I done my fair share of dilling out guides and sawing up old steel frames to make singlespeeds but I'm about to take 10mm off the bottom of a headtube of a mount vision frame making it better for a longer fork and probably making it nigh on un-sellable in the future
any last words before it goes one the lathe?
anyone else ever "ruined" a fame to see if something would work?
Have you done it yet?
If not, put down the tools...NOW!
How about sawing through the rear dropout of a brand new Scandal frame to convert it to belt drive and then discovering the rear cog was too big? 🙂
But it's ok, I did a practise run on my Pompino first 🙂
and that one works...
(and a new cog on the way for the Scandal)
not done it yet, trying to blag a front triangle to try it on first, been speaking with marin bods and they are keen to see the results
will not be doing it myself will be going to an engineering company
Have you checked the forks will still clear the down tube?
Didn't do it myself, but saw the result of somebody else doing it to use a fork with a short steerer.He was buying a new frame because his hacksaw had run off by about 15degrees by the time he was all the way through.
Kiwijohn has a good point there, either that or he just doesn't like a spot of schardenfreude:)
There's also possibly an issue of internal/external butting/machining meaning that there's not enough metal for the headset to locate to.
But I think forks hitting the downtube is more likely.
s'alright. if the forks hit the downtube you could always run one of them +10mm headsets.....
cant you find a 'short' (i.e. crown to dropout) long travel fork?
running a short fork saves about 7mm, need to save 20 to get the head angle and bb height right. Butting issues have been addressed as the large that I have has the same butting as a medium but with a longer un butted lower section. the forks are 19mm from the downtube at the closest point
still not sure if I'm brave enough
Why not just buy a longer travel frame?
what length fork are you putting on it, I've put a 130mm Z1 on my Eastpeak which I think was designed around a 80mm travel fork, its a bit slacker but still great to ride.
10mm off of the bottom of the headtube is only going to gain about 1/4 of a degree headangle?
I'm already running a 130mm revelation but I want to keep the current geometry but run 140mm maxle revelation at full travel
I'll not be chopping anything until the new fors arrive and i've run them at 120 and 130mm for a few rides first. Possible the stiffness is going to be enough without the extra travel
Surely you'll essentially have 140mm forks in the space of a 130mm fork?
Thats all very well having the correct height/angles at [b]sag[/b]
Have you thought what will happen when the fork is bottomed out (or close to)? It'll dive further/lower and will be steeper. As you'll want to run a little more sag being a longer travel fork, your sag point will be slightly steeper/lower too
Whats so wrong with just running a 140mm Rev when you've been running a 130mm one? Its only 10mm? Why all this faffing?
I am with james on this one, I have done a fair number of mods and can not help it - bikes, cars motor bikes even airplanes! But here I don't think there will be enough of a difference to notice/ matter - if the angle does change significantly save the slacker setting for the steep/rough stuff you will appreciate it even more.
And at least try it before the heavy cut. we have a 3 bikes in the house with slightly too long forks and all work even better, though others have needed to go back quickly to original angles. I also believe frames are better suited than ever to slightly longer and riding has definitely moved to slacker works more.
Though in you favour is the boys at Marin thinking - (what are they thinking?) it could be OK/good idea.
10mm travel difference does not necessarily mean 10mm in fork length, either static or loaded. In addition, it wont be 10mm difference once sag is taken into account...
I would fit the longer fork and slide the saddle forward 5mm.
"10mm travel difference does not necessarily mean 10mm in fork length"
It does from 130mm revs to 140mm maxle Revs though. perhaps not with sag then, more like 9-9.5mm higher assuming the same sag percentage?
In the days before aero tubes and disc wheels, I took an old frame and made it a bit more aero with the assistance of a vice and then resprayed it. I tried to build up a disc wheel using a fibre glass cover over the spokes. It sort of worked but was heavy, this was in 1982.
Hi Brant - nice short DS (Directing Staff) answer!, and one of those ( bikes) works even better with longer forks is one of yours!
I cut all the tubes off a Merlin Malt 1 and converted it to a pen holder which now sits on my desk
(actually, BB threads were all to cock after some hamfistery and while they could have been salvaged probably wasn't worth the cost effort. So not really a 'perfectly good frame' but still a workable one)
10mm all travel spacer
I'm thinking of cutting out/raising up the seat stay bridge on my yeti arc x because the mud clearance is dire. What do you reckon?
10mm = 0.5 degree, do you think you will notice this?
And how are you going to do this on a lathe?
I put a screwdriver through the seat tube of my pompino trying to get the old seatpost out. I had cut it down long ways but it was still stuck to the side walls.
It now has three jubilee clips round the hole.
did this happen? if not - how about just fitting maxle lowers to the 130mm revs?
[img] http://picasaweb.google.co.uk/rickaking/MTBSingleSpeed#5159418383570319634 [/img]
Steps into the unknown...my home made disc mount....
or link here http://picasaweb.google.co.uk/rickaking/MTBSingleSpeed#5159418383570319634 if the piccy doesn't show.
explain?
Good point al - it will be interesting to see a bike frame whirling round on a lathe. I guess it will be milled.
I would say don't do it - you could have frame / tyre clearance issues at full compression and I really doubt you will notice any difference if you follow brants sugestion.
I have a frame designed for 80 mm forks. It now has 130 mm forks. ( well U turns) At 130 mm the steering is a bit slower but that really don't matter - but its the change in weight distribution that is really noticable. wheelie tastic
never happened, new bike(s) mean the mounvision and the rev is for sale over on the classifieds
repeatly force an oscillating 93 kg weight on to my SDG bel air.