as I see it. However, operating at yield
stress (the stress that leaves permanent bends) leads to fracture,
which is a significant failure because it generally causes serious
injury. With todays sloping toptubes, seat posts must be excessively
long and are operating at stress levels not incurred with "old
fashioned" frames with horizontal toptubes at reasonable height with
which thin walled aluminum seatposts worked well without fail.

The Kalloy should work--provided it's long enough.


Jobst Brandt
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  #32  
Old April 2nd 08, 10:48 PM posted to rec.bicycles.tech
Michael Press
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Posts: 9,202
Default SM+ question: 700x35c -or- 700x38c for Chicago year round commuting?

In article ,
Werehatrack wrote:

On Tue, 1 Apr 2008 13:19:37 -0700 (PDT), landotter
may have said:

On Apr 1, 3:41*pm, Werehatrack wrote:
On Tue, 1 Apr 2008 04:49:41 -0700 (PDT), Jay may
have said:

RTC is having trouble getting my spec'ed 700x38c SM+ tires
(backordered). They do have the same tire in 700x35c. I am 210lbs,
20lbs cargo (pack on the rear rack + small backpack), 5000 road miles
per year.

Should I just go with the narrower tire?

3mm isn't all that much, but in this case I'd simply swap to a
different 38. *

A 35mm gumwall tire can take a heck of a load and abuse. I wouldn't
worry.


Yeah, back in the '60s, I delivered a paper route on a bike with EA3
rims, and 26 x 1 3/8 is about a 35mm tire equivalent. As long as I
didn't let the pressure sag, it didn't give me many problems with
pinch flats. Now, these damn 23mm tires on the current roadie are
another matter; I'm definitely swapping up to 28 this weekend. Two
pinch flats in one week is three too many.


There is a big difference between 23 and 25.
Try the 25. 25's come in 128 threads per inch,
but 28's only 67 tpi. I had some 23's and immediately
went to the 25's; happy ever since. I run 32 nominal
28 actual on a utility bicycle where they are
functional, but not nearly the fun of the 25's.

--
Michael Press
  #33  
Old April 3rd 08, 02:12 PM posted to rec.bicycles.tech
Jay[_2_]
external usenet poster
 
Posts: 741
Default SM+ question: 700x35c -or- 700x38c for Chicago year roundcommuting?

On Apr 2, 4:45*am, "
wrote:
On Apr 2, 11:11*am, Andre Jute wrote:





On Apr 2, 7:47*am, "


wrote:
On Apr 2, 1:17*am, Andre Jute wrote:


On Apr 1, 12:49*pm, Jay wrote:


RTC is having trouble getting my spec'ed 700x38c SM+ tires
(backordered). They do have the same tire in 700x35c. I am 210lbs,
20lbs cargo (pack on the rear rack + small backpack), 5000 road miles
per year.


Should I just go with the narrower tire?


J.


I weigh the same as you. I have 35mm Schwalbe Marathon Plus on my
Gazelle Toulouse and 38mm Bontrager Satellite Elite Hardcase tyres,
very similar to the SM+, on my Trek "Smover". I can't tell the
difference between the tyres in service in comfort or longevity; I
don't even see that they vary in responsiveness; I see no reason the
35mm (1 3/8 inch) Marathon Plus won't suit you as well as the so-
called 38mm (it's probably 40mm). I can tell you though that, having
seen the pictures of the SM+ construction and then felt the stiffness
and weight of the tyre as I was fitting it to the rim, I was very
surprised that the ride wasn't harsh when inflated as highly as the
manufacturer suggests. I see Chalo has noted this as "softened" ride
in his last post; I'm a hedonist with a sprung seat and fork on all
his bikes who pines for something as soft as Big Apples with the low
rolling resistance and quick response of the SM+, so I won't go quite
as far as Chalo; I'll just say that all the tyres I ever had on my
mountain bikes were a lot harsher than SM+. And the height of the
sidewall is good too, for the puncture mode on the Contis I had before
was double pinch flats picked up in riding too hard through the
ubiquitous potholes. Not a single flat in 5100km between the Marathon
Plus and the Bontrager Hardcase, so those tall sidewalls and those
rubber belts work for their living, and so they should for these are
pricey tyres.


Andre Jutehttp://members.lycos.co.uk/fiultra/BICYCLE%20%26%20CYCLING..html
All cyclists should ride in dignity as we do


What's the manufacturer's recommended pressure? How can they know what
it should be?


Joseph


Eh? Every tyre manufacturer recommends a range of *inflation pressures
for his tyres. It is usually embossed in the rubber of the sidewall.
He knows how much it should be by empirical tests to meet the design
specification.


The Bontrager Satellite Elite Hardcase on my Trek "Smover" should be
inflated between 50 and 85psi. *And the Schwalbe Marathon 700x35c/x40c
like Jay is getting and I have on my Gazelle Toulouse should be
inflated between 3.5 and 6 bar. I keep mine a fraction above the
middle of those ranges.


Andre Jutehttp://members.lycos.co.uk/fiultra/BICYCLE%20%26%20CYCLING.html


The ranges printed on sidewalls are so huge as to be meaningless.
Useful pressures are dictated by the size of the tire and the load, as
you have found no doubt by experimentation.

http://sheldonbrown.com/tires.html#pressure

Joseph- Hide quoted text -

- Show quoted text -


Yep. Tire pressure ranges (printed on the tire) are dictated by the
marketing and legal depts, as SB wrote. Not the engineers.

J.

  #34  
Old April 3rd 08, 05:00 PM posted to rec.bicycles.tech
Jay[_2_]
external usenet poster
 
Posts: 741
Default SM+ question: 700x35c -or- 700x38c for Chicago year roundcommuting?

On Apr 3, 8:12*am, Jay wrote:
On Apr 2, 4:45*am, "



wrote:
On Apr 2, 11:11*am, Andre Jute wrote:


On Apr 2, 7:47*am, "


wrote:
On Apr 2, 1:17*am, Andre Jute wrote:


On Apr 1, 12:49*pm, Jay wrote:


RTC is having trouble getting my spec'ed 700x38c SM+ tires
(backordered). They do have the same tire in 700x35c. I am 210lbs,
20lbs cargo (pack on the rear rack + small backpack), 5000 road miles
per year.


Should I just go with the narrower tire?


J.


I weigh the same as you. I have 35mm Schwalbe Marathon Plus on my
Gazelle Toulouse and 38mm Bontrager Satellite Elite Hardcase tyres,
very similar to the SM+, on my Trek "Smover". I can't tell the
difference between the tyres in service in comfort or longevity; I
don't even see that they vary in responsiveness; I see no reason the
35mm (1 3/8 inch) Marathon Plus won't suit you as well as the so-
called 38mm (it's probably 40mm). I can tell you though that, having
seen the pictures of the SM+ construction and then felt the stiffness
and weight of the tyre as I was fitting it to the rim, I was very
surprised that the ride wasn't harsh when inflated as highly as the
manufacturer suggests. I see Chalo has noted this as "softened" ride
in his last post; I'm a hedonist with a sprung seat and fork on all
his bikes who pines for something as soft as Big Apples with the low
rolling resistance and quick response of the SM+, so I won't go quite
as far as Chalo; I'll just say that all the tyres I ever had on my
mountain bikes were a lot harsher than SM+. And the height of the
sidewall is good too, for the puncture mode on the Contis I had before
was double pinch flats picked up in riding too hard through the
ubiquitous potholes. Not a single flat in 5100km between the Marathon
Plus and the Bontrager Hardcase, so those tall sidewalls and those
rubber belts work for their living, and so they should for these are
pricey tyres.


Andre Jutehttp://members.lycos.co.uk/fiultra/BICYCLE%20%26%20CYCLING.html
All cyclists should ride in dignity as we do


What's the manufacturer's recommended pressure? How can they know what
it should be?


Joseph


Eh? Every tyre manufacturer recommends a range of *inflation pressures
for his tyres. It is usually embossed in the rubber of the sidewall.
He knows how much it should be by empirical tests to meet the design
specification.


The Bontrager Satellite Elite Hardcase on my Trek "Smover" should be
inflated between 50 and 85psi. *And the Schwalbe Marathon 700x35c/x40c
like Jay is getting and I have on my Gazelle Toulouse should be
inflated between 3.5 and 6 bar. I keep mine a fraction above the
middle of those ranges.


Andre Jutehttp://members.lycos.co.uk/fiultra/BICYCLE%20%26%20CYCLING.html


The ranges printed on sidewalls are so huge as to be meaningless.
Useful pressures are dictated by the size of the tire and the load, as
you have found no doubt by experimentation.


http://sheldonbrown.com/tires.html#pressure


Joseph- Hide quoted text -


- Show quoted text -


Yep. Tire pressure ranges (printed on the tire) are dictated by the
marketing and legal depts, as SB wrote. Not the engineers.

J.- Hide quoted text -

- Show quoted text -


QED.

J.

  #36  
Old April 5th 08, 09:07 PM posted to rec.bicycles.tech
Matt O'Toole
external usenet poster
 
Posts: 657
Default SM+ question: 700x35c -or- 700x38c for Chicago year round commuting?

On Wed, 02 Apr 2008 12:50:33 -0700, landotter wrote:

On Apr 2, 2:38 pm, wrote:
6'4" isnt that tall. They must make a frame that fitswith normal
seatpost extension!!!!


They must? I'd email them with a few of those exclamation points and let
them know. As it stands the Royal 8 comes in one size. With compact frame
sizing, modern strong posts, long headtube, and an adjustable quill, it
can fit a big range of people--but 6'4" is on the tall end. I can
understand why Electra would try to make a one-size- fits-most with this
bike, as a $1K city bike is an unusual thing to risk stocking on the sales
floor in the US--much less in 4-5 sizes.


6'4" is definitely on the tall end of things, as far as bikes are
concerned. There are not a lot of mainstream bikes with frames available
to fit riders that tall very well.

Even at 6' I find the front ends of most bikes too low as they come from
the factory. Even with tall stems on my bikes, my bars are lower than
most people's (~4" drop from the saddle).

I don't think the bike industry does a very good job accommodating
tall or short riders. It's actually worse with short riders. Tall riders
are usually accommodated well with tall stems and seatposts, but it
requires spending extra money.

Matt O.

  #37  
Old April 5th 08, 09:23 PM posted to rec.bicycles.tech
Matt O'Toole
external usenet poster
 
Posts: 657
Default SM+ question: 700x35c -or- 700x38c for Chicago year round commuting?

On Wed, 02 Apr 2008 14:48:06 -0700, Michael Press wrote:

In article ,
Werehatrack wrote:

On Tue, 1 Apr 2008 13:19:37 -0700 (PDT), landotter
may have said:

On Apr 1, 3:41*pm, Werehatrack wrote:
On Tue, 1 Apr 2008 04:49:41 -0700 (PDT), Jay may
have said:

RTC is having trouble getting my spec'ed 700x38c SM+ tires
(backordered). They do have the same tire in 700x35c. I am 210lbs,
20lbs cargo (pack on the rear rack + small backpack), 5000 road
miles per year.

Should I just go with the narrower tire?

3mm isn't all that much, but in this case I'd simply swap to a
different 38. *

A 35mm gumwall tire can take a heck of a load and abuse. I wouldn't
worry.


Yeah, back in the '60s, I delivered a paper route on a bike with EA3
rims, and 26 x 1 3/8 is about a 35mm tire equivalent. As long as I
didn't let the pressure sag, it didn't give me many problems with pinch
flats. Now, these damn 23mm tires on the current roadie are another
matter; I'm definitely swapping up to 28 this weekend. Two pinch flats
in one week is three too many.


There is a big difference between 23 and 25. Try the 25. 25's come in 128
threads per inch, but 28's only 67 tpi. I had some 23's and immediately
went to the 25's; happy ever since. I run 32 nominal 28 actual on a
utility bicycle where they are functional, but not nearly the fun of the
25's.


I agree, 25s are better and most people should be riding them instead of
23s. The problem is finding them at a good price when you need them, and
being able to get them through the brakes when removing the wheels.

Tires bigger than 25 would be better still, but road frames and brakes
don't accommodate them these days. Some frames, like the Scott carbon
ones, won't even take 25s.

I could probably put 28s in my Klein frame, but they wouldn't fit through
the brakes. Even 25s are a tight squeeze.

Matt O.

 




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