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Conference noted::bicycle

Title: Bicycling
Notice:Bicycling for Fun
Moderator:JAMIN::WASSER
Created:Mon Apr 14 1986
Last Modified:Fri Jun 06 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:3214
Total number of notes:31946

1823.0. "Converting 27" wheel to 700C" by UKCSSE::ROBINSON (Old wheelmen never die....) Wed Jan 16 1991 07:57

T.RTitleUserPersonal
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1823.1Alas....IDEFIX::HEMMINGSLanterne RougeWed Jan 16 1991 09:2725
	I had similar problems, and reluctantly threw out a few perfectly
serviceable (but antiquated) frames.  In my case there was insufficient
adjustment in the brake stirrups and even with deeper reach brakes (if you can
find them), the look of the bike was completely wrecked.
	Indeed, sprints have always been "700", and if you could adjust before
between HP's and sprints, you will be OK with 700's.  The advantages of 700's
seem to be standardisation, availablity and choice - and this covers tyres, rims
brakes etc.
	
	Another annoying thing is the fashion for the Allen bolt fixing
which doesn't suit old frames and makes it difficult to fit mudguards (old-hat
I know but I prefer to look reasonably presentable when I go into say a
restaurant in winter, rather than a refugee from "The Boys from the Black
Stuff").  I had to search out some traditional bolts and convert my Campag
Chorus set.
	
	The final aggravation is the standardisation to 6/7 speed width hubs -
if the rear ends measure 125 mm or less, you are caught again!!
	
	All good for the industry and as usual pretty bad for the poor old
consumer.

End of "complaint-for-the-day" -- it's fine and sunny again, and we're due out
training Thursday and Friday.  I've done 271 k this year and Suddein-willing, it
should be a good year.........
1823.2tire sizeTALLIS::JBELLZeno was almost hereWed Jan 16 1991 13:5820
1823.3CHEFS::CLEMENTSDSo much to do...so little timeThu Jun 13 1991 06:432
    Chris, 700c's are the same dia (as near as dammit) to standards, they
    are just narrower. IMHO they give a better ride, very close to tubs.
1823.4the long and short of brake reach?CSCOA1::HOOD_RFri Sep 20 1991 12:2016
    
    I'm in a similar position... want to put 700 rims in place of 27" rims. 
    My question is in terms of brakes , though. I currently have some
    diacomps, and they appear to have the necessary reach for 700 rims. 
    But what about the future? If these brakes (for some reason) were to
    need replacement or if I should decide to get a better quality brake,
    what "reach" of brakes would I need? What exactly is "long reach" vs.
    "short reach"? Intuitively, it sounds like the distance from the 
    center bolt of the break to center of the the pad during braking... 
    or some such measurement. If so, I've noticed that all of the higher 
    quality brakes no longer come in long reach (50-59mm)
    anymore.... will long reach brakes be phased out as newer bikes all 
    come with 700 rims?
    
    doug
    
1823.5Long reach brake? Why not a new frame, Sir?UKCSSE::ROBINSONTwitching the night away...Mon Sep 23 1991 10:3917
    Doug,
    
    Since writing the original note I have mostly answered the question.
    Here are some of the things I have established:-
    (1) 700C wheels are only marginally smaller than 27". If it's just the
    wheels you change, the existing brakes would reach the new rims.
    (2) Long vs short reach brakes are needed to suit the frame. Modern
    frames are built to fit 700C wheels and have slightly less clearance,
    i.e shorter forks/stays. They can use a short reach brake. 
    If you have an old frame (built for 27" wheels) you would not be able
    to use the modern short reach brake but would need a long reach. As
    only old diehards like you and me stick with their old frames (so the
    manufacturers think), they don't make many long reach brakes now.
    
    This, of course, is called progress.
    
    Chris
1823.6Don't take no for an answer...IDEFIX::HEMMINGSLanterne RougeMon Sep 23 1991 14:3224
1823.7on TA vs. Campy...SHALOT::ELLISJohn Lee Ellis - assembly requiredMon Sep 23 1991 16:479
    
    BTW, the Campy chainring price that Robin quoted is about
    the same here (shops or mail order), and my local shop 
    suggested -- guess what -- a TA chainring instead.  This
    is a French product, fits fine, is a bit shinier than 
    Campagnolo, and for some reason, the tooth-count is stamped
    on the inside face, not the outside.  
    
    -john
1823.8TA vs Campag (contd)IDEFIX::HEMMINGSLanterne RougeTue Sep 24 1991 06:1813
Another that could run and run....

>>    BTW, the Campy chainring price that Robin quoted is about
    the same here (shops or mail order), and my local shop 
    suggested -- guess what -- a TA chainring instead.  This
    is a French product, fits fine, is a bit shinier than 
    Campagnolo, and for some reason, the tooth-count is stamped
    on the inside face, not the outside.  
    
As it happens, mine has no "tooth-count" stamped on it at all - I suspect this
is a special French poseur-ruse - I intend to stamp "56" on it so that they will
all think I am really macho, no-one will bother to dirty their designer track
mitts to count properly.......
1823.9NOVA::FISHERRdb/VMS DinosaurTue Sep 24 1991 10:296
    of course, real bikers could compare the curvature of the chain ring to
    that of the front derailleur and immediately discern the ruse.
    
    :-P
    
    ed
1823.10Foiled againIDEFIX::HEMMINGSLanterne RougeTue Sep 24 1991 14:031
I hate to admit it but I just went to Fusberti's and bought a 30 inner.....
1823.11ALLVAX::JROTHI know he moves along the piersTue Sep 24 1991 17:448
   I just thought I'd mention that I use 700C wheels on a Holdsworth which
   was origionally a 27 inch wheel bike.  I have long reach Campy brakes
   and the setup works - I like it since I also own a normal road bike
   and can interchange the wheels.

   So it can be done.

   - Jim
1823.12hex vs. standard/91 Sh vs 87 Diacompe?CSCOA1::HOOD_RWed Sep 25 1991 13:3513
    
    Okay.... I've checked out a few bikes and I can see that most 
    now use the short reach brakes (Hardly any clearance, but I suppose
    that it takes a lot of mush out of the feel of the brake?). Clearly,
    my Cannondale uses long reach brakes. My next question is : what's 
    the difference between hex bolt/standard bolt? Any idea how a 
    1991 Shimano 105 long reach brake would compare to the stock 
    1987 Diacomp brakes that came on the bike? The 105 is the 
    highest quality long reach I can find (really!). The aero levers look
    cool, too!
    
    doug
     
1823.13Do you mean AK?IDEFIX::HEMMINGSLanterne RougeThu Sep 26 1991 06:4613
I think you are asking the difference between std and AK fixing.

Std means a through bolt you can put a washer and nut on - also means you can
fit fenders to keep off motorists or mudguards to keep off mud.

AK means the bolt doesn't protrude beyond the fork or rear bridge and the AK nut
goes inside.  This means you really need a coutersunk hole on the back of the
fork crown or the front of the rear bridge and "old frames" are unlikely to
have this feature.  No problem with countersinking the forks, but it's more
difficult with the rear and fitting guards is less easy.

I believe you should be able to get "deep" 105's with a standard bolt but you
may need patience and persistance.
1823.14MOVIES::WIDDOWSONRod, VMSE-ED013. 824-3391Thu Sep 26 1991 07:568
>I believe you should be able to get "deep" 105's with a standard bolt but you
>may need patience and persistance.
    
    Yes you can, it's precisely what I put on the Kettlar this summer.  I
    was lucky my local bike shop had it in stock (although I got the last
    in the shop)
    
    rod
1823.15Another knife at Campag.KIRKTN::GGOODMANNumber 1 in a field of 1Thu Sep 26 1991 07:578
    
    Re.9
    
    	40 quid for a chainring! I got a 105 Chainset for only a tenner
    more.
    
    Graham.
    
1823.16enter the BB into the equationSHALOT::ELLISJohn Lee Ellis - assembly requiredThu Sep 26 1991 10:4017
    
    Yes, it's tempting to think of getting a whole new crankset.
    I thought of that.  If so, you need to start out with a BB
    that will take a low-enough-priced crankset to make that
    worth your while, while keeping the BB high enough quality.
    
    The 105's BB and crankset probably have the quality ... but
    when bearings and races are involved, I still give the nod
    to Campy.  So that implies a strategy of buying something
    like Chorus or Athena, I guess.
    
    BTW, even if 105's have the quality and styling to suit you,
    their Q-factor is different (from most road-bike cranksets').
    Some riders may like the crankarms being more spread out, 
    but those who don't should take heed.
    
    -john
1823.17Another brake/fork question..CSCOA1::HOOD_RWed Oct 02 1991 11:0817
    
    
    Now that I've got a fairly good idea about brake sizing/fitting, I have
    only a few more questions.....  Is the only difference between the 
    front and back brake in most brakesets the length of the mounting bolt?
    They appear to be identical except for that aspect. 
    Another question I have concerns the front fork. I suppose that if they
    are phasing (have phased) out long reach standard brakes, that front
    forks made for 27" wheels must be right behind them. How well do newer
    forks that are made for 700c wheels (short reach hex bolt brakes) work
    with older bikes? What affect does that 700c fork/wheel combo have on frame
    geometry? I would guesstimate that it would lower the front end by a 
    full 1/4" or more.... how would this affect bike handling?
    Your responses have been very helpful!
    
    doug
    
1823.18DANGER::JBELLZeno was almost hereWed Oct 02 1991 12:2214
> What affect does that 700c fork/wheel combo have on frame
>    geometry? I would guesstimate that it would lower the front end by a 
>    full 1/4" or more.... how would this affect bike handling?

If you drop the front and not the back, the effect will be
about the same as getting a bike with a head tube that is
0.358 degrees steeper.

Q: Will this effect the handling?

A: Let me show you this stack of matresses with a pea at the bottom.


-Jeff
1823.19did it...CSCOA1::HOOD_RMon Nov 04 1991 16:398
    
    Thanks, guys. I was persistent and I was able to locate a long(normal)
    reach brake and a bolt kit. The difference between the 105sc brake and
    the Diacompe is like day and night ( the Diacompe is VERY mushy in
    comparison).... the 105 is very nice!
    
    doug