JoeO

I've long known that the Cannondale Supersix Evo in model years 2013-2015 has narrow chainstays. I've seen many threads with people reporting that their tires (usually 25 mm) rub up against the chainstays. I run Shimano C24 wheels (20.8 mm external rim width) and 25 mm tires on my 2015 Supersix and I've been fortunate enough to have no problems.

I would like very to much to buy some aero wheels but these days it's nearly impossible to get anything -- at least from the brands I want -- narrower than 24 mm at the rim.

I'm willing to go down to narrower tires (23 mm) but I'm concerned that some of todays wheels might be so wide that my rims might even rub. I'm wondering how wide I can go. Can anyone out there with practical experience with these years of SuperSix Evo share their experiences?

What rim width is too wide for my chainstays?

I was hoping to buy some Hed Jet 6's. They're 25 mm wide at the rim but they also have minimal lateral flex

Dean V

Wouldn't the best indicator be to measure your own bike, or even put in the prospective wheel if possible?
Better than some unknown persons internet opinion.

JoeO

I don't have access to the most of wheels I would want to buy. And even if I did, sometimes, a wheel can seem fine when just seated in a frame but flex under load. I'm hoping to hear from anyone with such a frame who has tried wide wheels and what their experiences were. IF I can collect enough experiences, I can make a more informed decision.

goenrdoug

as a 2014 supersix owner with 11,000 miles on the stock mavic wheels (on 23mm tires), I'd be interested in the answer(s) to this question as well...

Ferrarif2002

I’m on a 2015 Hi-Mod with FSE 25 clincher wheels, which measure 25.5mm and run 23mm tires without rubbing. It’s tight but I’ve got maybe 2mm on each side.

Elvir

I got a 2014 Supersix Evo and I can only run 23mm tires. If the wheels fall out of alignment in the slightest bit, the chain stays rub, so I would definitely not want to run 25s.

JoeO

Wow. 25.5 mm? You are the first person I've heard who has been able to run wheels that wide.

Ferrarif2002

I was surprised they fit, I’ll post up a pic later today when I get home

Ferrarif2002

Hard to get a good shot but you can see there is room. Measured the tire (23mm Michelin Pro4) to be 25.9 inflated to 80psi

JoeO

Wow that is a tight fit. But as long as the wheels don't flex, it looks reasonable. I'm definitely looking into wheels with minimal lateral flex.

Thanks for the photos!

Ferrarif2002

It’s tight but the pictures make it seem like less room than there is. I’d say I have a good 3.5mm on each side so while not a lot it’s enough that I haven’t noticed and rubbing and I run my brake pads very close and no rub there either. For what’s its worth I’m not a power house (ftp around 250) and weigh 165lbs

edit-just jammed some plastic shims in between the chain stay and the wheels, then measured that with my calipers and it came out to be 3.25mm on each side

JoeO

If you don't mind, a couple of more questions:

1. Are those tires 23 or 25 mm? -- [edit, nevermind about this one, I just re-read your post]
2. Are you sure those rims are actually 25.5? I mean, have you measured them?

(You are and are about the same size with about the same FTP...)

Ferrarif2002

Just remeasured and I was a little off, the tire itself is 24.6mm inflated to 80psi. The rim measures between 25.8-25.88mm.

Different tires will balloon out to different widths depending on which wheels they are mounted on. I have GP4000SII 23mm on a 24.6mm wide wheel (17mm internal) and they measured similar to the Michelin’s (around 24.5mm) I had HED Jet 6 + on a different bike in the past and the same tire was much wider due to the wider internal width

JoeO

This is all good stuff. Thanks, I appreciate the time you took to answer all this.

Ferrarif2002

No problem, I was searching for weeks trying to figure out if I could fit my wheels before I ordered them, so happy to help

Dean V

Remember that deeper wheels are often as wider or wider some distance in, than what they are at the brake track.
Depending on the chain stay shape this may be an issue.

JoeO

I know, this does worry me, especially for toroidal shaped wheels. That's one big problem in attempting to figure this stuff out without having access to the wheels: Manufacturers all publish rim widths but only a few of them publish "widest" widths

hsuehhwa

I have a 2013 Evo, with Boyd Altamont rims (19.8 mm internal width, 24 mm external width). Continental gp4000s ii 23mm barely fits. the wheels have to be very true.


It's hard to do any new wheel upgrade since they are all wider nowadays.

SirHustlerEsq

I had one, just replaced it with a CAAD12 and really enjoying the ride on 25s that measure ~28mm.


That was a 23mm GP4K that measured 25.1mm on the tire and it rubbed for a long, long time. Any sort of imperfection in wheel shape would really screw the frame up. The super-flexy BB area of the frame doesn't help at all, either. No matter how small the wheel or tire, it would rub the frame on the trainer. That bike lives on my smart trainer now.

JoeO

Appreciate all the answers. However this all became moot recently. After all the reports of people having gouges rubbed out of their chainstays, I took my rear wheel off and took a really close look and sure enough, my 25 mm tires had rubbed a big gouge out of mine. Bad enough that when I asked the guy in the shop point blank, he said, "I wouldn't ride it".

The wheels were Shimano C-24s and fairly stiff and defininitely in true and properly dished; The shop measured them in front of me. But there it was. So my Black Inc Supersix Nano was now basically an expensive piece of junk.

To my great relief, Cannondale has decided to replace it. I could never have afforded to.

In the meantime I've been riding my Caad10. Forgot what a fun bike that is. It's no Supersix but it's great.

Elvir

I told you!

goenrdoug

This is the sort of hair-raising story that keeps me riding 23s on the stock mavic aksiums... A little googling will uncover all sorts of frightening photographs of NDS chain stays rubbed deeply by tires.

JoeO

You did indeed. But frankly, if I couldn't ride 25s, I'd end up getting a different bike anyway. Very happy that I'll still be on the bike I want with wider chainstays now.

Gotta get a new seatpost I guess, unless the frame ends up coming with it as they went to 25.4 for some reason...

Dean V

I am impressed that Cannondale replaced the frame.
To me it seems more like a case of operator error rather than any fault with the manufacture of the frame.

goenrdoug

Likewise.. I mean.. I'd like to run 25s, but my frame doesn't accommodate it, so I don't.

Am I to understand that if I just go ahead and do it anyway, they'll have my back with a replacement frame? Heck, Nashbar, here I come, Daddy needs some 25s!