bonz50

what size tires can you safely run on a Synpase (carbon or alloy)? stock they come with 25's, can I run 28-32's on 'em??

thanks.

Tim_Iowa

No one will be able to answer your question unless you post a year and exact model.

However, you can easily answer it yourself if you have the bike nearby. Look at the fork, the rear brake bridge, and the chainstays, and measure the tightest clearance of the three. (Harbor freight has super cheap plastic calipers that are very handy for bike tinkerers.) The tightest clearance may be vertical (brake bridge) or horizontal (fork or chainstay). Leave at least 1mm for clearance, and you should be able to estimate the max tire size compared to the current size.

If you don't have the bike handy, call a Cannondale dealer and ask very nicely for the shop guy to see how big of finger or pencil he can fit into those tight clearance spots.

Most road bikes max out at 27mm, i.e. a 28mm tire won't fit. That's why the Grand Bois Cerf blue is 27mm, to fit tight clearance road frames. However, a Synapse is an "endurance" road bike, so it may have a tad more clearance; you may be able to fit 28mm or even 30mm tires.

bonz50

I'm specifically asking about a 2014

edit to add - I found this picture of the rear tire/frame clearance with a stock 25 tire on it

seymour1910

I was about to ask where the brake caliper was but then I remembered the 2014 Synapse comes with disc brakes on a few of the models. I would think you could fit 28mm tires but I just don't know.

bonz50

let me follow up on this, I think for my commuting duties, which is typically 3 days per week weather permitting, I want to have a bike capable of using on the cinder MUP in the early morn. I mentioned this in the CX thread yesterday or day before. disc brakes are not a mandatory or even ~needed~ imho, however, I want to keep costs down as much as possible and a Synapse Alloy 105/Ultegra (disc brakes) is within budget, or a synapse carbon 6/5 (rim brakes). I'm wondering if 25-28 tires would be acceptable on the cinder MUP even though the bike would have no "tread" to speak of. I still want to be able to take the bike on weekend long rides 40-50+ miles.

if its safe to use slick 25 to 28 road tires on the cinder MUP an endurance road bike is going to end up being a better choice for me than a CX bike with a spare set up road rims for weekend rides. I've got plenty of time to decide while i'm hashing on the rehab on my foot but wanna start planning my budget as early as possible.

Tim_Iowa

Based on the picture, it looks like 28's should fit. I'm not sure what you mean by "cinder" MUP. Do you mean soft crushed limestone? If so, then you can ride any tire width as long as it's properly inflated. You only really need raised tread for loose surface/mud. Last weekend, my gf and I rode on the Katy trail in Missouri (crushed limestone) and she did just fine on the 27mm GB cerf blues.

bonz50

the MUP's around here I tried riding on the 23's on my current bike (on the road I inflate to about 95), it was squirrely to say the least, I had zero confidence and probably could have ridden faster on a low end rigid mt bike. when i refer to cinder I'm talking that very finely crushed limestone. generally quite hard on a dry summer but get any amount of rain and it stays mushy for weeks and gets rutted up and the 23's were just a nightmare to use on it. my thinkin is that the larger contact patch of the 25-28's should help not only cushion the roughness but provide a fair bit more traction in that situation and still be a tenable tire on road rides. am I off-base on that line of thinking??

Tim_Iowa

You're absolutely correct. 28's will give you a lot more cushion, a wider tire patch (vs. a longer one on the 23's), more traction, and will probably be faster on pavement too. A recent study on rolling resistance found that 28's are the sweet spot. They absorb enough of the road bumps to keep you more planted on road rides, but aren't fat enough to be slower than a 23.

I find 23's to be squirrely on anything but smooth pavement. Lots of practical cyclists (un-racers) won't ride on anything narrower than a 28, because there aren't any real advantages.

bonz50

most of my current riding is pretty smooth blacktop. next spring (after foot rehab) I'll be extending my work commute by riding a different route which will increase distance by about 50% and include about 70% MUP travel on this route. my distances are getting farther as I go and a comfort road bike seems a better choice for me than my GT, which I'm not complaining about on the shorter routes I typically have seen to this point. So, bikes that I'm looking at now are Synapse 105, Sectuer Expert, etc. I do want 105 components, but Tiagra might be the call if budget becomes a problem. just wanna make sure I can run the bigger tires, which is why I was considering a CX bike with slicks. going to the LBS today and gonna have a frank discussion with my guy about it and see what he has to say.

Tim_Iowa

CX bikes are a good choice because they are almost as light and responsive as a road bike, and have plenty of clearance for tires and fenders. Cantilever brakes are a bit trickier to adjust than side-pulls, but they leave the fork clear. The "comfort" and "endurance" road bikes are a sweet spot; more practical than a race bike but almost as fast.
See what CX bikes they have, and any Surly or other "alt" builders. They may offer bikes that solve your problem better than the biggest manufacturers' bikes. But then, I'm a "steel is real" guy, so I'd start with Surly/Soma etc.
And you'll probably find that 28's are just as fast, if not faster, on blacktop than the rock hard skinnies on your GT.

I'm not up on the latest differences between the product lines, but I've been happy with any Tiagra gear I've used. I do understand that usually the highest-end stuff is the same design as 105, but with lighter materials. Which you don't want if you expect your components to last.

bonz50

my LBS guy pointed me to an All-City Mr Pink as a viable option in steel, as well as a Salsa Colossal and Surly CrossCheck after we talked quite a bit. he liked Mr Pink a bit better for my needs considering the way the MUP's are constructed around here and what he believed would be appropriate tire selection needs for that ride. He thought that cantilever brakes or discs would be my best option and still leave me with a enough clearance for appropriate tires. Told me center pivot brakes and the narrow fork crown on the Colossal would be a limiting factor as well. We talked about the Synapse as an option and he basically said not unless its a second bike for me based on my riding mix/needs. He did really like the BMC GF02 Disc as a great compromise if I felt steel wasn't my thing. He felt it would be the closest thing to "two bikes" I could get with a spare set of wheels in the garage.






ya, I have absolutely zero desire to go above 105, I know tiagra is just a slightly dressed down 5600 set anyway so I am indeed keeping that as a viable option.

Tim_Iowa

Sounds like a helpful and versatile LBS. I agree that discs or cantis allow the most versatile tire selection. I like the All-City bikes, but the Mr. Pink has sidepull caliper brakes, which limits its tire clearance (Tektro R539s are nice, though). Maybe try riding the Macho Man CX bike, or Space Horse light tourer? They'll both be a bit heavier than the Mr. Pink, but more versatile with canti brakes. The Surly Straggler is new, it's a Cross-check with discs.

I don't know anything about the BMC (I don't pay much attention to aluminum bikes), but the company and its bikes are well-regarded. Looks like plenty of tire clearance (CX frames are good for this), and versatile disc brakes. However, spare wheels for disc brakes equals spare rotors too, so they cost a bit more. Make sure you fully ride-test the disc brake bikes; some folks are very unimpressed with the power and modulation of disc brakes commonly equipped on road bikes.

Other considerations before you spend the coin:
Handlebar height: make sure the bars are high enough for you before the steerer tube is cut. If it's cut already, ask for one that isn't. Measure twice, cut once, right? You can always have it cut down later once you've found the perfect bar height.
Rack/fender mounts: most carbon frames and forks lack eyelets for fenders or racks. If you're commuting, racks allow you to carry more, easily. And fenders allow you to ride on questionable days without a black stripe up your back. You can always take the rack or fenders off for fast club rides.

I think you're realizing what a lot of folks are: a fast frame with versatility is the best bike for most riders. This is Grant Peterson's bike philosophy, and what his Rivendell bikes strive to be (also, fancy and $$$). I own an early (slightly less versatile) Rivendell that is pretty much the perfect bike. Surly and All-City acknowledge the GP/Bridgestone/Rivendell influence up-front, but shoot for the less-fancy, less pricey market.

Ride what works best for you and your needs. I'm very glad that you're finding options with less compromises than the major-manufacturers' bikes (well, with compromises that make more sense for you).

bonz50

one thing i like about Mr Pink is that they claim clearance for 32's, which is about the size of many CX tires. even though side pull brakes. maybe dude was talkin about a different model and I got confusededed, LOL. lotta information from them, I typically stop thru there about once per month anyway so I'll bounce more ideas off of them and see what they have to say. Owner is going to be gone for about 3 weeks on a bike ride across Peru here soon, dude is really a super nice guy and just loves what he does. luckily I'm still looking at about April-ish as purchase timeframe so i've got a lot of time to decide.

NRZ

The new 2014 Synapse's sport 28c tires on all but the Hi Mod that sports a 25c, so my guess you can fit a 28c with no problems. Check the Cdale website for the specs on the tires they're running on the model you're most interested in.

bonz50

here's a related question about tire size, the BMC's stock wheel is a 24mm wide rim, can you install standard road tires ie. 25-28's?? it ~should~ work i would think, but don't know for sure.

Tim_Iowa

I understand that the rule of thumb is never install a tire narrower than the rim width. So, a 24mm rim shouldn't fit 23's or smaller, but 25 on up should be fine. A 25mm tire on that rim would have a shorter (less vertical) shape than on a narrower rim, but only by a mm or so. Not a big deal. They might be trickier to seat.

24mm is a good rim width for a CX bike, as most CX tires are 30-35mm. Which is also a great width for comfort and speed.

Ryan.Han

The Features page of all of the new carbon Synapses states explicit support for 28C tires. The aluminum frames are trickier because they don't say that and none of them ride 28s stock. So it really just depends on whether Cannondale built the aluminum wells out to be the same size as the carbon frames.

jam19

I have the 2014 Synapse Hi-Mod and installed 28c Conti Grand Prix 4000s II tires and noticed that the rear tire had self-clearanced itself on the underside of the rear brake bridge. Aside from the Challenge Paris Roubaix 28s (I'm reading mixed reviews about them) or the Grand Bois Cerf Blue (26c), any other tire suggestions for a wider tire that would work with the Synapse?