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Discussion Starter · #1 ·
For years now I've been riding my Tarmac SL3 with conventional width Reynolds MidV wheels and Conti 4000s clinchers either 23mm or starting last year 25mm. Going to the 25mm tires was a noticeable improvement in comfort and cornering w/ no real drawbacks.

Recently I got a set of CLX 32 wheels which have 20.7mm internal rim width. An installed/inflated 25mm Schwalbe Pro One plumps up to 28.5mm and is quite rounded looking.

80-85 psi tubeless in the CLX/Schwalbe setup and 95-97 psi in the Reynolds/Conti setup with light butyl tubes.

Compared to the Reynolds/Conti setup the CLX/Schwalbe setup feels more nervous. Also dropping into a turn at speed feels like it takes more effort to push the front end down. If I relax pressure the bike wants to stand up and open up the turn.

Cornering grip with the now 28.5mm tires feels great as does braking.

My moto friends say tires with 'pointy' profiles initiate turns more easily. The plump Schwalbes on the CLX wheels would not be considered pointy.

And I'm wondering if my perceived 'nervousness' of the CLX/Schwalbe setup is because of the wider & shorter contact patch not tracking as well as the longer/narrower contact patch of the Reynolds/Conti setup.

What have others experienced when 'upgrading' from conventional clincher setup to wide rim setup?
 

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I've made a similar change recently, but I also used bikes with different geometries, so that throws a wrench in the works. I went from 25mm GP4000's with tubes on narrow mavic wheels on my Tarmac SL4 to 32mm Hutchinson Sector tubeless on 21mm ID cross wheels on a Crux. I did a group ride yesterday with some fast curvy sections and had no problem leaning the bike into corners at high speed. But again, the geometry of the bike and angle of the fork is surely affecting that feeling.
 

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For years now I've been riding my Tarmac SL3 with conventional width Reynolds MidV wheels and Conti 4000s clinchers either 23mm or starting last year 25mm. Going to the 25mm tires was a noticeable improvement in comfort and cornering w/ no real drawbacks.

Recently I got a set of CLX 32 wheels which have 20.7mm internal rim width. An installed/inflated 25mm Schwalbe Pro One plumps up to 28.5mm and is quite rounded looking.

80-85 psi tubeless in the CLX/Schwalbe setup and 95-97 psi in the Reynolds/Conti setup with light butyl tubes.

Compared to the Reynolds/Conti setup the CLX/Schwalbe setup feels more nervous. Also dropping into a turn at speed feels like it takes more effort to push the front end down. If I relax pressure the bike wants to stand up and open up the turn.

Cornering grip with the now 28.5mm tires feels great as does braking.

My moto friends say tires with 'pointy' profiles initiate turns more easily. The plump Schwalbes on the CLX wheels would not be considered pointy.

And I'm wondering if my perceived 'nervousness' of the CLX/Schwalbe setup is because of the wider & shorter contact patch not tracking as well as the longer/narrower contact patch of the Reynolds/Conti setup.

What have others experienced when 'upgrading' from conventional clincher setup to wide rim setup?
Different tires pumped to different pressures on different wheels tend to feel different. Whether the combination is really more nervous or it is YOU that are nervous because you have not adapted to the change is an open question. The moto comment is probably irrelevant in this discussion. Mess around with pressures and maybe even swap tires from the old wheels to the new ones if you want to understand this better, but recognize that it is mostly "feeling" that is throwing you.
 

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Kerry Irons said it. Finding the optimum tire pressure for width of tire is very rider specific. Other riders can get you a ball park but you have to put the time in to find that sweet spot. And them monitor to make sure you stay there.

I am a rookie on the road bike. I went for Shhwable One and in retrospect I should have went with a more durable tire. I'm only racing myself. I didn't monitor the pressure and had a front tire loose some pressure. Didnt notice until I was 24mph or so into a turn and it broke on me. Couple swerves and I was lucky I didn't dump it.
 

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Discussion Starter · #5 · (Edited)
Different tires pumped to different pressures on different wheels tend to feel different. Whether the combination is really more nervous or it is YOU that are nervous because you have not adapted to the change is an open question. The moto comment is probably irrelevant in this discussion. Mess around with pressures and maybe even swap tires from the old wheels to the new ones if you want to understand this better, but recognize that it is mostly "feeling" that is throwing you.
Could you be more dismissive? The CLX/Schwalbe combination is definitely more nervous and doesn't track as well the Reynolds/Conti combo. I think this is because of the shorter/wider contact patch. It also does take more to push the front end down carving a turn. I'm not concerned about getting used to it, rather I wanted to discuss how a more full rounded shape will handle compared to a more 'pointy' shape. Do you not think the tire profile effects handling? Over the past 25 years I've tried lots of things & developed a breadth of experience while attempting to get better performance for racing and fast riding. Wide rims are new for me and I was hoping to discuss how they affect handling because of how they affect the tire profile.

Anyway... Over the past week I've gotten in a few more rides, lowering the pressure a couple psi each ride. 78/82 f/r is pretty comfortable. And I've 'gotten used to' pushing the front end harder. The 28.5mm wide tire with the full profile at relatively lower pressures does provide incredible traction. And that is quantified by my higher exit speeds descending mountain switchbacks without being nervous. The larger tire at the lower pressure does bounce a little more when sprinting. Doesn't make me nervous but it is noticeable.

What'll be interesting is when I try out a set of 23mm Pro ONE tires on the CLX rims. If the diagram part way down this thread is accurate the tire profile will become even less 'pointy' with the height decreasing more than the width.
http://forums.roadbikereview.com/wheels-tires/19mm-vs-23mm-rims-327980.html
 

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The "pointy" that your moto friend is referring to is called "triangular" in moto. Racing motorcycle tires are more triangular than cruiser motorcycles. And the reason you would want a more triangular tire (pointy) is because when you lean the bike, there is more contact patch (thus more support) from the sidewall, that is because you do not want your tire to go squishy when the bike is leaned over taking a high-G corner. But keep in mind that a higher contact patch from the sidewall does not necessarily means more "grip" (as many people think), grip is determine more by the rubber than tire profile. Well, there is a reason why racing motorcycles don't use wide and round tires used on cruisers, isn't it!

Michelin makes it a point give their tires the triangular profile. Most tires in the bicycle industry still use the "round bulbous" profile.

Another factor to consider is to use different tire at the front and rear. Front tire need to be made of soft rubber with a more supple carcass, rear tire needs to be made of a harder rubber and a harder carcass. The profile of the front needs to be lower, profile of the rear needs to be higher. So IMO, you'd get better handling performance if you use a 23mm front tire on a 25mm rim than use a 25mm tire for the front. What I would not want to use is the exactly same tire and wheel setup for both front and rear, makes no sense from a handling standpoint because their jobs are different. But I understand, it's ugly to mix and match different front/rear wheels from different wheelset, fine. But please do use different tires. Sure you might not look "cool" because your wheelset has mismatched tires, but rest assured you're doing it right.

BTW, I would never use a tire such as the Conti GP4000 for the front. This tire profile is too round and its rubber too hard. I'd use something like the Michelin Pro Competition or one of them thin Vittoria. Front end feel is more important than rear end feel.

eh just for curiosity I did once try the Hutchinson Sector 28 (28mm wide) on my HED 25mm tire in a tubeless setup, had it pumped to 60 psi (for my 120lb body) and a first dip into a corner at high speed had me shaking my head. Ditched the Hutchin Sector it immediately on Ebay, it was total junk handling. Sure it rides like a sofa at 28mm wide and 60 psi, but I didn't care for comfy much, that what my mtb is for, but handling was abyssmal.
 

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The "pointy" that your moto friend is referring to is called "triangular" in moto....
Good post.

I'm a lot more than your 120lbs; I'm about 215lbs, but still a strong rider. Here's how i do it...

If the tire looks like a light bulb that sucks. Gotta pump it up too hard for good cornering and supposedly it's less aero. I don't really care how big the tire is, only how big it is relative to my rims.

For the front, i can run any weight tire i want, really. I run a light (but not race-specific) tire with whatever rubber compound i think i can burn through before it starts drying out.

In the rear i run supple training tires and i'm not suuuper picky. Light tires tend to puncture and grippy rubber doesn't last. Lower TPI and reinforced casing is just fine for non-race riding.



Right now that means a specialized turbo pro 25mm in the front and a michelin lithion 2 25mm in back. They should both wear out about the same time ~3000 miles. Over all i think the weight distribution changes we can have from riding different size frames and being different sizes kinda overshadow tire choice.
 

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Compared to the Reynolds/Conti setup the CLX/Schwalbe setup feels more nervous. Also dropping into a turn at speed feels like it takes more effort to push the front end down. If I relax pressure the bike wants to stand up and open up the turn.

Cornering grip with the now 28.5mm tires feels great as does braking.
I'm trying to understand what you mean by the comments in the 1st and 2nd paragraph here. They seem to contradict each other. If the bike has more cornering grip and feels more planted in corners, how is it also "nervous" and "wants to stand up and open up in a turn"?

Could you please elaborate?
 

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Discussion Starter · #9 ·
I'm trying to understand what you mean by the comments in the 1st and 2nd paragraph here. They seem to contradict each other. If the bike has more cornering grip and feels more planted in corners, how is it also "nervous" and "wants to stand up and open up in a turn"?

Could you please elaborate?
Sure.
By nervous I mean if i ride no hands. The front wants to deviate more easily. Initial stability is lighter than the other setup.

I don't think that is at odds with how it feels when carving a turn where I have to push more with more intent to get the front end down in the turn. So if i relax pressure it wants to stand up.
 

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Sure.
By nervous I mean if i ride no hands. The front wants to deviate more easily. Initial stability is lighter than the other setup.

I don't think that is at odds with how it feels when carving a turn where I have to push more with more intent to get the front end down in the turn. So if i relax pressure it wants to stand up.
Interesting.
 

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I got to 28's on my travel bike, when I jump on it due to #1 being in the shop, I notice a big change in the handling. But I wouldn't call it nervous, the tires are so much wider it seems that one gets up on the side a lot quicker than the standard tires due to the 'round' vs 'triangle' prolile.
Just takes a minute to get used to, once that is over we are good to go.
I feel the 28's have about the same ultimate cornering grip, as I don't hold anything back on the corners with either. They just give a different feel as you go into the corner on the initial setup.
 
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