7-speed Deore XT levers: for cantis or V-brakes?

filo · Post by **filo** » 15 Jun 2020, 7:52am

I'm trying to help out a fellow member who needs a 7-speed rapid fire gear/brake lever for cantis.

I have a spare Deore XT (ST-MO92) r/h lever. Does anyone successully use this lever with cantilver brakes?

Thank you in anticipation.

Brucey · Post by **Brucey** » 15 Jun 2020, 8:40am

I would say it has to be a canti-brake lever simply because it predates shimano's use of V-brakes.

cheers

filo · Post by **filo** » 15 Jun 2020, 9:14am

Thank you for the reply Brucey. Anyone actually using this lever with cantis?

531colin · Post by **531colin** » 15 Jun 2020, 9:32am

To be sure to be sure, measure the distance from the lever pivot to the cable attachment; compare to KNOWN vbrake and canti levers

Brucey · Post by **Brucey** » 15 Jun 2020, 10:37am

the distance in question is not fixed, this being a 'servo wave' type lever. This type of lever is designed for use with cantis.

NB shimano recommend that you replace the cable anchor if it is 'A-type' using 'B type' instead.

https://si.shimano.com/pdfs/si/SI-U-023-000-00-ENG.pdf

which is their way of saying that they screwed up and the A type part may break in service.

cheers

Landy Mann · Post by **Landy Mann** » 15 Jun 2020, 12:03pm

I'm running ST-M095's with canti's and no complaints from me.

531colin · Post by **531colin** » 15 Jun 2020, 12:54pm

In that case, I don't think I've ever seen one!

Brucey · Post by **Brucey** » 15 Jun 2020, 1:22pm

531colin wrote:In that case, I don't think I've ever seen one!

you can see the servo-wave gubbins in this illustration

https://si.shimano.com/pdfs/ev/EV-ST-M092-1152A.pdf

FWIW ST-M095 is mainly just a cosmetic update of ST-M092. There are minor mechanical differences, e.g. to the servo-wave guide.

cheers

531colin · Post by **531colin** » 15 Jun 2020, 4:21pm

I understood the servo-wave V brake lever......

Brucey · Post by **Brucey** » 15 Jun 2020, 11:06pm

servo wave levers have the cable connected to a carrier with a roller on it which can ride in a slot which is aligned with its length pointing at the brake lever pivot. The slot angle is almost orthogonal to the brake cable too. However the angle between the slot and cable changes from obtuse to acute as the lever moves through its travel, so the roller wants to be at one end or the other of the slot depending on where the brake lever is in its stroke. The MA changes from 'low' (near to that used in full-V levers) to 'high' (slightly higher than that used in most canti-brake levers.

You can see the mechanism mid-stroke here;

In its early form there was a guide plate which engaged with both ends of the roller support so that the roller movement was constrained. You can see this in both ST-M092 and ST-M095 levers and it is slightly different between them. In later levers they increasingly did away with the guide.

By the time ST-M739 was made (which might be the first XT version meant for V brakes? ST-M737 was cantis only...)

https://si.shimano.com/pdfs/ev/EV-ST-M739-1587.pdf

they had done away with the guide plate entirely and there were optional 'adjustment blocks' (#10 above) which changed the working length of the slot and could be used to vary the extent of the servo wave -induced change in brake MA. If you altered the reach adjuster (#4) vs brake running clearance, you could alter the timing of the MA change in the lever pull too. On one bike I ran SL-M739 with V brakes such that the 'bite' was in the low MA part of the lever stroke and the MA increased as the lever was pulled. To my surprise with was rubbish in the rear brake (cable friction made modulation of the brake difficult, and I ended up with a fixed MA from choice, with three #10s installed or something) but when everything was set up correctly the front brake (with no #10s) was awesome; very powerful and surprisingly linear-feeling despite the changing MA.

https://si.shimano.com/pdfs/si/SI-B350F-000-00-ENG.pdf

describes how to set up the 739 lever with different numbers of #10 blocks and comes with warnings about excess power in the brakes.

cheers

filo · Post by **filo** » 16 Jun 2020, 8:14am

Thanks again for everyone who contributed.

Cyckelgalen · Post by **Cyckelgalen** » 16 Jun 2020, 2:11pm

I had those very XT 7-Speed shifters on a MTB bought around 1990 and it came with cantilever brakes. AFAIK V-brakes were introduced in 1996. Good shifters and brakes, I did have to repair the RH one at a point but they are still in excellent shape enjoying retirement somewhere In the shed.

531colin · Post by **531colin** » 16 Jun 2020, 5:26pm

I can now see how it works! I'm sure I've never seen one in the flesh.

IMG_5146 by 531colin, on Flickr

That's the Vee brake lever which I thought was servo-wave, but it isn't. Adjustable MA but it doesn't vary (much) over the stroke.

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7-speed Deore XT levers: for cantis or V-brakes?

7-speed Deore XT levers: for cantis or V-brakes?

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Re: 7-speed Deore XT levers: for cantis or V-brakes?

Re: 7-speed Deore XT levers: for cantis or V-brakes?

Re: 7-speed Deore XT levers: for cantis or V-brakes?

Re: 7-speed Deore XT levers: for cantis or V-brakes?

Re: 7-speed Deore XT levers: for cantis or V-brakes?

Re: 7-speed Deore XT levers: for cantis or V-brakes?

Re: 7-speed Deore XT levers: for cantis or V-brakes?

Re: 7-speed Deore XT levers: for cantis or V-brakes?

Re: 7-speed Deore XT levers: for cantis or V-brakes?