Crashola

I am having some maddening issues on my old Raleigh Supercourse. After tossing a defective Performance Forte 27 X 1.25 rear tire (the bead was separating from the sidewall), I picked up some Michelin Proteks as replacements. After mounting, I discovered that there really isn't any consistency in tire sizes. Although the Proteks are also labeled 27X1.25, they are considerably wider than the Fortes. I found this article that confirmed my suspicions.

Now I have two new tires with the rear big enough to rub if the wheel is in the slightest out of perfect alignment. I can get it aligned and crank down the QR pretty tight, but one good bump and I am rubbing on the left chainstay. Is there any fix for this, or am I SOL and in the market for my third set of tires in a month?

fietsbob

Cannot see a thing..

Is your axle broken?

JonathanGennick 

Is it the same clearance on both sides? Can dish be adjusted to alleviate the problem? Otherwise, I guess just source a narrower tire.

maddog34

sounds like you have a NEW style, external cammed QR on a horizontal dropout bike frame.... or the axle is too long, not allowing the QR to completely lock the wheel in place.

basically, the tire is the least of your worries!

P.S... tires do not have to be identical tread, front and rear.... and some bikes actually come with different treads and sizes as original equipment...

bikeman715

If the QR is not holding , try a Shimano QR or ruff up the dropout with a little sandpaper so the QR can "bite in " the dropout to hold the wheel in place . Another thing to try is a thinner tire in the back .

Andy_K 

Is the wheel all the way back in the dropout? If not, you can get a bit more tire clearance by moving it back. As others have said, the tire should not change its position after you've closed the QR.

Slightspeed

I mounted a set of 700c x 28 Paselas on my Super Course and there is tons of room between chain stays. I don't have a stop on the left side, but the derailleur claw located the right (drive) side. Make sure the wheel is straight after the right side is located. I do have a Shimano QR on my Campy hub because the Campy QR had flaking chrome. Try a 1" or 1 1/8 x 27 tire. I think they make drop out stops too that you can use to keep the wheel straight. My dropouts are chrome, and the QR holds nice and tight without any special prep. Picture is looking up from the bottom. Notice my wheel is a little off center, and still clears. There is a lot of variation in tire size. I had an old Bianchi where the tire tread would rub a little on the rear brake caliper if the tire was a little too tall. I think it was a 700c x 25.

maddog34

internal cam quick release, aluminum OR steel construction... https://img.ebest24.net/w21/x9/p100/bv565_3.jpg

external cam quick release, aluminum levers... https://exrepicture.com/images/exre/C...00BY/013B1.jpg

horizontal dropouts require the INTERNAL CAM type QR's... the external type will only work for vertical dropouts...

and if you have the internal cam levers, do be inspecting axle length... first thing to do is remove the springs from the QR assy. and put the wheel back on the bike, then take a test ride... no springs? someone else realized the springs take up room on the assembly and already removed them! or the springs were crushed beyond use by the too long axle and some narrower steel dropouts... old bikes that have been ridden a bunch rarely have the original hubs/rims, and people will fudge whatever they find onto the bike, so........

Sy Reene

I found this article interesting.. especially Vittoria's statement: "...the size of a race tire must be measured on a 15C rim, inflated at its max. air pressure." Is this a commonly adopted standard and the rim width that tire width labels are supposed to be based on?

xenologer

No,
there is no 'supposed'
that's just Vittoria's method, they aren't the only manufacturer

dsbrantjr

ISO 5775 specifies the measurement conditions including rim widths and tire pressures for tire sizing: https://en.wikipedia.org/wiki/ISO_5775

79pmooney

Yes, but it gives a range of rim widths for each tire width. So the question remains, how do you know within that range which one they used?

Ben

dsbrantjr

I believe that the chart to which you refer is recommendations for use, not test. I believe that the rim width for test is contained within the standard, but I do not care to shell out 118 Swiss Francs to find out the details. https://www.iso.org/standard/56559.html

rumrunn6

had the same problem w my Proteks. now I have to run them at a lower pressure to keep them narrower. you are probably better off trying them at a lower psi, they are strong so you won't see sidewall bulge. or sell them on craigslist & get the next width size smaller & run them at the pressure you want

my similar saga
https://www.bikeforums.net/hybrid-bi...ek-700x35.html

I love the tires but run them about 1/2 their max pressure. but you wouldn't know it to look at them, cuz they don't bulge at the bottom even when my 220lbs plus gear get on it

be glad you're not dealing w fenders too

Sy Reene

From the Wiki article: "The inner width of the rim on which the tire is mounted should be about 65% of the tire's nominal section width for tires smaller than 30 mm and 55% for those larger."

If we take that the historically most common road bike tire width was probably a nominally sized 23mm, that does indeed mean that a 15c rim comes closest to this standard. A 25mm tire might be nominally labelled as such as measured therefore on a 16c rim (though this is pretty uncommon). Certainly this explains a lot for the many folks who own wider rims and at the same time claim manufacturers are mislabelling their tires as narrower than they really inflate to (common example is how 25mm contis are 27-28mm on their wider rims (19mm+ interior).

Crashola

Thanks for all of the feedback. There is room in my dropout (maybe 1/4 inch) , but the bolt holding the derailleur hanger onto the frame prevents the axle from sliding all the way back. The QR knob on that side hits the bolt in question. I am glad to hear that I am not the only one with this problem with Proteks. Thanks Rumrunn6 for the suggestion. I will take some air out and start looking for a replacement.

Things seem to be working okay for now. I got it centered, cranked the hell out of the QR, and it has stayed in place for a couple of days. With probably less than a 1/16 of an inch of clearance! These tires are nice and plush, but much, much fatter than other 1.25s I have used.

sweeks

Could the axle possibly not be centered so only one side locks?
Steve

Hoopdriver

What year is your Super Course? I commute daily on a 72 SC on 700c Schwalbe Marathon Plus 32s, which fit fine. Previous to these tires I ran Michelon World Tour 35s, which fit but without much clearance. 27" tires would fit a bit tighter because of the larger diameter, but I can't imagine that they would be that much problem.

Slightspeed

I changed the derailleur claw mounting screw to an internal hex screw with a smaller head dia. Don't know the thread, but it was the same as a water bottle holder screw. My original screw was external hex with a slot through the center and was stripped on the thread end. I just had this one laying around. You could even use a smaller head diameter socket head cap screw if you need it.

maddog34

M5 x .80 thread ...

and being 1/4" farther back in the drops won't change things as to tire/chainstay rubbing... the button head allen looks worlds better though.... Just make sure that new, smaller headed screw doesn't stick through and hit the chain when the bike is in small cog.... or worse.

Crashola

Update on this problem. I have tried several things to fix the problem without much luck. First, I tried to tighten up the QR in hopes it would hold better. But a few miles of city riding would bump the wheel back out of alignment and rub. Then I tried a smaller mounting screw for the derailleur hanger, but it only provided a very small change. Then I threw my hands up and put a narrower tire hoping at worst i would have a misaligned tire that did not rub. Nope. So my problem is definitely in the QR -- it is not holding my axle in alignment. A few miles of city asphalt knocks it out of alignment.

I will check the axle length to determine if it is too long and preventing the QR to get a good bite. Also, do QRs wear out? These are some old school internal cam QRs. Would something like these Velo Orange's QRs be a good replacement?

Bill Kapaun

Is the lock nut serrated? That helps to 'bite" on the inside of the drop.

Crashola

I don't think so. But I will confirm.

As for the Velo Orange QRs I posted, I don't think they would work. They state for 130-135mm rear spacing. I think older bikes like my Super Course are more like 120 mm.

TimothyH

You always have the most interesting answers.

CliffordK

I had a similar issue on my Funny Bike. Not a lot of tire clearance.

What I found solved the problem was after putting the wheel in place, I gave an extra tug rearward on the QR nut (right side) so that the QR skewer rested on the back side of the axle. That gave just enough extra support that the wheel never moved.

HOWEVER, that won't really work if the QR nut is resting against the claw bolt, and the axle isn't already pulled all the way back in the slot. So, if you are bumping the claw bolt, try something thinner, as mentioned above.