Hi
I’m having trouble with the sliding dropouts on my ’06 Kona A. The serrated washers have dug into the frame and now the bolts won’t slide freely in the slot. I can file out the slot to fix this but I don’t want the problem to recur again. I’m thinking of using larger flat washers but am worried that they won’t hold the dropouts in place.

The ideal solution would be to have a screw through the dropout which seems to be the norm these days. Do you think it would be safe to get this done by a local machine shop? Is there a better solution?

Thanks

Anyone?

only 2 of my 4 sliding dropout bolts on my kona have the serrated washers. none of them on my solitude have them.

no probs not to, ime.

Not sure if the dropout design is the same as the Kona A, but my Explosif just has 4 bolts and washers, nothing is serrated.

Not sure what the dropouts on the A are like, but I’ve got a Sutra which I’ve SS’d, and I was having real problems trying to tension the chain. I tried a cobbled-together system with some modified On-One tugs, but I’ve now got a better system. There’s a curved steel plate that the seat and chain-stays are attached to, which is part of the dropout. I’ve drilled a 3.5mm hole in each one, in line with the dropout bolts, then tapped them to take a 4mm stainless bolt. As it’s pushing against the dropout rather than pulling, it’s more secure. I bought a tap and die set from Maplins to do the job, and the tap you need is the 4mm x 07 pitch. I’ve never attempted anything like this before, and apart from breaking one cheap HSS drill, (it never pays to skimp), it went without a hitch. Well chuffed with myself, and avoided a trip to the LBS. Just make sure you have a good powerful drill and sharp bits, the steel is hard, and use a centre punch to mark your drill position. Take your time and think it through first before starting anthing, but it should be possible to fix something up.

I had the same problem with a Cowan frame a few years back, it is not a very good execution of sliding dropouts especially on aluminium frames which deform too easily when the bolt head/washer only contacts with such a small amount of the frame slot.

I achieved a solution that I could live with by cleaning up the slots with a file and then found some big flat washers and fitted bolts with big heads. I had to use 2 washers as I couldn’t find anything thick enough and 1 deformed too easily (2 deformed but got the job done). Some singlespeed hubs (DMR revolver and Hope) come with bolts and washers that look like they would do the job but for a price.

On later frames they had an adjuster screw as you mention that should have helped, I looked at drilling and tapping the frame to fit one of these as there is a lot of material but the above method just about did the job and the bike got stolen 😥 so it is some else’s problem now …

My Voodoo Wanga came with big flat, non-serrated washers and they seem to work fine (no slippage so far)…

Just managed to find a closeup photo of the dropout on Dirt Rag, and to be honest it shouldn’t be a problem for you, the dropout is really only for gross chain length adjustment, you use the EBB for tensioning, so the fact the dropout doesn’t slide smoothly isn’t that important. Not like on my Sutra, where it’s the only way to tension the chain. I wouldn’t worry about it, TBH, while you could drill and tap like I did, the dropout is obviously much thicker, so it would be a lot more difficult to do.

Thanks all – I’ll try the big flat washers before I start drilling anything.

CountZero – The Kona A doesn’t have an EBB

The dropout looks like this:-

What colour is the front end of that Kona?

I re-read what I wrote and what I was trying to get across was that you need more over-lap from the bolt head to the frame slot so big bolt heads and fat washers should help.

It’s black

It’s an 05 then, not an 06 ….just being pernickety…sorry,

Mines an Identical frame and I took off the serated washers and just used big old grip washers.

Same as the 04 Explosif which I have. First off, see if you upgrade the sliders to the 05 & later parts which have a (feeble) built in chain tug – that works on those dropouts too as I have retrofitted them. They mean you don’t have to rely totally on a sheer grip to keep your chain tension.

Next, drop the serrated washers – they kill the dropouts. Find some bigger headed bolts & bigger washers, then file down the slots where they have deformed.

Warning – all this worked on my steel frame – anything you do on an aluminium frame is up to you!

Rather than using washers, I think that a better idea would be to make up a couple of 5mm thick S/S plates with clearance holes for the bolts.
You’d probably have to use slightly longer bolts, but that’s no big deal.

The plates could be 19mm wide and the length could be the hole centre dimension + 16mm. At least the slots in the frame wouldn’t get chewed up and wouldn’t “take a set” making fine adjustments difficult.

swap those allen-headed bolts for some proper 13mm headed hex-bolts (with flat washers) and all your woes will be over

Daffy – Every day’s a school day 🙂

Andy R seems to be talking a good idea here. One plate with two holes in for each dropout. Getting the plates made somewhere between 3 and 5 mm thick would ideal as then they should be thick enough to allow for some munching and spread the load over enough area to get grip and hold the rear wheel in place.

Countzero is talking about the same idea that Brant must have had when designing the first slidey dropout inbreds (I own and love mine :D) which seems to work quite well as mine have never slipped. Incidentally the washers on my bolts are irelevant as the chain tug Also has a plate like Andy R’s idea built in.

There you are – one mk1 sliding dropout inbred piccy. Probably rendering all my blabbering useless…..

Better piccy –

Can’t find a pic but the newer Kona sliding dropouts have a tension screw – massive difference between my older Cowan DS and my newer one with the tension screws.

There you go – I’d guess they’d be available aftermarket.

Those bolts can’t be standard?! Even the cheesy allen bolts that came on my Explosif had large domed heads. But they rounded off before you could get them tight enough so as JoB suggests, I replaced mine with some hex bolts which you can tighten with a proper spanner. Should’ve done it ages ago.

Those bolts ARE standard – at least they are on my Sutra