Narrower tires using same wheel?
 

So my girlfriend has had her specialized expedition bike for almost a year and we are trying to make it easier for her to get around town. She has 26''x1.95 tires that came with her bike. Would I have any issues installing 26''x1.25 tires onto those same rims?

Probably not -- MTB wheels often use narrower rims than they should, anyway. There are good slick 25x1.5" tires out there, too, if you want to be absolutely sure.

No problem.
I have these on my "grocery getter".

http://www.biketiresdirect.com/produ...et-runner-tire

I've had no issues in 3 years with them.

As long as the tires are 2-3 mm wider than the internal rim width and not run at very low pressure they should be fine.

i got 1.50 on my bike would like to try 1.25 to see if any difference at all

Maybe,depends on the rim width.

http://www.schwalbetires.com/tech_in...dimensions#rim

Check the rims for a decal that states the width,and compare it to the chart above. That will give you a safe range of tires to use.

All things being equal, narrower tyres are slower not faster - this is counter-intuitive because people think "friction" - but that misses the point of a wheel. Tyre performance is actually about hysteresis energy... Which you can reduce by using more pressure, which narrower tyres can sometimes take, but width alone is a poor guide to speed.

What you need are fast tyres fullstop, which is a matter of rubber compound and wall thickness. You may need wet weather grip as well, and puncture proofing. Schwalbe provide very decent ratings for their tyres on their site - the Marathon Supreme in 1.6 would be my pick; you can't get a much faster tyre, and the Supreme has great puncture resistance, wet and dry grip, and durability.

Are you sure she needs 1.25's? I regularly alternate 2.25's with 1.5's on my mountain bike rim with no problem. The 26 X 1.5 (Specialized Nimbus) slicks are just fine for my road rides and tours. Anything smaller and I'd probably just ride a regular road bike.

All things AREN'T equal though.
I'll never go back to anything bigger than my 1.25's on my grocery getter.

Wet weather grip**********???

Correct, all things are not equal. But I do agree that the specific tire choice is more important than width per se. I disagree strongly with the recommendation of any version of the Marathon, even the Supreme. That is not a fast tire at all. I would look at something like a Conti Contact Sport, or perhaps one of the Panaracer tires in the desired size. The Panaracer Pasela and Pasela TG are available in 26", that would be my pick.

I switched my rear tyre from a Kenda Kwest 1.50" to Schwalbe Kojak 1.33" and I roll much easier now. :)

I've managed to squeeze 1 & 1/8th inch tires on fat doublewalled rims. It wasn't easy, and no fun when it came time to change a flat, but it's possible. 1.25's should be a little easier. 1.50's give better ride over rough roads though, and there are lots of options for essentially slick tires in that size.

This is silly. If two tyres are made of the same compound to the same thickness and blown up to the same pressure, then "things" are equal. Yes, you'll normally blow the narrower tyre up to a higher pressure - but this has a much lesser effect than compound and wall thickness.

Sure. But also, so what? You have an ignorance-based opinion; why should anyone be influenced? (I'm an ex-messenger: trust me; I know about slicks and road speed. Plus unlike you I have actually read the tech docs that the tyre makers provide and I understand the physics - even strange words like "hysteresis energy".) The narrow tyres that you are using may well be faster than the wider ones you tried; your mistake is in assuming that there are not eg 1.6's equally faster - but with better braking, cushioning, puncture resistance, etc.

Yes. There is a thing called "rain". Some tyres grip much better for braking and turning in "rain" than others. This has a lot to do with the rubber compound used - more silica generally improves wet weather grip (while tread is useless on tarmac.) Conti Sports Contacts are fast, but riding them on a wet road is like being on ice (at least it was with the version I used a few years ago.) Supremes otoh grip almost as well as in the dry.

Every review of the Supreme you'll find on here will say otherwise, of course. Which isn't surprising, because it uses the same technology as Schwalbe's road racing tyres, just in a wider size - it's basically a wider Ultremo. People who tried other "Marathons" as you seem to have done think that the Supreme is a tweaked version, but Marathon is just a marketing category for Schwalbe and the different tyres use different technologies and so have very different RR.

People in the cross forum probably know more about tyres than anyone else (they are a huge thing in cross racing and tyre choice and use is very technical) and their bikes are much faster than hybrid commuters and the riders fitter, allowing quite interesting experiments - and basically, when it was put to a test, at anything less than road racing blast, a Supreme is as fast as a road racing tyre. There's also an experiment using the slightly treaded Dureme version on fire roads, where performance was nothing short of amazing.

This is the typical experience with Sports Contacts in the wet:

There are slicks just as fast that lack the frankly awful handling characteristics.

I stand corrected on the Marathon Supreme. The rest of that tire line is appalling (sacrilege in the commuting forum, I know). FYI - I'm a cross racer, well aware of tire importance. I've never put a Contact Sport on a bike where I was pushing its wet weather grip, suspect the OP's GF won't either. It's not like riding on ice, if you aren't pushing the traction isn't bad enough to be a problem, in my experience. That said, I think the Panaracer Pasela is a much better tire than the Contact. Both are about half the cost of the Marathon Supreme, in the case of the Pasela you still get a good, fast ride and good grip on wet pavement without as much damage to the wallet area.

I'm pretty sure that the Marathon Racer is also severely fast - in fact, Schwalbe rate it as faster than the Supreme (but at a big cost in puncture resistance.) The basic Marathons most people buy are optimized for absolute puncture resistance, which always costs either speed or money.

The Sport Contact is fine when you are on grippy, textured tarmac. But if you hit something smooth and wet at a moment when you need some grip - wipeout. Bricks, manhole covers, even tarmac where the texture has been smoothed out. Really: this isn't just me! Of course I am in the UK, where wet grip is a big thing... (And the Contact compound might have been improved since I used it.) Re. Pasela's: I don't think I've ever heard anything negative about them and a lot positive. I've also been told that Vitora Rubinos are excellent.

I just want the OP to be aware that

- Speed is more a matter of tyre compound than width

- That compound affects every aspect of handling on a bike, plus puncture resistance! And a lot of safety related factors and puncture resistance are harder to get right once you drop below 1.5. So consider what you want carefully, check reviews, and ideally buy from a maker who offers comprehensive information on the relative performance of tyres in their range - avoid surprises like finding you have bought a puncture magnet that won't stop in the wet. Schwalbe's ratings page is here http://www.schwalbetires.com/bike_tires/road_tires

..Marathon Supremes
http://www.schwalbetires.com/files/f..._supreme.gif?0

..Marathon Plus ATB
http://www.schwalbetires.com/files/f...plus_mtb.gif?0

Obviously, you shouldn't compare ratings between different manufacturers - and you shouldn't limit yourself only to makers with this info, just be aware that wet grip, etc, will vary, and make sure that you get what you need. I'm a bit fanatical about this stuff because it is a major safety issue and no one does anything to educate people about it - if I had my way every tyre sold would at least have a wet and dry grip rating. In my defense, this thread has shown that at least some people have no idea these factors exist at all...

This last part is not at all true. I've got 700x25 Ultremo ZX's on my road bike and 700x35 Marathon Supremes on my commuter. They're not even remotely in the same league. Granted, the Marathon Supreme is head and shoulders above a Marathon Plus in terms of performance, but the Ultremo is that much better than the Supreme.

Looking at Schwalbe's website I see that the Supreme are made with "RoadStar" compound at 67 EPI, while the Ultremos use "RaceStar" compound at 127 EPI. I also see that the Supremes weigh about twice what the Ultremos weigh, which isn't all because of the size.

On the other hand, the puncture protection of the Supremes is much better than that of the Ultremos.

On the Schwalbe site (and in the catalog), tire ratings across tire types won't be comparable, by that I mean you can't look at the ratings in the "Road" section and compare them with the ratings in the "Touring/Commuter" section. The ratings as stated relate to the other tires within the category.

I think to clarify one of the points that's being debated here (and I think both have some validity) the Marathon Supreme is as close to the Ultremo as you can get, and still have it be a tourning/commuting tire. Both have a triple compund that wears better on the rolling contact patch than on the cornering shoulders, and the cornering shoulder compounds are very similar in the two tires. That said, the Supreme has so much more material there that it won't deform and grip to the same degree that an Ultremo will and as Andy K mentions, the Ultremo carcass has a higher thread count (which makes the tire more supple), but the Supreme is probably as good as it gets (or nearly so) for a grippy touring tire.

Back to the original question, "can one go to a 1.25 tire on a rim that came equipped with a 1.95 tire?" The answer is a qualified probably, but depends on the width of the rim. If the bike is relatively new (and it sounds like it is), there should be an ETRTO rim size designation somewhere on the rim, either on one of the decals or actually stamped on to the rim. This number will have the form of "559 - xx". A 1.25 wide tire equates to a 32mm wide tire. A 1.95 wide tire essentially equates to a 50mm wide tire. The overlap as to which rims will work for both/either tire size is either a 17mm or 19mm wide ETRTO rim width. If the rims on the bike are wider than 19mm, proceed with caution on the 1.25, although a 1.50 would work without a doubt, the overlap is much more extensive.

One of the issues being discussed is rolling resistance, certainly a valid discussion point but the bigger issue would likely be weight. A lighter tire would definitely be an easier tire to accelerate and start/stop with, and a 32mm wide tire has plenty of volume so that the tire does not need to be run at ridiculously high pressures so as to truly negatively impact rolling resistance.

I went next door, and checked the rim size on their two Expeditions. OEM are 26X1.95, same as yours'. One is 18mm, and one is 20mm. Soooooo, yes, you would be OK with 1.25, but much better at 1.50........ Coincidentally, they are both also labelled for 26X1.50..

The Pasella with Reflex and TG , Or, Vitorria randonneuring tires with puncture protection, ould be excellent choices, in the 1.50 size.

If you want to spend more money, I absolutely love my Schwalbe Marathon Supremes. They are bulletproof, dependable, predictable, and roll like a dream. Get some Schwalbe tubes while you are at it. They hold air better than any tube I have ever used...... Yeah, they are expensive, but worth it to me.

I once put a 700x38 kenda kourier tire on the back of my carbon road bike. It ran just as fast as the 700x25 continental ultra sport that I normally run.

The lack of knobbiness of the tire is what really matters. The wider the better, so long as you're not adding pounds of weight.

If all things were equal then how is it possible that narrower tyres and wider tyres wouldn't be equally fast, Mr Smartypants? :p

Actually although you are correct that wider tires have lower rolling resistance, they're still slower because:
1. They're less aerodynamic.
2. They're heavier.
...which is why standard bike wheels are such large diameter because it's the only way to decrease rolling resistance without also increasing these two problems as wider tires do. Though of course decreasing diameter also improves aerodynamics and weight, and so it seems the optimal tradeoff is achieved with ~250g tires at whatever diameter corresponds to this weight for the tire widths needed to safely traverse the road imperfections:
Good roads = narrow and tall
Bad roads = fat and short

And, yes, better materials are also better, but in terms of tire geometry I've found the above guidelines to be best and, in particular, that 26-27" diameter tires are faster when they're pretty darn narrow.

These are some extremely fast rolling 349:32 tyres running at 85psi... they weigh 210 grams each.

http://www.ravingbikefiend.com/bikep...tonsugino1.JPG

These 559:50 tyres (Schwalbe Hurricanes) are incredibly fast, long wearing, and have yet to flat in 12,000 km... but they do weigh about 600 grams each. The secret lies in the dual compound tread that makes them roll like a road tyre at 85 psi and a softer outer casing and lug that makes them great on the trail at 35psi.

http://www.ravingbikefiend.com/bikep...nnew%20(1).JPG

These 630:35 Avocet Cross tyres are very fast and very smooth at 70psi... they have extremely low rolling resistance due to their inverse tread and handle off road riding exceptionally well too.

http://www.ravingbikefiend.com/bikep...11ccmpath1.JPG

These 630:35 Continentals are also fast... but perhaps not quite as quick as the Avocet Cross tyre which is rather amazing.

http://www.ravingbikefiend.com/bikep...lattimass4.JPG

These 700:25 tyres are extremely fast... they only weigh 195 grams each and stick to the road like velcro.

http://www.ravingbikefiend.com/bikepics/2012cooper1.JPG

When it comes to tyres it comes down to the casing and tread materials and matching them up to the right rims and running them at the right pressure, the pros are discovering that they are going just as fast on 25's at a slightly lower psi than they did on 23's at higher psi and Schwalbe's research shows that wider tyres can be just as fast or faster on the road.

Wider tyres are definitely faster on the trail and on rough surfaces where the speed is not as high and where a wider tyre decreases rolling resistance and does not experience as much momentum loss when things get rough.

As for Marathons... they are pretty slow but you are trading weight and performance for survivability and the Plus is even worse when it comes to speed although they are pretty much bombproof.

Have run Armadillos and felt like my tyres were full of water.

I just started running the 26 by 1.5 Marathon Racers on my touring bike as I will trade some of that survivability for a tyre that should not even call itself a Marathon as it is supple and very fast rolling... and I do not live in a place where goatheads grow.

Continental Ultra Sports are not that fast and not really that good of a tyre (they are flat prone), the discontinued Kevlar version came in a 700:23 and at 110 psi felt like a tubular as it was this supple and smooth and I found it to be a better tyre than the slightly lighter Gatorskin which imparts a harsher ride.

If the rims support a 1.25 this will not be a problem but if you run a crap tyre the performance will be crap.

Avocet has re-released their legendary Cross tyre for 26 inch rims... the 1.5 will be diabolically fast, secure, and long wearing and do everything they say it will.

http://www.avocet.com/tirepages/cross_2.html

Old geezers like me who remember running these when they were first available were pretty stoked to see them come back because they are that good.

Quote:

---

She has 26''x1.95 tires that came with her bike. Would I have any issues installing 26''x1.25 tires onto those same rims?

---

how wide are the rims , themselves? are the roads smooth and pothole free?

I fail to get the shallow sidewall fashion tires and custom wheels on cars.


a shallow D profile narrow tire on a wide rim on a bike = rim damage and pinch flats possibly ,
if you cant avoid the road hazards.

If you have wide rims consider a second set of wheels with narrow rims ,
and resell the other ones , as they have value ..
just not to you, and yours, as is, at this time.