1991 Pine Mountain on "slicks" and closer ratios

I'm putting slicks on one of my MTB projects with a 13-23 7 speed block. Ideally want to use a short cage rear derailleur and have an XT RD-M732 which is marked with max 28 total 28 which I understand is max cog at rear 28 and max capacity of difference in rear cogs (10 in this case) plus difference at front which is currently 24-36-46 ie 22 and hence total is 32 ie too much.

A bit of research says some of the Shimano figs are conservative, has anyone tried this sort of thing. Also I need to replace a couple of jockey wheels, and was wondering does having 10 or 11 toothed jockey wheels make much difference.

QUESTION RESOLVED - PICS FURTHER DOWN

get the same tooth cog as it was designed for. otherwise they'll probably not fit particularly well

Your setup will work fine.

thanks for that - good news, currently they are 10 tooth and assume thats right for the mech although most seem 11, if anyone can confirm that would be great, cheers

Shimano's figures are for what works guaranteed. Things that throw it out are: short chainstays, thick dropouts, fat seat tubes etc.

I reckon you will just about get away with it. Whatever you do, ensure it will work on the big-big combination (it might be a bit rattly) - small-small might have the chain tension a bit loose.

Worth a try I think.

If you do the calculation again without the big sprocket and big chain-ring / small sprocket and small chain-ring combination chances are you will be fine

The best case is that the chain goes slack on small-small, which is fine. Whatever you do, ensure you can engage big-big. If the chain is too short it tends to stuff the rear mech into the spokes, followed by a collapsed wheel and crash.

yes will try to avoid that one

I've always checked the chain length on big-big plus 2 links (without gears) when fitting to get the right number of links rather than big-small with gear at vertical ish but is there a definitive way to check chain length ?

Your method is exactly what Shimano recommend!

Cant find a pic but I ran a Ging chain device with my 32/11t - 39/53t drop bar on-off road work bike.

Edit: could be a 30t but it was an XT/ 600 mixamech!

finally got round to posting on this but all sorted and works ok with 13-23 on rear and 24-36-46 on front with XT mech as per OP, all runs pretty slick changes and no issues even in ratios that wouldn't use