jlmg

Hi
I have a Sirrus Sport from 2011 that has 700x28c tires with rim brakes. I would like to take it more on gravel, what is the max tire width I can install in it?, Can you recommend specific tires?

Thanks

JM

finch204

Try emailing Specialized. Your best bet is to take your bike to your LBS to have them measure the clearances to determine how wide of a tire it can fit.

Wanderer

I started out with 28s on my '04, next tried 30's. Went back to the 28's. and that's where I am now. If I need fatter, I have 35-40 on my Crosstrail.

MHO, The Sirrus does fine with 28's.

Derekve

I'd check with specialized or your LBS as different tire brands and rim combos can vary width wise. My 2015 sirrus base fits 35mm, but I run 32mm which was the stock size.

hokiefyd 

When I was at my local Specialized shop last week, I was looking at the Sirrus, and they said they could squeeze a 38mm tire to it, but that's the current frame (2017/2018). An older frame will likely have less tire clearance.

X_Vector

That's interesting.
About a month ago I visited the only closely located Specialized retailer and tried out what I believe was a current Sirrus Elite Alloy model, mainly for sizing reasons.
The salesman I spoke to was rather adamant about dissuading potential customers to go wider than the stock 30mm Specialized Espoir tyres these bikes are fitted with, even going so far as questioning the validity of a 32mm alternative.
He voiced the same reservation about the Cannondale Quick Disc models, which also sport 30mm (Schwalbe) tyres.

This is in fact the main reason I have now stricken these two brands off my list, as I'm looking for a fitness/hybrid bike that ideally supports 35mm tyres with fenders installed.
So far the only options I've found that come stock with this width is Cube (SL Road), BMC (Alpenchallenge), Merida (Crossway Urban) and Koga (Supermetro).

desmodue

Salesmen are typically full of ****, no matter what product they sell.

Wanderer

Go back to that same dealership, speak to someone who really cares about the company, and you will get a completely different answer. MHO

ksywa

That.

keep in mind that Sirrus models have either alu or carbon fork, with different width AFAIK. Take a tape measure and check the width of fork and chainstays. Check if there is pace on rear drops to move wheel back - larger tire might fit between chainstays, but might not clear the distanct to cross element between chainstays. Then see if you have enough clearance from chain in lowest gear (small chainring/largest casette element).

Some of Giant (Toughroad) and Specialized (AWOL) models are equipped with 40 or 50 mm tires, some other will be sold with 32 or 35mm and accomodate wider tires.

Also, search this forum. The subject of how wide tire into XXX is a recurring subject.

/ksywa

rumrunn6

coffee is for closers

fietsbob

1 measure the inside width.. report back what that is..

cycling705

I have a 2010 Specialized Sirrus Sport with rim brakes. The stock rims (Alex S500; double walled) have an interior rim width of 14mm. The original tires that came with the bike were 700c x 32mm. I contacted Specialized and was told that the max tire size for this bike is 700 x 35, but I'm confident that 38's would fit safely, and possibly even 40s.

Sheldon Brown's chart here suggests (roughly) that 32 is the max tire width. However, his chart and the manufacturer usually provide conservative recommendations.

Last year I tried Clement X'plor USH Tires (700 x 35) and they fit perfectly with plenty of room to spare between the chain stays and rim brakes.

There is some additional discussion on this topic at various points within the "Specialized Sirrus Thread" located here. In fact, post #241 shows a 700 x 38 setup.

Good luck.

cycling705

As an update to my previous post above, I decided to add an adjustable stem and larger tires to my Sirrus Sport to create a more comfortable ride.

As it relates to the tires (which was the original poster's question), I made the following change...

Original Tires: 700 x 32 Specialized All Condition Sport
New Tires: 700 x 40 Kenda Komfort

The tire clearances between the chain stays and the top of the rim brake cables are about 1/4" each for the Kendas. There is plenty of room.

Even though the "recommended" max tire size is 32-35mm, I've not had any issues with the Kendas.

The new setup is considerably more comfortable and smooth. I'm running the Kenda's at 65 psi (recommended range = 50-85 psi) compared to 100-110 psi on the original Specialized tires. The lower pressure and wider tires provide a much softer and stable ride with very little difference in speed / rolling resistance.

A complete overview of the new setup is located on post 164 of this thread.

Pictures of the new tires are located here: https://www.bikeforums.net/g/album/10019081

Hope this information helps someone.

hokiefyd 

The changes look great! Nice work!

AU Tiger

That has been my experience since moving from 28mm to 35mm tires on my Fuji Absolute a couple of seasons ago. The difference in rolling resistance is hardly noticeable, and the difference in comfort is much better than I was anticipating.

And I'm glad I didn't trust Fuji regarding the maximum tire width. If I remember correctly, they told me 30 or 32 when I asked. But after measuring for myself, I was pretty sure the 35s would fit. And they did. I suspect it's probably the same with other brands.

cycling705

I totally agree you.

To give credit where it's due, Specialized Customer Care was fantastic and very helpful.

They did mention though that 35mm was the max tire size for my model year and rim size. I'm sure some of their recommendation had to do with legal reasons.

I'm glad I took a chance on the 40mm Kendas. They still provide a quick ride, but the comfort at 65 psi has been fantastic. Bumps and cracks in the pavement are barely noticeable, and I like the look and feel of the larger tires.

Hope all is well.

hokiefyd 

It may also have to do with accessories. It may be that you can fit a 40 or a 42 in the frame, but then you couldn't run fenders on the bike. But maybe you can use fenders with 35s. I'm sure they (Specialized) keep things like that in mind when giving blanket recommendations.

cycling705

Makes sense. Excellent points.

altondavis2

Take a look at Trek and Diamond, they both have fitness bikes with standard 35's.

prj71

So will the new Sirrus Carbon fit 40 wide tires?

Cyclist0108

I put 38mm wide Compass tires on my wife's 2015 carbon. There is plenty of clearance in the fork, but very little clearance remaining in the rear triangle. 2015 was quick-release, not thru-axle, so YMMV.

canucksca

I know I am late to the party, but I looked at my 2017 Sirrus Sport Carbon and I don't see how one could run anything bigger than 32mm in the rear. I have the factory 30mm Specialized Espoirs and even they look a little tight on the bottom part of the rear triangle, especially if a spoke is slightly out. On the front, there does not seem to be a clearance issue and I think you could run quite large tires as there looks like plenty of room between the forks.

Laseranimal

2019 Sirrus Sport running 40mm tires on a 22mm rim. I don't think I can go much wider

hokiefyd 

Those look like a custom fit! If you have a dial or digital caliper, are the tires actually 40mm wide? Tires are sometimes a little wider or narrower than marked.

Laseranimal

just took a measurement and it’s spot on 40mm.