drousseau33

Good evening,

I have a 3 chainrings front derailleur (shimano sis pull down). Just changed my tires from 700*28 to 700*32.

Now the tire rubs on the front clamp holding my derailleur for about 1/4 of the wheel circumference.

Is there anything I can do?

bradtx

drousseau33, If the bike has vertical rear drop outs, you've exceeded your maximum tire size. If it has horizontal drop outs you maybe able to slide the hub rearward enough.

Bicycle wheels and tires are rarely perfectly round as there's often a 1 or 2 mm deviation. For vertical drop outs you can try finding where the most clearance is and rotating the tire on the rim to where the least clearance is...iffy at best.

Brad

saddlesores

how much do you wanna spend?
maybe look at a different model derailleur that might have a
higher or lower band position, or one of them bolt-on types
that uses a separate band clamp.......

drousseau33

Thanks! I have vertical dropout 😔

I have an inch between the wheel and frame, so could I change the front derailleur?

robert schlatte

can you ever so slightly adjust the position of the wheel in the dropout to avoid the rub?

bradtx

Before changing the FD you could file down the clamp just enough to clear the tire or try repositioning the FD a bit lower on the seat tube.

Brad

staehpj1

That is what I was thinking.

Snuts

I upped the size of drive tire on my road bike last fall from 25-28mm. Slight rub on my brake calipers. Only a short length in the pass. I brushed a file over the rubbing spot. The road grit polished it smooth again. I soon found out that as the pressure dropped from110-100 psi I had sufficient clearance.

Hope this might help.



-Snuts-

drousseau33

I've try playing with the wheel and with the FD/clamp position with no success. My clamp can't go lower since I won't be able to shift top gear, and Higher is even tighter...

Sounds like I have to look for a FD which has enough of 1" clearance and with pull down (my cable runs from the bottom).

Any suggestion not too expensive? 8spd (11-32), 3 gearchain (22-38-48)

Snuts

If you are willing to buy a new FD, try filling this one. What have you to loose?

Only my thoughts (out loud).

-Snuts-

drousseau33

Like it! I will tonight!

robow

Since we seem to be considering excessive solutions other than just buying a slightly smaller tire, btw all 32 mm are not equal in height and diameter and Conti's tend to run smaller than advertised. How about trying a different wider rear rim which will allow your tire to take on a wider but shorter profile.

drousseau33

Thanks Robow. Just bought my new tires and put the tags to the trash, so can't bring them back. Plus, it's for a touring bike, so going down to 28mm tires would be kinda small.

Changing the rim means mounting it, and I'm not that good at it

So option A, changing the FD, option B changing the RIM... hummm...

drousseau33

How wider should I go, mine has a 17mm inner diameter...

robow

What rim do you have now? Was that 17mm an inside or outside diameter? Mavic 719 and 319 have an inside 19mm diameter and I know that 2mm doesn't sound like much but it can make a difference.
But heck yea, try the file first, if that doesn't get it done, a lot of people might want to buy your tires around here and you can try some others. Best of luck in whatever you decide.

bradtx

I can't, off the top of my head, think of a FD or a clamp that can guarantee you the clearance you need with just a single purchase. The clamps I have are all thick enough to have a little material removed without compromising strength. It doesn't read like you need to remove much.(?)

Good luck,
Brad

andr0id

Oh a touring bike where you will be picking up mud, sticks and other debris on your tires, I don't think you can file off enough to get a proper clearance. You really need 1/4" clearance on tops and sides off tires if you don't want to end up with something getting jammed and bringing you to a halt.

Go back to the smaller tire.

drousseau33

Here is an image, you can see how the whole thing takes up the 1in space between the frame and tire

niknak

The photo helps. Those low mount derailleurs are bulky. Try something like FD-M531, where the clamp is above the derailleur body.

Snuts

Damn, those tires are to clean. Get out and ride the high spot off of it this eve!

pdlamb

That's why I like long chain stays.


I think the best idea is to go back to a 28 on the rear, and save the 32 for the front. After you wear out the rear tire, you'll probably have worn the front down enough that it'll fit on the rear.


Is your rear wheel true? If it's 1-2 mm too tall at that spot, fixing the wheel might fix the tire rub.

79pmooney

I'd go looking for a new front derailleur. Are you locked into a certain brand/model because if indexing issues? I am a little out of touch with the new stuff, I have never seen a derailleur that takes more than half the space yours takes. Usually the cable attachment and arm (I see you have a wheel for the cable; again a new one to me) is far enough to the right that the tire does not interfere.

A possibility would be to replace the front derailleur with a different brand of old style design and run a down tube or bar-end friction shifter for it (if you cannot find the matching index shifter). The was a famous bike racer who used to set his very high end bikes that way for key Tour de France mountain stages to save weight.

I've run rear tires so close to the seattube that I have had to cut a rectangle in the fender to accommodate the FD clamp. This with a derailleur like I was a talking about. (Edit: the cable ran under the BB on that bike. Cable and derailleur were completely clear of the fender and nowhere near the tire.) There are thousands of those derailleurs lying around.

Ben

bradtx

The photo certainly helps, I've never seen a FD quite like that. Replacing it is your best option and will allow for even larger tires in the future, if desired. Is the front shifting indexed?

Brad

robow

Thanks for the photo, worth a thousand words.
Yea, dump that derailleur for sure

saddlesores

dude, that's not the clamp your tire is rubbing on,
that's the pivot mechanism between the seat tube
and the tire.

had the same situation when fitting a 700c wheel
into a 26" frame. 9spd w/triple.

solution is a seattube clamp

https://item.taobao.com/item.htm?spm...d=523951417491

https://img.alicdn.com/imgextra/i3/1...1096782098.jpg

and a side pull bolt-on derailler, like this here sora FD-3503-F

https://gd2.alicdn.com/imgextra/i1/0...0-item_pic.jpg