HELP: rear disc adapter thingymabob

RickTheUncivil

Old School Grand Master
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I'm working on a project, and have a desire to fit discs. I have a brace / adapter thingy in the parts bin.
Have a read here (the link goes to page 3 with some piccies of the problems but there is some more info on earlier pages)

Any help greatly appreciated!

What we think we know so far:
This is an Onza / Tensite kit
The kit is incomplete
My head hurts

Anyone got ideas, spares etc to help get this kit working?
 
Re:

Hay ric have a look here

https://www.rockandrollbikes.com/tensil ... apter.html.

I got beat hah. ^^^^^^^^^

the pic on the whole kit (zoom in on the bag of bit) looks like they might use some thick washers/spacers to over come your very issue. I don’t think it would be a problem as I discovered recently that that’s what you have to do on older 20mm axle forks as well as they are 110mm which puts the disc mount out. I’ve done it on a junior t with 205 rotor. So on the back of a little bike would be fine imo.
 
Thanks guys. I had found that site but with few and small photos its not great for getting details.
You are right, it looks like maybe some spacers in there, and a sort of tophat washer to plug the dropout. Seems a bit faffy given they have gone to the bother of machining something for it not to fit. Guess its just too hard / too much work for them.

Measurements shouldn't be too hard to work out....

Dropout is what, 9/10mm across and maybe 4-5mm deep, and the skewer is about 3 (I have a ruler, I'm just guessing at this point), so getting something machined to fill the gap with a fairly flat top to hold against the side shouldn't be too hard (he says, with no machining experience or equipment). I suppose a spacer here will hang on the qr and slot into the frame, rather than fixed to anything. But for what purpose? In my head it needs some mechanism to extend the axle not just fill the gap.
The 'outside' has a recess for the head of the skewer so it should stay seated but I can't see that adding much to the strength of the whole thing. In my head it needs to be held firmly in place to resist the turning applied by the brake. If the bracket twists the pads move out of alignment with the rotor and that could be rather bad. I'm reluctant to drill a hole and fix the adapter directly to the frame but that's what the bumpf says so maybe that's what is needed. Again, seems a bit cack to me.

Spacers for the caliper - guess they are readily available for other applications, just need to make sure its ID is sufficient for the bolts. Ill hit the hardware store / ebay later and see what I find.

Does anyone have one of these who can shed more light?
 
How tricky would it be to fit a hub with slightly longer axle?

I seem to think that the good oldfashioned bolt-up axles on wheels from my yoof went far enough beyond the dropouts to poke out the end of the nut. I bet it would be long enough to make the difference here.
A non-QR rear wheel isn't the end of the world and if anything would give some reassurance that everything was bolted up tight and wouldn't inadvertently come loose.

hmm, think I might play around with some of the scrap hubs in the bin and see what it looks like
 
Rough numbers, 135mm OLD plus a bit for dropouts I'm guessing a 'normal' QR axle is around the 140-145mm mark. Nutted ones need an extra 5-10mm or so each end for nuts so I guess somewhere ~160mm is about the norm for MTB.
With a few mm each end to play with it might just work, or I reckon I can squeeze everything along towards the drive side a bit if needed to make the axle poke out of the NDS a bit more to make room.

Pretty sure I have a shimano (alivio I think) nutted rear hub in the shed so I'll give it a go.
 
Re:

The complete kit comes with an extra long skewer with a top hat washer and the anti torque arm to the brake boss. Original instructions say it needs flat sided dropouts to be tightened against such as found on aluminum frames. Potential extra long skewers are those used to attach BOB Yak trailers to bikes. Check out SJS cycles trailer spares. However using a solid 180 x 10mm axle with track nuts will work just fine.
Happy bodging, the kit actually works quite well ;-)
 
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