700c fork suggestions wanted

[cristin]

Hi, I just ordered my conversion kit and have been searching craigslist for suitable donor frames. Fortunately, I have a very long inseam (33+ inches, I normally ride a 65cm road frame) so finding one with a low enough top tube shouldn't be too hard.

I'm a long-time road cyclist, which is why I want to keep my 700c wheels. I also do a lot of wrenching, and built my last road frame from the ground up, so assembly of a kit won't be a problem.

My first question is forks: I've never used a bike with suspension, have no idea what to look for in a suspended front fork, and was wondering if you folks had any suggestions as to which model/brand fork I should choose. A quick search of the forums hasn't turned up much info.

Should I make sure to have a frame first before considering a fork?

 

[John Zabriskie]

My conversion experience was with a Trek carbon fiber Y-11, with an air adjustable Marzocchi bomber fork. This was lovely over RR Xings & potholed roads; however, it was a converted mountain bike. Note that the kit ads 10# to the bike. Also, unless you have a small frame or one with a low seat mounting tube, the center of gravity of the bike will be rather high. This is not a problem for normal riding; nose wheelies would only be a concern under really hard braking.

Perhaps you can find an older, lightweight fork in a 29er size with not a lot of travel. The light weight will be important. Since you come from the roadie side of things, you are probably not looking for long-travel suspension -- 30mm or so will take the edge off. Unless your roads are terrible, any travel over 50mm won't be used much. Make sure the fork has V-brake mounts. If it has disk mounts, you may have to grind these off to get the right clearances & fit.

You might consider getting the V2K frame. It keeps the center of gravity of the bike much lower than normal donor frames. It will also take 700c rims & 28mm tires, but not 37mm. I haven't checked any other sizes. Doug Burton has built a 29er & may have other recommendations. I can't remember if his was on a V2K or an older V1 Sofrider frame.

If you want more details, have other questions or want to talk about other options, please contact me.

 

[defjack]

Your best bet would be the Softrider frame and clyclocross forks. Jack

 

[Mark B]

I agree with Jack on the Sofrider frame.

For the front fork, I may be wrong, but I'm pretty sure you can run 700c wheels on a mtb fork, though you might have to do some adapting for brakes.

Your other option is to find one of the old Rockshock 700c forks they made for a short while. I see one on flea-bay every now and again. A friend of mine has one and they are kind of a cool thing.

Mark

 

[cristin]

Hey there,

I'm not so worried about weight as I am about budget at the moment, thus I am looking for an inexpensive donor frame instead of the Sofrider frame. I admit that having the Sofrider frame would take out a lot of guesswork, though!

Fabricating brake extensions wouldn't be horribly difficult, so I will just try with the fork that comes from the frame at first, and if that doesn't work out, the 29er sounds like a good plan.

Thanks!

 

[Doug Burton]

Hi Cristin,

This is a touch pricey but could work for you:

http://www.speedgoat.com/Catalog.aspx/Browse?Item=108671

Paul's Components makes a long reach adjustable V-brake, but those are $120 per wheel.

One of our folks here built a V-brake reach extender by adding aluminum angle to the brake arm brake pad mounting surface and cable anchors on standard v-brakes and that seemed to work well (can't find the post), and I think rearengine (Bill) has done the same thing.

MarkB is correct; most 26" MTB forks have enough crown clearance to accept 700 x 28c tires because they are intended to accept really wide-section 26" tires.

Please post some photos when you get the build going!

Best,

Doug

 

[cristin]

Hi Doug, thanks for the link to those mavic brake extenders, I ordered a couple and they work wonderfully with the fork I picked up. My 700c wheel fits quite well with only a little bit of spacers between the forward brackets and the fork.

 

[Doug Burton]

John Zabriskie wrote:
You might consider getting the V2K frame. It keeps the center of gravity of the bike much lower than normal donor frames. It will also take 700c rims & 28mm tires, but not 37mm. I haven't checked any other sizes. Doug Burton has built a 29er & may have other recommendations. I can't remember if his was on a V2K or an older V1 Sofrider frame.

I took a chance and ordered a set of Continental Sport Contact tires in 700 x 37c for the 29'r.

They fit fine and work really well. The trick is, for installing the wheels, you have to deflate the tire to get it between the dropout and the "brake bridge" on the swing arm, and the chainstay assembly and the dropout on the front. Once installed, just pump 'er up and you're ready to go. There's even fender clearance if you want it.

With the big wheels and wider tires, seems like there's nowhere this bike won't go now. And the Conti's roll very well - no apparent increase in rolling resistance over the 700 x 28c Michelins.

The components for this bike (well, the fork, steering parts and seat, anyway) came from a very early Sofrider V1 (it was an Interbike show prototype from 2006).

Good job, Cristin, let us know how you go.

Best,

Doug