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thinking of converting my Roadrat back to single speed. It's used as my muck around hack bike so would be good to get rid the gears, I don't really need them. I've currently got cable disk brakes on there and when it was in single speed config before I really struggled to stop the power of the disk brake from sliding the hub on the disk side. I could never get the QR sewer tight enough. I get away with it with gears as I can push the wheel fully forward and increase the QR clamping area, but know when I go back to single speed it'll be a problem again. Have any of you hard core single speeders got any tips? Any fancy chain tugs that might help lock the hub in place. I'm already using those chunky Shimano squewers that are recommended.
Thanks.
I'm impressed you're managing to make it slide to be honest!
Is it sliding backwards or forwards?
Chain tug (drive side) essential even without discs IME. I'm using a Surly Tuggnut but any old tug should do. I had wondered whether I'd need a second tug on the non-drive side, given the need to align the rotor, but actually it seems to line up correctly 90% of the time with just one and it stays put under both power and braking. YMMV; may also depend on caliper mounting position.
Tugnut would be the simplest answer. The other option is to change the hub axle for a bolt-up one, but that's probably a lot more faff and probably impossible on some hubs.
What Bez says.
I too can crank my NDS of the hub forward so have fitted 2x Surly Tuggnuts to my regular SS.
I used to use 2 surly tugnuts on my karate monkey too
2 chaintugs here as well.
I get away with one chain tug, but will prob add another on the nds at some point
Ah, I misread the op- I thought there was a chaintug on the driveside already. I've not found the need to use one on the disc side too (on a roadrat with discs)
mpressed you're managing to make it slide to be honest!
It's not through leg power, but disk brake power. The disk side was sliding backwards as the calliper is mounted on the back of the seatstay so resulting force is basically pulling that side of the hub laterally out backwards so the only thing resisting it is the friction of the QR squewer.
I'll measure my disks, I think I can go down to a 140mm disk so that would reduce the moment force, but I think tugs prevent the hub sliding forwards rather than backwards don't they? I did have a tug on the drive side but its the disk side that is sliding.
OP understands problem better than responders. Stoners Inbred has a chainstay mounted disc brake to eliminate the very problem the OP has.
Reaction force for seatstay mounted brakes indeed push wheel backwards. I have noted a chaintug on brake side can exacerbate this.
I never made a reverse chaintug to hang in front of dropout but it’s a thought!
I solved all issues by using a hub that uses bolts instead of a QR.
degrease and roughen up the dropouts? My bike with sliding dropouts managed fine with a cheapo QR and a disc
indeed, I have misread OP too. I though he had hub slip under pedal load (which I suffered from) rather than under braking.
OP should ziptie his qr forward to the rear triangle then 🙂
degrease and roughen up the dropouts? My bike with sliding dropouts managed fine with a cheapo QR and a disc
Don't sliding dropouts have a vertical dropout to hold the wheel and bolts to attach the dropout to the frame?
Seatstay mounted caliper here, 185mm rotor, and no movement yet. Possibly just lucky.
I think I can go down to a 140mm disk so that would reduce the moment force
A smaller rotor will increase the force at the axle. Moment is the same for any given rate of retardation, so a smaller distance to the braking surface means more force.
simon - maybe wrong term - slotted dropouts like track ends? Genesis ioid frame
I found the tugnut stop forward and backwards movement unlike some tugs I've used
slotted dropouts like track ends?
That's track ends 😉
Horizontal dropouts face forward, track ends face backwards, sliding dropouts face down and move in the frame.
Sliding dropouts or EBBs FTW 🙂
I'll give it w whirl as see what happens - maybe I won't suffer the same issue again now the drop outs have been dirtied up a bit over the last few years. Thinking about the disk diameter issue I think if I go any smaller diameter it would mean taking the wheel out difficult as the calliper will be past the vertical and prevent the wheel from sliding out - it already catches the calliper but a good bit of brute force gets it past, but a smaller disk would mean removing the calliper when removing the wheel.
Simon - yes, a bolted axel would probably be the best fix, but I don't think my hubs are able to be converted so would mean a new wheel which i'm trying to avoid.
What hubs are they? Bog standard Shimano cup and cone can actually be a cheap and reliable option - just rebuild with a £10 cromoly solid axle and use great big serrated nuts. No need for any tugs and they never slip.
My IO has reverse bolts to tension the wheel. Holds the wheel fine with the disc. Since that's not an option, it's tugnuts. Awful looking devices.
I solved all issues by using a hub that uses bolts instead of a QR.
worked for me also. found a nice bolt up hub in a sales bin in a Leisure Lakes of all places, and it transformed my SS. Had to carry a 15mm spanner around mind...
It's not through leg power, but disk brake power.
Aye, I got that, I just have the same setup on a roadrat and in 4 years of commute panic braking and touring loaded I've never made it move.
Actually, there's a thought- is it one of the old roadrat with the 132.5 dropouts and if so, what width hub do you have?
It’s an early roadrat possibly a MK1. The wheels were the ones that came wih it from Cotic, so Alex rims and some generic hub with Roadrat etched onto the hub body so not sure what make they are. It had a rim brake setup originally but I went to discs when I reconfigured it from the flat bar single speed to drop bar 20 speed.
I have the same issue on my jump bike if I yank the brake.
Toying with the idea of changing to bolt up axle (Deore hub), or getting some of those better chain tugs.
I do have some little spindly ones on now, but they don't seem to be up to the job.