Disc specific forks on an old frame....?

LikeClockwork · Oct 2, 2016

Quick question: If I've got a pretty old (non disc) frame and I put a V brake on it at the back, if I then put disc specific forks on the front, will the braking forces through the forks put a strain on the frame?

Bearing in mind it won't be gusseted at the head tube/down tube or anything. Can an older frame cope with something like this when it wasn't made with those kind of forces in mind....?

Adam_S · Oct 3, 2016

Should be alright. The only bit of the bike that would notice the difference is the forks I'd have thought and if they're disc specific anyway then if should be fine.

Have you thought about getting a bodge on disc mount for the back?

KermitGKona88 · Oct 3, 2016

Re:

It will completely destroy the frame........................................

Unless you sell me the Breezer for £20 inc post

Worth a try

jimo746 · Oct 3, 2016

Re:

The frame shouldn't be affected by the braking force from the disc, only the fork will.
However won't most disc specific forks have a longer axle-to-crown measurement than the original forks? Might change the handling slightly.

Adam_S · Oct 3, 2016

Re: Re:

jimo746":3tvirh0g said:
The frame shouldn't be affected by the braking force from the disc, only the fork will.
However won't most disc specific forks have a longer axle-to-crown measurement than the original forks? Might change the handling slightly.

You can get 80mm travel forks with disc mounts no problem. I wouldn't go much longer than that on an old frame though.

mattr · Oct 3, 2016

We ran a pair of 110 mm sus forks with a front disk on a bike designed for 80mm forks and v-brakes.

Did that for about 10 years. The frame is still in the attic, no cracks (i checked carefully, this particular frame is reknown for cracks in the welds anyway........)

jimo746 · Oct 3, 2016

Re:

Huh, I supposed they were disc specific rigid forks, no idea why...?

mattr · Oct 3, 2016

Oh, i'd like to add that the originally fitted/specced forks were old school elastomers with exactly no sag at all, needed a noticeable bump to get them to move, and bottoming out was all but impossible, i doubt i ever saw more than 50-60mm travel in the 8 or 9 years i had them. The new 110 forks were Air/oil with around 30% sag, and bottoming out wasn't exactly easy, but it happened on occasion.

The usual A-C length of each fork wouldn't have been too far apart, more like 5mm than the nominal 30mm suggested by the difference in travel!

elPedro666 · Oct 3, 2016

Re:

It's the extra leverage on the headtube from a longer a-c that you need to be wary of, as Matt implied. A small difference in length can make a massive difference to the force on the headtube (as well as buggering up the handling).

LikeClockwork · Oct 3, 2016

Re:

Thanks chaps

I should add, it IS rigid, I should have said that, and the axle to crown was the other thing that was on the back of my mind.

Definitely don't want to convert the frame itself to run discs, long story, and no, it isn't the Breezer that I'm going to do this to! And no, Mark, you can't have it.....

Disc specific forks on an old frame....?

LikeClockwork

Attachments

Adam_S

Retro Guru

KermitGKona88

jimo746

Adam_S

Retro Guru

mattr

Old School Grand Master

jimo746

mattr

Old School Grand Master

elPedro666

LikeClockwork

Similar threads

Latest posts