Mtb groupset on "road" bike.

General cycling advice ( NOT technical ! )
djnotts
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Mtb groupset on "road" bike.

Post by djnotts »

How difficult is it to convert a road set up to mtb, the purpose being to 1. have flat bars so that 2. can use hydraulic discs without expense of sti drop bar shifters?
My Boardman asr 8.8 runs OE Spyre cable discs. These are useless, particularly the rear, to the point that I won't ride it anywhere with long downhills. Should the front fail I will die!
I have changed cables to best recommended and fitted swiss stop pads. I have spent hours following every guide I could find in adjustments.
Spyre get mixed reviews. It may be that different levers work better than others, but an expensive business to try numerous different LH brifters!
It's reached the sell (but I love the frame/ride) or spend '00s of £s point.
And in all conscience I couldn't sell it complete - too dangerous.
Maybe someone could adjust to functioning brakes, but I have failed and am not prepared to keep trying.
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TrevA
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Re: Mtb groupset on "road" bike.

Post by TrevA »

You could try upgrading to HY/RD callipers, which are cable operated hydraulic disc brakes, giving the benefits of hydraulic without the outlay of a whole new hydraulic system.

I’ve converted a bike the other way - flats to drops and one of the potential problems is reach. On flat bars the riding position will be where the top of your drop bars are now, unless you fit a longer stem. Most roadies tend to ride holding the brake hoods which are a few inches further forward.
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djnotts
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Re: Mtb groupset on "road" bike.

Post by djnotts »

TrevA wrote: 31 Oct 2021, 9:56am You could try upgrading to HY/RD callipers, which are cable operated hydraulic disc brakes, giving the benefits of hydraulic without the outlay of a whole new hydraulic system.

I’ve converted a bike the other way - flats to drops and one of the potential problems is reach. On flat bars the riding position will be where the top of your drop bars are now, unless you fit a longer stem. Most roadies tend to ride holding the brake hoods which are a few inches further forward.
Considered the HY/RD option, but reviews suggest they also are a bit hit and miss in effectiveness - and pricey.

Reach is easily sorted. Longer stem and/or bar ends which pretty much replicate riding on the hoods.

I suspect the problem lies in the brake levers, but there is little consensus as to the "best".

Thanks.
Jodel
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Re: Mtb groupset on "road" bike.

Post by Jodel »

I'm surprised to read that the performance of your Spyre caliper is so poor.

I have a TRP Spyke caliper (the long pull version of the Spyre) on the rear of my tandem (203mm disk) and it is very effective. For example, riding without the stoker I can easily lock the rear wheel with just one finger on the brake lever. With the stoker aboard, we still have very good braking. The brake lever itself is just a simple bargain-basement Tektro V-Brake type.

I used to have a Tekro Lyra caliper and the performance from it really was dire. No amount of adjustment or different pad type made any difference, which is why I fitted the Spyke. My tandem was originally a drop bar type which I converted to flat bars. From memory, the brake levers were only about £10, so not exactly a fortune.

One possible solution may be to consider 'Top mount' levers? I have these on a drop bar bike (Specialized Tricross Sport) to allow braking whilst riding with hands on the flat section of drop bars. They give plenty of stopping power with only two finger pressure. Something like this:
https://www.tektro.com/products.php?p=208

They are pretty cheap and may resolve your issue?
the snail
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Re: Mtb groupset on "road" bike.

Post by the snail »

If you can find compatible flat-bar Road shifters and levers, that would probably be cheapest and easiest?
mattsccm
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Re: Mtb groupset on "road" bike.

Post by mattsccm »

Try the Aliexpress versions of the TRP things. 23 quid for both ends. Mine are brilliant.

Alternatively just sling a MTB groupset on.
djnotts
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Re: Mtb groupset on "road" bike.

Post by djnotts »

the snail wrote: 31 Oct 2021, 11:47am If you can find compatible flat-bar Road shifters and levers, that would probably be cheapest and easiest?
Yes. First experiment will be 2 x 9 flat bar shifters and road caliper/canti brake levers.
djnotts
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Re: Mtb groupset on "road" bike.

Post by djnotts »

mattsccm wrote: 31 Oct 2021, 12:50pm Try the Aliexpress versions of the TRP things. 23 quid for both ends. Mine are brilliant.

Alternatively just sling a MTB groupset on.
I'll have a look.

I suspect that only real solution is indeed a complete mtb groupset!
PH
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Re: Mtb groupset on "road" bike.

Post by PH »

djnotts wrote: 31 Oct 2021, 10:16am I suspect the problem lies in the brake levers
I very much doubt that it is, many people are using that combination and consider it fine, well most are more enthusiastic than that, I've just not heard of anyone suggest less than fine.
But it seems a sledgehammer solution to change the groupset because you don't get on with the brake, the road version of the BB7 will at the least out preform any rim brake.
djnotts
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Re: Mtb groupset on "road" bike.

Post by djnotts »

PH wrote: 31 Oct 2021, 1:33pm
djnotts wrote: 31 Oct 2021, 10:16am I suspect the problem lies in the brake levers
I very much doubt that it is, many people are using that combination and consider it fine, well most are more enthusiastic than that, I've just not heard of anyone suggest less than fine.
But it seems a sledgehammer solution to change the groupset because you don't get on with the brake, the road version of the BB7 will at the least out preform any rim brake.
A pair of bb7s cost much the same as 2nd mtb set up! OTOH the bb5s on my giant anyroad a whole lot better than the spyres.
ChrisF
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Re: Mtb groupset on "road" bike.

Post by ChrisF »

djnotts wrote: 31 Oct 2021, 9:15am
I have changed cables to best recommended
Did you also change the cable housings? I had a poor rear disk on a second-hand bike I bought. Changing the outer to a Jagwire one (which doesn't compress/stretch) has made it much better. Also I discovered (having unwrapped the bar tape to fit the new cable) that there was rusty kink in the old outer cable.
Chris F, Cornwall
djnotts
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Re: Mtb groupset on "road" bike.

Post by djnotts »

ChrisF wrote: 31 Oct 2021, 2:38pm
djnotts wrote: 31 Oct 2021, 9:15am
I have changed cables to best recommended
Did you also change the cable housings? I had a poor rear disk on a second-hand bike I bought. Changing the outer to a Jagwire one (which doesn't compress/stretch) has made it much better. Also I discovered (having unwrapped the bar tape to fit the new cable) that there was rusty kink in the old outer cable.
Yes, TRP Compressionless complete kit, including the noodles to lead from lever to bar flat tops. Improved the front a little, no effect rear. All new cap ends. Cable ends all carefully cut and squared.
Fitted tektro Cross top levers, front ok, worsened rear so removed and redone with one piece cable for the rear. Improved the cable runs.
I have spent many hours on all this!
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andrew_s
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Re: Mtb groupset on "road" bike.

Post by andrew_s »

Up to 9-speed, road and MTB rear cable pulls are the same, so you can keep the rear mech.
Front cable pulls have always been different, so you'd need an MTB front mech to go with MTB shifters.
Also, as noted, you may want a longer stem.

Drop bar levers have used about 3 slightly different cable pulls over the years, and the difference between matched brakes and levers and not matched is noticeable.
You'll get the best drop bar cable disc braking using MTB cable discs (Spyke or BB7 Mtn) and long pull "V" levers, but that means bar end or down tube shifters.
djnotts
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Re: Mtb groupset on "road" bike.

Post by djnotts »

Thanks for summary, mostly reinforcing my understanding.
Bar cons definitely feature in my "thinking".
slowster
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Re: Mtb groupset on "road" bike.

Post by slowster »

When you changed the pads, did you clean the discs?
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