Rail brake hose

[WilkyWay]

Has anyone replaced the rear brake hose on a rail? Or have a diagram/pictures of how the hose is routed past the motor?
I have a spare set of Saint’s I wouldn’t mind fitting but the hose is crimped to the fitting that bolts to the calipers so I can’t use the original hoses and it’ll have to be fed from the rear when fitting and it looks fiddly to say the least...
How much of a pain is it going to be to change?

 

[Doomanic]

Use this to screw the two hose together and carefully draw the the new hose through the frame with the old hose.
https://www.swinnertoncycles.co.uk/components-c169/rear-shocks-c260/spares-c261/rock-shox-barb-connector-reverb-stealth-p82668/s222675?

 

[WilkyWay]

Good idea. Tried and tested method?

 

[WilkyWay]

FYI anyone attempting this I don’t think it can be done with the motor in place. The routing above the motor together with the other cables in the same area would make fishing it through from the chain stay to the battery compartment impossible, even using the old hose to pull it through.
Please someone prove me wrong though...

 

[protowheeler]

I would drop the motor. It's not worth trying to force something through. And with the motor out (unplug all the cables from the motor first!) you'll possibly be able to slide the new hose under the lower and upper battery dockings without loosening them. When you reinstall the motor just make sure to not smash it up in there. Take your time!

 

[WilkyWay]

Motor is currently on the floor. Nice and easy to remove as long as you’re careful unplugging everything. Brakes will be on tonight.
Just waiting for some new motor mount bolts to arrive as well. Although I can’t find anything online for torque settings for the motor mount bolts....

 

[WilkyWay]

All done. When the new motor bolts arrive I’ll fit them then go riding until the battery is flat ? ️??

 

[protowheeler]

Did they recommend new motor bolts? It's true, the PreCote threadlocker is one-time use on those. Better safe than sorry!

 

[WilkyWay]

Did they recommend new motor bolts? It's true, the PreCote threadlocker is one-time use on those. Better safe than sorry!

I’m not sure if they recommend or not, I’ve found very little online about it but for what they cost it’s not worth the risk. I’d hate for them to come loose and damage the frame or motor.

 

[protowheeler]

FYI the torque is 20Nm +/- 2Nm.

 

[WilkyWay]

FYI the torque is 20Nm +/- 2Nm.

Perfect! Where did you find that nugget of information?

 

[protowheeler]

It's Bosch's own published value and generally applies to all bikes using that motor.

 

[WilkyWay]

It's Bosch's own published value and generally applies to all bikes using that motor.

Do you have a link to the literature anywhere?

 

[protowheeler]

I do not, sorry! Ideally your dealer will be able to confirm it though.

 

[DecoyD]

All done. When the new motor bolts arrive I’ll fit them then go riding until the battery is flat ? ?? View attachment 24906 View attachment 24907 View attachment 24908

Nice brake upgrade. After changing your rear hose and caliper, do you think it can be changed without dropping the motor? All my hoses run over the battery on my 9.7. I do have that red hose adapter to pull hoses thru frame. Any experience knowledge is priceless. Thanks

 

[Philly G]

@WilkyWay torque settings for all the major bolts on the Rail, including motor mount bolts, pinned at the top of the Trek section ?

Rail (625Wh) - Trek Rail Parts Diagram - Aluminium

MY20 Rail Alloy Parts Quick Reference

www.emtbforums.com

 

[WilkyWay]

Nice brake upgrade. After changing your rear hose and caliper, do you think it can be changed without dropping the motor? All my hoses run over the battery on my 9.7. I do have that red hose adapter to pull hoses thru frame. Any experience knowledge is priceless. Thanks

I don’t think it’s impossible, but for how easy it is to drop the motor I would say take it out. I’ve had mine out three times to fit a new dropper then the Kiox and it’s really easy.

 

[gfunkmc]

Nice brake upgrade. After changing your rear hose and caliper, do you think it can be changed without dropping the motor? All my hoses run over the battery on my 9.7. I do have that red hose adapter to pull hoses thru frame. Any experience knowledge is priceless. Thanks

Yes it's possible I have done it .. mine was easy (not saying all rails are going to be the same) all I did was lossened all the cable clamps behind battery and pulled new hose through with the red rockshox connector as in previous post ?

 

[Hob Nob]

I tried & failed with mine, it was easier to whip the motor out & poke it through.

Also gave me a chance to clear out half the forest that had accumulated in there too

Point of note - with the OP's pictures - I would pull a bit more cable through to the caliper end, the wheelbase on the Rail does grow through the suspension travel - I wouldn't be surprised if that was under some tension, having done this myself.

 

[WilkyWay]

I tried & failed with mine, it was easier to whip the motor out & poke it through.

Also gave me a chance to clear out half the forest that had accumulated in there too

Point of note - with the OP's pictures - I would pull a bit more cable through to the caliper end, the wheelbase on the Rail does grow through the suspension travel - I wouldn't be surprised if that was under some tension, having done this myself.

A sound piece of advice, and you were correct. It was too tight and rubbed through and cost me another hose. It’s now got a longer length between frame and calliper. Lesson learned!

 

[Don_Singer]

Just a couple notes from my brake replacement experience. The rear brake line was zip-tied to the motor wires, so impossible without dropping the motor. The active braking pivot changes the length of the brake line between the chain stay exit and the caliper. Vent the air, or remove your shock and fully compress the rear suspension before you position the brake line and cut it to length. I hate overly long brake lines so I took this opportunity to clean things up but ended up with a brake line that is a little short because I wasn't aware of the active braking pivot impact on length. I used an old mechanical brake cable, the braided metal part, to fish the brake line. With the cable end still attached it was easy to grab it. I installed Shimano Saints, great brakes, the pre-inserted olive is crap and easily gets misaligned and messed up. Make the lever connection the old fashioned way, slide on the cover, the nut, the olive, tap in the end, then thread everything into the lever.

 

[Hamina]

It's not so big thing to remove 4-bolt guard, 6-bolt motor and 4-5 electric connectors of the motor compared to space you get routing the rear cable. I would replace the gear cable at the same time, maybe the dropper also.

Caution: Do not loosen too much the battery's lower bracket. It's nearly impossible to install the nuts back without removing the motor first (or again..).

 

[Black8917]

My motor was a complete bitch to install after removal. I had to tape the cables to where they needed to be, install the motor, then pull the tape out. Took an hour at least just to get the motor in a place to line up all the bolts without pressing on the cables. Trek 9.8 2021 large.

 

[Hamina]

I copy this also here:

Just found out something today:

I was wondering why Bosch sells T40 1/4 torx with a 8 euros price tag here locally. Well one reason could be that Bosch CX GEN 4 T40 bolts are torx PLUS and not ordinary torx.

There's a small difference: