rseeker

I'm looking at a 1992 Trek steel-frame Multitrack. It's a 700C frame, probably 21inch frame size. It came with 700x35.

What would be the largest size tires the frame would accept?

How about if I also put on fenders?

(Assuming the frame is the limiting factor. I would get rims to match if the ones that come with it wouldn't work with wider tires.)

Thanks.

rumrunn6

40mm or 45mm tops I'd guess. fyi - different tire & wheel combos result in different actual width (& height) measurements. meaning a tire might measure wider (or narrower) than labeled depending on brand & model tire & the wheel it's mounted on.

I had some luck last fall (squeezed in some big tires & fenders) but also got surprised this spring (a tire didn't fit at max pressure)

for example, my 40mm Proteks measure 43mm at 90 psi, so I have to ride them at 45 psi which is OK, cuz they have strong sidewalls & don't bulge

as for fenders, that's always a challenge but there are ways to modify fenders if there are issues. I started a cpl threads (in mechanics & hybrids) that might be helpful but they might also bore you & I don't want to hijack your thread. a suggestion, if you want wide, get some 45mm tires & try them out. what's the worst that can happen? you sell them to a friend or a stranger on craigslist?

oh & the OEM wheels are probably just fine

https://www.bikeforums.net/bicycle-me...-fit-bike.html

https://www.bikeforums.net/hybrid-bic...ide-tires.html

https://www.bikeforums.net/hybrid-bic...ek-700x35.html

ksryder

For some reason I want to say 47 but I can't for the life of me remember where I saw that. 42 or 45 sounds right too.

If it's the original Matrix rims you can't kill them.

rseeker

Yeah that is surprising. I'm in the southeast and when Irma passed over the mainland the temp dropped into the 60s and my tires went all squishy and I pumped them up. Now it's back in the 90s and they're all taught again, and I had to check wheel alignment to keep it from touching the chain.

Nah, that's good stuff, thanks for the links.


I love the sound of that. They're actually not the original rims -- Sta-Tru is what the owner went with -- but I'd like to get back more to original equipment.

rseeker

And, sold to somebody else within two hours of posting on Craigslist, dang it. Next.

rumrunn6

good practice 7 good test of knowing what you want. be patient, another will come along. you might try expanding your search area too

corwin1968

My 1995 730 would take 40mm Schwalbe Duremes on Dyad rims (a relatively wide, touring rim) and that was pushing the maximum. I could have squeezed a little more tire in there but I'm not sure true 45's would have fit.

Those old Multitracks are great bikes. As my tastes changed and as I learned more about my personal fit needs, I found the top-tubes are too short for me and the tire clearances too low. I now ride a 2008 Surly Karate Monkey which has almost identical geometry to the Multitrack except the top-tube is 3cm longer (a HUGE difference in fit) and there is a ton of clearance around my 50mm tires.

rumrunn6

pics?

corwin1968

Trek 730 with 40mm Duremes and Karate Monkey with 50mm Maxxis Torches

This is my favorite picture of the 730 and shortly after it was taken, I moved every component that was compatible over to the Karate Monkey.







Old MTB's with slicks work well as hybrids

rumrunn6

really interesting bike & I agree. for while I was commuting on 3 different bikes, old '70s road bike, new hybrid (before modifying it) & an old MTB w big fat slicks. my fastest time over 17 miles was with the MTB. really surprised me, especially since that frame was too small for me

hokiefyd 

I have a 1995 MultiTrack 750 and I've had as large as an actual 39mm tire on it before. Nominal size was 42-622, but it inflated to about 39mm. It had decent clearance -- I don't think I'd go too much larger than a true 40 or 42mm tire, personally. At least on my particular frame. Some frames likely differ from year to year.

You mentioned the OEM Matrix rims...mine has the original Matrix Vapor rims, but I've actually just removed them and will use them on my wife's bike, which is very rarely ridden and only around the neighborhood. Those Matrix rims make it darn near impossible to mount nearly any tire. Every wire bead tire I've used is a REAL bear to get on (I have to use a bead jack tool) and I'd never be able to service it on the road to change a flat. Plus, I haven't gotten any wire bead tire to seat correctly on them. It seems that the bead seat diameter is just a hair large -- no wire bead tire will actually inflate properly -- there's always a part of the bead that will stay sucked down and won't inflate up. The tires that have worked the best on it are a pair of foldable Continentals in 42-622.

I have started using the Matrix 550 wheels that came on my wife's bike. They're black anodized, which I don't prefer, but every tire that I've tried to mount on the Vapor wheels (and didn't like the results) sit up nice and pretty on the 550s. I barely need a tire lever to remove a tire, and I don't need a bead jack to install one.

So I don't know what the deal is with the OEM Matrix Vapors that came on that 750. I don't know if it's just my two that are so difficult or if they're all like that. It's unfortunate, because I like the wheels, but I'm starting to ride longer distances and on trips further from home, and I don't feel comfortable riding rims that won't let me fix a flat in the field.

rumrunn6

wonder of that 550 number correlates to the 550 number on my Trek's Bontrager wheels (which are 622 x 20?)

hokiefyd 

They appear to be the same wheels. These are also 622 x 20 and have a relatively low profile box section with black anodizing on the inner surface, just like yours. These are laced to bright hubs (as opposed to black) that don't have a brand name.

I like these wheels better than the AT-750 on my Verve, just because of the width. The AT-750s are 622 x 16 and have a slightly taller rounded dish section.

I think Matrix was Trek's house brand wheel until everything fell under the Bontrager label. Yes, I would say my Matrix 550s are the same as your Bontrager AT-550s.

Is tire mounting pretty easy on yours? Tires practically mount themselves on my Matrix 550s.

rumrunn6

yeah they seem fine. happy happy to mount some 45mm tires on them which at max pressure measured 48mm. I haven't tried to go narrow, maybe I'll try 25mm tires on them some day. but those live on my road bike, so probably never. I also have 35mm studded tires w a wire bead on them. a little finesse & those went on w/o trouble

hoppydc

I know this is an old thread but I thought I'd reply in case someone else reads this...

I have a stock 1995 Trek Multitrack 720, women's 20". It came with 35mm tires. I replaced the back tire with a 42mm cyclocross tire and it fits fine, but there's only around 5mm between the sides of the tire and the chainstays. I can't imagine you could have fenders with that width, and I don't think a typical 45mm tire would work even without fenders. With fenders, I doubt you could go wider than 38mm, maybe 40mm, and that would probably be a close fit.

Of course, every tire is a bit different.

rseeker

Excellent @hoppydc, thanks for adding to the thread. This is all great information.