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blake711 03-15-07 09:25 AM

Tire and rim upgrade questions.
Ok so my trek 7.2 comes with Bontrager Invert Puncture Resistant, 700x35c tires. These things have a tread pattern and are pretty large. I have a few qustions about upgrading the tires or just getting new wheels with tires.

The wheels are Matrix 750 model 700c rims. First question are there diffrent widths of 700c rims or are they all the same? I ask that because I am not sure how narrow a tire I can mount on those rims. Now if they are all the same that means I should be able to install a 23c or 25c tire without issue correct?

I will have to upgrade my tubes also. Right now the rims have Schrader valve tubes. Second is the hole in the rim for the tube valve the same size for Schrader and presta?

Thrid any suggestions on an economical set of smooth tires and tubes?

Lastly I have been watching Ebay for a Set of Shimano R550 pull-offs from a new bike. Seems they show up form time to time and If I get lucky could get a new set with tires and tubes for around 150. Should I go that route and just wait till I can get a set of those and then keep these wheels and tires like they are? Or is it worth it to invest in new tubes and tires for the current rims.

As usual thanks for all your help,

slowandsteady 03-15-07 11:31 AM

Are you sure they are Schrader? If so, the rims are probably too wide for a 23c tire. And the hole is smaller for Presta valves than it is for schrader.

I love conti tires. They make Continental Ultra Sport tires that are very nice for $14. They come in 28c. I wouldn't bother upgrading the wheelset on a hybrid.

blake711 03-17-07 10:14 PM

Ok I Was in the LBS today and they said I can install 700x28 tires on my rims. The only ones they had were 30 bucks for some bontragers.. To much for a couple tires. I see some at Performance for 12 bucks I need to make an order there anyway. My question is will my current tubes work. Current tires get 60-80 psi with schrader valves. Will these tubes hold the 125 that the tires I am looking at call for?

Oh one other question. Some tires say wirebead.. What is the opposite of wire? What are pros and cons of wire and nonwire?


stapfam 03-18-07 03:16 AM

Wire bead is the ring that holds the tyre in a circular shape when off the wheel. It does not bend and adds weight to a tyre.
Kevlar bead is a flexible material and the tyre flops into whichever shape it wants to take--Off the wheel. However once mounted onto a wheel it takes the circular shape. Can be a bit awkward to mount on a wheel if you are not used to them but they are lighter and rotating weight does affect speed- or rather acceleration. The lighter Kevlar (Or folding) beads are better for acceleration. They are also more expensive.

Do not get confused with Kevlar tyres that have a strip of material under the tread area and are puncture resistant and are a lot heavier in general.

On the Tubes- Going down to a narrower tyre may require a new tube- but I would get the presta tubes in any case as they will take the higher pressures that a Schraeder valve may not. Schraeder is the Car Valve type. Another thing to think about is do you have a Pump that will take the Presta valve?

It may seem ridiculous but the lighter the tyre- the better performance you will get. Not just the tyre but the tube and the wheel. If you are looking for performance then go for the Kevlar or folding tyres and a lighter weight tube. If you are not that bothered- then go for economy and buy cheap.

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