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Conversion Questions... Long (xpost to 29er and SS boards)(4 posts)

Conversion Questions... Long (xpost to 29er and SS boards)lanpope
Feb 25, 2003 3:14 PM
Since I purchased my ss mtb (Bianchi SiSS) I have pretty much completely quite riding my geared bike. This is a real shame because it is a great bike and it is what really got me back into biking. So I have decided it is time for a conversion. I have been really itching for a cross/commuter, skinny tire, drop bar bike so here is what I thought...

What if I swap in a Kona P2 cross fork in place of the current squisher, put 700c wheels and 35c cross tires front and rear, Salsa Short and Shallow drop bars with a 90x115/125 stem, a single Dura Ace barend shifter for the rear (run the front with a single ring), Dia Compe 287v's so I can still use the front XT v-brake, and...

Here is where the problems come in...

After some research, I have only found two viable options for the rear brake issue(since the frame has no disc tabs, and I really do not want to add one):

1) Paul's MotoBMX ($$$$$)
2) and the option I prefer - Onza HOLA V's (if I can find a set on ebay)- which I understand have enough adjustment to compensate for the larger wheels (read about this here )
Of these options which is the best, or are there other options I am overlooking?

The next problem is rear wheel clearance. Since I only want to run the skinny (35-38c) cross tires, should this be a problem or will I be OK? Here is the clearance in the rear right now with 26" wheels and 2.1 IRC Mythos. The frame is a '98 Cannondale F400 large.

My final (I think), and most concerning problem is the geometry issue. The frame is suspension corrected so it seems like the angles should not be too messed up by taking off the squisher and going to the rigid 700c fork. Is this correct or will it feel crazy? And by putting the 700c wheels front and rear, that should cancel out any angle issues there...right? The other thing is that the frame has a 1.5" headtube w/ funky reducers. Will these reducers unacceptably exacerbate any issue with angles? Click here for pic of reducers.

This is all great, but half of me thinks I should just get some 26x1.25" WTB Allterainasaurus tires, some drop bars and just ride it like that. Here is a pretty good article that talks about that option!

Let me know what you all think...
Thanks
Depends on how much you plan to take it off-roadGlowBoy
Feb 25, 2003 9:48 PM
If you're mostly going to use it as a commuter, I'd say best bang for the buck is to stick with the 26" route and put on a big chainring up front. I think that on pavement, the performance improvement going from 26" and 700c (given the same width of tire) is pretty minimal. (And watch out for those WTB AT tires: they are downright dangerously slippery on wet pavement. Seriously consider slicks for commuting).

If you go off-road much ('cross racing, light trail riding) I think you'll see more benefit from the wheel upgrade, though whether it's worth all the money and hassle is a judgment call. I haven't added it all up, but you may come out ahead by selling your Cdale and buying an entry level 'crosser for $800.

If you do want to keep using the Cdale:

Dunno enough about the brake issue to comment, sorry.

Rear wheel clearance: I wouldn't want to guess, and tire clearance is hard to judge in pictures. Best to get hold of an actual 700c wheel (even a front one will do) and put it into the dropouts. Even if it has a road tire on it - just slip an MTB tire over the casing on one end to get an idea of how much taller a 'cross tire would be in there.

Geometry. First of all, I don't know that the reducers matter much because you'd have them with either the rigid or the pogo fork. Rigid 700c forks actually aren't that tall - usually in the 400-410cm range, which is shorter than most boinger forks and only as tall as the shortest "suspension corrected" 26" forks. So I don't think this will cancel out any geometry changes as you had hoped, but frankly I'm not sure you'd want to. Road and cross bikes have steeper head angles than MTBs for livelier handling, and if you drop the front down by, say 1.5", you'll be steepening the head angle by about 2 degrees, which may not be a bad thing since you won't need the off-road stability on technical terrain of a true mountain bike.

Also, a shorter fork will drop the BB slightly compared with a longer fork, which is a good thing. Because as an MTB it already had a higher BB than most 'cross bikes and the taller wheels are going to raise it even more. That's probably the biggest geometry issue you'll be encountering, and it could be a deal-killer. Your BB and your center of gravity are going to be pretty high compared to most 'cross bikes. Some people may like that, but many people would find that this makes the bike hard to turn and make it feel like you're hovering above the curves instead of carving into them. The steeper head angle may help this a bit, though. I'm a little out on a limb here so I can't say for sure.

Dunno if that was terribly helpful, but I hope you can find something useful in there. I guess if it was me I'd keep the 26" wheels on and not try to make the bike into something it's not. MTBs with slicks still make great commuters.

- Dan
I Think You Are Right...lanpope
Feb 26, 2003 3:56 PM
Looks like the best thing to do is turn this bike into a slick (26") tire commuter (much cheaper and less hassle).

Plus AEBike has the BLACK CrossCheck frame for $285, I do not think I pass this up.

An extra bike (or two) is never a bad thing...RIGHT?

Thanks for the help from everyone!
One thought on the brakes...Steve_O
Feb 26, 2003 12:32 PM
I've been hitting eBay pretty hard on canti brakes over the past two month. I have seen a couple of Onza brakesets come up but they are usually the HO's. The HO's were Onza's standary cantilever brakes and you probably could not move the pads enough to match the larger rim diameter.

The HOLA with the LONG ARM option were not out on the market very long before Onza bit the dust. I think you are going to have a very long search for them...

Oh... As for rear wheel clearance you might see if you can borrow a 700c wheel at your local shop and see if it fits with a road tire on it. That might give you a little indication...