replace 26in wheels with 700

bigkev said:

does any one know if it is posible to replace my 26in wheels on my giant boulder with 700 wheels as i like the stronger frames and i need new rims and trying to put bigger wheels on my bike for speed and what would i have to change to .thanks for any help

They won't fit due to the larger diameter.
Even if you could make them fit the brakes wouldn't work due to the difference in rim diameter.
There isn't that much difference in rolling resistance between the same type tires on 700C Vs 26" MTB. We ride both here.... including 700C and 26" MTB tandems. I have toured across the USA on 26" MTB and 700C touring bicycles.
Get well built wheels and use tires appropriate to the riding surface. If you are only riding on pavement use smooth .... bald tires.

Kev,

If you Boulder is a disc brake model, yes, http://www.velo.net.au/ had some Mavic Speed City 700c MTB wheels on special recently. http://www.mavic.com/ewb_pages/p/produit_roue_speedcity.php?onglet=2&gamme=asphalte

bigkev said:

does any one know if it is posible to replace my 26in wheels on my giant boulder with 700 wheels as i like the stronger frames and i need new rims and trying to put bigger wheels on my bike for speed and what would i have to change to .thanks for any help

I also beg to differ with the comment that 700c wheels won't fit in your MTB frame ...

One of my project bikes (I just need the bars wrapped, at this point ... the attached pic is from several months ago when it was in an early phase of piecing it together) is an "old" hardtail frame which is shod with 700c wheels.

The first caveat ... I laced a 700c (622-13) rim onto a 135mm rear hub ... if you have a 700c SHIMANO road wheel, you can swap the axle & spacers from a Shimano MTB rear hub and simply redish the wheel. If you don't do your own wheel building, then that is an added cost. The 700c wheels on some hybrids usually have 135mm rear spacing ... and, are often inexpensive ... but, the rims are 622-17 or wider.

The MTB frame that I used does not have disc brake mounts. I stared at the frame for a while before deciding to verify that a long reach (the former "standard" reach) brake would work. I did need to enlarge the back-side of the "fender" mounting hole in the seat stay's bridge to allow the recessed nut of a Tektro "long" reach brake to nest ...

Your frame's brake bridge may be too far away from the rim, but probably not.

The current crankset (subject to change!) is an FSA 130BCD 172.5 crank on a 118mm ISIS spindle (to ensure that the large rings clear the stays) ... basically, the BB you have should work if you opt to also install a road crank.

I briefly had some 105 9-speed shifters & rear derailleur on it ... the front derailleur is an 8-speed XT because that is what I had ... the chain is a 9-speed ... when I had the 105 shifters, I needed THREE clicks to move the chain (so, having a triple front shifter was definitely a plus) ... a double shifter would have required a 9-speed front derailleur. Of course, with the Campagnolo shifters back on the bike, the shift is what it is ...

Currently, an Alpha Q ROAD fork is on the front of the bike ... the "same" reach Tektro brake caliper works for the front (not seen/mounted in the picture).

THE second & MAIN CAVEAT is to note that the bottom bracket is higher (as you would expect) with 700c wheels instead of 26" MTB wheels (note the closer-to-horizontal chainstays than on a regular road bike ... and, that is with the lower front end of the road fork).

If I used a CX fork, 29er tires (700x58) might fit ... or, might not. Definitely, "hybrid" 700x38 tires will fit the frame AND a CX fork.

What it comes down to is that you can't just slap a pair of 700c wheels in your frame (unless, as noted, you are using disc brakes) ... but, 700c wheels & tires should actually fit with only some limitations.

My brother put together a Trek mtn. frame with 700c wheels. He just needed V-brake adapters that move the mounting point. He's quite happy with it.

lumpy said:

My brother put together a Trek mtn. frame with 700c wheels. He just needed V-brake adapters that move the mounting point. He's quite happy with it.

Did your brother FABRICATE the "V-brake adapters" or were/are they available commercially?

alfeng said:

Did your brother FABRICATE the "V-brake adapters" or were/are they available commercially?

No, he just bought them from a web site.

My brother has this
http://www.speedgoat.com/product.asp?part=108671&cat=30&brand=155

http://www.paulcomp.com/ has a brake set up that would work but it's expensive. Big Cheese also has an adapter for existing v-brakes I think.

lumpy said:

No, he just bought them from a web site.

My brother has this
speedgoat.comproduct.aspOpen ↗

paulcomp.compaulcomp.comOpen ↗ has a brake set up that would work but it's expensive. Big Cheese also has an adapter for existing v-brakes I think.

THANKS for the link ...

I'd seen the PAUL V-brake, before, and figured it had the vertical adjustment to allow 700c wheels in a MTB frame, but the pull rate would be affected AND the cost is high (as you noted).

Now, I want to go and measure my OTHER hardtail frame [obviously, I've never been motivated to check, before!] to see where its fender-mount/(brake) bridge is relative to the rear dropouts to see if a 700c would work in it with the "standard" Tektro ROAD caliper OR if one of the alternates would be required.