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Re: Audax/light touring groupset

Posted: 24 Nov 2012, 10:37pm
by 531colin
Its a funny old world, and I guess its a good thing we are all different.
I was complaining earlier about one manufacturer who doesn't publish their numbers....Stewart has bought two frames I don't fancy at all.....73.5 or 74deg head with 45mm offset .....I'd be looking for a long fork, not a stiff one!
Stewart, I'm too short and too light to get a shimmy out of my (overbuilt) bikes, but they say its worth trying a roller bearing headset.

Re: Audax/light touring groupset

Posted: 25 Nov 2012, 11:33am
by BigG
SUrely the whole point of seat tube angle is that the saddle moves back as it moves up to accomodate longer legs with the seat pin extension being governed by the whole leg length and the set back by the seat tube angle and the thigh length. I am 6'1" and get to ride frames from 23" to 24.5". All seem to require the same saddle set-back. The only seat pin that gave problems was a USE suspension one on which the clamp was on the pin centre line, not set back as on my Campag and SR Laprade models.

Re: Audax/light touring groupset

Posted: 25 Nov 2012, 12:46pm
by Brucey
yes but
a) people vary in build; long thighs (say) mean more setback even for people of average height so they may need different frame angles to accomodate them (which is OK I think, there is more choice in average sizes), and
b) a typical seatpost on a 21" frame might give 73degrees +/-1 degree adjustment, but the same seatpost on a 26" frame might give 73 degrees +/- 0.75 degree adjustment, i.e. the fixed saddle adjustment doesn't scale in proportion.

cheers

Re: Audax/light touring groupset

Posted: 25 Nov 2012, 1:12pm
by reohn2
Brucey wrote:yes but
a) people vary in build; long thighs (say) mean more setback even for people of average height so they may need different frame angles to accomodate them (which is OK I think, there is more choice in average sizes), and
b) a typical seatpost on a 21" frame might give 73degrees +/-1 degree adjustment, but the same seatpost on a 26" frame might give 73 degrees +/- 0.75 degree adjustment, i.e. the fixed saddle adjustment doesn't scale in proportion.

cheers

You'll have to explain why that is,I don't get it.Am I missing something :?
Providing the s/tube angle is the same on both bikes,and IMO that S/tube optimum angle could easily be 72deg in medium> frames,and 73deg in <medium,whatever the the wheel size.
It's the contact points ie;feet,sitbones and hands, that matter.
As has been established on here before some people have problem getting their saddle far enough back especially those with Brooks saddles,but so far no one has ever complained about not being able to get their saddle far enough forward,the problem is one of s/tube angles being too steep,never being too slack.
The optimum reach is established(once the optimum steering geometry is acheived)by t/tube length + or - 10mm where final adjustments can be made by stem length.

Re: Audax/light touring groupset

Posted: 25 Nov 2012, 1:42pm
by Brucey
reohn2 wrote: You'll have to explain why that is,I don't get it.Am I missing something :?


a) or b)?

BTW I agree that most people are looking for a slacker set angle not a steeper one, but this could be because moving the saddle forwards is relatively well catered for; as well as inline posts, there are some with layback that reverse, and yet others (for triathletes I think) where they allow the saddle well forwards by design.

cheers

Re: Audax/light touring groupset

Posted: 25 Nov 2012, 1:48pm
by BigFoz
At 114Kg, plus pannier etc I ride year round on 130OLN Campag wheels including on some of Scotland's "finest" roads into Glasgow through East Renfrewshire. My current set of Campag Ventos runs 24MM Vitoria Open Pave tyres, 24/27 spokes and has never even been trued in 3+ years. Me + luggage + laptop + bike has to be upwards of 130Kg (20+stone) load on my existing setup without issues over an extended period on foul road surfaces. I see no need for 135OLN hubs etc with huge spoke counts.

Re: Audax/light touring groupset

Posted: 25 Nov 2012, 2:29pm
by Brucey
Ventos have 'triplet' spoking on the rear wheel, i.e. there are two DS spokes for each NDS spoke, which makes the tension more uniform. The rims are fairly deep and stiff, too. For a lightweight wheel they are quite strong.

Some people will find that wheels of this type do not immediately fail when subjected to loading that is higher than that recommended. With some products Campagnolo recommend that if you are over 82kg, you consult your dealer as to the suitability of the product for your use, and also that you take special precautions to inspect the parts for wear, cracks etc. e.g. here;

http://www.campagnolo.com/repository/documenti/en/BORA_ULTRA_TWO_UK-08-09.pdf

This is their way of gently saying that if you are heavy, the product is quite likely to break.

In other cases they are more direct; e.g. here

http://www.campagnolo.com/jsp/en/downloader/docid_29.jsp

as well as more frequent inspections if you weight over 82kg etc, it advises that if you weigh more than 109kg you should not use the product because it can be 'irreversibly damaged'.

It says the same thing here

http://www.campagnolo.com/jsp/en/downloader/docid_155.jsp

in relation to Vento wheels, it says exactly the same thing regarding the current model Vento wheels, too. i.e. you could ride out of the shop at 110kg on a brand new set of wheels, and if they break, you are on your own. Plenty of people have broken these wheels even though they weigh a lot less.

Obviously not all wheels are made the same, but the simple fact remains that, all else being equal 135mm OLN wheels are stronger than 130mm OLN wheels.

cheers

Re: Audax/light touring groupset

Posted: 25 Nov 2012, 3:04pm
by foxyrider
531colin wrote:After I showed that bike to Simon Gershon, Orbit started doing bikes with an offset back end...Simon (or somebody at Orbit) realised that if you offset the dropouts just 4mm to the right, both spoke flanges move 4mm to the right, and you lop 8mm off the left/right difference. You get a really durable wheel, and the frame looks "normal".

I would just like to point out that i was their sales manager at the time, we built several models with offset frames, the biggest problem was that nearly every time a shop had to work on a rear wheel they tried to correct the 'incorrectly built' rear wheel which caused no end of problems. It seems most people can't get the concept of frame dishing as opposed to wheel dishing clear in their heads. Having been on the inside of the industry the over riding reason given by the big boys for this concept not making it into mass produced bikes is that for 99.9% of riders it isn't a problem. So shoot me, its true.

Bearing in mind we specialised in touring/audax machines, we succesfully used Campagnolo, Sachs (as Sram was then), Shimano and Hope hubs (we had more issues with Hope than any of the other brands.) in the same framesets. One thing that we found did make a difference was thorough destressing of the wheels during building, our 16 stone plus wheelbuilder used to literally jump on the wheels and spoke tension was checked mechanically on every wheel. As a result spoke breakages on std or undished wheels was almost nil, hub flanges gave us more trouble, almost always on the drive side.

Campagnolo was our drivetrain of choice (ease of use, undertape cables, robustness) generally teamed with Sugino chainsets which we custom built to get the best ratio set up. (9sp Campy ergo with 8 speed Sachs cassettes was a popular choice, Shimano cassettes needed re-spacing to work. Mix and match was almost the company motto!

Re: Audax/light touring groupset

Posted: 25 Nov 2012, 4:06pm
by Bogawski
Interesting thread,
Cycleruk said on page 2 Friday that in order to get lower gears, 23"-103", he used a Shimano 8sp set up.
I have Campag Centaur 10sp 30 40 50 and 13-29 cassette, Veloce derailleur which gives me about 30". I do need a gear like 23" as I am now finding it a bit of a struggle on long climbs.
Two years ago I went into the Campag shop on Boxhill and they said there was nothing they could do, "Campag don't go any lower", I tried a couple of other shops as well and short of changing the whole setup £400!! they said the same.
I am no mechanic and all I want to do is take the bike to an independent shop and be able to tell them what to do and know it is going to work. Shall I just go in with a printout of Cycleruk's post and see what they say?
The bike is an Audax/ light tourer and a nice ride and I have had it for 7 years, however I do need lower gears especially when loaded.
Thanks.

Re: Audax/light touring groupset

Posted: 25 Nov 2012, 4:33pm
by 531colin
I've corrected more than one wheelset for offset-frame Orbits. Its a shame that people don't understand the concept, I don't think its that complicated really.
Simple enough to build, you just need an 8mm spacer and a dishing stick.
Anybody who handbuilds wheels without stress-relieving them is missing the point....stress-relieving is the main reason why handbuilds are more durable than machine builds.
To me, thats the attraction of the offset frame or the 2:1 spoking....both offer the possibility that cheap machine wheels could one day be as durable as handbuilds, without the cost......proper durable wheels on £600 bikes sounds attractive to me.
EDIT....Its difficult not to notice its always the rear wheel that fails...........when I see equal numbers of trashed front wheels as rear, I will believe rear wheel strength is not an issue.
I have 2 Orbits in my shed, both with offset frames, one is the 853 Romany that was reviewed by the magazine(s?), Simon sold me that at a good price, as it was a bit secondhand, the other is a Gold Medal ....both are still running the original Sachs (Neos?) hubs, I hope they never need a new freewheel! They are 135mm dropouts, so no Campag. The rest of the transmissions were all Shimano, with the exception of a Sachs chainset and front mech. on the GM......also both had downtube shifters, long before the days of STI and Ergo/whatever.
I think the bikes were OK, its a shame they're gone...both the Romany and the tiny 26" wheel (Mercury?) were genuine trailblazers.

Re: Audax/light touring groupset

Posted: 25 Nov 2012, 4:40pm
by RickH
Bogawski wrote:Interesting thread,
Cycleruk said on page 2 Friday that in order to get lower gears, 23"-103", he used a Shimano 8sp set up.
I have Campag Centaur 10sp 30 40 50 and 13-29 cassette, Veloce derailleur which gives me about 30". I do need a gear like 23" as I am now finding it a bit of a struggle on long climbs.
Two years ago I went into the Campag shop on Boxhill and they said there was nothing they could do, "Campag don't go any lower", I tried a couple of other shops as well and short of changing the whole setup £400!! they said the same.
I am no mechanic and all I want to do is take the bike to an independent shop and be able to tell them what to do and know it is going to work. Shall I just go in with a printout of Cycleruk's post and see what they say?
The bike is an Audax/ light tourer and a nice ride and I have had it for 7 years, however I do need lower gears especially when loaded.
Thanks.

As long as the rear will take the capacity (I have the comp triple front & rear) you can quite happily run a 26t inner chainring (the triple front mech would probably cope with a 24 but I haven't tried it) - I have been running 50/39/26 & a 13-29 10s for several years with no problems (apart from slight chain clatter on the bottom of the front changer if I accidentally use the 13-15 end with the 26.

Rick.

Re: Audax/light touring groupset

Posted: 25 Nov 2012, 4:42pm
by reohn2
Brucey wrote:b) a typical seatpost on a 21" frame might give 73degrees +/-1 degree adjustment, but the same seatpost on a 26" frame might give 73 degrees +/- 0.75 degree adjustment, i.e. the fixed saddle adjustment doesn't scale in proportion.

cheers

Brucey
This bit,though having read it again I now know what you mean :oops: .
73 deg on 21in frame would be tolerable as more than likely the rider would have much shorter thighs than a rider who needs a 26in frame,who would benefit more from a 71deg s/tube.
That said the 21in frame wouldn't suffer from the 71deg s/tube,just needing an inline seatpost,and having looked at more touring frames than I care to,there is always enough clearance between the seatube and rear mudguard,even with big tyres,so I conclude as does CJ that the problem is that frames are made to conform to racing geometry wherever the industry generally sees fit.
That's not the case with all frame makers but the big boys tend to play it stupidly and consistently steep!
The stupidest of which was mentioned by Stewartpratt upthread
........For example the Genesis Day One - which would in many respects be an ideal bike for me - has a 74deg seat angle........

having looked at the genesis site I can't see a road/touring frame with anything slacker than 73deg :? .

Re: Audax/light touring groupset

Posted: 25 Nov 2012, 5:31pm
by cycleruk
Bogawski wrote:Interesting thread,
Cycleruk said on page 2 Friday that in order to get lower gears, 23"-103", he used a Shimano 8sp set up.
I have Campag Centaur 10sp 30 40 50 and 13-29 cassette, Veloce derailleur which gives me about 30". I do need a gear like 23" as I am now finding it a bit of a struggle on long climbs.
Shall I just go in with a printout of Cycleruk's post and see what they say?
The bike is an Audax/ light tourer and a nice ride and I have had it for 7 years, however I do need lower gears especially when loaded.
Thanks.


My Donohue:-
Donahue2.JPG

Chainset 110/74 BCD with 46/36/24 rings. Cassette - 8 speed, 12/28.
10 speed Veloce ergos - 105 triple Front derailleur
STX Rear Derailleur. (this will allow an even bigger cassette. 32 or 34 but the jumps between cogs will be quite high)
Tyres 700x25. 531M frame.
Weight a bit heavier than the Bob Jackson but due to stronger wheels and saddle bag.
I have used this for some very hilly 100k Audaxes.

My Bob Jackson "Audax":-
BJ1.jpg

Chainset 110/74 BCD with 50/40/30. Cassette - 8 speed, 12/28.
10 speed Veloce ergos - 105 triple Front derailleur
Sora Rear Derailleur. Tyres 700x23. 631 frame.
Weight about 24lbs.
This is my most used bike for day rides but have never used it for an Audax :oops:

I have now changed the Jackson to 10 speed 105 groupset. 50/39/30 with 12/27 cassette. So higher gearing than before.

Re: Audax/light touring groupset

Posted: 25 Nov 2012, 8:24pm
by Brucey
Bogawski wrote:Interesting thread,
Cycleruk said on page 2 Friday that in order to get lower gears, 23"-103", he used a Shimano 8sp set up.
I have Campag Centaur 10sp 30 40 50 and 13-29 cassette, Veloce derailleur which gives me about 30". I do need a gear like 23" as I am now finding it a bit of a struggle on long climbs.
Two years ago I went into the Campag shop on Boxhill and they said there was nothing they could do, "Campag don't go any lower", I tried a couple of other shops as well and short of changing the whole setup £400!! they said the same.
I am no mechanic and all I want to do is take the bike to an independent shop and be able to tell them what to do and know it is going to work. Shall I just go in with a printout of Cycleruk's post and see what they say?
The bike is an Audax/ light tourer and a nice ride and I have had it for 7 years, however I do need lower gears especially when loaded.
Thanks.


your campag triple should have a 74mm BCD for the inner chainring. If so this should alllow you to fit a smaller one, down to 24T. Problem solved, all for ten quid.

cheers

Re: Audax/light touring groupset

Posted: 25 Nov 2012, 8:42pm
by Bogawski
Thanks All,
I am pretty much convinced now and will go for the 24t, nice looking bikes Cycleruk!