Disc +rear rack

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unnamed
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Disc +rear rack

Post by unnamed »

I have a Genesis Fortitude with BB7 brakes and a non disc Tubus rear rack,but there's not enough clearance to fit the rack.
Would TRP cable actuated brakes give enough clearance? Or shall I get a disc comp rear rack?
What's best?
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Redvee
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Re: Disc +rear rack

Post by Redvee »

You are going to need a disc compatible rack for the seatstay mounted calliper. If the calliper was on the chainstay then your current rack would be suitable.
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foxyrider
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Re: Disc +rear rack

Post by foxyrider »

You could space out the rack, I've had to do that on occasion to clear particularly chunky seatstays with badly positioned mounting points - total cost pennies as opposed to @ a ton for a new rack! :D
Convention? what's that then?
Airnimal Chameleon touring, Orbit Pro hack, Orbit Photon audax, Focus Mares AX tour, Peugeot Carbon sportive, Owen Blower vintage race - all running Tulio's finest!
Brucey
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Re: Disc +rear rack

Post by Brucey »

a TRP spyke/spyre will allow more clearance for the rack for sure but whether it will be enough to allow no rack spacers at all on the LHS is debatable.

cheers
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meic
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Re: Disc +rear rack

Post by meic »

Does the bike have fittings for a rim brake?

I gave up on the disc brake and went back to using rear cantilevers, mounting a rack securely was a main reason for doing so.
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iandriver
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Re: Disc +rear rack

Post by iandriver »

Tubus do sell a rack extension

https://www.sjscycles.co.uk/carriers-ra ... extension/

Fettling still required probably.
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PH
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Re: Disc +rear rack

Post by PH »

unnamed wrote:I have a Genesis Fortitude with BB7 brakes and a non disc Tubus rear rack,but there's not enough clearance to fit the rack.
Would TRP cable actuated brakes give enough clearance? Or shall I get a disc comp rear rack?
What's best?

I'm no expert but have just for the first time fitted a disc brake and rack to a new frame. There's bound to be differences, I don't have the same tubus and the disk brake is mounted off the dropout.
My first choice of brake was the BB7, there was no way this was going to fit without more spacing than I was prepared to use. I changed it for a TRP Spyke which is a lot narrower, still not enough for the rack to completely clear it, requires 6mm of spacers to clear the brake body and a further 3mm to clear the fixing screw heads. Mine needs to clear the bolts to be perfectly level, so I have three options - add the extra spacers, accept a slight angle, or swap the bolts for some with a shallower head then the supplied cap heads.
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unnamed
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Re: Disc +rear rack

Post by unnamed »

Thanks guys, yeah I might need both, slimmer calipers AND disc rack.


meic wrote:Does the bike have fittings for a rim brake?

I gave up on the disc brake and went back to using rear cantilevers, mounting a rack securely was a main reason for doing so.

No, it only has fitting for discs.
PH
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Re: Disc +rear rack

Post by PH »

foxyrider wrote:You could space out the rack, I've had to do that on occasion to clear particularly chunky seatstays with badly positioned mounting points - total cost pennies as opposed to @ a ton for a new rack! :D

Do you have any concerns about that weakening the rack fixing point? and would you need to do it both sides for the rack to fit centrally?
My feeling is that for the load carried a 5mm screw is strong enough to handle a few mm spacing, but I'm sure I've read it's not a good idea to put the mudguard stay on the inside which is only a couple of mm.
John_S
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Re: Disc +rear rack

Post by John_S »

Hi unnamed,

I have a 2014 Genesis Day One Alfine 8 and this has disc brakes with the calipers mounted on the seatstays. Therefore in order to get around the calipers I got a disc specific rack called the TorTec Transalp Rear Disc Rack per the link below.

https://www.sjscycles.co.uk/carriers-racks/black-tor-tec-transalp-rear-disc-rack/

The one thing to take note off with disc specific racks is that the weight they are rated to carry is often lower than a non-disc specific rack and I think that this one is rated to 25kg. It's worth baring in mind depending on what your intended use is for it. For example if you're doing touring with heavily loaded panniers it may not be suitable.

Mine is used for commuting and I put a Deuter Rack Top bag on it and that's worked fine as a setup over the last few years but this is a pretty lightweight setup in terms of what I carry when commuting.

From an aesthetic point of view I think that this rack is a but fuggly looking because it sticks out quite wide but that's necessary to get around the caliper. For me I think it makes it look a bit odd but that's just subjective and obviously I don't notice it when cycling along and it's performed absolutely fine for me from a practical point of view rather than the looks.

Good luck finding the right solution for you.

John
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foxyrider
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Re: Disc +rear rack

Post by foxyrider »

PH wrote:
foxyrider wrote:You could space out the rack, I've had to do that on occasion to clear particularly chunky seatstays with badly positioned mounting points - total cost pennies as opposed to @ a ton for a new rack! :D

Do you have any concerns about that weakening the rack fixing point? and would you need to do it both sides for the rack to fit centrally?
My feeling is that for the load carried a 5mm screw is strong enough to handle a few mm spacing, but I'm sure I've read it's not a good idea to put the mudguard stay on the inside which is only a couple of mm.


Tubus actually supply 10mm spacers with their racks for just this sort of need. Indeed I have to do that with my front rack to clear the fork blade so i've no qualms over at least that amount of spacing - providing the bolt is of suitable quality and has several threads in the frame/fork. I guess i'd be more cautious if I was taking a big load over unmade surfaces for an extended period.

You could 'stretch' the rack symmetrically and space both sides but i've generally gone assymetric when doiing this. As for not putting the mudguard stays inside on the same bolt - it's often the only way to do a double instal, I can't -magine anyone having an issue with that set up - might even be enough spacing on some bikes to clear a seatstay mounted brake.

My disc braked tourer runs either a Tubus Carry Ti or Steel Logo spaced by the mudguard stays to clear the oversize seatstays. In three years of abuse not had as much as a bent bolt despite regularly carrying either camping gear or the weekly shop on less than perfect roads.

Racks like the Tortec disc specific are a bit of a con - if they were designed properly the bolt would only need to be standard length (it was on early examples) but you now need a 25mm bolt - that unsupported length is the weak point! A lot of people with discs have bought them and found they don't need the super wide clearance.
Convention? what's that then?
Airnimal Chameleon touring, Orbit Pro hack, Orbit Photon audax, Focus Mares AX tour, Peugeot Carbon sportive, Owen Blower vintage race - all running Tulio's finest!
Brucey
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Re: Disc +rear rack

Post by Brucey »

this photo

Image

shows very nicely how much extra clearance you get with a Spyre/spyke caliper; quite a lot!

cheers
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unnamed
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Re: Disc +rear rack

Post by unnamed »

Wow! Thank you everyone for their input!
Really useful!
I think I'll upgrade to the Spyke and go from there once I see the clearance.
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unnamed
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Re: Disc +rear rack

Post by unnamed »

Brucey wrote:this photo

Image

shows very nicely how much extra clearance you get with a Spyre/spyke caliper; quite a lot!

cheers

Thanks Brucey, this photo is great!
rmurphy195
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Re: Disc +rear rack

Post by rmurphy195 »

I think this post illustrates a potential problem with disc braked bikes, depending on the caliper mount position. Mine is in the angle between the chainstay and seatstay, so doesn't come anywhere near where the rack or mudguard stays go. Something to cnsider for those who haven't purchased a bike yet but are thinking of it.

I must admit one of my considerations was whether or not I would need a special rack with built-in spacers - it seems wrong, somehow, to have what appears to be extra leverage on the mounting point.
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""You know you're getting old when it's easier to ride a bike than to get on and off it" - quote from observant jogger !
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