[ziggurat22]

Not exactly 29er, but here she goes:

A buddy of mine has a steel Mongoose Alta, circa 1993. He found that he can stick a pair of 700c rims on that frame (w/ the original fork) with decent width cross tires.

I think he told me he trouble lining up the brakes for the larger diameter wheel. I know for the front, he can nab a 700c cross fork w/ the canti mounts in the right place, however, the canti mounts for the rear brakes are probably causing a bit more of an issue.

Is there a fix for this? If there is, is it worth it, or should he just scrap the project altogether? He's not hell-bent on doing it, but it would be a neat project.

Thanks in advance.

 

[SpinWheelz]

It's a bit of a gamble so it might be worth it to break out the ruler or what not, but I did the same thing for a lugged steel Trek MTB frame. I found that I could use long-reach road brakes bolted onto the fender mounts on the frame and fork.

It might be worth measuring the distance to see if long-reach brakes can work (assuming there are fender mounts to bolt them to)

 

[ziggurat22]

That looks about right. I'll pass this on to him. Thanks for your help!

 

[el-cid]

Your friend's other option would be to run Paul's Motolite v-brakes; they have adjustable pad mounts on the brake arms so you can adjust them up to fit the 700c wheels. They're a bit expensive and he still won't have a 29er or a cyclocross bike; he'll still have a mountain bike with a high bottom bracket and skinny tires.

 

[messofzero]

christ, spinwheelz

how many times have you posted a picture of that bike now?

 

[cjsbike]

My conversion

Last year I converted a 1991 Trek 8700 to a cross bike. I used a Kona Project 2 fork up front and machined adapters for the rear brakes. It works very well. The only problem is the old school geometry with the fork. A little chopper style in the front.

------Chad

 

[CJLED]

Mavic post adapters

I seem to recall Mavic making post adapters for use with their Speedcity wheelset (700c intended for slicks on a 26" wheeled MTB...don't know if they are available separately

 

[SpinWheelz]

how many times have you posted a picture of that bike now?

As often as necessary to help illustrate my replies. Sorry, was I invading your personal space with those pictures?

 

[ziggurat22]

Good stuff. My buddy should be able to pull this off.

SpinWheelz: Thanks for the pix. Very helpful and I sent them along to my friend.

Those adapters seem pretty cool as well.

 

[tonyfromDC]

Last year I converted a 1991 Trek 8700 to a cross bike. I used a Kona Project 2 fork up front and machined adapters for the rear brakes. It works very well. The only problem is the old school geometry with the fork. A little chopper style in the front.

------Chad

Did you repaint it or is that original?

 

[cjsbike]

Repaint

Did you repaint it or is that original?

This is the 4th paint job on the bike.

1st-original neon orange from Trek 1991
2nd-red with smoke black lines by local painter 1993
3rd-metallic red from Trek for seat tube replacement 1997
4th-metallic red because Trek forgot to add the primer. 1997

After that, Trek did not want to see the bike ever again!

In its new life as a commuter, it has logged 3400 miles!

----Chad

 

[Lutarious]

Paul Brakes....

Your friend's other option would be to run Paul's Motolite v-brakes; they have adjustable pad mounts on the brake arms so you can adjust them up to fit the 700c wheels. They're a bit expensive and he still won't have a 29er or a cyclocross bike; he'll still have a mountain bike with a high bottom bracket and skinny tires.

They make a brake arm which does not have the recessed section at the top too. On the one pictured here, you can't slide the pads as high. On the other one, you can slide it up way further....

 

[Ptor]

...however, the canti mounts for the rear brakes are probably causing a bit more of an issue. Is there a fix for this?

The kooks at Dreambike have a conversion kit. Somehow, somewhere they've got their hands on brake mount adapters -- exactly what you're looking for. Maybe you can get them without the other stuff in their kit...

http://www.dreambike.com/69.htm

 

[SpinWheelz]

That heart of that Dreambike crackpot package looks like it's nothing more than a set of Mavic Caliper Adjusters, which one can order for $25 a pop from a your local bike shop. Tire size is limited, but cross tires should fit them OK (as long as they're not Panaracer Fire Cross 700x45c, that is!)