dynaryder

Good to know that you know more about tires than the manufacturers.

I've had no issues running 2" Supremes and Big Apples @70psi,and 1.95" Crossroads @80psi,all of which are within the specifications marked on the sides of the tires. And I've seen 2" knobbies that were marked at a max of 100psi. Do what you want,but don't tell people that you know more than the companies that made their tires.

I wouldn't run any of the bikes in my fleet on the street at 30-35psi. BTW,I've also never gotten a pinch flat or had a blowout. So I must be doing something right.

sreten

Hi,

Running fat tyres near the maximum indicated on the tyre means you
understand very little about tyres, and the loads put on wheel rims.

Your not going to ever get pinch flats running silly high pressures.
You may be simply be lucky on the blowout front, others aren't.

Your giving up a lot of comfort for no good reason, and reducing
your tyre life by not running your tyres at appropriate pressures.
And reducing the grip / braking available from the tyres a lot.

I seem to know more about the silly numbers put on some tyres
than you do, which sometimes is mainly the marketing department.

A 100psi 2" tyre ? Get a grip on reality and real physics and safety.
I know more that the idiot who decided that should go on the tyre.
Its an utterly inane number for a 2" knobbly noone would ever use.

Optimum tyre pressures depend on physics, and tyre drop, but
vary depending on intended use and some user compromises.

Good tyre pressures are fundamentally related to the the tyre width,
and tyre drop, the fatter the tyre the lower the optimum pressure.

Carry on in your ignorance if you like, it is your loss.

Try googling "tire drop".

rgds, sreten.

The 1.75" front tyre on my folder is horrible above ~ 40 psi.
If it is too hard it bounces of little bumps, rather than rolls,
gives a teeth rattling ride, has no grip and is very unpleasant.
(And quite dangerous, totally losing grip on bigger bumps.)
It goes to an entirely academic 65 psi maximum on the front.

daihard 

Can you elaborate on your last statement? What makes MTB (26") wheels more appropriate for a 5' 2" person than 700c wheels?

Turbo231

Yes. My Trek 800 Sport came with knobby tires, 26x2.125 or similar, wide and loud and OEM. I changed them to 26x1.50 with a slick profile...looks like snakes back and forth but mostly flat. Night and day difference. It rolls so much better it's crazy. My bike is still heavy, but now a small breeze can push me where before it was like going though mud even on pavement.

I ride on pavement and gravel. Just my .02.

cyccommute 

Think about it. How long an inseam does a 5'2" person have compared to a 6' tall person or even someone 5'6" tall? That couple of inches of standover height comes in handy when your butt is closer to the ground. A bike with 26" wheels can also be made with a smaller frame that is more appropriate for a smaller person. Small people shouldn't have to ride bikes that look like a Coker.

daihard 

Thanks! That makes sense.

I think our best option is to go to the LBS and get their own feedback before making our decision. I'm personally leaning towards installing road-like tyres on her Marlin rather than getting her a new bike, but we'll see.

ThermionicScott 

+1. If you want your wife to stick with riding bikes, get her a bike that she can enjoy riding NOW. Making her suffer with a heavy and slow bike (even with slicks) is a great way to turn her off to biking. Don't think about what you'd be willing to tolerate, put yourself in her shoes.

daihard 

The thing is, she's kinda wondering if investing in a new bike is worth it. I see your point, though. I'd think a brand new bike that she can enjoy riding _will_ help her remain passionate about biking. I'll talk to her again this afternoon before hitting the LBS. Thanks again!

cyccommute 

The problem is that the Marlin, if it was the right size for you, is the wrong size for her as well as being too heavy. When you are at the bike shop, try a bike that is 2 sizes too big for you and see how much you enjoy it.

I would suggest looking at this Terry Symmetry that is listed on Craiglist. $500 is a bit much but my 5' wife rides one and couldn't be happier.

daihard 

Thanks for the suggestions. Actually, the Marlin is probably the right size for her as I originally bought it from a female friend who's just as tall as my wife (at 5' 2"). The seat tube is about 14 inches long.

That said, the Terry Symmetry bike looks nice. I've just never bought anything from Craiglist. I'll look into it.

ThermionicScott 

+1 on the Terry. I bet she'll love riding it once it's set up properly, and then it will be well worth whatever you spend.

dynaryder

You should work for a tire company then. Or at the very least let them know what they've got wrong.

And as I've said before,my Big Dummy handles funny when the 2" BA's are below 50psi. Guess I'm just not riding it right.

sreten

Hi,


Its impossible to make a bike that fits a 5'2" person with 700C
wheels without compromising the geometry. It is possible with
a 700C wheel on the back and a smaller wheel on the front.

(Toe strike is an issue almost impossible to solve well.)

(I think that Terry has a 700C rear and 24" front.)

Just as you have smaller wheeled bikes for younger people,
hybrids or road bikes based on 559mm size (MTB) wheels
will fit smaller persons better than a "small" 622mm (700C)
wheeled design, "small" will be better proportioned.

Especially for women. "Teenage" (26") road bikes do come
with shorter cranks, narrower bars, smaller reach levers
and other considerations along with the smaller wheels.

Not saying that MTB wheel based hybrids do, or all MTB
wheeled road bikes do, but they should simply fit better.

rgds, sreten.

For the same sized tyres 559mm wheels sit 1.25" lower than
622mm tyres, not the 2.5" difference in the rim diameter.

Similarly junior 24" wheels are only 1" lower than 26",
and kiddies 20" wheels only 2" lower than the 24".

sreten

https://www.bikepedia.com/quickbike/B...r&model=Marlin


Hi,

I can't work out why it being said this is a very heavy boat anchor.
Looks more than OK and not that heavy to me, lots of alloy bits.
The frame and forks are alloy.

Bike fit counts more than anything else and as its an XS
seems it would be a shame to simply give up on using it.

Slap some road tyres on it and go for it. These should go like stink :
https://www.nashbar.com/bikes/Product...39_-1___202472
A lightweight person doesn't need 85 psi, 60psi should be enough for 32mm.
I don't know about setting the front pressure with forks, same as the rear ?
I'd normally suggest something like 55 psi back and 45 psi front, here.

rgds, sreten.

At 50+ its taken me 6 months + to get even reasonable at doing hills. But
that bike will fly along compared to the original knobblies with those tyres.
(And FWIW drop the whole bike a little being relatively quite small.)

Camilo

People say you can't fit a 5'-2" on a 700c bike - but that's just not true. My daughter is about 5-2 and fits an XS Giant OCR (now known as Defy) just fine. The reach, saddle-bar drop, saddle height and position are all perfect. My wife, who's about an inch shorter, fits a 48cm Specialized Dolce. She would have also fit the size smaller (I think it's a 44cm), but since the effective top tube on both were within 1/2 cm of each other, and she prefers the tall head tube of the larger one, that's the way we went. Again, the reach is just fine and the saddle is positioned to her liking well within normal seat post and fore-aft adjustments. Both use 70-80 mm stems, but there's absolutely no problem with that. Both are very happy and comfortable on those bikes and ride them as far as 60 miles without physical problems. The "standover" is a little tight, but both, not being experienced riders, learned (from me) the first ride that you rarely if ever stand straddling a road ibke, and standover is totally mitigated by simply putting one foot down and leaning the bike.

It's probably significant that both of these frames have a slanted top tube, but that's so common these days it's hardly worth mentioning.

But regardless, both of these short women have absolutely no problem and are very happy and comfortable on 700c road bikes. Plus, my wife has a 700c hybrid that she also enjoys and is perfectly comfortable on.

As for toe overlap - meh. Every person below about 5'10'' will almost be assured of toe overlap. I'm 5-8 and I don't believe I've ever owned a frame without it, in about 40 years and about 10 frames. I currently have 3 road bikes (actually one's a cross) and all have toe overlap. It's just not a functional problem.f Neither my wife nor my daughter ever mentioned it nor ever had a problem because of it.

Just my experience with two short people I have a lot of knowledge of!

Retro Grouch 

That's an issue that comes up a lot.

If you wanted to get your wife to jog with you would you start her out with a pair of your old running shoes to see how well she likes it?

krobinson103

Huge difference. 1.75 knobblies as compared to 1.5 70psi slicks is night and day over 200km.

sreten

Hi,

I don't know the exact height it becomes an issue and it varies with the type of bike.
The more aggressive the geometry, the more of an issue it is. At some point a road
bike based on 26" wheels will be a better bet. I note a lot of charts start at 5'2".

rgds, sreten.

Burton

Bike tires are like car tires in that there's a relationship between tire pressure and maximum load. A 700x50 Marathon Supreme inflated to its maximum 70PSI rating has a load rating of 135 kilograms. I guess if you and the combined weight of the bike and whatever you're carrying weighed 595lbs I can see why you might think that kind of pressure is necessary. I usually run a lot lighter than that myself and have never seen a need to go over 50PSI.

Camilo

I wouldn't have been averse to looking into 650/26" type frame, because there certainly is a logic in fitting the overall bike to the person's physique. But they're so uncommon (frames, wheels, tires) that they're quite a bit less practical, at least where I live. I was happy that they found comfort and enjoyment on 700 frames. I just wanted people to know that it can work just fine.

daihard 

Thanks for all the insight and feedback.

After test riding 6-7 different bikes (ranging from a road bike to a 26-inch-tyre mountain bike), my wife decided on a Trek 7.4 FX WSD. She listed several factors.

1. It is available in 13-inch frame size. (15 inch was just a bit too big for her.)
2. Pretty lightweight.
3. Ride was smooth yet she was able to take a little rough pavement without getting too much shock or vibrarion.
4. Saddle was very comfortable.
5. She was able to ride up this mild hill (which we usually use for comparison) quite a bit more easily on the Trek than on the Marlin.

The salesperson at Gregg's (Alice) was very helpful. She was literally with my wife over an hour helping her choose and test-ride all the different bikes. Being new, she did have a few moments where she needed help, but then my sales guy Curtis was always there to jump in. Those two rocked!

dynaryder

Or maybe I just like it. Note:I have CT issues and DC roads suck. If running 70spi in my 2" Supremes doesn't bother my wrists,then there's obviously nothing wrong with doing it.

Whatever works for you. I just slam sreten because he fetishizes his tire pressure chart and claims to know more than the tire manufacturers do. I'm pretty sure when Vittoria marked my 28mm Rando's with a max of 85psi,and Specialized marked my 28mm All Conditions with 115min-125max,that they knew what they were doing.

sreten

Hi,

Your just pretty sure about your own opinion of numbers on tyres, not facts. 85 psi max for a 28mm tyre
is quite reasonable, and given 70 psi is about right for a 28mm tyre for an average weight person it is a
little low for the really heavy types, but then they should really be using a wider version of the tyre.

The 28mm 120psi tyres will take heavy riders and probably weigh more as they are stronger built,
though a recommended 115 psi min and 125 psi max is pure utter nonsense, and pure fantasy.
(Many 28mm road slicks are 115psi max, nevermind an "all conditions" general purpose tyre.)

There is nothing right about running 2" tyres at 70 psi, especially with CT issues and bad roads.
Schwalbe recommend 3 bar/45psi for their 50mm tyres and 5 bar/70 psi for their 32mm tyres,
as starting points. 45 psi rear and 40 psi front will be way better for 2" tyres than 70 psi.

The 50mm Supremes are specified as 30 psi min to 70 psi max and it takes some
considerable belligerence and ignorance to imagine they work best at maximum.

rgds, sreten.

cyccommute 

An excellent choice. Go out and ride the wheels off it!

Just a warning, however. Don't get too caught up in upgraditis. This is a good bike as it sits. It could be better...all bike "could" be better...but it's not worth too much more to upgrade with lighter parts. You'll spend a lot of money upgrading but not have anything that much better than the next level or two above it. Ride it, enjoy it, grow with it but don't spend a whole lot of money making it "better".

dynaryder

YOU'RE. Please spell check before flaming me.

So the numbers printed on the sides of my tires,by the manufacturers,are my opinions,not facts?

The All Conditions are lighter than the Randonneurs.

Again,please contact Specialized and set them straight.

Except my CT doesn't bother me on that bike,and the bike handles just fine. So basically,I'm doing it right.