Sliding dropouts versatility « Singletrack Forum

Bike Forum

[closed]

Sliding dropouts versatility

30 posts & 14 voices | Started 2 years ago by Scienceofficer | Latest reply from oxym0r0n

Tags:

No tags yet.

Scienceofficer - Member

Hmmm.

Thinking out-loud here and I'd like some opinions please.

I have a frame on order with Paragon sliding drop-outs - This is intended for versatility. I'll be running SS most of the time, with the prospect of gearing it for events or fast and long summer work.

I've learned that the price for neatness is a whopping 220g or 0.5lb, pretty much the weight of the few extra links and and the rohlhoff tensioner I use on my current bike to make it single speed. All things being equal, logic would dictate that I would get an SS bike the same weight, with or without the paragon sliders and have a slightly lighter geary, as the chain tensioner weight would off-set some of the geared transmission parts.

ergo, a normal geared dropout frame would actually be lighter, if slightly less neat.

Am I on the right lines?

Posted 2 years ago #
cynic-al - Member

have a slightly lighter geary

You may be well be right, the hwole point of sliding dropouts is neatness & lack of stupid chain tensioner - I would never see a tensioner as better.

Posted 2 years ago #
Scienceofficer - Member

why? Its perfectly fine for a geared transmission. Is it an aesthetic thing?

Posted 2 years ago #
cynic-al - Member

No chain slap, no chain drop, looks prettier.

It's a personal choice though. I doubt I'd buy Paragon dropouts but I got some German ones for £35 (doubt they'd add 1lb too).

Posted 2 years ago #
Scienceofficer - Member

I not experienced any chain drop since shifting to the Rohloff tensioner and chainslap is so very occasional that its really not an issue.

What are the issues with Paragon sliders that mean you'd not bother?

A pound

Posted 2 years ago #
cynic-al - Member

Oops! 1/2lb sounds realistic.

Paragon are £££ are they not?

Posted 2 years ago #
Scienceofficer - Member

£25 extra for this particular build.

Posted 2 years ago #
funkynick - Member

Isn't 220g for the whole shebang, including the section that would be welded/brazed onto the chain/seat stays? In which case the only extra weight would be the difference between that and the weight of a standard set of dropouts... however much that is.

If you are interested, then I can try weighing the slidey parts when I get home to see how much they weigh as the bikes in bits anyway...

Posted 2 years ago #
Scienceofficer - Member

That would be both informative and useful Nick. Thanks.

Posted 2 years ago #
cookeaa - Member

My only experience of a sliding dropout was on a Kona Cowan Jump bike, quite similar to the paragon design I think.

A very clean solution to the whole issue of SS chain tensioning, and allowed the use of a QR hub, but I did find the brake side dropout (used with a 6” - Hayes HFX9) would on occasion move forwards; putting the back wheel on the piss, not ideal I’ve seen other designs with set screws, not sure if the paragons have this, it may help mitigate the problem, I’ve never heard of anyone else suffering the same problem so it may have been a one off…

Just about every proper SS solution involves some additional components/weight; ECC BB, Horizontal DO with a tugs, hanger mounted tensioner, BB or ISCG mounted tensioner, all have some added weight. The only zero weight solution is the mythical “Perfect Gear” if you can find it and live with it… realistically I reckon Sliding DOs come a close second to an Eccentric Bottom bracket in terms of neatness and function but it probably weighs a bit more, still weight saving isn’t the only consideration, mechanical robustness and simplicity is probably more useful that a ½ lb saving…

Posted 2 years ago #
Scienceofficer - Member

'still weight saving isn’t the only consideration, mechanical robustness and simplicity is probably more useful that a ½ lb saving…'

this is the bit I'm struggling with TBH. No-one has really given a satisfactory answer on what what these other considerations are, or suggested how compelling they are, even given my comments above. The most prominent reason so far appears to be 'because it looks nicer'.

Posted 2 years ago #
Clink - Member

If I could chose a method of chain tensioning for a ss it would be sliding dropouts (like Paragons); might not be the lightest but work well and can be used for gears or ss. Everyone will have a different viewpoint on this though.

PS Do they have an anti-sheep adaptor you could get?!

Posted 2 years ago #
Scienceofficer - Member

Enough of your cheek. Its was your fault anyway. It was so overwhelmed by your Gore catalogue look it didn't know whether it was coming or going!

Posted 2 years ago #
Clink - Member

It was so overwhelmed by your Gore catalogue look

How very dare you!

Posted 2 years ago #
Del - Member

+1 for Clink's comments ( wardrobe aside ), but also if you break your mech off, when sullying you bike with gears, it's easier to ss your broken ( fixed? ) bike with slidey's or an ebb.
have seen a mate struggle week after week to keep his ebb tight, which was eventually replaced, and slidey's are so simple there's elegance enough in that solution for me, despite what some say about them being ugly, IMO. YMMV.

Posted 2 years ago #
simon1975 - Member

You could always buying yourself an Inbred with track ends (they're calling them "slot-dropouts" now) and steal the dropouts from there... What do you think you would get in scrap value for the rest of the frame?!!!

I've got a Kona Unit (sliders with bodged chaintug) and a Pompino (track ends) and the track ends are so much better all round. Paragons would be prettier though

Posted 2 years ago #
Nicknoxx - Member

I prefer these:-

Posted 2 years ago #
funkynick - Member

Well, I've just weighed the slidey bits and including the bolts it all came to 120g, and breaks down as follows:-

Drive side slidey mount 30g
Non-drive side (with disc mount) 58
Bolts (x4) 8g each

I can't find the Rohloff mount, but at a guess it would be about 80g, or maybe a touch more.

And, if you got a drive side one with a mech hanger on it, I'd expect it to be about the same weight as the Non-drive side disc mount.

If you have a look at the Paragon machine works website, they do have some new more fancy slidey things on there now, but these are just the bog standard ones that they have made for years.

Hope that helps...

Posted 2 years ago #
inbred853 - Member

Nicknoxx - what bike are those dropouts on? Ive seen a very similar type made by a US custom builder, that has a bolt at the top of the dropout on the seat-stay, enabling frame splitting and possible belt drive.
Swing Dropout
Bolted Swing Dropout
The frame builder is Vulture Cycles somewhere in the US
Linky

Posted 2 years ago #
Nicknoxx - Member

http://www.blackcatbicycles.com/

Posted 2 years ago #
ir_bandito - Member

Liking the swinging dropout. Don't Nicolai do that too?
If you have a problem with slipping dropouts, try using Nordlock washers to lock them up.
Sliders have got to be the way forward. EBBs look best, but weigh a reasonable amount and are a faff to tighten trailside. That said, I've got an EBB on my Thorn and have just ordered a Singular which also has one...

Posted 2 years ago #
Dibbs - Member

I've been using this design since 2005.

Posted 2 years ago #
Scienceofficer - Member

Those swinging dropouts are a very elegant solution.

Nick, Thanks that helps alot - comparing your weights to those of the extra chain and rohloff tensioner weight I'm using at the moment, theres little in it.

The chain tensioner alone is 110g.

Posted 2 years ago #
Candodavid - Member

Colin, think of the weight you are losing in total.....

Posted 2 years ago #
cynic-al - Member

simon1975 - Member

the track ends are so much better all round.

Not in use with discs I take it? Entirely different.

Posted 2 years ago #
cookeaa - Member

No-one has really given a satisfactory answer on what what these other considerations are, or suggested how compelling they are

Like I said “mechanical robustness and simplicity” ignore aesthetics and what “looks best”.

If your having a frame built for SS use rather than making do with an off the peg solution specify the best method, having your rear wheel axle fixed (i.e. not in a sliding, pivoting or Horizontal DO) is preferable as the wheelbase stays fixed and a standard vertical DO is the best way (least prone to failure) of holding your wheel in…

A proper eccentric BB (oversized shell with an insert, either clamped or with an expanding wedge) is a great solution (forget those horrific gash eccentric cup efforts), it’s tucked away from the most of the shite, it’s easily adjustable with a hex key (although they all are I guess) and worst case failure means the BB moves a bit and you loose chain tension, worst case with the various DO solutions on offer can range from back wheel going on the piss and rubbing the inside of the stay to the back wheel coming out (very unlikely, but still possible)…

If I were speccing a custom frame then an Eccentric BB would be my choice, bollocks to the weight, it’s not like your lugging gears about anymore…

Posted 2 years ago #
simon1975 - Member

Not in use with discs I take it? Entirely different

Back brakes are for girls

Point taken, but a slotted disc mount seems pretty foolproof to me.

Posted 2 years ago #
cynic-al - Member

I've heard of too many problems with EBBs and have had none with my sliding dropouts - ergo my view opposes yours!

Posted 2 years ago #
messiah - Member

A tensioner will have drag and you can't carry out bizzare fixie experiments with them.

Go with adjustable dropouts.

Posted 2 years ago #
oxym0r0n - Member

Sliders on my Wanga have been pretty much foolproof for the last 2 years - easy wheel removal/easy adjust/QR rear wheel. Important for fixing punctures and loading in cars for me, but those blackcat dropouts look gorgeous

(BTW I also have a horizontal dropout bike with tensioners and v's and chose the sliders for the next frame for all the reasons above)

I don't think weight is too much of an issue as the bike is sub 23lbs approx and very sprightly!

Posted 2 years ago #