Problem with Hope T-Rex 40t setup

Hi chaps,

I’ve just installed a Hope T-Rex on my 10sp setup. Indexing is fine, b-tension is good – the problem is the chainline. When back pedalling the chain drops two rings at the back.

The chain was a little noisy when pedalling normally, so I’ve popped in a very thin spacer behind the T-Rex, which resolves that – but the chain still drops when back pedalling a couple of gears.

My OneUpComponents 42t doesn’t do this, it’s absolutley fine back pedalling.

Anyone got any ideas? Or had this same problem? I am thinking of sticking a spacer on the BB to move the chain line – but I shouldn’t need to.

Cheers

Ricks

I’ll offer up some of my thoughts:

– Worn Thick/Thin ring, on the left hand side, causing the chain to be pulled further to the right, and not retained.

– Chainline wrong – this isn’t the case, as the chainline further out on the exact same bike, but with the OneUp ring, is more than happy. Therefore, the chainline being actually worse on the other bike being fine, means that it should have nothing to do with the issue

– The ramping on the T-Rex ring is a bit odd – causing the dropping when back pedalling

Before anyone asks… I backpedal quite often on very steep big rocky step ups, at times – so that I don’t get pedal strikes, or so I can get my feet in the right place.

Any other ideas?

More fettling done.

Tried a different crankset, with a different type of Thick/Thin ring.

Still the same problem.

Well, looks like it’s the Hope ring. That sucks.

we had initial back pedalling problems on James’ but it was brand new chain so there was no lee way for imperfections. Since then the chain has worn in and it doesnt happen on either of ours. Have you tried mega slightly altering your b screw, I had back pedal issue for about five mins and I tweaked the b screw and it made it vanish.

Yep, tweaked the B-Screw quite a bit, all the way out, and then just enough in so I get clearance. It is a new chain, well, two rides old – so possibly it’s a wearing in problem.

I didn’t have this issue with the OneUp ring though, which is what’s really confusing me.

Hmmm… got me thinking now. If the plates are too narrow and tight on the chain, like you said the margin for error is very small. But once they wear in, and become a bit more sloppy due to the rivets wearing, there will be more sideways movement.

Hmmm indeed.

I has this on a newly fitted T-Rex with totally new drivetrain.

I have just fitted a oneup to the Scalpel and it doesn’t do it all.

I would suggest that it is a Hope thing.

When do you ever pedal backwards when climbing on the hope ring?

See my comment above 😉

Before anyone asks… I backpedal quite often on very steep big rocky step ups, at times – so that I don’t get pedal strikes, or so I can get my feet in the right place.

I noticed the same problem on mine today, I am running a new hope retainer ring, recent chain, cassette Nd hope trex. It doesn’t bother me though as I don’t back pedal climbing

Cheers chaps, good to hear it’s ‘normal’. I’ll drop a mail to Hope, and a link to this thread.

I had this to start with. I had fitted a new chain. Also, the Hope 40T was new. Fine tuning the B screw and wearing all the components in together seemed to do the trick. The B screw was very sensitive indeed.

yep mines comes off as well back pedalling, rickon what spacer did you use for back off cassette as i meed to adjust my chainline ever so slightly ??? my email is in profile

yep mines comes off as well back pedalling, rickon what spacer did you use for back off cassette as i meed to adjust my chainline ever so slightly ??? my email is in profile

Well thats stopped me ordering for the time being.

Mine does it too.

Not a fit and forget thing then….

Mine will go down 3 rings if I backpedal. It doesn’t do it on the 36. I don’t think I’ll ever use it except when climbing and only backpedal on descents.

Mine is a OneUp rather than a Hope but tbh I didn’t have any of these issues. It was a total pain in the arse to get it set up right, lots of fannying about with the b-screw- I ended up sticking it on the turbo trainer and combining an intervals session with an indexing session 🙄 Just seemed to be a wee bit counterintuitive

😯 glad its not just me, i thought it’s me who doesn’t know how to setup gears anymore.. So common issue then.. I fitted 2 weeks ago a new KMC chain and dropping cogs whenever i slightly backpedal to prepare for an obstacle … And last week replaced the chain a slightly older used kmc chain from the other bike and all is smooth but wont engaged in my t-rex but it must be me didn’t fine tune re-indexing again when i replaced worn chain which doesn’t need to really 😐

Odd, no issues on my wife’s bike with this.

No setup issues, chucked it on, wound out the B tension screw & off she went.

Certainly a vast improvement on the Leonardi she had on there before – great idea, executed like sh*t.

Same here on my Fatty
got two sets of wheels. one sram and one Shimano. put one on each and no adjustments to owt it works a treat
feeling a bit miffed I must have a couple of faulty ones as cant make them drop down when backpeddling ever.

No problems with mine either, works a treat.

Thinking about getting one of these and wondered could the problem be with chain growth on some full suspension designs ?

I don’t have any problems with the T-Rex on my BFe. Admittedly, the chaps at 18bikes fitted it for me along with sorting a few other bits out but it’s been faultless in use.

I had this issue and I fixed it, I think by winding the B screw in some more. Also don’t be shy of making your chain longer.

No issues here either. Set-up: New Sram Chain (1090), New Sram 11-36 X9.

I’ve started with a Hope thick/thin 30T on the front as I like to spin, but left a couple of extra links in the chain so I could move to a 32T if I felt this was too small. Maybe its the extra chain? Oh and its on an Alpine 160 if this helps.

The only other thing is that I’ve got an old knackered X9 rear mech. A bit of play in there might be helping.

Craig

Maybe its the extra chain?

I did a bunch of tweaks but I think it was the longer chain that did it for me.

Has anyone shared this link with hope themselves see if they have any input ?????

Mine will go down 3 rings if I backpedal. It doesn’t do it on the 36. I don’t think I’ll ever use it except when climbing and only backpedal on descents.

I wonder if the angle on the 30t causes the issue.

I had the same experience as Northwind with the OnUpComponents ring, works faultlessly but was a total pain to get setup right.

The Hope ring is easy peasy to index and get the right b tension, but back peddling causing derailment of the chain.

After initial set up it was dropping 3 rings, after one ride its down to dropping 1 ring.

Its not chain growth, and the chain length or the b tension won’t have anything to do with it, as those all have no affect in the top of the drivetrain, which is what is derailing when back peddling.

It must be tooth profile, affected by the angle of the smaller ring, and the lateral angle. I can see it sorting itself out once the rivets wear a little, so the plates can move laterally.

On the plus side, during practice for the Gisburn Enduro, my clutch mech went funny and seemed to stick forward, leaving me with a very slack chain. And still the chain didn’t fall off 🙂

Hope 32t retainer ring.

does it on mine with 34t hope front retention ring

No probs with my 40t, running on a shimano 36t cassette, XT shadow + med cage rear, and a RF narrow/wide 32t front.

Oooh, that’s the setup I’ve tried which derails for me.

No issues for me here.
Raceface normal 32t front ring. SLX med-cage mech.

I fitted the same set up as chipbutty a couple of days ago, all new parts and new chain.
Mine drops two sprockets while back pedalling.
I tried adjusting the b screw despite not seeing how that could make any difference, which it did not, but I found if it was not wound in enough the chain would drop two sprockets then jam between the mech and cassette. I then tried using the supplied longer b screw and found if the b screw was screwed in too far it also jammed between the mech and cassette after dropping two sprockets.

So went back to the original screw screwed all the way in which was where I started.

The chain still dropped two sprockets but did not jam and climbed easily and quickly the moment you pedal forward.
I think this is due to tight tolerances in the new components and the narrow wide chainring which has very tight tolerances by design.

I really can’t see it being a problem as I don’t pedal backwoods accept for maybe when coasting behind some one slower while waiting for them to give way and defiantly not in a situation where I would be in such a low gear.

And if turning half a turn for pedal positioning I would always pedal forward.
I also think as the drivetrain wears this will sort itself out anyway.

Well moved from hope retention ring 34 to 32 t and still comes off 2 rings didnt think it would help and its not the reason i changed. Much prefer the 32t ring at the front.

Anyone running an XT long cage clutch rear mech with the T Rex?

Would prefer to run what I’ve already got if possible (not sure whether a new chain comes with enough links to accomodate long cage and 32t chainring?).

If not I’m presuming a medium cage XT clutch mech will be ok?

Thanks

Hi all,

Myself and a friend are having this issue.

Hope 32t retainer on SLX crank
XT long cage
XT cassette
Hope Pro2 hub
New chain

To me it’s a chain line thing, the angle is too aggressive off the chain ring. Maybe with time the wear will help smooth things out but i also find it a little too noisy therefore the wear will be high.
I’m going to try moving the 32t over to the frame by 2mm if i can find the right spacers and replacement bolts to take up the extra space.

I also dropped Hope an email, they are normally good at responding. May be they could knock up some CNCed spacers and bolts as a kit!

Well it might shift of the 40T when back pedalling but I found the shifting onto and off it going the normal way to be flawless on Sunday. I made a few horrible max stress changes going up some steep bits and it worked very well indeed.