powerglide

PerformanceBike said they'd be fine but I have a feeling I over did it....

Its a hybrid bike, running Bontrager Select wheels. It came with 700x35 tires...

SheldonBrowns tire table and my rule of thumb (two sizes up or down) says these are pushing it....

Then I see compete bikes for sale with the same rims with 23 tires...

confused, please advise.

Thanks

-Tom

PS I ride on road only weigh 230 lbs, GF Utopia with suspension fork

supercub

I'm thinking of going 35 to 28. I'm still not 100% convinced that it's necessary change. I guess it depends how much faster you hope to go.

Nermal

I'm also thinking of going from 35 to 28, but these blasted tires just won't wear out. For my mixed riding, though, the 35s are pretty good.

kf5nd

You'll like smooth 700x28 with 110 psi in them

powerglide

yeah defintely hoping to go faster and corner better.
The question: is 700cx23 too narrow....

DMF 

No they're fine (assuming that they fit on the rims). What pressure do you run?

powerglide

I actually just cancelled the order because I ordered a bunch of ultralite tubes instead of the regular tubes.... but I still want the tires so I'm undecided if I should order the 23 or 35's...

I'll run them at the max pressure of the tire, not sure what that is but around 100-130 I'm guessing.

howsteepisit

You need to evaluate your type of riding and surfaces and then match that to your tire selection. For me, at age 50 and 210 pounds, 23 are pretty small and give a roughish ride on the local roads. I am currently riding 28's which I can ride at 85 ish for rougher roads, and up to 100 or so for smoother surfaces. Makes a big change in the comfort of the ride.

powerglide

Thanks howsteep!
I guess I was more focused on 'will it fit' than the comfort issue....but you're right.
Although the width may only change by a couple of millimeters (23 vs 25) but the volume of air in there goes up much quicker (exponentially maybe) hence a big change in the ride.
I ride on bike paths and sometimes on roads (during organized rides) and have lately been thinking about just going faster...but I forgot about ride quality...

25 and 28 tires sized are harder to find too...

howsteepisit

In Manhattan Beach 25's and 28 are hard to find? Wow, that's kind of a biking Nirvana! Try finding them in Montana! I got the 28's Ruffy Tuffys from Rivendell, and they are quite nice, and are wearing very well. Over 2000 miles and only slight wear is even detectable on the rear, none on the front. I think a couple of thousand more is likely, especially if I rotate them. There are lots of other mail order companies out there, if the locals don't stock them, then mail order/internet is the way to go. BTW, I always try the local shops first, I appreciate them shopping in my store too.

powerglide

Yeah...my LBS (just in there over lunch) certainly had many 23's but only one 25's and no 28's. He thinks if going fast is what I want, the 23's will be appreciably quicker than the 28's but noticeably stiffer riding. That said, since my rim measures 19MM wide on the outside (so most likely 15mm inside width) it would fit a 23mm. (sheldon brown tire rim chart also agrees if the inside width is indeed 15mm)

I'm assuming that the rims walls including the lip are probably 2mm on either side (hence 19-4=15mm inner width)...does that sound reasonable?

dwainedibbly

I'm 49, 195 pounds, and commuting 7 miles each way on 23s on narrow rims. I carry a cell phone for flats, but haven't had any yet. (Oh, hell, I just jinxed myself.) In contrast, I built an ebike to commute on in the hot months with 32s, with tire liners.

It all depends on where you ride, really. My route isn't too bad, and I take extra care on the rough parts. The thing about commuting is that you ride the same route daily, so you really get to know where at least some of the hazards are.

Changing from 35s to 23s is a huge change. I'd go to 28s as an interim step. Try that out & see how it goes.

Nermal

You ride in Manhattan Beach, Powerglide? I visited my sister in the tree section in Sept. I expected to see more bikes, and less of them on the sidewalks. Ah, what heck, it wasn't a weekend, or anything.

powerglide

Thanks for the comments folks, there's definitley lots to think about and it makes sense to go from 35 to 28 first as in interm step..

I took my wheel to the shop last night, the outer measured 19mm wide and inner 15mm so 23mm works fine. I'm really on the fence here but am inclined to go whole whole hog for the 23 and if its too rough then put the old 35's back on and save the 23's for the roadbike I am hoping to buy sometime soon!

Yup, lucky enough to be living 3 blocks from the beach in the sand section (i.e. 3 blocks to one of the best bike paths in LA) There's alot of bikers here for sure, you see many on the weekends but not so much the weekdays. That said, I see some serious looking/equipped team riders out there on most weekday lunch time. (thats when I ride because the pedestrian traffic is lite) Also, the fact that the path has a 8MPH limit (I think) and that certain parts require walking the bike (or get very expensive tickets) sends many riders into the PV Peninsula. I think that's where the SouthBay Wheelmen ride (they put on the Manhattan Beach GP)

alanbikehouston

It is important to match the tires to the rims. If a bike leaves the factory with a 35mm tire, it is likely to have a rim designed to provide a good fit for tires in the 32mm to 38mm range.

Measure the width of your rims from one braking surface to another. A tire should be wider than the rim it is seated on. So, you can use a 32mm tire on a rim that is 30mm across (braking surface to braking surface) But, if the rim is 32mm across, a 32mm tire is a bit too narrow.

I have bikes with tires ranging from 22mm to 35 mm. On the broken, torn, beaten up streets of Houston, Texas, tires in the 28mm to 32mm range perform the best. A high quality Continental or Bontrager tire in a 32mm width provides great protection against road shock, and superior handling on wet, dirty, and broken concrete.

A 32mm tire is far more stable than a 23mm tire on a slippery surface, as it has a wider contact patch. You can corner on a dirt or gravel surface at a speed that will leave you upsidedown with 23mm tires.

Pros ride on 23mm tires because they are paid to suffer, and have a "free" replacement tire just behind them on top of the team car. But, at Paris-Robaix, many pro riders insist on riding 28mm tires, even if they can't ride their sponsor "stock" tire or "stock" bike. A 23mm tire may not last a full day on THOSE roads...they look like roads in Houston.

I doubt you are being paid to ride. If you are riding for pleasure, for fitness, recreation, or as a commuter, there is no valid reason to consider tires less than 28mm or 32mm wide. (Unless you own one of those goofy bikes that have chainstays too narrow for a 28mm tire).

A final factor is rider weight. A 110 pound rider puts less stress on a tire and rim. A 23mm tire can provide adequate "cushion" for that rider. But, the heavier the rider, the more cushion is needed between the rim and the pavement. A 200 pound rider should not consider anything less than a 28mm tire, and would be better of with a 32mm tire.

MKahrl

Since moving from 23mm to 27mm and then to 32mm my MTBF (Mean Time Between Flats) changed from months to years. The performance boost you are seeking may be had by getting really nice tires like Schwalbe Marathon Racers in 30mm (actual width, 28mm).

Travelin' Jack

I'm 270 pounds and ride fine on my Trek 1400 with 23mm tires. I have about 10 pounds worth of lights, tool bag, water bottles, etc and have a 20 pound backpack on more often than not. I'm currently riding it around 150 miles a week. No flats, no broken spokes. I run them at 120-125psi. But as always, YMMV.

powerglide

My new tires have arrived (waiting at home)...its the Hutch Fusion Comp 23.
I decided to try it....my usual rides are exclusively smooth bike paths so I think they will be ok. (I am 230 lbs)
For long rides (Tour de Palms Century) I think I will put the original 35's or buy a pair of slick 28's so that it will be more comforatble and more puncture resistant.
I'll report back with results after I ty the new tires tomorrow!
Thank you everyone for your input.

powerglide

So I got the tires last night, and installed them. Below are some pictures o the before and after look, plus a side by side comparison of the mounted tires. I think it looks great!

I took it for a ride today during lunch on my usual 10 mile path. It definitley feels fast and stiffer (but not punishing). I'd say the ride is harsher but better yet maybe my old 35m tires were too squishy becuase these felt great. Here's what I found: Generally a 10% + improvement in speed.

Where I used to cruise at 15 MPH, now some effort gets about 16.6 MPH
Where I used to cruise at 20 MPH, now some effort gets about 22 MPH
The sprint portion of the course I used to do about 22 MPH now almost 25 MPH.

So thats about 10% across the board and 15% at the top end!
Also it corners much better too.

Only negative I noticed was that it was easier to lock up my rear tires now...

Its only been 10 miles so these are just first impressions...we'll see how it holds up!

Side by side comparision picture:


Before: 700c x 35 Tires


After: 700c x 23 Tires

Dogbait

Did you re-calibrate your computer for the smaller tires?

powerglide

My computer doesn't have that fine an adjustment so I did not....its a cheapo!

Anyway, the gain is more than speedo error, I'm pretty sure.

So here's the math:

Difference in outer diameter between mounted old tire vs new is: 1.5%-1.7% approx
Crunching the numbers for difference in circumference comes to about 33 mm per revolution which is about 1.5 % error on the speedo.

This is 'back of the envelope' stuff but clearly about an order of magnitude difference between the improvement in speed vs the calibration error.