marin fsr disc brake conversion

cljcars

Hi chaps and chapesses.

I have acquired a Marin fsr think its a 2004 model with Tara. I will upload some photos tomorrow. I am trying to update the brakes etc as I go along. Got the whole bike for 100 quid put full deore groupset on it. But need better brakes.
Been given some giant mph hydraulic brakes, done no miles and look new. They won't fit back, need a mount for the front dart 3. (intend changing these)

Do you know if there is an adapter available to put the IS (presume mph brakes are) on the bike. It has mounting lugs for the hydraulic hose on the frame so it must have had them before.

Help much appreciated.

cycleclinic

IS to post mount adapters are available for different disc sizes.

cljcars

New to this stuff, any help on a good place with knowledge to get some. On the wirral northwest England.
Cheers chapsss.

nicklouse

It could have post mount fitting on the swing arm.

Which mph are they asthe later ones were pst mount with adaptor for IS use.

Also what disc size are yo planning on using.

Any bike shop will have a box wit some adaptors in.

Or any online shop but you need to know what to order and for that we need o know exactly what you have.

Pics are good, as are th FAQs above last page for the disc mount one, Parktools link in sig is also worth bookmarking.

cljcars

Some Photos, what have I got?









Help much appreciated already.

At worst I will have to make some brakets, luckily I have access to a miller.

nicklouse

Looks like a marin special which would then end in an IS mount.

miller or Ebay but have a look on Betd.co.uk first they may have something.

cycleclinic

Also good v-brake pads can sort your braking problems. Aztec charcols are pretty good as a swisss stop pads. If it is XC riding you are doing I prefer V's or canti's.

cljcars

Missed the most important photo.

This is my problem, Does anyone know what the distance between centers is supposed to be on an IS mount? There must have been some sort of bracket there in order to get the clearance for a disc.

Marin Special? will there be any markings anywhere, last owner bought it off a chap that shot blasted it and laqued it, no more info apart from approximate age.
Pads are pretty good but I am nearly 16 stone and stopping me comming down a hill takes some hefty brakes. Mixed riding most likely.

pedalling

It kind of looks as though it is DISKMOUNT 2 or 7 from the following document that would do it:
http://www.marin.co.uk/downloads/Marin%20Diskmount%20Guide%20for%20Older%20Models.pdf

Though they date back to 2000, maybe it didn't change. It's worth dropping Marin an email, I found them pretty helpful when in a similar situation with a 98 B17. They were able to supply some drawings that enabled me to knock one up, or you could pass the drawings on to an engineering firm if you don't fancy the drilling and sawing.

You can get offcuts of sheet aluminium on ebay pretty cheap that will be the correct thickness and material.

BTW Standard Rear IS Mounting hole centres should be 51mm according to this document:
http://www.hayesdiscbrake.com/wp-content/themes/hdb/pdf/Rear%20QR%20IS.pdf

nicklouse

cljcars wrote:

Does anyone know what the distance between centers is supposed to be on an IS mount?

so you have not read the FAQ on the brake mounts. it is there. bolt isze and hole spacing and that is not IS.
there is even the tec drawings for you should you get the milling machine fired up.

nicklouse wrote:

there are two main types of mount for your disc brakes.

Post mount as found on the majority of Manitou and Some Rockshox and Marzocchi forks.

Post mount can also be found in 2 sizes 6" and 8". the distance between the mounting holes is 74mm in both cases.
In these cases the post mount caliper will bolt straight on with out any adaptors for the disc size, i.e. a 6" post mount will run a 6" rotor and 8" post mount runs an 8" rotor.
Of cause a post to post 8" adaptor can be added to allow you to run an 8" rotor on a 6" post mount or a post to IS 203mm adaptor can be used to run a 203 rotor on a 6" post mount.

Be aware there was an early Post mount which had mounting hole spacing of 69mm

To run an IS mount caliper on a Post mount fork you need a 20mm bigger disc and adaptor.

IS mount is found on most frames and on the majority of forks but the sizing is different.
A caliper (or caliper with adaptor) when moved from the rear of a bike to the front will require a disc 20mm larger than originally fitted on the rear.
Moving one from front to back needs a disc 20mm less than the original disc size you had fitted on the front.

Some 20mm axled fork have the caliper mounts 5mm further away from the fork center line, this requires a 5mm spacer or a specific 20mm axeled fork adaptor.
Please Note that just because a Fork has a 20mm axle it does not always require a 20mm adaptor or the 5mm spacers.

If the fork does need the spacer they usually come with the 5mm spacers (Marzocchi do this). This Offset IS mount is called a DH INTL STD 8" Rotor Setup by Marzocchi.

Two of the fork producers have also decided to produce mounts for the down hill forks that are unique:

Rockshox with the boxxer mount.
Fox with the mount on the 40 range.

The current IS standard came out in 2000 so it is often referred to as the disc IS 2000.
Before that there was the IS 1999 which is only slightly different to IS 2000, and before that Formula standard which was/is mainly found on pre 2000 marzocchi forks.

Formula Standard (or FS) looks the same but the caliper mounting holes are spaced at 49mm rather than 51mm and the bolts used to mount the caliper are 4mm not the current 6mm, also the Over lock nut to disc mounting face is different.

if you want the tech drawings here they are.
in there true form. Please note the dimensions are for true versions of each. ie. there are very few true 20mm hubs out there most are modified 9mm hubs.
6" post mount
Front IS mount
Front IS 20mm mount
Rear IS mount
Front Qr hub
Front 20mm hub
rear Qr hub

Pictures of Marz 20mm axle fork fittings.

but yes 2 or 7 depending on the disc size.
and i would say your bike is a few years older than you thought.

cljcars

Brilliant info, thanks very much for all that info.

Looks like I will be getting the miller fired up, got some ally.

I think I will get the wheel and disc on and measure up, Can get the right thickness alloy then for the rotor size and alignment.

Thanks Again.

cljcars

This looks like the set up I have perhaps it is 2004?

http://www.marin.co.uk/downloads/Year%2 ... 202004.pdf

pedalling

They started the TARA setup in 02/03 so could be a bit earlier. Best place to look is probably bikepedia and match up the design:
http://www.bikepedia.com/QuickBike/Bikes.aspx?Year=2003&Brand=Marin

cljcars

Ok, Nearly finished the conversion.

Back is done now. Made a template out of wood to ensure I got the right spacing for the holes with an old disc wheel I had with a 160 mm disc. Then I got some 6mm aluminum sheet and cut that to size and drilled the holes using a pedastal drill to ensure that they where square.

some photo's, Thanks again for the drawings and help.







Should really get some nice stainless allen caps instead of the current, all I had though.

cljcars

Got the disc wheels last night, Not as easy as first thought.

The bracket needs bending slightly towards the disc at the top lug and bottom lug away to bring the bracket in line with the disc and hold it solid. Trial and error, but got it in the end. Used some spacers (washers) to move the caliper nearer the disc.

Fitted it all back together with pads and still catching. One of the pots was stuck and not moving, back off again freed it up. Back together. Works really well.

Just waiting for a hope adapter from chainreaction to go from 74 mm post to is for the fork now. Job done. ( I am learning)

Not had a mountain bike with hydraulic discs before, I am converted.

YeehaaMcgee

Good bodging skills!
I'm surprised at the non-standard calliper mount, however, since my old Marin is quite a bit older than yours, and has a standardised IS disc mount. Strange that they'd go back from IS to their own design.

cljcars

Cheers.

Lining them up properly took ages, there was no way apart from tweeking a bit then re-assembling. Perhaps the original drawings from Marin may have helped. Nobody ever got back to me.

I had to make sure the gaps front and back of the caliper where equal compared to the position of the disc. The original brake pads where worn on a terrible angle, they must have been installed at angle originally to have such terrible wear. The mis alignment probably didn't help with the sticky pot either.

When the brake is applied when the wheel is still the disc doesn't move or flex in any direction, and the capliper pots move in an equal distance each side, as far as I can tell by eye!