Finished my budget Inbred build. Used Surly 1×1 forks with 453mm A-C. Surly state they’re sus corrected for 100mm travel forks, though On One’s rigid forks which are ss corrected for 100mm are 440mm.

On test ride they do feel slack, but that’s possibly me coming from riding road bikes and 90s MTBs.
There is visible flex when braking.

I suppose what I’m asking is, is this too long a lever on the frame or within normal usage. I can see that 453mm is comparable to a 100mm sus fork with sag, but a sus fork would obviously continue to compress when landing or hitting an obstacle, rather than transmit all of the leverage into the frame.

I know there are loads of threads about what length sus fork should be used on hardtails, but it seems to me to be more critical with a rigid fork because of the leverage being almost wholly transmitted to the frame…

Pics are here: http://imgur.com/a/JoNiD

Opinions welcomed!

Cheers,

Sb88

It used to be something of a fashion to run the 26″ inbred with a 29″ rigid fork, so as to achieve a slacker head angle.

The Inbred is a tough little frame. I wouldn’t worry about it.

They’ll be fine, no risk of damaging the frame. I ran the 473mm versions on my 29er Inbred with no problems. Similar spacing between the top of the tyre and the crown too.

Sort out the miles of stem spacers though!! 😉

I’ve never had an Inbred, so might be talking rubbish here, but I’ve got something in the back of my mind about the Inbred having ‘quite’ a high BB, if so, that might affect the handling a bit more than you’d otherwise expect from just adding slightly longer forks?

Looks fine the photos tho’.

😉

Probably no help whatsoever, but …

I’ve [literally] just fitted some ECR forks (~465mm A-C) on my recently regenerated Genesis 26er (with a 200mm rotor) …

… and have happily run 29er PII’s (470 A-C) on my ’92 Kona for ages (180mm rotor). Both feel / work great (subjectively, of course).

I dunno about your frame but that Kona there, is from a time before such big numbers even existed but I’ve never given the leverage a second thought. (The Genesis doesn’t count on that question tho’ as it was built to take [upto] 130mm forks – (and has done)).

the old inbred was rated up to 130mm forks.
i’m sure it’ll be fine.

Thanks for your replies. Now they’re fitted I might as well run them for a while, though suspect I may find the front end a bit high. Could always slam stem and cut steerer, but bit reluctant to cut it if I have doubts over them. Better than impaling one’s sternum I suppose…

Inbred rode best at 120mm travel or a 470mm rigid fork.
Namely down to me wanting a higher front to get some weight off my hands.
The 440mm (100mm) was far too low at the front.
Pic below is with 470mm rigid.

[url=https://flic.kr/p/ayDTa1]IMAG0225[/url] by pten2106, on Flickr

Huh, seems like lots of people have used a 460mm+ fork. How did any of you go up hills with that?! Mine is def as high as I’d go. Possibly if I had a smaller frame size I would need a higher front end so the saddle – bar drop wasn’t drastic.

Takisawa2 – did your forks flex? I know it’s normal but a bit disconcerting – never seen my forks visibly flex, even skinny steel road forks.

There shouldn’t be a problem. I’m not riding an Inbred but have a 465mm A-C rigid fork on my Pipedream Sirius which is also designed around 100-130mm sus. forks. Perhaps I never quite got the sag right on my 100mm sus. fork, but a 450mm rigid felt a little low.

Pipedream advised my that the frame would happily run with a rigid fork in the 440-480mm rigid fork without risk of damage and the fork manufactures themselves recommended the 465 length (I was originally looking at a 445 for my frame.

For the record I was always under the impression that the On-One rigid (steel) forks at 440mm were designed around the earlier 80-100mm Inbreds and the equivalent of an 80mm sus. fork. On-One’s current carbon rigids are 450mm A-C (100mm equivalent) and they suggest (in their carbon monocoque description) that a 470mm A-C fork would be appropriate for those wanting a slightly higher ride position on a 26er.

Cheers for all the replies. Seems like should be fine then! May try some other surly forks I have which are 425mm a-c. Then if they feel too short I’ll know I’m after something in between. Unless anyone’s flogging anything around the 440mm mark?

Cheers for all the replies. Seems like should be fine then! May try some other surly forks I have which are 425mm a-c. Then if they feel too short I’ll know I’m after something in between. Unless anyone’s flogging anything around the 440mm mark?

Del – Member

the old inbred was rated up to 130mm forks.

Just meant it was strong enough- it rode like most 100mm bikes do if you shove 30% extra fork in, imo, ruined it.

The On-One rigids flexed, but nowhere near as much as Pace rigids, they were frightening.
Just get out of the habit of looking down when braking.