Dropouts

For discussions about bikes and equipment.
fastpedaller
Posts: 2786
Joined: 10 Jul 2014, 1:12pm
Location: Norfolk

Dropouts

Postby fastpedaller » 5 Dec 2014, 9:48pm

I have often wondered why the 'horizontal' rear dropouts were so popular - If you look at what they achieve compared to others......
If you are riding fixed then track ends off the most adjustment. If riding freewheel, then you only need the wheel to be in one place, there is no NEED for adjustment and a vertical dropout gives a better clamping area for nuts or quick release. I suspect the horizontal dropout may have been favoured because of it's 'good for all situations' adjustability, but to my mind it's just a compromise. Certainly when dropout width for geared bikes changed from 120mm, their use could have been expected to plummet? But apparently not the case.
What do others think?

User avatar
531colin
Posts: 13417
Joined: 4 Dec 2009, 6:56pm
Location: North Yorkshire

Re: Dropouts

Postby 531colin » 5 Dec 2014, 9:57pm

I think the "difficulties" of horizontal dropouts are over-stated.
We all used to turn the wheel over and ride fixed in the winter....."chain tugs" were unheard-of, (except on roadsters with the open end of the dropout at the rear) and I never had a wheel pull over. Track ends and mudguards are an unhappy marriage, and even "short road ends" have enough adjustment, you really only need 1/2".

SilverBadge
Posts: 577
Joined: 12 May 2009, 11:28pm

Re: Dropouts

Postby SilverBadge » 5 Dec 2014, 10:16pm

Vertical dropouts demand a well aligned frame. If horizontal dropouts were going to be useful for clearance adjustment, they should be parallel to the brake blocks to minimise consequential adjustments.

User avatar
531colin
Posts: 13417
Joined: 4 Dec 2009, 6:56pm
Location: North Yorkshire

Re: Dropouts

Postby 531colin » 5 Dec 2014, 10:48pm

SilverBadge wrote:Vertical dropouts demand a well aligned frame. If horizontal dropouts were going to be useful for clearance adjustment, they should be parallel to the brake blocks to minimise consequential adjustments.


"parallel to the brake blocks" is a neat way of looking at it. :D
Also, to make the best use of the brake "drop", when the wheel is in the centre of its forward/back adjustment, the brake block slot needs to be on the line of a wheel radius....that will be the "high point" of the brake block adjustment, moving the wheel forward or back from this point means lowering the brake blocks.
(unless the brake has silly sloping slots, of course!)
This matters if you are trying to squeeze maximum clearance from a dual pivot brake.

fastpedaller
Posts: 2786
Joined: 10 Jul 2014, 1:12pm
Location: Norfolk

Re: Dropouts

Postby fastpedaller » 5 Dec 2014, 11:10pm

SilverBadge wrote:Vertical dropouts demand a well aligned frame.

My Spa Steel Tourer fits that criteria nicely :wink:

Brucey
Posts: 43043
Joined: 4 Jan 2012, 6:25pm

Re: Dropouts

Postby Brucey » 6 Dec 2014, 1:24am

cynically, I suspect that the manufacturers like VDOs because it means that they can spec a cheap and nasty QR and the wheel will still more or less stay put even if it isn't tightened properly.

That said I think that VDOs are more or less mandatory if you have an overhead disc brake caliper.

I've pulled a few wheels over in horizontal DOs, but mostly when the nuts were not tight... :roll: or the serrations in the locknuts were shot to bits and/or the ends were chromed. On all machines that don't have an overhead caliper or excessively low gearing, I will happily accept the slight possibility of slippage in return for the option to run an IGH, coaster brake, singlespeed, etc. as well as being able to offset a damaged wheel in an emergency, so that it still clears the chainstays.

To give easy mudguard fitment with HDOs and a neat installation, I think it isn't a bad idea if the stays are made adjustable at the hub end. GB mudguards are like this anyway, and when I can be bothered to make my own stays up, I do them in a similar kind of fashion.

cheers
-------------------------------------------------------------------------------
~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

User avatar
531colin
Posts: 13417
Joined: 4 Dec 2009, 6:56pm
Location: North Yorkshire

Re: Dropouts

Postby 531colin » 6 Dec 2014, 9:23am

Brucey wrote:cynically, I suspect that the manufacturers like VDOs because it means that they can spec a cheap and nasty QR and the wheel will still more or less stay put even if it isn't tightened properly.....................


In a culture where many peoples bike buying decisions favour fashion and form over comfort and practicality, I often see fat old men struggling along on overgeared race bikes where they can't reach the drop handlebars.
The bikes will always have fashionable fag-paper clearances, so you "have to have" dual pivot sidepulls worked by fashionable drop-bar STIs.
As has often been said on here, you have to work at it to get a 28mm tyre and a mudguard under a dual pivot sidepull, and even then the clearance isn't generous. If you use vertical dropouts, all the end user has to do is to put the wheel back where he found it. With even "short" road ends, you are immediately into compromises.....the chainstays have to be long enough to get the wheel out, so you have an un-fashionable "gap" between the seatpost and wheel. **
If you want to run singlespeed or fixed, then you need to actually use the horizontal slot to tension the chain.......accommodating the wheel in different positions immediately takes a slice off the already inadequate brake clearance.

All my bikes now have vertical dropouts.....I'm not going to be riding fixed in the Dales, and the wheel just drops in where I want it.

**Somebody actually produces "full-length" mudguards for their bikes which have cut-outs under the brakes....if I remember correctly the bikes in question have such short chainstays they have no chainstay bridge, and the mudguard terminates at the seat tube.....its amazing how fashion drives bike design to such things.

User avatar
cycleruk
Posts: 5568
Joined: 17 Jan 2009, 9:30pm
Location: Lancashire

Re: Dropouts

Postby cycleruk » 6 Dec 2014, 10:11am

The only time I can see horizontal dropouts being helpfull is if the wheel gets slightly buckled.
This would possibly allow the wheel to be canted over so it wouldn't catch the chainstay.
(the brake caliper would probably have to be adjusted wider as well.)
I have had a few wheels pullover, usually under circumstances either climbing a steep hill or setting off at a road junction. :x

When I ordered my steel bike I asked for the dropouts to be changed to vertical.
The shop queried this mentioning the buckled wheel scenario to which my reply was I carried a spoke key. :)

Obviously horizontal dropouts are an easy way of chain adjustment with a single speed or a hub gear wheel.
You'll never know if you don't try it.

reohn2
Posts: 40711
Joined: 26 Jun 2009, 8:21pm

Re: Dropouts

Postby reohn2 » 6 Dec 2014, 10:26am

531colin wrote:

**Somebody actually produces "full-length" mudguards for their bikes which have cut-outs under the brakes....if I remember correctly the bikes in question have such short chainstays they have no chainstay bridge, and the mudguard terminates at the seat tube.....its amazing how fashion drives bike design to such things.


Which is a sad sate of affairs IMHO,they want a close clearance race bike and for it to take m/g's too which is only possible with such concoctions.
Fashion,a master that can never be satisfied

All my bikes now have vertical dropouts.....I'm not going to be riding fixed in the Dales, and the wheel just drops in where I want it.

Same here,VDO's work very well with dérailleurs and TBH I can't see any reason why I'd ever want a bike with HDO's unless it was running an IGH.
Someone mentioned frames with VDO's needing to be made with perfect alignment.Is that such a hard thing to achieve by any framemaker,one off craftsman,small batch or high volume production?
-----------------------------------------------------------

mrjemm
Posts: 2933
Joined: 20 Nov 2011, 4:33pm

Re: Dropouts

Postby mrjemm » 6 Dec 2014, 10:45am

Just posting on my phone, so can't add a pic right now, but tinkering with Mme's Surly Straggler yesterday, trying to get the mudguard on properly. Problem was that having fitted fatter tyres, they were rubbing against the FD mech (short guards ending above). Answer... Slide the wheel back in the dropout. And the overhead disc caliper? Fine, as yet, but when I eventually need to get the full length guards (planned) in, those slide also. Was quite pleased how easy it is to align everything too (so disc doesn't rub), and then fix position for next time with the 'screws'. Trolls and Ogres have something similar, but more conventional looking.

Have put all this on hold at mo though, as may be making some bigger changes to set up soon...

Brake clearance for mudguards is an issue on another bike of Mme's though, and currently tis 'bodged' with some terrible pliers bending inwards creativity. :oops:

SilverBadge
Posts: 577
Joined: 12 May 2009, 11:28pm

Re: Dropouts

Postby SilverBadge » 6 Dec 2014, 10:52am

fastpedaller wrote:
SilverBadge wrote:Vertical dropouts demand a well aligned frame.

My Spa Steel Tourer fits that criteria nicely :wink:
All but one of my handbuilt frames have too - the exception being a tiny TT frame with 24" front wheel and 17" curved seat tube. It was adequate when I received it but a later spread of the rear end to 130mm made it worse, the error was vertical not longitudinal and I cured it by filing one dropout a fraction taller.

User avatar
531colin
Posts: 13417
Joined: 4 Dec 2009, 6:56pm
Location: North Yorkshire

Re: Dropouts

Postby 531colin » 6 Dec 2014, 2:02pm

cycleruk wrote:The only time I can see horizontal dropouts being helpfull is if the wheel gets slightly buckled.
This would possibly allow the wheel to be canted over so it wouldn't catch the chainstay.
(the brake caliper would probably have to be adjusted wider as well.)
I have had a few wheels pullover, usually under circumstances either climbing a steep hill or setting off at a road junction. :x

When I ordered my steel bike I asked for the dropouts to be changed to vertical.
The shop queried this mentioning the buckled wheel scenario to which my reply was I carried a spoke key. :)

Obviously horizontal dropouts are an easy way of chain adjustment with a single speed or a hub gear wheel.


I'm still running one lugged and brazed 531 frame with short-ish chainstays which are fairly round where they enter the Bottom Bracket shell, and not flattened further along next to the tyre, so the tyre/chainstay clearance is limited.

However, my light tourer with a welded Ti frame has chainstays which are oval at the Bottom Bracket end, and further flattened to clear the tyre....

Image

The chainstays aren't short at 455mm, but there is 60mm of daylight between them at a point which I hope corresponds to the maximum mud buildup on a big tyre.
That is a 28mm tyre on at present, but I wanted the flexibility to be able to go much bigger. I'm running full-size Vee brakes, so for me there is no downside to having big clearances.

mattsccm
Posts: 3678
Joined: 28 Nov 2009, 9:44pm

Re: Dropouts

Postby mattsccm » 6 Dec 2014, 6:11pm

Can't say that I have never noticed any issue with horizontals. I agree that its a touch fiddly with very short chainstays but other than that I actually think they are easier to use. When you have the back of the bike in the air all you have to do is get the axle into the dropout then tighten the QR , not do them both at the same time. Of course in days gone by the use of 1 bike was more common, indeed we used to swap from geared to SS often so horizontals were the best to use.

User avatar
willcee
Posts: 1207
Joined: 14 Aug 2008, 11:30pm
Location: castleroe,co.derryUlster

Re: Dropouts

Postby willcee » 8 Dec 2014, 12:26am

The maker of the Guards which Colin531 refers to are Giant, for their Defy range and they work well in that frame series..the brake bridge fitting is very low down on the radius of the guard because of the very sloping frame seatstays, and as he says.. they stop about 5 inches on a frame boss rear side on the seattube ..i had looked at using them on one of my own winter tight clearance machines but the low position of the brake bridge and the neat steel jointer which gives brake and tyre clearance under the dual pivot brake bridge would have meant a fettling which was not going to work well imo.. will

User avatar
531colin
Posts: 13417
Joined: 4 Dec 2009, 6:56pm
Location: North Yorkshire

Re: Dropouts

Postby 531colin » 8 Dec 2014, 2:34pm

I'm not keen on them, to be honest, Will. I ride fairly regularly with a couple of "new cyclists" who have them. With narrow, flexible single stay front mudguards, neither bike is fitted with stay releases.....is that how the guards come? The bikes have fag-paper clearances, if the roads are mucky, you can hear them "chuffing" along as soon as a bit of mud builds up under the guard, and if the road is rough you can hear the guards rattling. If an experienced cyclist chooses to ride a close-clearance bike with no mudguard release that's up to them, but I have a problem with these bikes being sold to new cyclists as suitable for riding through a UK winter fitted with these guards. Am I missing something? Maybe if you get a mudguard jam the hardware is supposed to break before the wheel locks and throws you off?
This year we have already had one pile-up caused by somebody riding an old bike with no mudguard release, front wheel locked, he went over the top, somebody else ploughed into him and came off......resulting in a couple of sore bodies and sundry other minor damage.