700c's on my Kona Hahanna - what will the problems be?

[DMZ]

So my plan is to put 700c road/race style wheels on my 1993 Kona Hahanna (see my avatar). I tinker with bikes, have built a simple single speed before but I am easily tripped up...

Issues I am aware of:

-Brakes not reaching rims. I am aware of mavic adapters, and I have access to a workshop to make something similar (and suggestion of disc brakes but that complicates the hubs).

-Clearance for diameter with smallest tires - measured, should be fine.

Issue that I am not sure of:

-Cassette. Will there be any complication in taking the existing cassette off the 26" wheel already on it and putting it on a 700c rear? What do i need to consider when getting my 700c with regard to fitting the cassette? At present it is running its original 21 speed, 7 on rear. I will change these eventually but one thing at a time, unless I can find something cheaply and is easy to fit.

- Drop spacing 135mm with a 130mm hub. Steel frame. The more I read about this the more confused I get. Why can one not simply put equal spacers either side? Does it crew the chain line up that much? The chain runs at odd angles depending on the gear used anyway, I'm sure it gets displaced more than 2.5mm...

Or is it easy/cost effective to use a 5mm spacer the other side and ask a bike shop to redish the wheel? Or to have a wheel rebuilt with the correct size hub?

Rode 22 miles on it as it is the other day....with its current wheels...and really did think...now is the time.. Any wheels anyone would like to offer, go for it. Suggesting 'why are you doing this' 'buy a road bike' 'get a hybrid' 'put slicks on it' is not an answer.... :roll: The bike is my choice, I know people do all kinds of crazy builds, it's just my first time. It is identical to this, but seat height/bars the right way round in terms of height! http://www.retrobike.co.uk/forum/viewto ... ?p=1596776 (sadly I wasn't quick enough off the mark to get this beaut...I think someone bought it for their wife/child - as usual!) Identical gears etc.

So if anyone knows their stuff, it would be appreciated...

 

[dbmtb]

Seems like an awful lot of trouble to go to for a Hahanna ... but.

Wheel - best get it rebuilt on a new hub or change the axle and get it redished.
Cassette - won't be a problem as long as hub has same freehub width.
Question about cost effectiveness. - This project is never going to be cost effective.

 

[DM]

How will you get the brakes to work?
(OK, just read that bit. I also used the Mavic adapters. Worked OK).

FYI, I tried it on a 95 Kona & got nasty steering & toe overlap even with skinny tires and no mudguards (19-inch frame).

 

[DMZ]

Yes, it is an experiment so I am just going to get some cheaper second hand wheels to start with and see what happens. I know about the overlap; if I ride too much on my heels (like an idiot with the wrong shoes on) with my toes sticking way forward I am prone to clipping the front at low speed, but only if my feet have slipped - I am well clear usually with the right position when riding on the balls of my feet. But am I wrong in thinking the 700c's aren't going to be a vast amount bigger? I recall once getting my head around all this, doing all the measurements and finding that they were slightly bigger but there was clearance.

DM, how did you cope with the back wheel? Did you do as dbmtb suggested?

 

[DM]

DM, how did you cope with the back wheel? Did you do as dbmtb suggested?

I used a Mavic adapter for the rear.
Also, I tried it on a Humu with track ends, so just slid the wheel back until it cleared at the chainstays.

I didn't do any re-dishing or wheel building. I didn't get beyond riding down the street, because the larger wheels altered the BB height and (more importantly) the steering geometry.

I swap between lots of bikes, from small-wheel folders to 29ers.
It takes a little time to adapt to their different handling. But the 700Cs with a 26er fork sucked.

 

[Dead Rats]

if the OP has holes in the seatstay bridge and fork crown he could use road calipers to stop the 700c wheels? Seen it done, just leaves the canti bosses looking naked.

personally, I'd only do such a conversion on a disc frame with CX / hybrid 700c wheels as some use MTB width (135mm) rear hubs... so much easier on a disc frame to do this, you can swap back to 26" in a matter of minutes

However I don't know if a redish would be definitely necessary if you're considering fitting a longer axle to take a 130mm 700c rear wheel out to 135mm, just as you say 2.5mm more spacers per side to start with and see how it works out?

 

[oldave]

"However I don't know if a redish would be definitely necessary if you're considering fitting a longer axle to take a 130mm 700c rear wheel out to 135mm, just as you say 2.5mm more spacers per side to start with and see how it works out?"

+1. It should still sit centrally (I think!). But as others I can't really see any point - except as "let's see if...."

 

[Yetidh9]

Just to give you some idear about tyre clearence on 700cc wheels on a Kona frame... This is mine mid 90 Kona with 700cc wheels (and disc tabs welded on)... Please ask any questions if If you need info...

http://www.flickr.com/photos/42814613@N ... 3112/show/

 

[paininthe]

I didn't get beyond riding down the street, because the larger wheels altered the BB height and (more importantly) the steering geometry.

This - why I took mine to bits again.

 

[raidan73]

It is identical to this, but seat height/bars the right way round in terms of height! http://www.retrobike.co.uk/forum/viewto ... ?p=1596776 (sadly I wasn't quick enough off the mark to get this beaut...I think someone bought it for their wife/child - as usual!)

That would be me

You'll be the first person I contact if I ever decide to sell