Technium92

First post! I have a 1992 Raleigh Technium with Mavic Open 4 CD hoops. I currently run 700x25 and want to try 28s. I know people have said you can run 28s on them, but I’m concerned about tire clearance in addition to being worried about rim/tire compatibility. I’d like to soften the ride slightly but don’t want to risk flats, rubs, etc. Can anyone offer any insight? It looks like it may be a close fit, and it’s tough to find specs on this bike anywhere.

shelbyfv

Use a set of hex wrenches to check clearance beyond your 25s. Check fork, bottom of brake caliper, chain and seat stays. Will be easy to judge, though actual mounted size of tires will vary. No problem with your rims.

Iride01 

28 - 25 = 3. Do you have that amount of distance plus whatever excess you want for clearance everywhere on your bike? Don't just look at sidewall clearance, look at tread clearance too. Tires grow in diameter about the same as in width.

Actually you'll probably find that you only fill up 1.5 more mm on any side of the existing tire. Though tire brands and models aren't uniform in advertised sizing, so that leaves you a safety fudge factor.

If you are changing to something with a real odd ball or aggressive tread, then cross your fingers.

Technium92

Thanks for that info. The 1.5mm addition all around estimate is something I hope holds true. If I end up with a true +3 difference all around I might be pushing it. Not much clearance on these older road bikes. I’m sticking with the same tire make/model in Conti Gatorskins.

Axeman88

Stop by your local bike shop, and inquire about the price of a set of new tires. When you hear the price, nod and agree that it's quite reasonable. Then, ask if you can have a used, tired 700x28 and also a 700x32 out of their trash bin so you can verify fit before purchasing. Try mounting these on your bike and then you will know what is what.

I'm of the opinion that different makes and tread patterns have different dimensions.

Moisture

It should work fine.. but you want to figure out how wide your rim is and what an ideal tire width would be in terms of optimal fit.

Iride01 

Just realize you need some clearance for things your tires might bring up with then. Sometimes the road here after a rain will have a really sticky gumbo mud washed out over them in patches. That stuff clings to your tires and you will be brought to a halt from it being jammed between tire and frame. If you have enough clearance, you can just let it sling itself off. Without, you'll have to get more dirty as you carry your bike to wherever you can find a hose to spray it off.

veganbikes

What is your claim based on?

Sometimes a wider tire can fit but not always and not always comfortably. You want to have clearance around the tire for any incidentals. If the wheel goes out of true or moves in the dropouts or anything like that you could have issues if you don't have some clearance. If you are looking for a better ride, try using a softer more supple 25mm if the 28s don't work. Yeah more chance of flats but a better ride, Anything open tubular or cotton/poly sidewalls will do nicely but I happen to like the Vittoria Corsa G+s or Challenge Stradas are a good option but there are others. You can also add latex tubes for even more supple ride.

I can technically fit 28mm tires in my Phil Wood frame but there is barely any clearance and I easily got rubbing if I was pedaling with even just some slight vigor. I swapped to 25 Vittoria tires and am fine with it, it is steel on steel so a little extra comfort there.

biker128pedal

I tried 25mm GP5000s on my 2005 Madone 5.0. Front fit so close it would pick up pebbles and jam them under the fork crown. Wear a groove in the tire. This was tires bought well over a year ago. Bought 23mm tires too. They were also close. Bought 23mm GP5000s last fall and they were narrower. So there was a change. Also I have 19mm inside width rims. Not original so that spread and made the tires taller and wider. If all else fails I buy one tire to test.

shelbyfv

Only if you plan to buy your new tires from the shop. Otherwise you are wasting their time ($)

bikemig 

Lots of good advice on this thread. Fitting 28s on your rims is a non-issue.

A pic of the bike would help. As a rule of thumb, if your bike has standard reach brakes (47-57 mm), you should be fine but nothing beats actually trying out the tire you want to use on your bike. The brake is not the only limiting factor as the tire may rub against the frame but most bikes that I've seen with standard reach brakes can take a 28c tire.

https://www.bicycling.com/bikes-gear...-reach-brakes/

ddeand 

I have a 1974 Raleigh International that I’m running 28s on Open Pro rims. It’s a great ride!

mstateglfr 

Are you an expert on early-mid 90s Technium tire clearance?
A 28mm tire may fit, but it doesnt fit on a lot of road bikes from that era due to clearance issues at the chainstays, brake bridge, seat tube, and fork crown.

Technium92

Just swapped to 28mm from 25s. Left in the smaller tubes (18-23) so as to avoid opening a brand new four pack of tubes meant for 25-32 in case the tires didn’t fit. 5 mile test ride and so far, so good. My first tire change! Thank you all for the insight!

BikingViking793 

How much clearance do you have?

Technium92

About 2.5-3mm at chainstays with a little extra beyond that at the other key points. Noticeably smoother roll.